Abstract:[Objective] This study assessed the temporal and spatial variation of rainfall erosivity at Pingjiang basin in the upstream of Ganjiang River to provide a basis for the formulation of watershed management measures in this area.[Methods] Daily precipitation data from 1989 to 2018 from ten stations in the Pingjiang basin were used. Rainfall erosivity was calculated using a simple algorithm, and temporal variation in rainfall erosivity was analyzed using the Mann-Kendall method and climate tendency rate. The spatial variation of rainfall erosivity was analyzed via the Kriging interpolation method using ArcGIS 10.1.[Results] Annual rainfall erosivity from 1989 to 2018 at Pingjiang basin was 4 233 MJ·mm/(hm²·h·a), while the maximum value[6 766.5 MJ·mm/(hm²·h·a)] occurred in 2015 and the minimum value[2 191 MJ·mm/(hm²·h·a)] occurred in 2003. Rainfall erosivity at Pingjiang basin from 1989 to 2018 was relatively stable, showing an insignificant increasing trend in interannual distribution over the study period. The annual distribution was consistent with precipitation levels, showing a bimodal pattern in June and August. The spatial variation of rainfall erosivity at the basin showed a decreasing trend from the northeast to the central south and an increasing trend to the southwest. The maximum value appeared near Chenggang station at the north of the basin, and the minimum value appears near Longkou station at the south central of the basin.[Conclusion] The spatiotemporal variations of rainfall erosivity in the Pingjiang basin are largely consistent with precipitation levels. For the prevention and control of soil and water loss, attention should be focused on the northern part of the basin in spring, and the southwestern basin during summer and winter.

Abstract:[Objective] Analysis of the characteristics of runoff and sediment yield under different rainfall patterns, and its responses under different vegetation cover types and vegetation coverage was conducted to provide a theoretical basis for studying the dynamic characteristics of runoff and sediment yield of yellow soil slopes in karst areas.[Methods] Based on field measurements from 2014-2018 in Yangjichong watershed (Longli County, Qiannan Prefecture, Guizhou Province), and based on the K-means classification method, the rainfall types in the study area were divided into four categories, and the correlation analysis, regression model, and exponential function analysis of each indicator were carried out.[Results] Different rainfall types had diverse effects on sediment yield in the study area, and significant differences existed between rainfall characteristics on sediment yield under different vegetation cover types. The A-type rainfall pattern (low-frequency rainfall events with extremely high intensity, extremely high amounts and medium duration) was more likely to cause erosion. There was significant correlation between runoff yield and sediment yield on slopes, soil and water conservation effect in an economic fruit forest. The B-type rainfall (high-frequency rainfall events with high intensity, medium amounts and short duration) was the main rainfall type in this region. Among the four rainfall types, the soil and water conservation effect of mixed forest was the best, compared with other vegetation cover types. Sediment yield was positively correlated with rainfall intensity and runoff depth, and negatively correlated with vegetation coverage. The sediment yield was strongly influenced by runoff depth, followed by average rainfall intensity and vegetation coverage. When vegetation coverage reached about 80%, the reduction effect on runoff and sediment was stable.[Conclusion] Under certain rainfall, vegetation is the key factor affecting slope sediment yield. For a slope of yellow soil in karst areas, increasing surface coverage is not only the basis for reducing sediment yield, but also an important measure to prevent soil erosion.

Abstract:[Objective] The effects of depression caused by long-term freezing-thawing and water erosion on soil respiration in Qinghai-Tibet Plateau were studied to provide a scientific basis for the evaluation of carbon cycling process at an alpine marsh meadow.[Methods] We conducted a field experiment at an alpine marsh meadow with a depression and a non-depression in Qinghai-Tibet Plateau. We measured the air temperature, relative air humidity, soil respiration, soil temperature, and moisture content at 5 cm depth in May 2019, and investigated plant traits, such as dominant species, above-ground biomass, plant height, and community coverage in August 2018.[Results] ① The average rate of soil respiration in the depression caused by freezing-thawing and water erosion was significantly lower than those in non-depression regions; ② Freezing-thawing and water erosion causeed the surface sink, leading to an increase in relative air humidity and a decrease in air temperature, which was similar to the polythermal effects of basin regions. The depression caused by freezing-thawing and water erosion increased soil temperatures at 5 cm depth, and had a profound impact on soil respiration.[Conclusion] The depression caused by natural freezing-thawing and water erosion processes of Qinghai-Tibet Plateau changes the soil environment and the soil respiration in the primary system, which further modifies the carbon cycle of alpine marsh meadow ecosystem.

Abstract:[Objective] The mechanism of soil phosphorus loss from engineered slopes in a southwest alpine-subalpine region was studied to provide a theoretical basis for the restoration of the ecological environment on the same type of slopes.[Methods] The characteristics of total phosphorus (TP), sediment total phosphorus (STP), dissolved phosphorus (DP) migration, and their relationships with soil erosion, were studied under two slope gradients (30°, 50°) and four rainfall intensities (25, 45, 65, and 85 mm/h) using indoor simulated rainfall experiments and undisturbed soil removal.[Results] ① The average DP concentration of runoff from the engineering slopes was generally low and was less affected by rainfall intensity. The STP concentration was higher at the beginning of the rainfall and then decreased, or tended to be stable. ② The curves of the DP loss rate and STP loss rate from the engineered slopes had obvious differences under different rain intensities. When the rain intensities were 25 and 45 mm/h, the STP loss rate and DP loss rate from the engineered slopes were lower and more stable. When the rainfall intensity was 65 and 85 mm/h, the loss rate of STP and DP of the engineering slopes increased rapidly in a parabolic trend and tended to be stable. When the rainfall intensity increased from 45 to 65 mm/h, the loss rate of STP and DP increased rapidly. ③ The soil erosion rate was positively correlated with the DP loss rate, mean DP concentration, STP loss rate and concentration, and TP loss rate. The runoff rate was positively correlated with the DP loss rate, STP loss rate, TP loss rate, and mean DP concentration, but not with the STP concentration. The rate of TP loss from the engineered slopes increased gradually with the runoff rate and soil erosion rate in the form of a power function.[Conclusion] Rainfall intensity and slope gradient have significant influence on change of the dynamics of phosphorus loss from engineered slopes, and the trend of phosphorus loss first increases, and then decreases.

Abstract:[Objective] The mineralization processes of soil organic carbon under different water and nitrogen additions were studied to understand the relationship between the soil properties and carbon mineralization, and to provide scientific references for revealing the soil carbon conversion pattern in alpine steppe under global change.[Methods] A laboratory experiment was conducted with four different soil water contents (45%, 60%, 75%, 90% water-holding capacity, WHC) and four nitrogen levels (0, 0.2, 0.4, 0.8 mg/g). The following parameters were measured:CO₂ concentration, dissolved organic carbon (DOC), microbial biomass carbon (MBC) content, and enzyme activity.[Results] ①Within the experimented range of water and nitrogen addition, carbon mineralization volume showed a parabolic pattern. Soil carbon mineralization was more sensitive to the addition of water and the effect of the nitrogen addition on soil carbon mineralization was dependent on the water content. ②Increasing the water content from 45 to 60% WHC led to a faster leaching of the soluble substances from the soil, indicating a greater carbon mineralization. The soil organic carbon and microbial biomass carbon also showed an upward trend with an increase of the nitrogen addition from 0 to 0.4 mg/g. ③The soil carbon mineralization was inhibited either with the high WHC(90%) or by the addition of a higher content of nitrogen (0.8 mg/g) at 45% WHC. The high water content led to a lower soil carbon mineralization by a reduction in the soil porosity; whereas the addition of a high nitrogen content (0.8 mg/g) led to the inhibition of the soil carbon mineralization process by decreasing the availability of the DOC of the soil, level of MBC in the soil, and activity of soil microbial enzyme. The carbon mineralization inhibition by high-content nitrogen addition was alleviated at a high WHC(90%).[Conclusion] The predicted continuous increase in nitrogen deposition and precipitation in the Tibet Plateau may inhibit the carbon mineralization processes of the alpine steppes and benefit the accumulation of soil organic carbon.

