Abstract:Erosion processes and modes may be changed on unpaved road formed by rolling original ground. The objective of this study was to reveal the changing mechanisms of water and sediment yield by a series of outdoor artificial rainfall simulation experiments in Shenfu coalfield. Results show that: (1) Flow regime is mainly the transitional flow on unpaved road and the laminar flow on original ground, and both of them are the subcritical flow. (2) Reynolds number, shear force, Froude number, flow velocity and stream power on unpaved road are higher than those on original ground, while the Darcy-Weisbach friction coefficient and the Manning roughness coefficient on unpaved road are lower than those on original ground. (3) Hydrodynamic parameters on unpaved roads are not absolutely consistent with those on original ground. (4) Sediment yield on original ground is lower than that on unpaved road and increased as runoff yield increases. (5) Correlation coefficients for the responsive relationships between sheet erosion rate and hydrodynamic parameters on unpaved road are in the following order: runoff kinetic energy> mean stream power> mean flow shear stress.

Abstract:Five factors affecting soil erosion were chosen including precipitation, topology, soil texture, vegetation cover and land use to evaluate the soil erosion sensitivity in Zhuxi small watershed using the spatial analysis function of ArcGIS. The results showed that: (1) The area of high sensitivity is largest, accounting for 55.96% of total area; followed by percentage of slight sensitivity, which account for 38.62% of the total area; the percentage of high sensitivity and none sensitivity erosion are low, accounting for 4.22% and 1.20% respectively.However, the area with extrem sensitivity erosion only accounts 0.001%; (2) The erosion of slight sensitivity and sensitivity are the main types of soil erosion in the east, middle and west of the whole watershed, and the proportions of high and none sensitivity area are small. Extreme erosion sensitivity area spreads in the middle of the watershed. Generally, the erosion sensitivity in the east is higher than that in the central and west of the watershed; (3) The soil erosion sensitivities are not consistent with soil erosion degree in many regions, because the human activities are the main factors affecting the soil erosion in this area. The proportion of erosion sensitivity is the largest, nevertheless the main degree type of soil erosion is micro erosion.

Abstract:The research area is located on Jiagu hillside of Lianyungang City, Jiangsu Province. Soil there is granitic gneiss gravelly sandy loam. The characteristics of sediment yield and its influencing factors were analyzed based on rainfall and soil erosion data under six kinds of typical land uses in the past 20 years. Results showed that: (1) The annual sediment yield in different land utilizations increased with the annual rainfall amount, except terrace. (2) The annual sediment yield in different landuse types had significant differences. The land use types, in order of decreasing average annual soil loss, were the slope farming area, standard area, commercial forest area, grassland area, timber forest area and terrace area. Under different landuse patterns, terrace was most effective in controlling soil erosion and contrarily, slope farming area had the largest soil erosion. (3) Under different land uses, the relationship between sediment yield on hillside and rainfall erosivity could be expressed by a power function, with a high correlation coefficient reaching extremely significant level.

Abstract:This paper was aimed at the distribution and composition of organic carbons in water stable aggregates in typical arable cinnamon soil in Heibei Province. The size distribution of water stable aggregates was as irregular "W" shape with two lower "shoulders". Soil organic carbon content in Gaocheng City (12.49 g/kg)was roughly equivalent to that of Xingtang County(11.20 g/kg). The distribution of soil organic carbon(SOC) in soil was predominately constrained by the allocation of aggregates. Organic carbon in preponderant aggregates (1000~250 μm and 250~53 μm)accounted for 69.53% and 82.71% in Gaocheng and Xingtang area, respectively. Organic carbon content in <20 μm aggregates was 12.78 in Gaocheng City and 20.02 g/kg and in Xingtang County, respectively, which can be considered as a stability index for cinnamon soil carbon sequestration in studied area. Fourier transform infrared spectroscopy showed that aromatic carbon (macroaggregates:57.35%;microaggregates:67.69%) and carbohydrate carbon (macroaggregates:29.43%;microaggregates:25.2%) were the major organic carbon in studied area. Organic carbon in macroaggregates was mainly composed of labile carbon such as aliphatic carbon and carbohydrate carbon,et al. The stable aromatic carbon tend to be protected in microaggregates (Gaocheng City:57.89%;Xingtang County:77.51%).

