Abstract:[Objective] Soil erosion is complex and diverse in Tibet Autonomous Region locating in the southwest of China, attributed to its special environment represented by high altitude and cold climate. Through field survey, this study aims to systematically understand the characteristics of soil erosion in densely populated areas in Central and Eastern Tibet, and to provide a basis for regional soil erosion control in the future.[Methods] The survey was conducted from August 12 to 28, 2018. We selected 11 typical watersheds along a transect across Linzhi, Gongbujiangda, Lhasa, Qushui and Shigatse areas. We investigated and analyzed soil erosion of local primary land use types, including forest, grassland, and farmland.[Results] In the southeastern part of Tibet, continuous rainfall caused severe erosion in forest, farmland and on road slope. Small gullies appeared in the forest, collapse occurred in the cropland with ongoing developed headward erosion, while drop sill, gully, and upper-soil collapse occurred on the road slope. In the valleys of Central Tibet, gully erosion on the proluvial fan/pluvial tableland and terraces were severe. The densely distributed gullies and channels destroyed the landforms, and seriously affected local agriculture and animal husbandry. The wide valley area presented complex erosion characteristics influenced by both wind and water.[Conclusion] The soil erosion process in Tibet Autonomous Region is complex and diverse at present, and it has a high risk of accelerated erosion due to climate change and intensifying human activities. Thus, it is necessary to systematically study soil erosion process and mechanism, and urgent to enhance the soil and water conservation work in this area. Moreover, it is also important to strengthen our awareness of environmental protection to this fragile ecological environment in Tibet. All these provide the foundations for the implement of the green development concept "lucid waters and lush mountains are invaluable assets" proposed by the government of China.

Abstract:[Objective] To investigate the variations and relationships of temperature, precipitation and runoff during 1970-2016, in order to explore the impacts of climate change on precipitation and runoff and simulate the evolution of runoff in Qingyuan River, the source region of the Weihe River.[Methods] The inter-annual variations and the relationships between climatic elements and runoff were analyzed. Three temperature modified climate-hydrological models and general hydrological models were compared to explore the impacts of climate change on runoff.[Results] The period from 1994 to 1995 was the dividing line of the main meteorological and hydrological elements in Qingyuan River basin. During 1970-1994, there was no significant variation in the annual average temperature, precipitation and runoff. However, temperature showed an increasing trend while precipitation and runoff showed a decreasing trend after 1995. Compared to the period of 1970-1974, the annual average temperature increased by 0.9℃ in 2010-2016 (with a rate of 15.79%), while the annual precipitation and runoff decreased by 13.48% and 31.82%, respectively. The three climate-hydrological models, MQPT_1-1, MQPT_2-1 and MQPT_3-1, showed higher accuracies than the general hydrological model by simulating the annual precipitation and runoff processes. Especially, the mean simulated error of MQPT_2-1 (modified model based on air temperature disturbance) was only 3.03%, which was 11.62% higher than the general hydrological model (without considering climate change).[Conclusion] Temperature variation had significant impacts on runoff in the last 50 years in the Qingyuan River basin, especially after 1995. In addition, the impacts of temperature and other major meteorological factors should be involved in runoff simulation analysis.

Abstract:[Objective] To explore the effects of Robinia psedudoacia plantations on the soil moisture and nutrient characteristics, in order to provide theoretical basis for vegetation restoration and ecological reconstruction in semiarid loess hilly region.[Methods] Based on data collected from soil sampling in the field and laboratory measurement, the soil moisture and nutrient characteristics under different R. psedudoacia plantations with various ages were analyzed in the loess hilly region of western Shanxi Province.[Results] R. psedudoacia plantanations effectively improved soil moisture conditions, especially in the early stages of the planting. The average content of soil organic content and total nitrogen increased significantly, and showed an apparent surface aggregation. Surface soil moisture and nutrient conditions were better than that of the underlying soil layers after R. psedudoacia restoration. Soil moisture inside the pits above 40 cm was 3.97% higher than that outside the pits, and 2.74% higher in soil below 40 cm. Soil organic content, total nitrogen, total phosphorus and total potassium inside the pits was increased by 6.61%, 6.14%, 1.55% and 1.98% respectively, than those outside the pit at 0-20 cm soil layer, while there were no significant improvements for the total phosphorus and the total potassium content below 20 cm soil layer.[Conclusion] R. psedudoacia plantanations has improved moisture and nutrients conditions in surface soil layers.

Abstract:[Objective] The effect of seasonal freeze-thaw on soil micro-aggregates in the context of climate change was studied in order to provide references for the reserch of soil biochemical processes near the timberline.[Methods] Soil samples from three typical vegetation types (meadow, Larix principis-rupprechtii and Picea meyeri) near the timberline of Wutai Mountain were collected for soil column in situ experiment. Soil micro-aggregates contents and fractal dimensions (D) were measured.[Results] The variations of 2~0.25 mm and 0.25~0.05 mm aggregate contents were different among the three plots. The content of 0.05~0.02 mm aggregate reduced initially, then increased and finally reduced. The content of 0.02~0.002 mm aggregate reduced initially and then increased (except in Larix principis-rupprechtii plot), and the content of <0.002 mm micro-aggregates increased firstly and then reduced. The content of micro-aggregates changed significantly (p<0.05) due to seasonal freeze-thaw events in initial freezing and thawing periods, while there was no significant change in deep freezing period (p>0.05). Soil micro-aggregate contents also changed significantly (p<0.05) in the growing season. Different vegetation compositions caused significant differences (p<0.05) among micro-aggregate contents in three plots, especially, in initial freezing and thawing periods. During the freezing-thawing period, D values were increased, and that of Picea meyeri plots was the lowest. In growing season, D values were decreased, and that of meadou plots was the lowest. Significant differences (p<0.05) of D values among three researched plots were only observed in the late growing season, and the least D value is obtained in H. principis-rupprechtii.[Conclusion] Freeze-thaw cycles have great impacts on soil micro-aggregate contents. The responses of soil structures to seasonal freeze-thaw events are significantly different, and mainly occur in initial freezing period and thawing period. The D values of all plots are increased by freeze-thaw cycles. Although the D value of soil microaggregates increased during the incubation period, it gradually decreased to the pre-incubation level after entering the growing season. Soil aggregations and structures of all three plots vary periodically and have certain self-recovery capabilities.

Abstract:[Objective] To study the windproof efficiency of shelterbelt composed by Haloxylon ammodendron and Caragana korshinskii and its response to wind directions in order to provide theoretical basis for shelterbelt construction on the periphery of desert oasis, desert road and desert railway.[Methods] Prototypes of H. ammodendron and C. korshinskii with different individual characteristics were used to make simulation plants, and then constructed into high-low shelterbelt, which was recorded as AmBn pattern. Here, the capital letter "A" represented the simulated plant H. ammodendron, "m" represented that the planting space was 15 cm×40 cm, the capital letter "B" represented the simulated plant C. korshinskii, and "n" represented that the planting space was 8.5 cm×25 cm. When the wind direction was opposite, the shelterbelt was recorded as BnAm pattern. By the wind tunnel simulation experiments, the airflow field, wind speed acceleration rates and the windproof efficiency were analyzed with the controlled wind speed of 7, 10, 15 m/s.[Results] ① When the airflow reached to the front of the shelterbelt, the wind speed decreased overall. According to the variation intensity of wind speed, the air flow could be divided into 3 layers:the upper layer (above the 30 cm), the middle layer (5-20 cm), and the lower layer (below 3 cm). The speed recover point behind the shelterbelt in AmBn pattern and BnAm pattern was 23 H and 12.5 H, respectively. ② The wind shadow range of AmBn pattern was greater than that of BnAm pattern. The wind shadow core areas were formed at the canopy height of both "A" plant and "B" plant, namely, a dicaryon pattern was formed. ③ Under the controlling wind speed of 7, 10, 15 m/s, the average windproof efficiency of shelterbelt AmBn was 34.44%, 34.98% and 32.51%, respectively. The average windproof efficiency of shelterbelt BnAm was 22.62%, 19.70%, 19.41%, respectively. ④ In vertical direction, the forest belt played a role in slowing down the airflow below the height range of about 1.5 H, which accelerated the airflow above this range. In the horizontal direction, the windbreak efficiency of the AmBn type forest belt was better than that of the BnAm type forest belt before, within and after the belt.[Conclusion] The windproof efficiency of shelterbelts is related to the occurrence order of the plants along the wind direction. In view of the protection efficiency and protection distance, the shelterbelt in AmBn pattern is suggested to be constructed.