Abstract:[Objective] The relationship between erosion gullies and terrain factor was studied to clarify the effects of catchment topography on the development and distribution of erosion gullies in Jilin Province, and to provide a scientific basis for future erosion gully comprehensive management and land use planning.[Methods] The dimensions of 25 total gullies were measured using real time kinematic (RTK) positioning in Liaoheyuan Town, Dongliao County, Jilin Province. Digital elevation models (DEMs) of the gully catchments were generated based on 1:10 000 scale topographic maps using ArcGIS software, and the relationship between gullies and their topographic factors were obtained and analyzed.[Results] ① Gully density in the study area was 5.99 km/km², and the proportion of valleys within the slope area was 5.12%. Erosion gullies were mainly distributed at the middle and base of the farmland, and the erosion intensity was severe; ② The proportion of gully areas to the slope area first presented an increasing trend and then a decreasing trend with the slope changes. The maximum value of proportion was reached in the slope ranged from 6 to 9 degrees; ③ Additionally, there was a power function relationship between gully density and the average width of the confluence area; ④ Gully density decreased with the proportion of gully area to the slope area increasing in the slope steepness from 3 to 6 degrees, whereas increased with the proportion of gully area to the slope area increasing in the slope steepness from 6 to 9 degrees; ⑤ There were linear positive correlations among the average width of gully/catchment and shape coefficients, and the correlation coefficients were 0.57 and 0.84, respectively.[Conclusion] The gully erosion intensity was severe and have a tendency of worsening in the hilly area of Jilin Province. Erosion gullies were mainly distributed in farmland areas and featured slope steepness of 6 to 9 degrees.

Abstract:[Objective] We studied the effects of different mulching measures on the soil water, heat, salt, and soybean yield in the farmland, in order to provide a reference for promoting crop yield in the mountain terraces of Ansai County, Shaanxi Province.[Methods] The soybean(Zhonghuang 35) was used as the material where this experiment included four treatments:film mulching (M), mulching with 5 000 kg/hm² straw (J₅), mulching with 2 500 kg/hm² straw (J₂) and traditional tillage (CK).[Results] ① The soil water storage of M and J₅ treatments during growth stages were higher than that of CK treatment, except for the podding stage in the 20-40 cm soil layer. Additionally, the soil water storage of M in the seeding stage was higher than the J₅ treatment in each soil layer. ② In each 0-60 cm soil layer, the soil temperature of M was higher than the CK treatment, during the entire growth stage. The soil temperature of J₅ was lower than the CK treatment, except during the podding stage. ③ M treatment can improve soil conductivity in a certain extent. The conductivity has a significant difference between M and CK treatments (p<0.01) in the 0-20 cm soil layer. ④ The soybean yield of M and J₅ were significantly higher than that of the CK treatment, by 46.73% (p<0.01) and 34.61% (p<0.05), respectively. ⑤ There was a positive correlation between soybean yield and average soil water storage, soil temperature, and soil conductivity, during the entire growth period in a certain extent. Compared with other growth stages, the physical soil conditions had a significant effect on soybean yield during the seedling stage.[Conclusion] There is a significant positive correlation between soybean yield and soil water storage and conductivity, during the seedling stage. Therefore, film mulching can improve soil water storage and electrical conductivity during the seedling stage and promote soybean yield.

Abstract:[Objective] The effects of the intercropping of Lycium barbarum with Onobrychis viciaefolia in different saline soils on the water and salt transport mechanism and on the yield of L. barbarum were researched. The aime was to provide a theoretical and technical support for the planting pattern of L. barbarum and the saline-alkali land improvement in the Gansu Yellow River irrigation area.[Methods] Two planting modes were set up, namely:L. barbarum monoculture and L. barbarum intercropping. Further, different degrees of salinization were prepared:non-(S₁), mild (S₂), and moderate (S₃) salinization. The variations in soil water and salinity as well as the yield of L. barbarum under different planting modes and salinization degrees were analyzed.[Results] Compared with L. barbarum monoculture, L. barbarum intercropping with O. viciaefolia was observed to significantly increase the soil water content in the 0-20 cm soil layer under three salinization conditions. The soil water content in 0-120 cm soil layer showed that L. barbarum intercropping with O. viciaefolia was lower than that of L. barbarum monocropping, and the difference was most significant under the S₁ condition (p<0.05). Moreover, within the 0-60 cm soil layer, the soil of L. barbarum intercropping with O. viciaefolia was desalinated. The relative desalination rates of L. barbarum intercropping with O. viciaefolia were 6.539, 3.078, and 2.455 under the conditions of S₁, S₂ and S₃, respectively; whereas the soil of L. barbarum monocropping exhibited a salt accumulation. With an increase in the salinization, the 100-grain weight and the yield of the L. barbarum fresh fruit decreased gradually. Under the conditions of S₁ and S₂, the 100-grain weight and the yield of L. barbarum intercropped with O. viciifolia were higher than those of the L. barbarum monoculture; this difference was significant (p<0.05).[Conclusion] L. barbarum intercropping with O. viciaefolia can simultaneously improve the water content of the surface soil and reduce the salt content of soil. It is also beneficial to increase the yield of L. barbarum. Moreover, the effect is better under the condition of non-salinization (S₁).

Abstract:[Objective] The variation characteristics of grassland soil moisture under natural and management factors were analyzed to provide a scientific reference for the ecological restoration of degraded grassland.[Methods] Twelve sloping area plots were monitored by fixed points. A time-domain reflector (TDR) and probe were used to determine the soil water content of the top 0-10 cm of two degraded grassland slopes with sierozem and brown-red soil. The data were compared and statistically analyzed. Combined methods were used to analyze the effects of natural factors such as rainfall, temperature, slope position, and irrigation, and soil management factors on hillslope soil moisture dynamics.[Results] Rainfall and temperature had significant effects on the surface soil water content, and varied rainfall intensity had different effects on the surface soil water content. The slope position has no significant effect on surface soil water content. Brown-red soil had a high water capacity, and the surface soil moisture content was higher than that of sierozem. Among the various management measures, the horizontal ditch treatment maximized the surface soil water content after rainfall, and the grass-cover treatment significantly reduced the decrease of surface soil water content after rainfall. There was no significant difference in surface soil water content under different rainwater harvesting methods, but supplementary irrigation with harvested rainfall can increase the surface soil water content in a short time.[Conclusion] The surface soil moisture is mainly controlled by factors such as rainfall and management. Therefore, soil moisture can be controlled through artificial cultivation management to achieve vegetation restoration.

Abstract:[Objective] The dynamic characteristics of soil moisture of five different vegetation types were studied to provide a theoretical basis for optimizing plantation mode.[Methods] Five typical vegetation types from the semi-arid loess hilly region of Dingxi City, Gansu Province, were selected. The soil moisture content of the soil layer from 0 to 200 cm in depth was observed in 2017 and 2018 using a soil moisture tachometer. The characteristics and stability of soil moisture of different vegetation types were analyzed.[Results] ① The soil moisture content of different vegetation types was:mixed forest of Armeniaca sibirica and Platycladus orientalis (11.24%) > Medicago sativa grassland (10.97%) > natural grassland (10.66%) > returning farmland (9.99%) > Caragana korshinskii forest (9.55%). ② According to the orderly clustering method, the 0-200 cm soil layer of the five vegetation types could be divided into three sublayers:dynamic change layer (0-40 cm), utilization layer (40-100 cm), and weak utilization layer (100-200 cm). In the dynamic change layer (0-40 cm), the soil moisture content was the highest in the natural grassland (14.23%) and lowest in the C. korshinskii forest (11.04%); In the utilization layer (40-100 cm), the soil water content was the highest in the M. sativa grassland (12.16%) and lowest in the C. korshinskii forest (9.15%); In the weak utilization layer (100-200 cm), the soil water content was the highest in the natural grassland (10.81%) and lowest in the returning farmland (8.61%). ③ The layer stability of soil moisture (coefficient of variation) in the different vegetation types was:returning farmland (19.9%) < mixed forest of A. sibirica and P. orientalis (21.3%) < natural grassland (21.9%) < M. sativa grassland (22.6%) < C. korshinskii forest (23.6%). ④ The temporal stability of soil moisture (coefficient of variation) in the different vegetation types was:natural grassland (25%) < returning farmland (25.2%) < mixed forest of A. sibirica and P. orientalis (26.5%) < C. korshinskii forest (27.1%) < M. sativa grassland (31.9%).[Conclusion] In the semi-arid loess hilly region, the soil moisture content was the lowest in the C. korshinskii forest. This vegetation type also had the most unstable layer and temporal stability. The soil moisture content in mixed forest of A. sibirica and P. orientalis was higher and more stable than other vegetation types.