Abstract:Xinzhuangzi mining reclamation area, which located in Huainan City, was selected as the research area and seven soil enzyme activities(urease, phosphatase, invertase, protease, cellulose enzyme, hydrogen peroxide enzyme, polyphenol oxidase) were measured. The results showed significant differences among heavy metals pollution to seven soil enzyme activities. It was found that the seven soil enzyme activities were inhibited in different degrees, and the sensitivity of soil enzymes to heavy metals were not consistent. Factor analysis method was used to extract the principal component and establish evaluation index of the compound soil pollution of total enzyme activities which intended to evaluate the pollution degree of soil heavy metals in this area. The level of soil heavy metals pollution was obtained by grey clustering method. The relationship between soil enzyme activity and the heavy metal pollution in mining subsidence area were analyzed, which further proved it was feasible using the comprehensive index of soil enzyme activity to evaluate soil heavy metal pollution in special case of mining subsidence area. The overall evaluation index of soil enzyme activities, as a simple means of evaluation, will finally provide reference and theoretical basis to heavy metals pollution repairing in Xinzhuangzi reclamation area and similar coal mining area.

Abstract:The expansive soil is studied as the object of the research in Yichang City, Hubei Province. Different content of lime, cement, coal fly ash and weathered sand are put into the expansive soil to modify it, then the unconfined compressive strength is tested under standard conditions with the days of 7, 14, 28 d. The research shows that the unconfined compressive strength can be improved in an effective way with the above four materials, the strength of expansive soil with cement grows obviously in the first 14 days, then the growth rate slows down with the curing age goes up; the unconfined compressive strength of expansive soil with lime is nearly in a linear growth trend with the curing age goes up; the unconfined compressive strength of expansive soil with coal fly ash is also in a linear growth trend, but the unconfined compressive strength is smaller than that of expansive soil with lime; the curing age has little effect on the unconfined compressive strength of expansive soil with weathered sand.

Abstract:By collecting soil samples from the red-soil hilly region in the south of Jiangxi Province and comparatively analyzing soil physical properties, soil effective elements and the microbial content under different recovery modes, ecological effects of soil under the recovery modes were investigated. Results show that soil capillary porosity, noncapillary porosity and total microbial content of artificial restoration land and prohibited land significantly increased as compared with bare land. Moreover, soil available nutrient content of artificial restoration land was higher than that of bare land and prohibited zone. The landuse mode of planting orange trees has the highest contents of soil saturated water, available water and soil organic matter, as well as relatively higher content of soil total microbial. Based on the comprehensive analysis, the landuse mode of planting orange trees is not only optimal in improving soil ecological effect, but also has the better economic benefit. The prohibition mode also has a fair effect on soil improvement, but is lack of economic benefit.

Abstract:To identify distribution and development of coast erosion in the Liaodong Peninsula, the development characterietics of erosion and siltation are studied based on the data from field investigation. Results show that coast erosion in the Liaodong Peninsula can be divided into five grades of serious erosion, intensive erosion, erosion, micro-erosion and stability. The sandy coast in Suizhong and Bayuquan area, rocky coast in Jinshitan area and silt-muddy coast in Zhuanghe area have been eroded seriously. Moreover, developmental characteristics and formation causes of coast erosion in typical coastal zone of Liaodong Peninsula are evaluated. The typical coastal zone is important to erosion control and management in a coastal zone. Recently, the decrease of river sediment into sea is the main reason for coastal erosion of Liaodong Peninsula, and sea level rise caused by climate warming plays a controlling role on coastal erosion. In addition, sand excavation and unreasonable coastal engineering have further intensified the degree of local coastal erosion.

Abstract:A field experiment of three treatments, i.e., traditional cultivation without mulching(CK), white plastic mulching(WM) and black plastic mulching(BM) was designed and performed to determine the effects of film mulching on soil temperature, water content, bulk density, and porosity and respiration rate in the 0-40 cm soil layer under Populus euramericana. Results indicated that the WM treatment had better warming effect than the BM treatment, but had no significant difference in the soil water content. In the 0-20 cm layer, the WM and BM treatments significantly increased the soil total porosity, capillary porosity and non-capillary porosity and however, the soil bulk density was visibly decreased, which was reduced by 15.44% and 9.56%, respectively. Besides, the soil respiration rate in the WM treatment had no significant difference as compared with CK, but the soil respiration rate in the BM treatment was obviously decreased. The 20-40 cm soil layer showed the variation trend similar to the 0-20 cm soil layer, while the differences among CK, WM and BM were decreased in the 20-40 cm soil layer, demonstrating that the effects of plastic film mulching on poplar weakened with the increasing of soil depth. In conclusion, the two plastic film mulching treatments significantly ameliorated the physical property of topsoil, while the black plastic mulching treatment evidently inhibited the soil respiration. Therefore, the white plastic mulching was obviously better than the black plastic mulching.