Abstract:[Objective] To reveal the probability of snow flow in the three northwestern provinces(Xinjiang, Inner Mongolia and Gansu), in order to provide a theoretical basis for disaster prevention and control of snowstorm disasters.[Methods] We used the ground meteorological data from 130 district stations from 1981 to 2010, to classify the probability level of snow flow.[Results] ①In the study area, 65.4% of the regions have the probability for snowstorm disaster, of which 16.9% had a higher level probability for snowstorm disaster. ② The most severe months of snowstorm disaster were March and December, and few areas were affected by terrain. ③ The meteorological data of the study area fluctuated within a certain period during the past 30 years, but the probability of snowstorm disasters was not decreased.[Conclusion] The three provinces in Northwest China should pay attention to the prevention and control of snowstorm disasters, especially in March and December. Meanwhile, ecological restoration should be strengthened to reduce the snowstorm disasters.

Abstract:[Objective] To investigate the litters and soil water-holding in apple tree plantation in the Loess Plateau of east Gansu Province, in order to provide scientific basis for economic forest management and ecological benefit evaluation.[Methods] Taking the stand age of 1, 3, 7, 13 and 29-year old apple tree plantation as the research object, we collected soil samples and used indoor immersion method and cutting ring knife method to analyze the hydrological properties of litters and soil at 0-80 cm depth.[Results] ① The litters layer volume, maximum water holding capacity and effective interception volume of 7-year apple forest land were significantly higher than that of 1, 3, 13 and 29-year apple forest land. ② The maximum water holding capacity of litter was 5.02~20.66 t/hm² and had a logarithmic correlation with immersion time (R>0.90). The maximum water holding rate of litter was 120.46%~352.53% and had a power function relation with water immersion time (R>0.64). ③ Soil bulk density changed little with the increasing stand age, and the change range was 1.173~1.372 g/cm³. In contrast, the total porosity, capillary porosity and maximum water increased initially and then decreased, the range was 52.46%~57.06%, 46.34%~51.87% and 1 049.15~1 141.26 t/hm², respectively. Non-capillary porosity and effective water showed an overall increasing trend. ④ The initial infiltration rate and average permeation rate of 3-year old apple plantation were higher than those of other forest ages, which was 3 a > 1 a > 29 a > 7 a > 13 a. Therefore, the permeability of apple forest land aged 3 years was higher than other forest lands during the entire penetration time.[Conclusion] Apple economic forest can significantly improve the water conservation and soil and water conservation functions, but the hydrological effects of litters and soil are not synchronized, and with the increase of stand age, there will be a trend of functional decline.

Abstract:[Objective] To selecte the optimal application amount of soil structure amendment for the growth of rice in saline alkali land in the Yinbei irrigated area of Ningxia Hui Autonomous Region, in order to provide scientific basis for the improvement and application of saline alkali land of the same type in China.[Methods] A field experiment was conducted in Yinbei irrigation region in 2016. Different application rate of soil structure amendment (0, 150, 270 and 375 kg/hm²) with uniform desulfurized gypsum application rate (22.5 t/hm²) were used in the experiment.[Results] With the application of desulfurized gypsum and structure amendments, the pH value, total salt content and bulk density at 0-20 cm soil layer showed a decreasing trend, while the total soil porosity and water-stable aggregate content showed an increasing trend. The improvement effect was better at 0-20 cm layer, but the effect was not obvious below the depth of 40 cm. Application of the amendment increased the survival rate, plant height and yield of rice, and there were significant differences between treatments (p<0.05).[Conclusion] The application of desulfurized gypsum and structure amendment can significantly improve the physical and chemical properties of the takyr solonetz soil and promote the growth of rice. Considering the economic factors, the optimal soil structure amendment rate was 270 kg/hm² and the optimal desulfurized gypsum application amount was 22.5 t/hm².

Abstract:[Objective] To reveal the effect of wood vinegar concentration on soil enzymatic activities in order to determine the optimal application concentration of wood vinegar in low and medium fertility soils in Northwest Liaoning Province.[Methods] Pot experiments were conducted, and wood vinegar with different concentrations (0.10%, 0.15% and 0.30%) were selected. The agronomic indexes of pot grown pakchoi were determined and the soil enzyme activities were measured to evaluate the soil fertility quality.[Results] Wood vinegar significantly improved the stem diameter and the root length of pakchoi, and consequently increased the yield of pakchoi. Wood vinegar with 0.30% concentration showed the best effect in low fertility soil while wood vinegar with 0.15% concentration showed the best effect in medium fertility soil, and the fresh weight of pakchoi was increased by 57.78% and 46.06%, respectively, compared with the control. Wood vinegar also significantly enhanced the activities of soil amylase, urease, protease, phosphatase, catalase and dehydrogenase. Biological index of fertility and enzymatic activity number were the highest, in low fertility soil with 0.30% concentration of wood vinegar and in medium fertility soil with 0.15% concentration of wood vinegar.[Conclusion] Wood vinegar can be used as a good soil amendment to improve soil fertility and increase vegetable yield in Northwest Liaoning Province.

Abstract:[Objective] To reveal the distribution pattern of soil aggregates and its influencing factors in the Eastern Hu'nan Province, in order to provide a theoretical basis for the study of soil aggregates cementation mechanism in Southern China.[Methods] Typical natural forest land, dry land and paddy developed on three common soil-forming parent materials (quaternary red clay, weathered granite and shale) were selected in the Eastern Hu'nan Province. Totally, 54 soil samples from surface layer (0-20 cm) and bottom layer (40-60 cm) were collected. The water stable aggregate content of these soils were analyzed by wet sieving method.[Results] Land use pattern, parent material type and soil location significantly affected the composition and stability of soil aggregates, and their interaction was also very obvious. Generally, the soil aggregate stability in paddy was the highest, while that in dry land was the lowest. But the influence of land use patterns on the stability of soil aggregates was limited to the surface soil, and it was not obvious in the soil developed from weathered granite. The soils developed from quaternary red clay had the highest aggregate stability, while the soils developed from weathered granite had the lowest aggregate stability, but this pattern was not exist for the soils in surface layer or soils in dry land and forest land. The soil aggregate stability of surface layer was usually higher than that of bottom layer, but there has no significant difference between surface or bottom layer in paddy or clay soils developed from quaternary red clay.[Conclusion] The distribution of soil aggregates in the Eastern Hu'nan Province is influenced indirectly by soil parent material, utilization method and soil layer position through the influence of soil texture, organic matter and oxides.

Abstract:[Objective] To study the effects of paclobutrazol(PP₃₃₃) and rooting powder(GGR₆) on chlorophyll fluorescence parameters of Cerasus humilis, in order to provide scientific and theoretical basis for strong seedling cultivation techniques of C. humilis seedlings.[Methods] Single factor analysis was used to study the 1-year-old C. humilis seedlings, which were respectively dipped into PP₃₃₃ and GGR₆ with a concentration of 0, 50, 100, 150 and 200mg/L, and the fluorescence was measured by PMA2500.[Results] With the increasing concentration of PP₃₃₃ and GGR₆, the electron transfer efficiency (ETR), actual photochemical quantum efficiency (ΦPSⅡ), photochemical quenching (q_P) and maximum photochemical efficiency (F_v/F_m) were increased, while the non-photochemical quenching(q_N) decreased.[Conclusion] The best plant growth regulator was GGR₆, and the optimal concentration was 200 mg/L. With the same concentration, the effect of GGR₆ on the fluorescence parameters of C. humilis seedlings was better than that of PP₃₃₃.

Abstract:[Objectives] To study the effects of bioorganic fertilizer application on soil physical properties and microbial biomass carbon and nitrogen in different soil layers, in order to provide scientific data for applying bioorganic fertilizer in soil improvement, soil and water conservation and the sustainable development of agricultural facilities.[Methods] Field soil tests were conducted to study the effects of bioorganic fertilizers on soil hydraulic properties, aggregate and microbial biomass carbon and nitrogen in 0-15 and 15-30 cm soil layers of fluvoaquic soil. The application rates of bioorganic fertilizer were 0, 10 and 20 t/hm², respectively.[Results] The application of bio-organic fertilizer could significantly reduce soil bulk density, increase soil porosity and hydraulics indexes. The soil bulk density decreased by 10.37%~19.26%, the field capacity and saturated hydraulic conductivity increased by 13.12%~32.25% and 37.28%~67.11%, respectively. Bioorganic fertilizer could also increase the content and average mass diameter of soil aggregates and reduce the fractal dimension of aggregates. Application of bio-organic fertilizer could increase the content of soil microbial biomass carbon and nitrogen by 33.66%~52.67% and 11.52%~22.64%, respectively. Soil physical properties had a significant correlation with microbial biomass carbon and nitrogen.[Conclusions] Application of bioorganic fertilizer can effectively improve the structure and hydraulic characteristics of fluvoaquic soil, increase the capacities of soil water storage, improve soil aggregate content, stability and microbial biomass carbon and nitrogen content.