Abstract:[Objective] The response mechanism of soil moisture in moving dunes according to different precipitation patterns was discussed to provide a reference to prevent degraded vegetation and land desertification of grasslands on desert steppes.[Methods] With the desert steppe in Damao Banner of Inner Mongolia being used as an example ecosystem, based on the hourly soil moisture and precipitation of soil moisture at automatic observation stations from 2016 to 2018, statistical methods were used to study the effects of precipitation on soil moisture.[Results] When the precipitation intensity was lower, the soil moisture response depth was 10 cm, 20 cm, and 50 cm, respectively. The days of the moisture response was 6 d, 7-9 d, and 10 d accordingly when the precipitation amount was 5.1-10.0 mm, 10.1-25.0 mm and >25.0 mm. The higher precipitation intensity led to deeper infiltration when the precipitation amount was 5.1-15.0 mm or 20.1-25.0 mm. When the precipitation was 15.1-20.0 mm, higher precipitation intensity corresponded to shallower infiltration. When the precipitation intensity was lower, the soil moisture of the 0-10 cm soil layer responded significantly after one hour regarding the number of total precipitation-amounts of 5.1-10.0 mm, 15.1-20.0 mm, and 20.1-25.0 mm, respectively. However, when the precipitation intensity was higher, the soil moisture of the 0-10 cm soil layer responded significantly after 5 h, 8 h, and 8 h, respectively.[Conclusion] The response of soil moisture to precipitation is mainly dependent on the precipitation pattern, including the precipitation amount, intensity, and duration. The intensity had positive feedback on soil moisture infiltration depth and negative feedback on soil moisture infiltration velocity when the precipitation amount was 5.1-15.0 mm or 20.1-25.0 mm. However, the precipitation intensity had a negative feedback on soil moisture infiltration depth and velocity when the precipitation amount was 15.1-20.0 mm.

Abstract:[Objective] The relationship between Cd morphologic transformation and bioorganic fertilizer application in paddy soil and the accumulation and distribution characteristics of Cd in rice plant were analyzed in order to provide an economical, safe, and a scientific basis for rice production in polluted areas.[Methods] A two-year field experiment for the red paddy soil was conducted in Changsha City, which was situated in the Hu'nan Province. The soil and rice samples were collected from five disposals (0,10,20,30 and 40 t/hm²) in their maturation period. The morphologic change, distribution of Cd in rice, and continuous influence of bioorganic fertilizer were analyzed.[Results] ①The application of bioorganic fertilizer can change the acid-soluble Cd into its reducible form in the soil, thus reducing the accumulation of Cd in rice and transferring the coefficients of the soil-root and stem-grain. ②On employing a high concentration of a bioorganic fertilizer, the concentration of acid-soluble Cd was significantly reduced in 2017 and 2018; the maximum range of decrease was observed by 22.42% and 7.05%, respectively. The amount of Cd in different parts of the rice was observed to vary in the following order:roots > stems > leaves > grains. ③The bioorganic fertilizer had an impact on the Cd content in the rice grains by regulating the factors (pH value, soil organic matter, and cation exchange capacity) that affect the acid-soluble Cd.[Conclusion] The application of bio-organic fertilizer can facilitate an improvement in the soil fertility and rice yields by reducing the biological availability of acid-soluble Cd in Cd-polluted paddy fields. In conclusion, when the applied amount was 30 t/hm², the straw bioorganic fertilizer with an organic matter of 255.32 mg/kg could play a better repairing role.

Abstract:[Objective] The characteristics of soil erosion and nutrient loss in a small watershed on the upper reaches of the Kulü River were quantitatively analyzed to provide a scientific basis for soil and water conservation in small watersheds on the upper reaches of Chaohu Lake.[Methods] A remote sensing system (RS) and geographic information system (GIS) were used to assess quantitatively the soil erosion and nutrient loss in the research area using the revised universal soil equation (RUSLE). The relationships between soil erosion intensity and factors such as slope, elevation, and land use types were also analyzed.[Results] ① The average soil erosion modulus in the research area in 2018 was 394.45 t/(km²·a), the intensity of soil erosion was mainly at micro or mild level. ② The intensity of soil erosion was positively correlated with the slope gradient, and with increase of the slope gradient, the proportion of erosion area that was intensely eroded increased gradually. Within the same range of elevation, different land use types had different impacts on soil erosion. The average soil erosion modulus of each land use type was unused land[1 022.55 t/(km²·a)] > forest land[655.04 t/(km²·a)] > dry land[285.78 t/(km²·a)] > paddy field[139.80 t/(km²·a)]. ③ The trend of the spatial distribution of soil nutrient loss was consistent with that of soil erosion. The average losses of soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) were 3.66, 0.27, and 0.07 t/(km²·a), respectively.[Conclusion] The distribution characteristics (high to the south and low to the north) of soil erosion and nutrient loss at the small watershed on the upper reaches of Kulü River are significantly affected by topography and geomorphology. Soil and water loss are the most serious in hilly areas. In the research area, mountain forest land and sloped farmland are the key areas for soil and water conservation.

Abstract:[Objective] The ecological footprint and spatial and temporal characteristics of ecological carrying capacity during 2000-2015 in the Ordos Plateau were studied in order to provide a theoretical basis for the sustainable development of the local economy and society of an ecologically fragile area.[Methods] The Landsat images and social as well as economic statistical data in 2000, 2005, 2010, and 2015 were utilized. This data was based on the transfer matrix analysis of land use and cover change and was used to study the temporal and spatial variation characteristics of the ecological carrying capacity in the Ordos Plateau. This was achieved by employing the modified ecological footprint model with the development index of the social and economic system.[Results] ① Grassland and unused land were the primary land use types in the Ordos Plateau from 2000 to 2015. The ecological footprint was observed to increase rapidly from 2000 to 2010; subsequently, it relatively slowed down after 2010. From 2000 to 2015, the average annual ecological footprint showed a gradually increasing trend with an average speed of 15.93% per year. ② The total ecological carrying capacity in different locations was observed to be in the following decreasing order:Jungar Banner, Dalad, Hanggin Banner, and Otog Qian Banner. The per capita ecological carrying capacity of Hanggin Banner was the highest, followed by the Otog and Jungar Banner. Moreover, the values of the Dongsheng District were relatively the lowest for the period of 2000-2015, except 2000.[Conclusion] The Ordos Plateau demonstrated an ecological surplus status from 2000 to 2005. However, this status changed into an ecological deficit from 2005 to 2015. The ecological carrying capacity was seriously overdrawn in the Ordos Plateau, and the local sustainable development had to face increasingly significant challenges.

Abstract:[Objective] According to serious water pollution in rivers and lakes, six species of aquatic plants were selected for treatment of polluted water and water purification testing, in order to provide a basis for aquatic plant treatment in polluted water.[Methods] Six kinds of ornamental aquatic plants were chosen:Acorus calamus, Canna indica, Pistia stratiotes, Eichhornia crassipes, Ceratophyllum demersum, and Myriophyllum spicatum. Static hydroponics were used for the plants, in combination with different concentrations of phosphorus to simulate the effects of total phosphorus in the sewage purification.[Results] E. crassipes was found to be the best for removal of high (2 mg/L) and medium(0.5 mg/L) concentrations of total phosphorus in the water, with removal rates of 95.9% and 93.4%, respectively. C. demersum demonstrated the highest removal efficiency in the water with a low concentration (0.1 mg/L) of phosphorus, with a removal rate of total phosphorus of 91.1%. The combination of aquatic plants that was best for the removal of total phosphorus with a high concentration of phosphorus was C. demersum + A. calamus + E. crassipes, with a removal rate of 96.0%. In water with a medium concentration of phosphorus, A. calamus + E. crassipes + M. spicatum was the best for the removal of total phosphorus, with a removal rate of 98.8%. In water with low concentrations of phosphorus the best combination for total phosphorous removal was A. calamus + P. Stratiotes + M. spicatum, with a removal rate of 94.3%.[Conclusion] All the six aquatic plants have a specific total phosphorus removal rates, and the optimal allocation of the number, area, time and combination of aquatic plants can be used for the purification of polluted water.

Abstract:[Objective] The sources and use strategies of soil water absorbed by an oil peony were explored in order to provide a basis for the improvement of the survival rates in rational plantations of the plants and the development of the oil peony industry.[Methods] Two kinds of oil peonies of different ages were used as materials. The ratios of stable hydrogen and oxygen isotopes in the plant and soil water were tested to analyze the sources of soil water absorbed by oil peonies in spring and autumn.[Results] ① Mature individuals of oil peonies developed strong root systems and consequently more optimal strategies of water use than young individuals did. In spring (or dry season), oil peonies with two ages mainly absorbed water from surface soil (0-20 cm). However, mature oil peonies used more water (70.7%) from the surface soil than young ones did (61.8%), comparatively. In autumn (or relatively humid season), there was high water content in the surface soil. Mature oil peonies conversely tended to absorb soil water from deeper layers of soil compared with young peonies. ② On the basis of the analysis of soil water content, the contribution rates of different sources of soil water to the growth of peonies, and their relationships, it was found that the soil layers with high contribution rates of water to the growth of oil peonies had low soil water content.[Conclusion] An oil peony tends to absorb water from soil layers with low water content during spring and autumn. This verifies both the tolerance of an oil peony to drought and its intolerance to waterlogging.

Abstract:[Objective] To effectively prevent the irreversible water pollution and damage in Baihua Lake in the karst plateau region, the lake was taken as a research object and its water quality and changes over years were studied. This was aimed to provide a basis for the scientific development, utilization, and protection of the water source for relevant water resource management departments.[Methods] Based on an analysis of the physical and chemical parameters of the eight water bodies in Baihua Lake from 2013 to 2016, and to ensure that the water quality evaluation results were as objective as possible, the fuzzy comprehensive evaluation and grey correlation analysis methods were used to comprehensively evaluate the water quality of Baihua Lake and to reveal the category that its water quality could be classified.[Results] Baihua Lake had class Ⅰ water quality, but the class Ⅱ, Ⅳ, and Ⅴ values were relatively high.[Conclusion] The quality of water in Baihua Lake is getting worse. It is imperative to propose countermeasures to stabilize the ecological environment.

Abstract:[Objective] Rainfall accumulation, penetration, and purification are implemented in a railway station area to alleviate the barrier of water resources caused by the construction of a high-speed railway station in Northwest China. The aim is to promote the utilization of rainfall resources and ecological environment protection and achieve the sustainable construction of a high-speed railway.[Methods] The west railway station in Lanzhou City, Gansu Province was selected for this study. Based on stormwater management model(SWMM), the rainwater runoff effect were analyzed under traditional development conditions, after the independent implementation of a biological retention pool, permeable pavement, and green roof, and after the combined implementation of the three measures above. The three low impact development (LID) measures were simulated.[Results] Different LID measures can effectively reduce total runoff, flood peak flow, overflow, and delayed peak time. The combined LID measures had the best control effect, and the total flood rate and runoff reduction rate reached a maximum of 75.9% and 41.6%, respectively. The permeable pavement and bioretention ponds had a significant effect on the reduction of flood peak flow and total runoff; when the green roof was implemented separately, the storm flood control effect was weak.[Conclusion] The use of LID measures can effectively result in the sustainable management of rainwater and reduce flood disasters in railway station areas.

Abstract:[Objective] The regulation and control benefits of rainfall-runoff after sponge reconstruction in residential districts were calculated to provide a technical reference for sponge city construction.[Methods] The interception capacity of rainfall-runoff and the utilization rate of low impact development (LID) facilities was calculated under different rainfall intensities, based on LID facilities in a residential district of Guyuan City, Ningxia Hui Autonomous Region. The total annual rainfall-runoff interception capacity and the rainfall-runoff interception capacity of each LID were measured using the rainfall data of Guyuan City from 2004 to 2014. The annual rainfall-runoff control benefit of each LID was determined using the calculated rainfall-runoff interception and storage capacity data of LID facilities, the resource and environment economics, the annual regulation benefit, and the unilateral rainfall-runoff control benefit.[Results] After sponge reconstruction, the average annual rainfall-runoff storage increased by 11 568 m³, the benefit was 111 302 yuan per year, and the benefit of unilateral rainfall-runoff control was 9.62 yuan/m³. The average annual benefits for each LID facility were 45 273 yuan per year for a rain water garden, 27 103 yuan per year for a sunken green space, 6 654 yuan per year for a rain water bucket, and 32 272 yuan per year for a rain pool.[Conclusion] Sponge reconstruction in residential areas can effectively control the external displacement of rainfall-runoff and improve the total annual runoff control rate, which has economic, environmental, and social benefits.

Abstract:[Objective] A simulation model of the multi-source joint allocation for the Hanjiang to Weihe River water transfer project and Heihe River diversion project of Shaanxi Province was established. This was aimed at providing a basis for the sustainable development of water resources in Xi'an City.[Methods] Based on the analysis of the water supply project and the consumers of water in Xi'an City, the mixing rule was determined. This was achieved by constructing a network generalization map of the system of water resources and by building a simulation model of the multi-source joint allocation. Through a long series of calculations, the joint deployment scheme for different water supply frequencies was obtained.[Results] In 2020, when the incoming water frequency will be 50%, 75% and 95% respectively, the water supply of the Hanjiang River will be 39.74%, 37.59% and 35.33%, respectively. In the special dry year, the water supply of the Hanjiang River was 1.19×10⁸ m³, accounting for 36.28% of the total water demand in Xi'an City.[Conclusion] The water shortage in Xi'an City can be effectively alleviated by the implementation of the water diversion project, which has played a significant role in ensuring the safety of the water supply in Xi'an City.

Abstract:[Objective] The specific sources of sediment in Shuanghe reservoir were quantitatively studied in order to provide scitific references for the comprehensive management and sediment source research of the river basin in the northwest of Yunnan Province.[Methods] This paper selected the Shuanghe reservoir catchment of Jianchuan County as the study area. Proposed sediment sources were woodland, grassland, farmland and coal land, which were analyzed for their respective contribution to the reservoir sediment by using a combined fingerprinting technique. Twenty-seven geochemical factors were selected, the best combination of fingerprint factors was confirmed by the conservation test and Kruskal-Wallis H test. Then, the contribution rate of each sediment source was calculated by using the multivariate linear mixing model.[Results] ① A total of 8 fingerprint factors (S, Ca, Sr, TP, Cr, Ba, K, Mg) was confirmed to be the best fingerprint factor combination, with the cumulative contribution rate of 89.60%; ② The total contribution rate of sediment was grassland (37.28%), farmland (34.62%), woodland (27.86%) and coal land (0.24%); ③ The descending order of sediment contribution rate per unit area was farmland (9.55%), grassland (3.78%), coal land (1.24%) and woodland (0.38%).[Conclusion] The combined fingerprinting method is applicable to the identification of sediment source in the Shuanghe reservoir basin. Cultivated land is still the land type with the most severe soil erosion, while grassland is the land type with the high sedimentation, due to its large area and low surface coverage.