Abstract:[Objective] To analyze the changes of soil nutrients after temperature increase, in order to provide data support for responses to global warming in the future.[Methods] The brown soil of cultivated land in North China plain was taken as study material. Sedimentation Siphon method was used to study the composition of three granular organic-inorganic complexes and the variation of organic carbon and total nitrogen in soil under increasing temperature.[Results] The distribution of soil organic and inorganic complexes showed no significantly change under the condition of increasing temperature. Organic carbon content increased while total nitrogen content decreased. In terms of different grain levels, the content of organic carbon in all three grain grades increased, while the content of total nitrogen only increased in some small soil grain. No significant change was fond in the content of total nitrogen in sand grains. The soil carbon nitrogen ratio was relatively stable. The distribution of organic carbon tended to shift to large grain size, while the distribution of total nitrogen showed no obvious pattern.[Conclusion] Temperature increase accelerated the decomposition of organic matter, and increased the content of soil organic carbon, especially in smaller grain size. In contrast, the total nitrogen content decreased as a result of anti-mineralization, but it showed a relative increase trendcompared with the control group.

Abstract:[Objective] To investigate the potential salinization of soil in Quzhou County, Hebei Province in recent years, in order to provide scientific basis for preventing soil salinization.[Methods] The brackish water irrigation experiment, soil profile observation and soil sample analysis was conducted to study the soil salinity transport and its potential salinization to the soil in Heilonggang basin from the aspects of altitude, soil depth, groundwater depth and soil texture.[Results] Rainfall and brackish water increased the possibility of surface salt leaching to the lower layer, which leads to the accumulation of soil salinity in 40-100 cm soil layer. Soil with more sticky texture appeared at 56 cm depth, which prevented the movement of soil salt and accumulated on it, thus creating potential conditions for soil salinization. Micro-topography affected the redistribution of salinity, and soil salinity content and altitude showed a good correlation (R²=0.76). The change of texture types in the soil layers at different depths affected the redistribution of soil salinity. The phenomenon of surface aggregation of HCO₃^- was obvious. The contents of SO₄^2- and Ca²⁺ in all soils were significantly correlated with total salt content (0.88^*~1.00^**, 0.89^*~0.97^**), and there was a significant relationship between the contents of SO₄^2- and Ca²⁺ (0.86^*~0.97^**).[Conclusion] The change of micro-geomorphology and soil profile pattern will affect the redistribution of soil salinity, and have an important impact on the potential salinization of soil.

Abstract:[Objective] To explore the trend of water quality since the start of the comprehensive regulation project in Shaanxi section of the main stream of Weihe River, in order to check the effectiveness of regulation works and provide technical support for subsequent river pollution prevention and control.[Methods] Based on the water quality data of the main monitoring points in Shaanxi section of the Weihe River main stream during 2010-2016, the temporal and spatial variation characteristics of water quality were analyzed, the trend of water quality was expounded by using Mann-Kendall test, and the future trend of water quality was identified by using R/S analytical method.[Results] From 2010 to 2016, the water pollution had changed from severe pollution to mild pollution. The chemical oxygen demand(COD) and NH₃-N concentrations of 4 exit monitoring points in Baoji, Xianyang, Xi'an and Weinan cities during the dry season were generally higher than those in the flood season. After the treatment, the decrease of the pollution in Xi'an City exit section was the most significant, but still was the most polluted section. The concentration of NH₃-N in Baoji, Xianyang, Xi'an and Weinan cities showed a significant downward trend, and this trend would continue. The concentration of COD in Xianyang, Xi'an and Weinan City showed a significant downward trend, but the future sustainability was weak. The increasing trend of COD concentration in Baoji City was not significant.[Conclusion] After the comprehensive treatment, the pollution level of the river is obviously reduced and the water quality is changed obviously. However, the concentration of pollutants in some sections shows an upward trend, which needs special attention.

Abstract:[Objective] We studied the effects of geotextile plus plastic film mulching method on soil moisture conservation and its durability in order to provide a scientific reference for further development of water-saving agricultural technologies in Weibei dryland regions of Shaanxi Province.[Methods] Due to the fact that plastic film is easy to weathering, poor durability, short service life, and the residual debris is harmful to the environment, while weed-blocking geotextile is high strength, weathering resistance, but poor water penetration, this study used a combination of geotextile plus plastic film mulching (plastic film below the geotextile) to monitor soil moisture in-situ for one year.[Results] ① Under both mulching and non-mulching conditions, the variations of soil moisture content showed a high-low-high trend with the increase of soil depth. ② Under geotextile plus plastic film mulching conditions, the daily average soil moisture at 15, 30, and 50 cm depths increased by 11.2%, 8.0%, and 5.3%, respectively, compared to the bare soil area. ③ The impacts of limited rainfall on soil moisture were mainly reflected in the top 15 cm depth in the bare soil area, but extended to 30 cm depth in the mulched area. ④ During the experimental period, the properties of the geotextile was well preserved. The plastic film covered by the geotextile was also intact, similar to its initial state, except for the exposed edge areas that was fragmented due to weathering.[Conclusion] The geotextile plastic film mulching method not only showed advantages in water conservation and weed control, but also effectively extended the life of plastic film.

Abstract:[Objective] The dynamic changes of soil respiration rate and their relationships with soil enzyme activities under 4 different tillage methods of no tillage (T_n), medium tillage (T_m), subsoiling (T_s) and fall turnover (T_f) were studied in Minqin desert oasis, to provide basis for the establishment of feasible soil carbon management measures.[Methods] Based on a 2-years field experiment, the soil respiration rate in different growth stages (seedling, heading and maturity stage) was measured by LI-8100 soil carbon flux measurement system. Soil enzyme activities and physicochemical properties were measured by collecting soil samples at 0-20 cm soil depths.[Results] (1) Oasis soil respiration in Minqin desert showed a typical diurnal variation. The diurnal variation of soil respiration rate of the four tillage showed a single peak curve in the whole growth period of maize. The soil respiration rate were ranked as:T_f > T_m > T_s > T_n. There was a significant positive correlation between organic carbon content and soil respiration rate (P<0.05), indicating that traditional tillage significantly accelerated the release of soil carbon from maize fields in Minqin desert oasis area. (2) The activities of soil urease, invertase, protease, catalase and beta glucosidase were significantly correlated with soil respiration (p<0.05). The pH value, available potassium, organic carbon and the activity of urease, invertase glucose and beta glycosidase reached an extremely significant level (p<0.01).[Conclusion] Different tillage can change soil respiration rate by changing the physical and chemical properties of soil and stimulate enzyme activity in the desert oasis area, thus, influence the release of CO₂ in summer maize field.

Abstract:[Objective] To survey the regeneration characteristics of Rhus typhina in urban forest in Tianjin City, in order to provide basis for ecological invasion and restoration of urban forest.[Methods] The regeneration characteristics of R. typhina in urban forests in Tianjin City were investigated, and compared with the existing natural regeneration data. Based on the characterization of five aggregative intensity indices, the quantitative characteristics, inter-annual variation of diameter structure and spatial pattern of regeneration seedlings of R. typhina in urban forest were studied.[Results] ① The annual density of regeneration seedlings fluctuated between 3~8 plants/m², the one year old seedlings were majority, and the age structure showed a typical pyramid type. The population belonged to the growth type, and the regeneration ability was strong. ② The regeneration seedlings at the low level of diameter and height accounted for the vast majority of the total. ③ The regeneration seedlings of R. typhina showed a typical aggregation distribution.[Conclusion] The regeneration ability of R. typhina in urban forests is strong, and the invasion is still significant. It is necessary to take effective measures to monitor and control it.

Abstract:[Objective] To obtain the optically simulated luminescence (OSL) age of parent material of the representative soil profile in the source region of the Yellow River, reveal the development and formation of parent material based on the paleoclimate records, in order to provide scientific basis for the soil conservation and sustainable development of the area.[Methods] The silt-sized (38~63 μm) quartz optically stimulated luminescence single-aliquot regenerative (SAR) dose protocol was used to obtain the OSL ages of parent material layer at the bottom of 10 different soil profiles. The soil particle size was measured by Malvern 2000.The content of soil organic matter was determined by potassium dichromate-sulfuric acid digestion.[Results] ① The soil was mainly composed of silt (account for 85%), and the average grain size was ranged between 14 and 37 μm. The content of soil organic matter was between 13.1 and 41.1 g/kg, and the average value was 27.2 g/kg. ② Soil in the source area of the Yellow River mainly developed since late Holocene, especially since the near 2000 years. ③ In this region, the average thickness of soil profile was (0.46±0.05) m, and the average dust accumulation rate was (16±0.07) m/km².[Conclusion] The remarkable characteristics of the modern soil in source area of the Yellow River included thin soil layer and relatively high storage of organic carbon. As a sequence, the formation and development of soils mainly occurred in in a relatively dry and cold climate condition of late Holocene, and the development model was mainly aeolian dust aggradation.