Abstract:[Objective] A survey of hillside field utilization and management measures was conducted at household scale from economic perspective, in order to understand the causes of the hillside field abandonment. The aim was to improve land use efficiency and land use policies and countermeasures in Southern Shaanxi Province.[Methods] A targeted questionnaire was designed to survey the utilization of cash crop slopes and terraced fields, the economic profit, and the governance and economic needs of farmers in Shangzhou District, Shaanxi Province. The problems of land use in Southern Shaanxi Province were analyzed using the binomial Logistic regression model and the proportion analysis method. The slope management proposal was put forward by comparing the advantages and disadvantages of different treatment measures and methods.[Results] There were 93 farmers from 6 villages involved in the survey. The average annual income of the farmers' households was 39 419 yuan in 2018. The agricultural industry income mainly came from the operation of cash crops, with an average annual income of 3 661 yuan, or only 11.26% of the total income. The economic income from sloping agricultural operations was low, leading to the abandonment of cultivated land and terraced fields; the proportion of abandoned farms increased with 15%. The main driving forces of abandonment include low economic return, inconvenient transportation, insufficient rural labor, poor land quality, and low output. Transforming hillside fields into terraced fields was a necessary measure to improve land use efficiency, but there were still problems such as water accumulation and a thin soil layer. The dry masonry terraced fields were the most advantageous in terms of permeability and durability.[Conclusion] Arable land abandonment on hillsides in Southern Shaanxi Province was a major issue. It is necessary to consider factors such as population, economic benefits, and environmental benefits to formulate policies for soil and water conservation and land use with ecological and economic benefits.

Abstract:[Objective] The impacts of straw mulching technology on the gully erosion in black soil area were evaluated in order to provide reference for vegetation restoration and soil erosion prevention.[Methods] Field experiments were conducted to observe the variations in soil hydrothermal conditions, alfalfa growth, and soil as well as water loss in two slope aspects of gully banks under the presence and absence of straw mulch.[Results] ① Straw mulching was observed to significantly improve the soil water and heat conditions in the gully. Straw mulching on the shady and sunny slopes increased the soil moisture by 1.8%-6.8% and 1.1%-4.0%, respectively, and reduced the soil temperature at 14:00 by 0.6-3.1℃ and 0.9-3.6℃, respectively. ② Further, the straw mulching evidently improved the growth and biomass accumulation of alfalfa in two slope aspects of the gully banks, which was conducive to the vegetation restoration of gully banks. ③ Straw mulch could also effectively reduce soil erosion on the gully banks. The annual average runoff and sediments reduction rates were 57.34% and 67.60%, respectively.[Conclusion] The results obtained indicate that straw mulching is an effective measure for the control of gully erosion; consequently, the promotion of this technology will facilitate the reduction in the soil and water loss in the black soil area, which will ensure the food security of the country.

Abstract:[Objective] The joint distribution of flood peaks in small and medium watersheds in mountainous areas of South China was examined to provide a theoretical reference for flood control in mountainous areas.[Methods] Based on the Archimedean Copula function and the Kendall measure, three kinds of recurrence levels of the combined distribution of flood peaks in selected watersheds of three mountainous areas were analyzed. The "OR", "AND" and Kendall return periods and their design flood quantiles for the joint distribution of flood peaks were calculated based on the Gumbel Copula funtion and Kendall measures.[Results] ① There was a high correlation between flood peak and flood volume (Kendall correlation coefficient >0.76); ② The probability of flood peaks in three basins was very high, all exceeding 81%; ③ In terms of engineering economic security, the comparison of the set-up period showed that the Kendall return period between the "OR" and the "AND" return periods more accurately reflects the risk ratio of the joint distribution of flood peaks; ④ The flood design value calculated by the two-variable "OR" return period and the same frequency were higher.[Conclusion] The design value of peak flood volume calculated from Kendall recurrence period can provide new safety insights for flood control projects in small and medium-sized mountain basins.

Abstract:[Objective] The economic, environmental, and social benefits of rainwater utilization at urban sponge community were evaluated and the cost comparative analysis were conducted in order to establish a reference for the evaluation of the construction of a sponge community.[Methods] The second batch of six sponge communities was obtained as the research object; this was sourced from the Southwest New District of Guyuan City in Ningxia Hui Autonomous Region. The water balance method, alternative engineering method, shadow engineering method, market value method, carbon tax method and afforestation cost method were used to generate the sponge community. The rainwater resource utilization, carbon sequestration, oxygen reduction, noise reduction, storage runoff, culture and education, etc, the ten benefits in three categories were quantitatively calculated. Further, the cost-benefit ratio was used for the static and dynamic cost-benefit analysis.[Results] The total benefit of the six sponge communities in the southwest of the New District of Guyuan City was 2.91×10⁵ yuan/year. Moreover, the benefits of the rain garden, sinking green land, and planting grass were 1.03×10⁵, 7.99×10⁴, and 6.15×10⁴ yuan/year, respectively. The economic, environmental and social benefits accounted for 22.84%, 76.89%, and 0.27%, respectively.[Conclusion] Therefore, the use of rainwater in the sponge community has noteworthy investment benefits. Accordingly, the construction of the sponge community in Guyuan City has produced good economic, environmental, and social benefits, which deserves further research and promotion.

Abstract:[Objective] The multifunctional land use in Jiangxi Province from 2004 to 2017 was analyzed to support regional sustainable land use.[Methods] An evaluation index system was developed, and the multifunctional changes of land use in Jiangxi Province were measured using the TOPSIS model based on the entropy method. The obstacle model was used to analyze the main restrictive factors.[Results] The dynamic degree of land use comprehensive function change in Jiangxi Province from 2004 to 2017 was 297.90%. The dynamic degrees of economic function, social function, and ecological function were 224.37%, 207.14%, and 2 021.61%, respectively. The degree of ecological dysfunction decreased, and the degree of economic dysfunction increased year after year. After 2010, the main obstacle factors were the comprehensive Engel's coefficient, industrial structure, economic density, per capita GDP, wastewater discharge intensity, per capita water resources, and urban registered unemployment rate.[Conclusion] The overall function in Jiangxi Province shows a steady upward trend. However, changes varied between the functions, and the changes in the land use ecological function were the largest. The land use function demonstrated the transition from an economic society to an ecological society. The factors that limit the land use functions vary at different stages, and the main limiting factor is currently economical.

Abstract:[Objective] Aiming at the problem of wind-sand disasters on the main traffic lines in desert areas, the solidification performance of local salt-containing iron tailings sand was studied to realize the preparation of mechanical sand barriers and the control of wind-sand disaster using waste.[Methods] Ordinary Portland cement and Huaxia I ionic curing agent were used to solidify salt-containing iron tailings. The durability and changes in strength of the test block were evaluated comprehensively after a dry-wet cycle, freeze-thaw cycle, and natural weathering test. The analysis emphasized the influence mechanism of pore structure change on durability.[Results] The strength of solidified specimens reached >2 MPa by mixing in 7% to 10% cement. The strength and durability of cured specimens could be improved obviously by adding 0.2‰ ionic curing agents. Analysis of the micro-pore structure showed that after the durability test, the total pore volume and the proportion of medium or large pores increased due to the migration of water vapor and salt. However, there were no connected large pores and the loss of strength was small.[Conclusion] Salt-containing iron tailings sand can be used as an engineering material, and can be solidified using cement and ionic solidifying agent to prepare mechanical sand barriers. The strength and durability tests were able to meet engineering requirements and thus have value for practical application.

Abstract:[Objective] The primary factors which are responsible for poverty in ecologically sensitive areas were studied in order to provide a theoretical basis for implementing anti-poverty measures.[Methods] This study selected an eco-clean watershed as the research target, which was located at Jiaying in the He'nan Province. In particular it was situated in the area of the water source of the Middle Route Project of South to North Water Diversion. The gray correlation model based on the entropy weight was employed to calculate the correlation degree between the poverty rate and the influencing factors in the small watershed; further, the primary factors affecting the poverty rate in the small watershed were analyzed.[Results] ①The poverty rate in Jiaying eco-clean watershed was 5.69% in 2017, which was regarded as 2.21 times higher than that of the average in the He'nan Province at the same period. ②The average poverty rate in the middle reaches of small basins was 7.13%, which was significantly higher than that in the upper (6.26%) and the lower reaches (5.65%). ③Various factors were observed to affect the poverty in small watersheds, namely:the amount of cultivated land per capita, proportion of the labor force in the total population, annual household dietary expenditures, proportion of junior middle schools, household annual average wage incomes, ground slope, and annual average medical expenditures of households. ④However, the primary factors affecting the poverty of each village in the small watershed were different, exhibiting regional differentiation.[Conclusion] The key to solve the problem of poverty in small watersheds is to take measures to alleviate the poverty according to the local specific conditions, and by rendering the complete use of the surplus labor force and the surplus working time. Further, an increase in the investment with regard to education is necessitated with appropriate solutions for tackling poverty caused by disability and disease.

Abstract:[Objective] An ecological vulnerability assessment in Xiangxi Prefecture of Hu'nan Province was assessed to serve as a reference for upcoming "green" and sustainable development, and the research areas were classified into "suitable" or "restricted" for development zones.[Methods] Spatial-temporal characteristics of the evolution of ecological vulnerability in all counties were comprehensively analyzed using GIS and ecological environmental characteristics were considered using socioeconomic statistical data from 2015 to 2018, remote sensing imagery, and digital elevation models.[Results] ① The spatial patterns of ecological vulnerability indicated high vulnerability in the west and low vulnerability in the east. Moderately low and low vulnerability zones were mainly distributed in Yongshun and Guzhang counties in Western Hu'nan, and high and extremely high vulnerability zones were distributed in portions of western Longshan and Baojing counties and Jishou City. ② Overall ecological vulnerability trended toward high vulnerability, while the area of moderately-low vulnerability zones decreased sharply and that of extremely high vulnerability zones increased dramatically, indicating that the ecological environment has deteriorated over the study period.[Conclusion] Attention should be focused on the positive impact of human activities on the ecological system and on ensuring that environmental protection work is carried out according to actual ecological conditions while poverty alleviation work is strengthened.

Abstract:[Objective] The spatial distribution and the spatial-temporal changes of cultivated land use characheritics were analyzed at provincial level since the second national land survey in China. The aim was to promote sustainable use of cultivated land, to make specific adjustments on the improvement measures.[Methods] A spatial GIS method, an index model and other scientific methods were applied to the data on the national and provincial annual land-use from 2009 to 2016.[Results] ① The total area of cultivated land in China decreased during the period from 2009 to 2016. The decrease of area in dry land was higher than the increase of that in paddy fields and irrigated land and the total area of cultivated land decreased by 4.64×10⁵ hm². The distribution and utilization of cultivated land areas varied with the difference in resource funding and socio-economic development in the provinces. ② Spatial and temporal policies on cultivated land protection largely contributed to temporal and spatial changes in cultivated land use. ③ The current cultivated land protection policy needed to be optimized based on scientific data and the analysis of the temporal and spatial changes in the use of cultivated land in China. The policy was needed to manage the development of regional cultivated land use and the environment.[Conclusion] The current cultivated land resources have substantial spatial and temporal heterogeneity and dynamic features. The change of cultivated land at the provincial level in China is affected by the evolution of global and regional policies and human intervention. It is necessary to implement appropriate and reasonable policy regulations taking into account the differences in the development of cultivated land use at the provincial level to accomplish the protection and utilization of cultivated land. Proper regulations will ensure food security, coordinate resource matching, and promote regional sustainable development.

Abstract:[Objective] The ecosystem service value and the sensitivity of ecosystem service values to land use changes in Chengdu-Chongqing economic zone were evaluated to provide scientific references for optimizing the allocation of regional land resources, protecting the environment, and promoting sustainable development.[Methods] Chengdu-Chongqing economic zone was selected as a case study. The evolution of land use type changes and ecosystem service values were studied using ArcGIS software, based on the Landsat TM/ETM/OLI remote sensing image data of 2005, 2011, and 2017. The sensitivity of land use type change to the ecosystem service value was analyzed using the coefficient of cross-sensitivity.[Results] ① The land use type conversion in the economic zone mainly occurred in cultivated land, forest land, grassland, and construction land, and the land use dynamics of cultivated land was relatively large with a value of about 40%; ②During the research period, the ecosystem service value in the economic zone slightly fluctuated, but showed an upward trend. The forest land and cultivated land contributed to the ecosystem service value for more than 90%; ③The coefficient of cross-sensitivity between water and cultivated land increased from 2.06 in 2005 to 2.15 in 2017 which the type of land use conversion in the economic zone showed high sensitivity and increasing trend. The ecosystem service value caused by the conversion of water and construction land decreased, and the coefficient of cross-sensitivity was high. The results indicate that human activities had a significant impact on the ecosystem service value.[Conclusion] Land use policies should be formulated to optimize land use structures and to manage the development of regional ecological environment integration in the Chengdu-Chongqing economic zone.

Abstract:[Objective] A calculation of land consolidation supply and demand was conducted based on the public perspective, and in order to provide a scientific basis for improving the content of land consolidation.[Methods] From agricultural development, living and ecological environmental improvements, and leisure culture and tourism, the research constructed a supply and demand index system. This revealed the matching degree of land consolidation supply and demand in Xiaoshan District, Hangzhou City, Zhejiang Province.[Results] ① The matching degree of agricultural development in Xiaoshan District was high overall (>0.88); The matching degree of living and ecological environment improvement was all above 0.85, and the matching degree of leisure culture and tourism was lower, the lowest was only 0.83. ② Land consolidation overemphasized the supply of agricultural development, while the supply of living and ecological environment, leisure culture and tourism was relatively insufficient, and the lack of mechanism for public demand expression and public participation, resulted in the inability to meet the demand for land products.[Conclusion] The land consolidation supply and demand matching model based on the public perspective and supply and demand theory, can effectively measure the matching degree quantitatively.

Abstract:[Objective] A coupling degree and coupling-coordination degree model between the ecological environment system and the socio-economic system in Yuanzhou District, Guyuan City, Ningxia Hui Autonomous Region was established to provide a scientific basis for the coordinated development and regulation of the region.[Methods] Based on ecological environment and socio-economic data for 2002-2016 in Yuanzhou District, an index evaluation system for the regional ecosystem of Yuanzhou District was constructed. The entropy method was used to calculate the weight of each evaluation index and the comprehensive evaluation index. By establishing the coupling degree, coupling coordination degree model, and gray prediction model, the development trend of the coupling degree and coupling coordination degree of the eco-environmental and socio-economic systems, and the type of coupling coordination, were obtained and predicted.[Results] From 2002 to 2016, the evaluation index of the social economic system in Yuanzhou District steadily increased. Due to the impact of pressure on the ecological environment, the comprehensive evaluation index of the ecosystem first had a tendency of decline, and then fluctuated. The economic system developed faster than the ecologic system. The coupling degree and coupling coordination degree were rising, and the type of coupling coordination developed from the moderately dysfunctional type of economic lag to the end, a dysfunctional type of ecological environment. Through model prediction, the coupling degree and coupling coordination between the ecological environment system and the socio-economic system was projected to gradually increase from 2017 to 2025. This type of coupling coordination would continue to evolve toward an ideal state.[Conclusion] The economic development of Yuanzhou District is faster than the construction of ecological environment, which restricts the overall coordinated development of the region. Therefore, to achieve sustainable development of the regional ecosystem in Yuanzhou District, it is necessary to strengthen construction of the ecological environment.

Abstract:[Objective] The spatial pattern change of vegetation coverage in the coastal zone of Fujian Province was studied in order to provide a decision-making reference for resource environment monitoring and early warning based on the type of major functional zone.[Methods] Based on the NDVI index, the Landsat series remote sensing data of 2001, 2006, 2011, and 2016 were selected to evaluate the vegetation coverage of the study area to characterize the change in the ecological carrying capacity of that area.[Results] ① During 2001-2016, the area of low vegetation coverage was observed to decrease, and the variation in the lower and higher vegetation coverage was more moderate; whereas, the high vegetation coverage showed an upward trend. ② During 2001-2016, the area of the improved ecological carrying capacity increased by 10.78%, while the basic stable area underwent a minor change; further, the degraded area decreased by 7.05% and the significant degraded area decreased by 3.48%. ③ During 2001-2016, the vegetation coverage area of the major functional areas was observed to decrease, and the improvement in the ecological carrying capacity was the primary change.[Conclusion] The vegetation coverage and the ecological carrying capacity of the coastal zone in Fujian Province have generally increased, and the ecological environment of the coastal zone has been continuously improved from 2001 to 2016.