Abstract:[Objective] Studying the spatial distribution patterns of soil and water loss in the megacity is of great importance to make conservation strategies and promote constructing beautiful China in new era.[Methods] Spatial distribution patterns of soil and water loss in Wuhan City, Hubei Province, was investigated by spatial overlay analysis of land cover, vegetation coverage and ground slope according to the methods in standards for classification and gradation of soil erosion.[Results] The spatial distribution patterns of soil and water loss in Wuhan City was summarized as four circles. The core was the built-up area where the ground hardening was high and the soil and water loss was slight. The second circle was urban expansion area around the core area where the most severe soil and water loss occurred due to urban construction. The third circle was the agricultural production area in the plain around the second circle where the soil and water loss was low, but the agricultural non-point source pollution was very severe. The fourth circle was the outskirts of hilly area, mainly forest land with a small amount of slope farmland.[Conclusion] The management and maintenance of urban green space and underground drainage system should be enhanced in the core area. A great mount of urban building projects should be strictly supervised in the second circle. The construction sites should be restored to the most extend and the urban ecological landscape should be built to minimize the man-made soil and water loss. The agricultural non-point source pollution should be controlled and ecological clean watersheds should be built in the third circle. The slope farmland should be managed, ecological restoration should be improved, and the man-made soil and water loss caused by tourism development should be controlled in the fourth circle.

Abstract:[Objective] This paper measured the environmental efficiency of cultivated land in Jiangxi Province from 2001 to 2015 in order to judge the degree of coordinated development of cultivated land use and environment, and to propose corresponding improvement strategies.[Methods] Based on the panel data of farmland inputs and outputs of 11 prefecture-level cities in Jiangxi Province from 2001 to 2015, the environmental efficiency of cultivated land was measured by using slack-based model directional distance function.[Results] ① The utilization of cultivated land use and the environment in Jiangxi Province was in a relatively coordinated development stage, and the coordinated development presented a "rising-falling" trend. ② The development of cultivated land use and environment in different cities showed different statues and trends. Ganzhou City and Jiujiang City were in an inconsistent development all the year round, and they were the key areas for government supervision. ③ The potential of coordinated development and improvement of cultivated land use and environment in different cities mainly relied on the reduction of non-expected outputs and the redundancy of cultivated land inputs, and the improvement strategies were different among vary regions.[Conclusion] ① The efficiency of cultivated land use can be improved, the pollution of arable land can be reduced and the quality of cultivated land can be improved, by transforming cultivated land model to connotative model based on technical efficiency and technological progress. ② The related policies need to be made to solve the land source pollution issues. ③ Cultivated land recuperation and rest system need to be explored. ④ Different solutions should be focused on promoting the coordinated development of cultivated land use and environment in different cities, and strengthen exchanges and cooperation between cities.

Abstract:[Objective] The land use change and its impact on the ecosystem service value in Shandong Province were analyzed to provide guarantee for the regional environmental protection and food security.[Methods] The data of land use types of Shandong Province in 1995, 2005 and 2015 was obtained by using the GIS technology. Then, combined with the relevant evaluation model, the spatial and temporal dynamic evaluation and characteristics of the ecological service values were analyzed in the research area.[Results] ① The land use type in Shandong Province were mainly the cultivated land. Areas of cultivated land, forest land, grassland and unused land were all reduced, while the construction land and water area continued to increase during the period from 1995 to 2015, and the construction land was mainly transformed from the cultivated land. ② From 1995 to 2015, the total value of the ecosystem service in the research area decreased by 6.62×10⁹ Yuan, with a change rate of -2.07%. In those years, the ecological service value of hydrological regulation increased rapidly, while the value of other individual ecological service decreased. Spatially, the value of ecosystem services varied greatly, showing a high spatial distribution in Ludong and Lunan areas, while a low distribution in Luzhong and Luxi areas. The ecological benefited area was small, and the ecological impairment region was widely distributed with an increasing trend. ③ The value of ecosystem services in Shandong Province was inelastic, and the ecological value coefficient adopted was reliable.[Conclusion] Efforts should be made to optimize the land use structure and layout in the future, and land use change should be comprehensively controlled through planning and other measures, so as to promote the stable development of the ecological environment in Shandong Province.

Abstract:[Objective] The temporal and spatial variations of soil conservation service function of the Yangtze River economic belt from 2010 to 2015 were analyzed.[Methods] The revised universal soil loss equation (RUSLE) was used to analyze the soil conservation service function.[Results] The average amount of annual soil conservation was 1.88×10¹⁰ t/a, and the soil holding volume per unit area was 91.54 t/(hm²·a) during the study period. The soil holding volume per unit area of forest, grassland and farmland ecosystem was 129.09, 111.47 and 40.38 t/(hm²·a), respectively. The soil conservation service function of the Yangtze River economic belt showed an upward trend from 2010 to 2015. The service functions of slope soil in the national optimal development zone, key development zones, agricultural production zones and key ecological function zones was enhanced.[Conclusion] Soil conservation capacity of forest, grassland and farmland decreased in sequence. The implementation of major function oriented zoning strategy was significant in improving the ecological security capability of the Yangtze River economic belt.

Abstract:[Objective] Based on the original regionalization of Hanzhong City, Shaanxi Province in 1986, to complete the link between provincial and municipal divisions, and further integrate the characteristics of soil erosion in Hanzhong City in order to provide supports for the soil and water conservation work in this area.[Methods] By overlapping map analysis, and combined with the natural conditions and the development trend of soil and water loss, soil and water conservation zone in Hanzhong City was re-divided.[Results] The city was divided into four areas including the northern water source conservation ecological maintenance area, the central human settlement environmental water quality maintenance area, the western water source conservation water quality maintenance area, and the southern soil conservation ecological maintenance area.[Conclusion] The northern water source conservation ecological maintenance area should be paid attention to the protection and rational development of natural forest and grass resources. Deforestation should be strictly prohibited, and the shifting cultivation in steep slopes rim should be changed into strip intercropping. The central human settlements water quality maintenance area should be paid attention to revetment of beaches, rectify rivers, continue to do a good job in urban greening, build high-standard basic farmland, optimize the ecological agriculture environment, and improve the living environment. The western water source conservation water quality maintenance area should improve the ability to control surface source pollution. For the types of land used for sloping farmland, excavation exposed surface and grassland, remediation and vegetation restoration should be carried out well to maintain the water quality of the water source area. In the southern soil conservation ecological maintenance area, it is necessary to carry out hill closure and afforestation in a certain area of sloping farmland and some gentle slopes above 25°, returning farmland to forests and grassland, so as to effectively protect forest grass and soil resources, at the same time, economic forest fruits with high economic benefits and remarkable ecological benefits should be promoted.

Abstract:[Objective] To delineate the ecological protection redline in Chongqing Municipality under protection of ecological function in order to maintain the ecological stability and sustainable development.[Methods] Based on the characteristics of the regional ecological environment, the important factors of ecosystem service function such as water conservation, biodiversity maintenance and soil conservation, as well as the sensitive factors of soil erosion and kast rocky desertification, were selected to assess the ecosystem service function and eco-environment sensitivity in Chongqing Municipality.[Results] Four types of ecological protection redline areas with a total area of 30 790.91 km² were delineated, accounting for 37.33% of the total area of Chongqing Municipality. Ecological protection red line areas were mainly located in the Qinba Mountain, Wuling Mountain, Three Gorge Reservoir, Metropolitan "Four Mountains" and Dalou Mountains in Southern Chongqing Municipality.[Conclusion] In recent years, great progress has been made in the construction of ecological protection area in Chongqing Municipality, which plays a positive role in maintaining and improving the service function of regional ecological system.

Abstract:[Objective] To regionalize the ecological functional zoning and coordinate the contradiction between economic development and ecological protection in order to realize the regionalization management of ecological environment.[Methods] Fushun City was taken as the research area, a regional aquaculture sensitivity assessment system was introduced into traditional evaluation indicators according to its actual ecological environment characteristics, and ArcGIS 10.1 software was used, to evaluate the ecological environment sensitivity and ecological service function of water source, soil and biology in Fushun City. Then, the method of geographical correlation was used to regionalize the ecological function zoning, to compare the service function difference of functional areas, and to set up the partition management plan.[Results] According to the analysis, the sensitivity of the study area was mainly mild and insensitive, showing a "claw" pattern. The extremely and highly sensitive areas were mainly the Laohutai and Longfeng mining areas, and the steep slopes (approximately 1.08% in total). The distribution of the importance of ecosystem service was similar to the topography distribution. The major ecosystem of the most important areas was forests in the southeastern part of the country (about 79.46%).[Conclusion] Fushun City belongs to normal temperate and theropencedrymion ecological areas and is divided into two ecological function sub-areas and eight ecological function areas. According to the functional differences, it can be divided into ecological conservation zone, ecological restoration zone and ecological prohibited zone.