Abstract:[Objective] The relationship between economic development and the ecological environment was studied in order to provide a reference for high-quality development in the Yangtze River economic belt and coordinated development of the economy and ecology in the Three Gorges reservoir area.[Methods] Taking the Chongqing section of the Three Gorges reservoir area as a study area, the decoupling status of the economy (absolute decoupling, relative decoupling, critical, coupled) and the ecological environment from 2006 to 2018 was judged based on the decoupling model. After combining these data based on the exploratory spatial data analysis(ESDA) method, the spatial differences and pattern evolution characteristics of the decoupling data were analyzed using ArcGIS and OpenGeoDa.[Results] The overall decoupling coefficient of the Chongqing section of the Three Gorges reservoir area was low and the spatial correlation was weak. The decoupling coefficients showed mainly positive spatial correlation in 2006-2010 and 2014-2018 and showed negative spatial correlation from 2010-2014. Local indicators of spatial associaton(LISA) chart analysis showed that the significance was weaker, and the overall change showed significant inversion of the V-shaped development trend in the three time periods.[Conclusion] From 2006 to 2018, the coupling characteristics of economic development and the ecological environment in the Three Gorges reservoir area fluctuated greatly. Therefore, it is urgent to study this area further and formulate relevant regulation measures.

Abstract:[Objective] The spatial and temporal changes in land use and ecosystem service value from 2007 to 2015 in Dongguan City, Guangdong Province, were analyzed. The aim was to determine the ecological effects of land use change and to provide a decision-making reference for sustainable use of regional land resources and ecological environmental protection.[Methods] The spatial and temporal changes in land use and ecosystem service value were analyzed using the theories and methods of land use and ecosystem service value, remote sensing, and geographic information technology.[Results] ① From 2007 to 2015, construction land in Dongguan City accounted for more than 50% of the total area of the study area, and increased continuously. The increased construction land mainly replaced cultivated land and forest land. The area with water and forest land first increased and then decreased, and the area of cultivated land and grassland decreased continuously. ② During the study period, the value of ecosystem services showed a downward trend. The total value of ecosystem services decreased by 1.97×10⁸ yuan. The value coefficient of ecosystem services was the highest for forest land and the water area, and the profit and loss of ecosystem services fluctuated considerably. The value of forest land and water area decreased by 1.40×10⁸ yuan in 2015. ③ From a spatial distribution perspective, the ecosystem service value of Dongguan City was centered in the central region and extended to the east and the west, forming a "high-low-high" spatial distribution pattern. The main urban area corresponded to the low-value center of the ecosystem service values of Dongguan City.[Conclusion] The land use of Dongguan City changed significantly from 2007 to 2015:the total ecosystem service value decreased, and the ecosystem service value presented heterogeneity and uneven spatial distribution.

Abstract:[Objective] The main factors affecting the water environmental quality of water storage ponds were explored to provide a scientific basis for water environmental protection and water quality improvement of water storage ponds.[Methods] Eight typical water storage ponds in Yangling Agricultural Hi-tech Industries Demonstration Zone of Shaanxi Province were selected, taking into consideration the function, capacity, area, and structure of the ponds. Six water quality indicators were measured:pH value, ammonia nitrogen (AN), dissolved oxygen (DO), chemical oxygen demand (COD), NH₄⁺-N, total nitrogen (TN), and total phosphorus (TP). The multivariate statistical method and the single factor index were used to determine the variance of the pollutants in the water quality samples.[Results] ① The concentration of water pollutants in the water storage ponds was significantly different at different sampling points (p<0.05). The average TN and TP concentration in each pond was between 4.70~78.13 mg/L and 0.03~4.27 mg/L, respectively; The average NH₄⁺-N concentration was between 0.36~39.18 mg/L; The average COD concentration was between 33.0~1 067.40 mg/L; The average DO concentration was between 1.5~7.3 mg/L; The average pH value was between 7.85~8.64; ② Most water storage ponds were seriously polluted. The water quality was inferior to the Ⅴ category, and the pollutants were mainly nitrogen-based. ③ The pollution levels of the water storage ponds in the survey area were:point source pollution + measures < non-point source pollution + no measures < point source pollution + no measures.[Conclusion] The installation of sewage treatment facilities and anti-seepage measures at the bottom of the pool were essential for improving the water environment of the water storage pond. A better result would achieved if the measures are supplemented with the repair and management of endogenous water bodies.

Abstract:[Objective] This paper evaluated the degree of wind erosion damage in the mainstream of the Tarim River basin and calculated the economic compensation for the wind erosion in different desertified areas in order to provide reference for interpreting the information of ecological damage of Tarim River basin, and the restoration and improvement of the basin ecology.[Methods] Based on the MOD13A1 and MCD43A3 data, the desertification difference index (DDI) was established by determining the spatial relationship between the normalized difference vegetation index (NDVI) and Albedo. The soil wind erosion model was used to calculate the amount of sand damage and further, the corresponding wind erosion damage compensation[Results] ① From 2010 to 2015, there was degradation but an improvement in the degree of desertification in the study area. ② During 2010-2015, the overall desertification status of the study area alleviated, and the area of desertified land in the middle and high grades declined to varying degrees i.e., "intense desertification" to "moderate desertification". ③ In 2015, the damage of different desertified land was 4.49×10⁵ t/a for extreme desertification areas, 1.33×10⁵ t/a for intense desertification areas, 3.72×10⁴ t/a for moderate desertification areas, and 2.04×10⁴ t/a for mild desertification areas.[Conclusion] In 2015, the total economic compensation amount was 3.23 million yuan i.e., in line with the local economic development level.

Abstract:[Objective] The interaction between water resources systems and urbanization systems was studied in order to provide a theoretical basis for the coordinated development of resource exploitation and urbanization.[Methods] Analytic hierarchy processes, factor analysis, and a response model were used to quantitatively study the influencing factors, spatio-temporal characteristics, and response relationship of water resources utilization and urbanization development respectively, in Harbin City from 2006 to 2017.[Results] ① The development and utilization of water resources and urbanization in Harbin City increased in stages. Both stages had 2011 as the node time, showing the stage characteristics of early fluctuation and later stabilization. ② The three subsystems of economy, space, and society, in the urbanization system rose and developed synchronously. The subsystem of population urbanization fluctuated greatly and risked systematic recession. In the water resources system, the utilization degree was deepened, and the management level was improved, however the resources were unstable and the urban water consumption load increased. ③ In the calculation of the response relationship, urbanization development was more sensitive to the change of water resources, economic agglomeration, and spatial expansion that produced an obvious resource consumption effect. The development and utilization of water resources had a restrictive effect on the development of urbanization.[Conclusion] Systematic thinking should be used to maintain the moderate development of urbanization based on the spatial and temporal distribution of water resources, rationally restraining the demand for water use and enhancing the management ability will help reduce the water constraints.

Abstract:[Objective] Forecasting agricultural water demands aims to provide a basis for holding the 2022 Winter Olympic Games, while helping with a reasonable utilization of future water resources and sustainable development in Chongli District, Zhangjiakou City, Hebei Province.[Methods] Based on the relationship between water supply and demand, this study evaluated the water resources carrying capacity from 2005 to 2016 and forecasted the water resources carrying capacity for 2022 and 2035.[Results] The index of water supply and demand (IWSD) decreased from 0.54 in 2005 to 0.06 in 2016. Water resources carrying capacity in 2016 tended to be in a critical state. When the guaranteed rate equaled to 25%, IWSD indexes were equal to 0.27 and 0.25 respectively in 2022 and 2035, which indicated the water resources had an adequate carrying capacity. When the guaranteed rate equaled to 50% or 75%, the water resources carrying capacity was overloaded, particularly with the guaranteed rate equaled to 75%, IWSD indexes were -0.77 and -0.81, respectively, in different years. When adjusting the local planting industry and irrigation water quota, the guaranteed rate equaled to 25% and 50%, IWSD >0. The amounts of shortage water in different years declined by 22.68% and 36.31%, respectively, with guaranteed rate equal to 75%.[Conclusion] To address overloading water resources adjusting the agricultural irrigation area, decreasing irrigation water quotas, and increasing surface water use, as well as decreasing groundwater exploitation will help maintain an adequate carrying capacity.

Abstract:[Objective] The trend change and frequency of climate drought on the Loess Plateau during two periods of 1901-2017 and 1981-2010 were analyzed in order to provide a scientific basis for planning strategies coping with climatic drought in the region.[Methods] Based on a climate dataset with high spatial resolution and a long time-series, the annual standardized precipitation evapotranspiration index (SPEI) of the Loess Plateau region from 1901 to 2017 was calculated, and the change in trend and frequency of climate drought in the region were analyzed in turn.[Results] Over the entire Loess Plateau, the climate exhibited four alternating stages:"humid-arid-humid-arid" during 1901-2017. During this time, the variation trend of the annual SPEI was not significant, and there was no significant mutation. During 1981-2010, an area with a significantly increasing trend in drought (based on the SPEI) was detected in the hinterland and midwestern part of the Loess Plateau, accounting for 3.43% of the total area. During 1901-2017, an area with a significantly decreasing trend in drought was found distributed in the eastern and western marginal region, with an area ratio of 1.05%. Moreover, an area showing a trend of significant increase in drought was found in the northwest, with an area ratio of 4.16%. In the most recent 30 years, light and heavy droughts frequently occurred in the central region of the Loess Plateau. In 1981-2010 and 1901-2017, the occurrence frequency of severe drought in most of the northwestern region was lower than in other areas, and no extreme drought occurred.[Conclusion] With the increase in drought severity, the spatial variability of drought frequency gradually decreased on the Loess Plateau. Furthermore, drought frequency of different grades in the Loess Plateau region has obvious spatial variation characteristics.

Abstract:[Objective] The changing pattern of vegetation coverage in "two lakes and one reservoir" (Hongfeng lake, Baihua lake, Aha reservoir) from 1973 to 2017 in Guiyang City was discussed in order to provide a scientific approach and theoretical basis for quantitatively exploring the monitoring of the ecological environment evolution of urban drinking water sources.[Methods] Five remote sensing images, including multi-spectral scanner (MSS) image in 1973, thematic mapper (TM) data in 1993, 2001, 2008 and operational land imager (OLI) data in 2017, and GIS technology were used to study the change of surface vegetation coverage, based on a dimidiate model and vegetation coverage dynamic model.[Results] ① The overall vegetation coverage grades of the study area showed a concave type curve, indicating that the proportion of area with low and high coverage increased, while the medium-low coverage, moderate coverage, and medium-high coverage decreased. ② During the period from 2008 to 2017, the annual rate of vegetation coverage change was significantly higher than the previous three periods, namely 1973 to 1993, 1993 to 2001, and 2001 to 2008. The sum of the proportions of medium-high coverage and high coverage areas in 2017 was greater than the sum of the two in 1973. The area proportion of high-vegetation coverage had been steadily rising.[Conclusion] The vegetation coverage in the study area is degraded and improved over time, however the overall coverage is mainly degraded, due to the expansion of urban construction land. Socio-economic activities and regional development policies are the driving forces for the evolution of surface vegetation coverage, especially for areas with low and moderate vegetation coverage.

Abstract:[Objective] An analysis of the land-use landscape pattern and a evolution characteristics of the ecological vulnerability were carried out for the coastal zones in the cities of Ningbo, Taizhou, and Wenzhou in the Zhejiang Province. This was aimed at promoting the sustainable development of the coastal zone and for providing a theoretical support for ecological construction and restoration.[Methods] Based on the land use data of the 1995-2015 phase Ⅲ of the Yongtaiwen coastal zone, the "pressure-sensitivity-resilience" evaluation model was used to evaluate the landscape type vulnerability and the ecological vulnerability of the study area.[Results] ① The change in the landscape pattern was as follows:The area of the cultivated land decreased the most, which was followed by tidal flats and woodland. Further, the area of construction land increased the most, and the amount of patches of cultivated and forest lands were observed to increase, showing a fragmentation trend. ② The areas with high ecological vulnerability were concentrated in Yuyao, Cixi City, and the Luqiao District of Taizhou Bay located on the south bank of Hangzhou Bay. In the past 20 years, the high vulnerability regions of the observed area had increased, and the overall ecological vulnerability had also intensified. ③ The regional ecological vulnerability was significantly and positively correlated with the disturbance index and the fragmentation degree; further, it was completely associated with the landscape vulnerability index.[Conclusion] Various landscape types in the Yongtaiwen coastal region have significantly changed and the ecological vulnerability has been observed to increase.

Abstract:[Objective] To provide a theoretical basis for regional sustainable development and ecological environmental protection, the changing trend with altitude of Taiwan's terrestrial vegetation ecosystem and its response to climatic were investigated.[Methods] Based on SPOT/VEGETATION NDVI satellite remote sensing data, meteorological, and digital elevation model (DEM) data from 1998-2018, we combined a regression analysis and correlation analysis to assess the normalized difference vegetation index(NDVI) trend and regional response of vegetation in Taiwan Province under climate change.[Results] The average growth rate of NDVI of vegetation in Taiwan Province from 1998 to 2018 was 5.09%; The proportion of area occupied by different elevation ranges in Taiwan Province was quite different, the area proportion <500 m area was as high as 52.49%, the area proportion >3 600 m area was only 0.01%, and NDVI in the two altitude ranges showed lower values, 0.72 and 0.73; From 1998 to 2018, except for the altitude of >3 600 m, the mean value of NDVI in other altitude ranges increased significantly (p<0.001). In the elevation range of 500-3 600 m, the annual mean of NDVI was significantly correlated with temperature and rainfall (p<0.05).[Conclusion] The higher the altitude, the more sensitive is the growth of vegetation to the change of rainfall as compared to the change of temperature.

Abstract:[Objective] The new progress of soil and water conservation researches and the current status of rural place creation in Taiwan from 2010 to 2019 were summarized in order to discuss the natural engineering design concepts and guidelines suitable for the environmental conditions of hillsides, to serve the social and economic revitalization of rural areas, and to provide references for related researches and similar area development.[Methods] By comprehensively combing through relevant research literature published mainly in the past 10 years, sorting out many ideas, and summarizing the results according to some relevant surveys, new research content on the core issues of Taiwan's ecological engineering and soil and water conservation science, as well asrural regeneration and place creation progress were reviewed in detail.[Results] Rural place creation should focus on community growth, adhere to both hardware and software construction, and incorporate these projects into local governments' joint implementation strategies to expand participation and cooperation mechanisms. Soil and water conservation can create a good ecological environment for the countryside and is fundamental work in rural place creation. Policies to promote place creation, plan for college students to travel back to the countryside, soil and water conservation, and ecological engineering implementation are important guarantees for rural place creation and regional ecological security.[Conclusion] By advocating green lifestyles, enhancing the public's awareness of autonomous disaster prevention, constructing a strategic layout for green development, advancing industrial ecology and eco-industrialization, and implementing rural regeneration strategies, will effectively promote the rural place creation.

Abstract:[Objective] The achievements of the comprehensive management and current issues of small watersheds in the highland region of Loess Plateau were evaluated in order to provide a theoretical basis and practical evidence for high-quality development during the new era of ecological civilization.[Methods] With Wangdonggou small watershed in Changwu County, Shaanxi Province as a study area, the changes in ecological, land productivity, and economic aspects using monitoring data since 1986 at the small watershed, and research findings at different phase during 30-years in the highland region were summarized and analyzed.[Results] There were significantly periodic and phrasal changes of the small watershed during the comprehensive management process. ① Comprehensive management phase(1986-1995):Taking enhancing land productivity as a breakthrough, it was emphasized to increase food production and per capita income. Simultaneously, the comprehensive management of soil and water loss was carried out from tablelands to gullies, and the land was exploited rationally. ② Ecological protection phase(1996-2005):The management of food production and apple industry was updated and upgraded. The ecological environment were protected and improved, then land productivity at the small watershed were further stabilized and improved. ③ High quality development demonstration phase(2006-2019):Wangdonggou watershed was took as a pilot project with studying and demonstrating from the perspective of the development of green and efficient technologies, to explore the technology system suitable for the concentric and high-quality green development of small watershed, thus laying a foundation for the high-quality development of the highland region.[Conclusions] Guided by the concept of ecological civilization, ecological management of watershed and development of technological innovation system must be addressed to realize high-quality development in the region. The ecological quality of human settlements, socio-economic sustainable development, and the harmony and integrity of watershed structures and functions must be considered on the basis of soil and water loss regulation of the highland region of Loess Plateau.