Abstract:[Objective] To estimate the function value of soil and water conservation service in order to provide scientific basis for the comprehensive control of soil and water loss and the sustainable development of soil and water conservation.[Methods] Soil and water conservation function was defined, and the reference method, market value method and alternative cost method was used to estimate the service value of soil and water conservation function in Dongzhi tableland, Qingyang City of Gansu Province.[Results] The total value of service function of soil and water conservation was 1.94×10⁹ Yuan, and the value of soil and water conservation service function of land and water conservation measures was 4.32 Yuan/m². Among them, the value of carbon sequestration and oxygen release service was the highest, amounting to 7.05×10⁸ Yuan, followed by the functional value of improving species diversity, which was 5.34×10⁸ Yuan, and the least was the function value to preserve soil fertility, which was 3.37×10⁷ Yuan.[Conclusion] Soil and water conservation measures in Dongzhi tableland of Qingyang City have high value of functional service. In the future, relevant water and soil conservation measures should be maintained or improved to give play to greater value of functional service.

Abstract:[Objective] Ecological benefit of combating desertification in east edge of Hobq desert was studied in order to provide scientific reference for benefit evaluation of desertification control.[Method] The assessment index system of ecological benefits of combating desertification was established, and the ecological benefit was evaluated by analytic hierarchy process and fuzzy comprehensive evaluation method.[Results] Among the ecological benefit evaluation indicators, the top three were vegetation coverage, aboveground biomass and grass height. Vegetation factor was more important than other factors in desertification control, and vegetation recovery had a significant impact on the management of the desertification. Based on the fuzzy comprehensive evaluation, the assessment index value of ecological benefit of combating desertification in the east edge of Hobq desert was 53 as the general level. Farmers generally believed that sand control had obviously improved the local ecological environment, and most of the farmers had a higher degree of recognition for the desertification control.[Conclusion] With the promotion of ecological policies and management measures, management benefit will show a good sitution. The farmers' awareness of eco-environmental protection is poor and need to be strengthened, and their cultural level need to be improved.

Abstract:[Objective] To study the mechanism of effective participation of famers in rural land consolidation project in order to provide basis for policy making of the government.[Methods] Based on the survey data from 26 rural land consolidation project in Hubei Province, this paper used quantile regression and anti-fact decomposition model to investigate the differences and causes of effective participation of farmers between hilly engineering mode area and pre-service plain engineering mode area.[Results] ① The increase of participation ability, opportunity and motivation of farmers had an important effect on improvement of effective participation. ② The feature differences caused by the participation ability of farmers explained the most part of effective participation difference, but the coefficient differences caused by the participation opportunity and motivation of farmers also should not be neglected.[Conclusion] The enhancement of participation ability, the increase of participation opportunity and the promotion of participation have important impacts on the effective participation of farmers. Meanwhile, the land resource department of the government should make relevant incentive policy according to the actual situation to improve the effective participation of farmers in different area.

Abstract:[Objective] To quantitative analyze the landscape stabiligy of Altay forest farm in order to provide the basis for planing and constructing the forest landscape scientifically and rationally.[Method] Taking the Landsat 8 OLI image in 2016 as the data source, landscape stability assessment models were created by using principle component analysis method. The stability of forest landscape in the whole research area was analyzed by Kriging interpolation.[Results] Shrub land and arbor forest were the dominant forest landscape in the study area, which were widely distributed. The area of nursery land and forestry auxiliary land was small, but the distribution was more concentrated. Forest landscape presented high landscape heterogeneity. The stability of forest landscape among different landscape types was significantly different. The stability was ranked as:shrub land > arbor forest > nursery land > barren land > sparse woodland > forestry auxiliary land.[Conclusion] In 2016, the stability of forest landscape was at a high level, the distribution of regional differences was relatively balanced. In the southwest mountainous areas, the ecological environment was good, and the forest landscape structure was intact.

Abstract:[Objective] Taking Xingcheng City, Liaoning Province as the research area, this study evaluates and analyzes the topographic conditions of arable land in order to provide the basis for guiding crop cultivation, arable land quality evaluation, soil erosion and debris flow disaster prevention, and ecological environmental protection of the arable land.[Methods] Based on the digital elevation model (DEM), the slope, aspect, surface undulation, plane curvature and terrain roughness were selected as the evaluation factors, to evaluate the cultivated land topographic conditions by the multi-factor weighted comprehensive evaluation.[Results] The terrain condition of the arable land of Xingcheng City was as follows:85.57% of the total arable land was good arable land of grade Ⅰ and Ⅱ, 14.17% was general arable land of grade Ⅲ and Ⅳ, and only 0.26% was grade Ⅴ.[Conclusion] The topographic conditions of arable land in Xingcheng City are relatively good as a whole. However, few arable land is in poor topographic conditions, which is not suitable to reclaim and needs to be returned to farmland.

Abstract:[Objective] The spatio-temporal dynamics of carbon sequestration were monitored and the capacity of carbon sequestration in different land use types were discussed in order to provide supports for management of ecosystem services.[Methods] Based on the land use data from 1995 to 2015 and carbon density data, the spatio-temporal changes of carbon sequestration were evaluated by InVEST-Carbon sequestration model in Rizhao City of Shandong Province.[Results] ① The areas of cultivated land and grassland were decreased, while the area of forest land, water area, construction land and unused land area were increased from 1995 to 2015. ② The total carbon storage in Rizhao City showed an increasing trend, which were 6.976×10⁶, 6.978×10⁶, 6.957×10⁶, 6.987×10⁶, 7.015×10⁶ t in the year of 1995, 2000,2005,2010 and 2015, respectively. ③ The highest carbon storage was farmland among all land use types.[Conclusion] The total amount of carbon storage increased by 3.90×10⁴ t from 1995 to 2015, and the carbon sequestration rate showed a rising trend. The carbon sequestration capacity in the eastern coastal areas was relatively weak, which should be fully developed.

Abstract:[Objective] The water resources carrying capacity of the economic belt in the north slope of Tianshan Mountain was eveluated in order to provide the basis for the development and utilization of water resources in the future.[Methods] According to the current situation of water resources in the northern slope economic belt of Tianshan Mountain, a comprehensive evaluation index system consisting of three hierarchies and 12 individual evaluation indexes was established. The weight for each evaluation index was determined based on state variable weight vector, and then the evaluation criteria and two-level comprehensive fuzzy evaluation method were developed.[Results] Comprehensive score of water resources carrying capacity of Urumqi, Shihezi, Turpan, Hami, Tacheng, Yili, Karamay, Changji and Bozhou cities was 0.41, 0.49, 0.43, 0.45, 0.76, 0.56, 0.45, 0.51 and 0.48, respectively.[Conclusion] The carrying capacity of water resources in the northern slope of Tianshan Mountain has reached a certain scale. Comprehensive measures such as water-saving technology and industrial structure adjustment should be adopted to improve the water resources carrying capacity. Rational plan and effective utilization of water resources will promote the social and economic development on the northern slope economic belt of Tianshan Mountains during the "13th five-year plan".

Abstract:[Objective] Zhangjiakou City of Hebei Province is the host city of snow events for the 2022 Beijing Winter Olympic Games. Xuanhua District in Zhangjiakou City is an important industrial area that has a decisive influence on local water use and water quality. The analysis of water resources in Xuanhua District, is crucial for the smooth progress of the Winter Olympic Games.[Methods] This study analyzed water use of agricultural, industrial and daily life in Xuanhua District from 2007 to 2014 by using water footprint theory.[Results] ① The average blue water footprint was 57.650 million m³, and industrial sector was the largest consumer. The average green water footprint was 9.900 million m³, and it all came from agricultural sector. ② The average grey water footprint was 42.235 million m³ based on the COD indicator. ③ According to the average water quantity scarcity index (I_blue is 3.55) and the average water quality scarcity index (I_grey is 0.51), Xuanhua District was a serious water shortage area, and the water quality scarcity was getting worse.[Conclusion] According to the condition of water resources in Xuanhua District, it is urgent to optimize the industrial structure, improve the utilization rate of unconventional water resource and improve local water management strategies.

Abstract:[Objective] To study the changes of ecosystem services in Beijing-Tianjin-Hebei Region in recent years, in order to provide suggestions for developing projects of ecological restoration and conservation and designing ecological compensation mechanisms.[Methods] Changes of land coverage were recorded and analyzed in Beijing-Tianjin-Hebei region during 2005-2015 using land cover transfer matrix analysis, leading level analysis and coverage degree analysis. The ecological service change and its driving factors were analyzed.[Results] ① In 2015, the ecological service increased compared with that in 2005, and the ecological environment was improved significantly. ② The regions with high ecological services values were mainly distributed in Yanshan-Taihangshan ecological conservation area (mainly trees and grass) and coastal ecological protection area (mainly wetland and water). Consequently, these areas were identified as the main ecological service supply areas in Beijing-Tianjin-Hebei region. ③ The dominant types of land cover conversion were (causing changes in ecosystem services) from grass land to forest lands, from arable land to forest lands, and from arable land to grass lands. The major driving factor was the ecological policy.[Conclusion] The quality of the ecological environment is gradually improving in the Beijing-Tianjin-Hebei region during 2005-2015.

Abstract:[Objective] To study the basic ecological characteristics of the Berberis community in order to provide a basis for resource conservation, sustainable use and population restoration in the wild fruit forest of West Tianshan Mountain.[Methods] The typical Berberis community was randomly selected to investigate their species composition, vertical structure, population diameter structure and species diversity.[Results] There were 50 species belonging to 19 families and 47 genera in the Berberis community, of which, 92.00% were dicotyledons. The vertical structure of the community could be divided into three layers:tree layer, shrub layer and herb layer. The importance value of Berberis in the shrub layer was 196.25%. The complexity of species diversity in all layers was showed as:Herb layer > arbor layer > shrub layer. The population of adult Berberis in the community was significantly more than the seedlings, saplings and elderly individuals.[Conclusion] According to the subordinate distribution area, the temperate properties of Berberis community in this area are obvious, and Berberis is the single superior species of the constructive species of the community. The maintenance of the Berberis population depends on middle-aged individuals. The age structure of the Berberis population is spindle-shaped and belong to declining population.

Abstract:[Objective] To calculate the carbon content of the main forest stands in the abandoned land in Jinchuan mine of Gansu Province, and estimate carbon storage years of vegetation in restored areas to provide scientific basis for incorporating ecological restoration system into the voluntary reduction of greenhouse gases in China.[Methods] The organic carbon content of the main species in the restoration area was determined by dry burning method. The average carbon content, vegetation carbon storage density and carbon storage of the main species in the restoration area were estimated and their characteristics were analyzed.[Results] In the repair area, the carbon content of the trees was 0.462 9~0.403 8. The carbon content of the shrubs ranged from 0.413 9 to 0.453. The average carbon content of 8 herbaceous plants was 0.144 5, which was ranked as follows:trees > shrubs > herbs. The average carbon storage density of vegetation in the ecological restoration area of Jinchuan mine abandoned land was 6.209 2 t/hm², and the total carbon storage was 635.10 t. Among the total carbon storage allocation, the arbor was the highest, accounting for 86.71%, and the shrub was the second, accounting for 12.65%. Plants accounted for a small proportion of total carbon stocks.[Conclusion] The ecological restoration of mine wasteland can increase the capacity of carbon storage in the mine area, and there is a great potential for the mine wasteland to be included into China's voluntary greenhouse gas emission reduction.

Abstract:[Objective] To understand the basic evolutionary trend of carbon sources/sinks of farmland ecosystem of Jiangsu Provinc in recent years and identify the important sources of carbon emission in the process of agricultural development, in order to guide the development of low carbon agriculture.[Methods] The carbon estimation model was used to estimate the quantities of carbon emission, carbon uptake and carbon footprint, respectively. And the dynamic changes of the carbon footprint were analyzed.[Results] ① The total carbon emissions of farmland ecosystem tended to increase. The carbon emissions in 2016 (4.60×10⁶ t) were increased by 3.4% compared to 2001 (4.44×10⁶ t), and fertilizer was the main contributor to carbon emission. The intensity of the carbon emission showed a decline trend, and it was lower than 1 t/hm² at all stages. ② The carbon uptake showed an increasing trend. From 2001 to 2016, it increased by 3.57×10⁷ t, the annual compound growth rate was about 2.2%, and the carbon uptake per unit area showed an overall increase trend. The carbon uptake of horticultural crops was significantly higher than that of food crops and cash crops. ③ The carbon footprint of farmland ecosystems showed a declining trend, and there was a large ecological surplus.[Conclusion] ① The quantities of carbon absorption of farmland ecosystem was significantly higher than carbon emission from 2001 to 2016, which showed that the farmland ecosystem had good carbon sequestration capacity and could be used as the carbon sink. ② The impact of agricultural inputs on carbon emission was different, and the fertilizer was the most critical factor affecting agricultural carbon emissions.

Abstract:[Objective] To analyze the vegetation restoration effectiveness and development trends in the Tarim River basin in order to provide research basis for the ecological management of the basin.[Methods] Based on MODIS-MOD13 Q1 multi-spectral remote sensing data from 2007 to 2017, EVI (enhanced vegetation index) was used as a breakthrough point. ArcGIS software was used and time series models of vegetation cover were constructed to dynamically monitor the vegetation changes in the Tarim River basin.[Results] ①The vegetation coverage of Tarim River basin was low, and the spatial-temporal heterogeneity of vegetation index was large. The highest vegetation cover in the main steam was only 23.56% in July, 2017, while the highest vegetation coverage in the upstream was 3.36 times of that of the downstream section, and the annual maximum ratio of the vegetation coverage in the upper reaches was 4.28. ②There was no significant difference in vegetation coverage between 2017 and 2007 in the whole basin. Time series model showed a positive trend for the future vegetation restoration of the Tarim River. ③There was no significant difference between NDVI and EVI, but NDVI tended to be low in areas with low vegetation coverage, while it tended to be high in areas with high vegetation coverage.[Conclusion] The vegetation coverage of the Tarim River basin remains stable currently. Moreover, the ecological environment will be improved in the future. Dynamic monitoring and quantitative analysis of vegetation restoration effectiveness based on EVI index is feasible.

Abstract:[Objective] To analyze the dynamic change of the major water bodies in Western Jilin Province in order to understand the current situations of water resource in the area, and to provide strong support for the protection, utilization and sustainable development of water resources.[Methods] We extracted the area and spatial distribution of major water bodies in Western Jilin Province by visual interpreting, based on MODIS images from 2000 to 2017. Moreover, the inter-annual and intra-annual variations of water area and the corresponding impact factors were analyzed.[Results] Since 2000, a northward tendency was showed in Yueliangpao reservoir, Xianghai reservoir and Chagan Lake, and the water area had increased. There was an obvious annual periodic change of the water area. Specifically, relatively larger water areas were found during the rainy season, which were compatible with the seasonal climate. The climate change, especially changes of precipitation had significant impacts on water area. In addition, human activities also played a significant role in promoting the growth of water area.[Conclusion] Affected by climate change and human activities, the water area of the major water bodies in Western Jilin Province has increased since 2000.

Abstract:[Objective] Due to the fact that there are only three bands (red, green and blue) in most UAV(unmanned aerial vehicle)images, a method of extracting water body and monitoring water changes based on texture feature is proposed in order to provide technical support for water conservancy department.[Methods] We used eCognition software to divide the UAV images into multiple scales, and from the image object firstly. The angular second-order moment, mean, entropy and other texture features of the image object was then calculated. These texture features was combined as the image band to highlight the water body. Finally, the water body was extracted by ISO classification method, and the water body extracted from different periods was analyzed to obtain the change area of the water body.[Results] By testing in different regions, the accuracy of the water extraction and detection for water change was above 90%.[Conclusion] The proposed method can effectively improve the efficiency of the water body change monitoring, and reduce the amount of manual labor.

Abstract:[Objective] To study the precise classification method of land cover in the alpine river-source area in order to provide references for future land classification and provide data support for land resources and ecological environment supervision in the Qinghai Lake basin.[Methods] High spatial resolution remote sensing images were used to derive the land cover information through six different kinds of supervised classifiers (parallel hexahedron, minimum distance, Mahalanobis distance, maximum likelihood, neural network and support vector machine). And the land cover status of the Shaliu river basin in Qinghai Lake was statistically obtained through the best extraction method.[Results] The classification accuracy of support vector machine, neural network and maximum likelihood was high, the overall classification accuracy was greater than 96%, and Kappa coefficient was greater than 0.95. The classification accuracy of the parallel hexahedron was the lowest, and the error was largest. Support vector machine showed the best classification effect by combining all kinds of classification accuracy and classification image local details. Through interpretation, it showed that the land cover of the Shaliu river basin was dominated by grassland, and accounted for 71.09% of the total area of the basin. Bare land and wetlands accounted for 16.26% and 10.24% of the total area of the basin, respectively. Water, farmland, and construction land was small, accounted for 2.41% of the total basin area.[Conclusion] By using high spatial resolution remote sensing images, a good classification of land cover in Shaliu river basin of Qinghai Lake was achieved by support vector machine classifier. The whole basin has a high vegetation coverage and good ecological environment.

Abstract:[Objective] To explore the spatial distribution of rain flood pattern in order to provide references for the construction of sponge city.[Methods] A GIS database was established, combined with ArcGIS simulation, SCS-CN and SWMM models, the characteristics of runoff and flood distribution were quantitatively analyzed in Luohe planning area.[Results] Total runoff and runoff coefficient (equal), runoff volume, total peak, inundation area of Moran's I coefficient was 0.338 (p<0.001), 0.142 (p<0.001), 0.101(p<0.001) and 0.918 (p<0.001), respectively, indicated that the distribution of runoff and inundation had a remarkable agglomeration. The impact of land type and pipe network distribution on runoff was greater than that of accumulated water process, but the influence of topography was opposite. Total runoff and runoff coefficient were decreased from center to outside. Total peak and runoff volume were affected by catchments area and pipe network distribution. The impermeable surface of the runoff high risked area accounted for 82.73% of the total area. The runoff risk decreased from center to outside. The catchment area of runoff coefficient > 0.7 and the inundation area > 70% were concentrated in the urban center. Agricultural land, urban green space and road land were the main types of land use in the inundation area, accounting for 36.56%, 21.39% and 21.82% of the total area, respectively, and there were significant difference in the distribution characteristics.[Conclusion] Urban surface change was closely related to the distribution of runoff and inundation. The comprehensive quantification method could directly reflect the characteristics and trends of urban flood pattern.

Abstract:[Objective] To evaluate the capacity in flood disaster prevention and reduction in order to provide effective references for the regional government to make scientific and effective policies in flood disaster prevention and reduction.[Methods] The index system for flood disaster prevention and reduction capacity was composed of flood monitoring and warning, flood disaster prevention and waterlogging control, rescuing and rehabilitation as well as disaster management. The traditional entropy weight method was improved based on the minimum relative entropy principle and the rank ration method, and the weight of each index was calculated by the improved entropy method. The improved entropy method and cloud model was used to establish the evaluation model, and the capacity of flood disaster prevention and reduction of the Huaihe River basin in Anhui Province was then assessed.[Results] The flood disaster prevention and reduction capacity was at middle and lower leve land the spatial difference was obvious. Flood disaster prevention capacity in the northern part of the basin was higher than the south, and the eastern part of the basin was higher than the west. The flood disaster and reduction capacity was relatively high in the urban area, and relatively low in the rural area. Feixi County, Huaibei City, Bengbu City, Huainan City, Chuzhou City were at the high level. Changfeng County, Wuhe County, Fengtai County, Xiaoxian County, and Tianchang City, Fuyang City, Luan City was at a relatively high level. Feidong County, Suixi County, Dangshan County, Sixian County, and Suzhou City, Jieshou City, Mingguang City were at a middle level, while the others were at a relatively low and even lower capacity of flood disaster prevention and reduction.[Conclusion] Based on the evaluation results of flood disaster prevention and reduction capacity, the vulnerable spots in flood disaster prevention and reduction in the area can be identified, and the overall capacity in flood prevention can be improved.

Abstract:[Objective] Taking Wangjiang County, Anqing City of Anhui Province as the research area, this study designed twenty year flood disaster in order to provide a scientific basis for the application of remote sensing and geographic information system (GIS) in disaster analysis.[Methods] Using remote sensing and GIS technology, land use was supervised and classified based on remote sensing and DEM data base. The submerged area was calculated by seed spread algorithm, calculation, and the proportion of each type of land use in the submerged area was obtained. A flood disaster assessment model was established, and the flood disaster in 20 years was simulated and analyzed by analogy method.[Results] With the influence of the flood disaster in Wangjiang County in 20 years, the affected area was more than 50% of the total area, and the affected population was more than 90%. Using submerged data combined with cases data, the case could be characterized as large flood disaster. By analogy with typhoon "Pearl" with similar evaluation coefficients, disaster relief and rescue measures were designed with test data.[Conclusion] The combination of remote sensing and GIS technology provides a platform for flood design. By using submerge data, the disaster level can be evaluated as soon as possible. Through analogy analysis with the same level of disaster and combining with the actual situation, the disaster relief measures can be drawn up quickly and accurately, and the case can be assessed as a case for reverence.

Abstract:[Objective] The discharge of acid mine drainage in metal mining area causes serious environmental pollution, and is difficult to control. This study designed and implemented the technology system of acid mine drainage control based on the combination of source controlling and terminal treatment, which provided a new solution for the treatment of acid mine drainage.[Methods] Based on the principle of "source control and terminal treatment", a comprehensive prevention and control technology system for acid mine drainage was established in Dabaoshan mining area of Guangdong Province.[Results] A cut-off drainage system was established to implement rainwater and sewage diversion, and to reduce the amount of acid mine drainage generated from the source. The storage capacity of the mud tank was 2.81×10⁶ m³. The new sewage treatment plant could process acid wastewater as much as 4.50×10⁴ t/d. The mine acid wastewater treatment system established in this study can achieve the goal of prevention and control in acidic wastewater during the rainy season.[Conclusion] Based on combined utilization of ditch (cutting ditch), canal (drainage), reservoir (blocking mud), and plant (sewage treatment plant), it is possible to achieve the goal of prevention and control in acidic wastewater under certain conditions. The technical system constructed in this study can be used for acid mine drainage treatment in similar mining areas.

Abstract:[Objective] A new type of high salt-tolerant superabsorbent polymer was prepared by grafting acrylic acid (AA) with chitosan (CTS) and guar gum (GG), with ammonium persulfate (APS) as initiator and N, N'-methylene bisacrylamide (NMBA) as crosslinker. The optimal reaction conditions in the synthetic process were investigated to study the effect of the superabsorbent polymer on the water and nutrient retention in the saline alkali soil.[Methods] The superabsorbent polymer was prepared by aqueous solution polymerization and the optimized reaction conditions were studied based on single factor experiment (degree of neutralization of AA, addition of GG, APS and NMBA). The molecular structure and characteristics of the product were confirmed by fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The absorbent efficiency of product was studied in different saline solutions with different pH value. In addition, the effect of superabsorbent polymer in reforming saline alkali soil was studied by leaching test.[Results] The absorbent efficiency of the product reached the highest when the degree of neutralization of AA was 85%, the amount of GG was 0.2 g, the addition of APS and NMBA were 0.3% and 0.02% of the total monomer, respectively. Under this condition, the absorbent efficiency of product were 1 128 and 185 g/g in deionized water and 0.9% NaCl solution, respectively. The results of FTIR and SEM showed that CTS, GG and AA were involved in the polymerization, and the products had a good spatial network structure and surface morphology. The superabsorbent polymer had a relatively stable absorbent efficiency in the pH value range of 4~10. However, the absorbent efficiency decreased obviously when there were the co-existing cation in the solution, and inhibitory effect of cations on the absorption efficiency was ranked as:Mg²⁺ > Ca²⁺ > Na⁺ > K⁺. And the superabsorbent polymer could not only improve the water holding capacity of the soil but also inhibit the leaching loss of nitrogen and potassium fertilizer.[Conclusion] The superabsorbent polymer prepared in this experiment has better salt tolerant effect and wide range of solution pH value adaptability. The synthetic monomers of the superabsorbent polymer are environmentally friendly, and can effectively reduce the leaching loss of the soil water and fertilizer in the saline-alkali soil.

Abstract:[Objective] To obtain the best sand-fixing measures along the Geku railway in order to provide a theoretical basis for the deployment of sand-fixing measures along the line.[Methods] The ANSYS fluent numerical simulation was used to study the change of flow field, the protective distance, the sand accumulation process of high density polyethylene (HDPE) board and the hardened sand square grid.[Results] The results showed that when the airflow passed through the HDPE board and hardened sand square grid, six velocity zones were formed including:low air speed zone at windward side, air flow uplift zone, air flow accelerated zone, the first air flow deceleration zone, the second air flow deceleration zone and air flow speed recovery area zone. At the same height, the effective protection distance of hardened sand square grid was greater than that of HDPE board under the same wind speed. The sand accumulation in the HDPE board and hardened sand square grid were dynamic processes. Sand control form of ventilated HDPE board and non-ventilated hardened sand square grid were dominated by sand accumulation and sand resistance.[Conclusion] The economical practicality and the sand control effect of HDPE board were better.

Abstract:[Objective] To investigate the landscape cover plants in Zhangjiajie City, Hunan Province in order to analyze the quality of landscape cover plants in the urban area.[Methods] Using the analytic hierarchy process (AHP), the landscape quality of the 82 species of landscape cover plants were evaluated, sorted and graded.[Results] There were 82 species of landscape cover plants in Zhangjiajie City, belonging to 71 genera and 47 families. The ground plants of grade Ⅰ were ornamental and adaptable with excellent landscape architecture quality, and plants of grade Ⅱ were inferior in ornamental value and adaptability, plants of grade Ⅲ were the worst. The main factors affecting the landscape quality included plant species, color and the habitat.[Conclusion] In the construction of landscape architecture, it is important to consider the diversity of plant species and colors, and make full use of the diversity of plant habitat.

Abstract:[Objective] To investigate the heavy metal pollution and chemical forms and identify the hypertolerant plants in Western Guizhou Province in order to provide a scientific basis for preventing and controlling heavy metals pollution in the area.[Methods] The ecological risks of heavy metals in mining areas and non-mining areas were evaluated using potential ecological risk and fuzzy mathematic assessment models (the single factor deciding and the weighted average models). The physical and chemical indexes affecting soil fertility were tested. The chemical forms of heavy metals in soil samples were analyzed by risk assessment code. Bio-concentration factors were used to select plants with high tolerance to heavy metals around the coal mining area.[Results] The average concentrations of Hg, Cd, As, Zn, Cr and Ni in coal mining areas were 3.37, 1.11, 1.50, 1.63, 1.23 and 1.73 times higher than the background values. The potential ecological risk of studied heavy metals in coal mining area followed the order of:Cd > Hg > As > Ni > Cr > Pb > Zn. The single factor deciding model of the fuzzy mathematic assessment showed that the pollution of non-mining area was higher than that of mining area, but the weighted average model was opposite. The potential risk indexes of Cd, Cr, Cu, Mn, Ni, Pb and Zn in coal mining area were 69.17%, 7.97%, 8.24%, 40.10%, 45.29%, 53.70% and 29.90%, respectively. The As enrichment coefficient of Pteris vittata was greater than 1.00. The Cd enrichment coefficient of Pyracantha fortuneana, Broussonetia papyrifera, Rhus chinensis, Coriaria nepalensis, P. cretica and Hypericum patulum were greater than 1.00. The Pb enrichment coefficient of C. nepalensis and Artemisia stelleriana were greater than 1.00.[Conclusion] There existed more serious pollution in mining areas, especially Hg, Cd and As pollution. The potential risk of heavy metals in soils around the coal mining area is in the order of Cd > Pb > Ni > Mn > Zn > Cu > Cr. In conclusion, P. vittata can be used as the primary plant for remediation of As pollution surrounding the coal mining area. In addition, P. cretica could be used as the primary plant to repair the Cd pollution, and C. nepalensis could be used as the primary plant to repair the Pb pollution.

Abstract:[Objective] To reserch the vulnerability of urban water resources, and reveal the ability of the sustainable development of urban water resources in order to provide reference for building sustainable cities.[Methods] This article listed the water resources of 21 administrative cities of Guangdong Province and Shunde District of Foshan City as empirical subjects. The evaluation index system was established from three perspectives including natural, human and bearing capacity factors. Based on the entropy weight method, the water resources vulnerability assessment model was constructed using the linear weighted summation method.[Results] Water resources in Guangdong Province were relatively vulnerable, and the water resources in Shenzhen City were not vulnerable. Among 22 research subjects, water resource vulnerability of Shenzhen City was most stable.[Conclusion] According to the results of water resources vulnerability assessment in Guangdong Province, and sustainable development of smart city, water resources vulnerability in Guangdong Province was high. The utilization of water resource can be improved through the reform of industrial structure, the construction of smart water affairs and the utilization of science and technology.

Abstract:[Objective] To reveal the relationship between the main influencing factors and the level (orthogonal design) of microbial in situ remediation in order to provide a theoretical basis for the parameter design of bio-remediation engineering in oil-contaminated sites.[Methods] The effects of pollution intensity, nutrition, oxidant, surface active agent and inoculation amount on soil remediation were investigated by orthogonal design with 5 factors and 4 levels in the experiment.[Results] After the preliminary screening of crude oil as the sole carbon source, 16 dominant bacteria strains for petroleum hydrocarbon degradation were obtained. By the bacterial rescreening, two symbiotic fungi DPF₂ and DPF₄ were obtained. The highest synergistic degradation rate was 87.77% after 7 days. The degradation rate of oil-contaminated soil was the highest when the oil pollution intensity was 10 after 60 days, and the degradation rate of oil-contaminated soil reached to 94.12%. The degradation rate of oil-contaminated soil with pollution intensity of 25 was 90.17%. SPSS data analysis showed that oxidants, surfactant and nutrients were the most important factors affecting bio-remediation, followed by the intensity of contamination and the number of bacteria.[Conclusion] The initial addition of surfactant, oxidants, and nutrients could be of great significance to petroleum bio-remediation. The pollution intensity had a certain effect before 35 days, and had the least influence in the later stage of remediation. During the whole remediation process, the mean variance of inoculation amount was the smallest compared with other factors, so the factor level had no significant effect on the oil degradation ability.

Abstract:[Objective] To study the responses of wine grapes for different nitrogen fertilizer application rates and depths, in order to supply theoretical basis for the nitrogen fertilizer application on wine grapes in the Liangzhou irrigation area of Gansu Province.[Methods] Field experiments were conducted to study the effects of different nitrogen fertilizer application rates and depths on grape yield, nitrogen content of fruit, leaf, stalk and residues of nitrate nitrogen in 0-200 cm soil layers during harvest and the second germination season.[Results] There were no significantly difference in the yield, nitrogen content of fruit, leaf, stalk and residues of nitrate nitrogen in 0-200 cm soil layers during harvest and the second germination season between 10 cm and 30 cm fertilization depths. The effects of different nitrogen fertilizer application rates on yield and nitrogen content of stalk reached significant level, but the effects on nitrogen content of fruit and leaf were not significant. There were no significant difference in yield, nitrogen content of fruit and leaf between high level (300 kg/hm²) and middle level (240 kg/hm²) nitrogen fertilizer treatments. Compared with low levels (180 kg/hm²) nitrogen fertilizer treatment, the yield significantly increased by 28.6% and 24%; The nitrogen content of leaf significantly increased by 17.4%, and 11.3%; and the nitrogen content of stalk significantly increased by 40.7% and 33.0% for high and middle levels nitrogen fertilizer treatment, respectively. Compared with middle and low levels nitrogen fertilizer treatment, residues of nitrate nitrogen in 0-200 cm soil layers for high levels nitrogen fertilizer treatment during harvest and germination season increased by 53.8%, 94.4% and 41.8%, 76.1%, respectively. As to the interactions between nitrogen fertilizer application rates and depths, only the nitrogen content of leaf reached a significant level.[Conclusion] Under the conditions of current experiment, the effect of nitrogen application depth on wine grape was not obvious, due to the influence of soil texture and traditional irrigation. The suitable nitrogen fertilizer application rate was 240 kg/hm² for wine grapes, but there is also a risk of nitrogen loss. Therefore, reasonable fertilization amount and fertilization mode should be determined based on irrigation mode in Liangzhou irrigation area.

Abstract:[Objective] To analyze the importance of the factors that influence the change of cultivated land area in order to predict the amount of cultivated land area resources, and to service the protection of cultivated land.[Methods] Taking Qingyang City of Gansu Province as a case study, the random forest algorithm was used to construct the prediction model of cultivated land area. The results were compared with those of BP neural network model, and the importance of the factors that influencing cultivated land area change was sorted.[Results] The relative error and root mean square error of the prediction results of the random forest algorithm were smaller than that of BP neural network, and the prediction accuracy was high and the results were stable. The cultivated land area in 2020, 2025 and 2030 was predicted to be 4.515×10⁵, 4.513×10⁵ and 4.512×10⁵ hm², respectively, showing a decreasing trend. The importance of the main influencing factors was ranked as:agricultural machinery general dynamics > agricultural population > GDP > fixed asset investment.[Conclusion] The random forest algorithm is suitable for the prediction of cultivated land area and can measure the importance of factors that influence the change of cultivated land area.

Abstract:[Objective] To understand the risk of water quality safety in main canal for water diversion from Yellow River to Qingdao City, in order to provide basis for the safety management of main canal, and to ensure the the drinking water safety of Qingdao City.[Methods] Based on the monitoring data obtained along the main canal, the key control factors which determine the water quality in the main canal were identified, and a list of the water quality safety risks was determined by further analysis of the risk factors.[Results] The water quality of the main canal was improved firstly, and then deteriorated. Nutrients were the main indexes affecting the water quality of the main canal. The south-to-north water diversion project alleviated the eutrophication of the main canal obviously. There were larger sources of iron and phosphorus pollution in the main trunk canal between Songzhuang water diversion and water inlet of Jihongtian reservoir.[Conclusion] It is feasible to apply the key control factors identification method in the long distance water diversion projects. The existing safety risks in the main canal include total nitrogen and total phosphorus from the Yellow River, organic matter and sulphate from the south-to-north water diversion project, and iron, phosphorus and organic pollutants in the latter half of the main canal. The potential safety risks are eutrophication and release of metal ions caused by the changes of water intake volume in south-to-north diversion or the Yellow River and the failure of the wetland system.