Abstract:Soil hydrological characteristics were studied for different forest ecosystems in Jingsha River basin. Results showed that soil bulk density increased with the increase in soil depth, while total soil porosity and capillary porosity decreased. Average infiltration rates of different forest soil types ranged from 0.78 to 2.42 mm/min and stable infiltration rates ranged from 0.10 to 0.53 mm/min. Average and stable infiltration rates presented such an order as: Pinus armandii forest land> Pobulus yunnenensis forest land> Acacia bealbata forest land> Aluns cremastogyne forest land>wasteland. The transient phase of infiltration occurred in the first 5 min, the gradual phase occurred between 5 and 80 min, and the stable phase occurred after 80 min. Kostiakov Model best fitted the infiltration process determined by double-ring method compared with Philip and Horton Model.

Abstract:Due to the periodical water level change of the hydro-fluctuation belt in Three Gorges reservoir area, soil of the hydro-fluctuation belt repeatedly experienced the process of flooding-drought. Thus, most of the original plants were difficult to adapt to the new habitat and that lead to seriously damage of the original ecosystems in the hydro-fluctuation belt. This research imitated the regular pattern of soil moisture condition of the hydro-fluctuation belt in Three Gorges reservoir area and investigated the photosynthetic physiological characteristics and ecological adaptation mechanism of Vetiveria zizanioides under alternating flooding-drought stress with four treatments in 30, 60, 90, and 120 d as cycles. Results showed that different alternating flooding-drought stress significantly affected growth and photosynthetic physiological characteristics of Vetiveria zizanioides seedlings. Plant height, net photosynthetic rate, stomatal conductance, and chlorophyll content physiological variables of each group showed different trends with time. Meanwhile, the alternating cycle was greater, the variation was greater. Whatever, each group eventually can gradually restore or stabilize the state, to maintain a high survival rate. Therefore, Vetiveria zizanioides have a good tolerance and adaptability to flooding and drought. It can be chosen as a plant species for ecological construction in Three Gorges reservoir area.

Abstract:To understand the variation of soil water content in loess slope due to rainfall infiltration, the soil water content and rainfall were monitored on a typical natural loess slope in Baota Mountain of Yan'an City, Shaanxi Province. The monitoring results showed that there was temporal hysteresis and spatial difference in the responses of soil water content to rainfall infiltration. The impact depth of rainfall infiltration was less than 1.0 m when the daily rainfall was 10 mm or the 10-day cumulative rainfall reached 70 mm. When the daily rainfall was 50 mm or the 10-day cumulative rainfall reached 140 mm, the impact depth was less than 2.0 m. The rate of rainfall infiltration was 0.04 m/h at the shallow depth of 0.2 m and it decreased to 0.033 m/h from the depth of 0.2 m to 1.0 m when the cumulative rainfall reached to 10.4 mm per hour at the study area. The rainfall infiltration rate decreased with the increase of depth.

Abstract:The paper investigated and compared the soil physical properties of the soils under ten different vegetation types(30 a) in psammophyte garden in Yulin City, which locates in the south of Mu Us sandy land. The results showed that vegetation restoration could improve the soil physical properties. Compared with the moving sandy land, soil bulk density of surface soil decreased by 0.1~0.5 g/cm³ and the soil total porosity increased by 1%~10%. Although the sand grains was still the dominant component of soil particle composition it showed a trend of refinement. The content of 1~0.25 mm decreased significantly, and other size fractions increased to certain degrees. Significant difference was found in different vegetation types on the amelioration of soil. The shrub was better than herb and tree in improving soil properties, of which the Caragana was much superior to other species.

Abstract:This study focused on the responses of microbial biomass and respiratory quotient of 4 vegetation types to grazing disturbance at the upper reaches of Minjiang River. These vegetations were Robinia pseudoacacia, Artificial Poplar, Grassland and Berberis shrub. Three grazing disturbance intensity were set with different distances from sample plots to grazing-path. Then analyzed soils under different treatments. The results showed that at different vegetation types, the values of soil organic carbon(SOC) and microbial biomass corbon(MBC) decreased with the increasing grazing intensity; the values of q_CO2 of surface soil increased by 15.14%~100.54% with the increase of grazing pressure(except moderate disturbance in shrubs). These data illustrated that grazing disturbance accelerated the turnover rate of microorganisms, decreased the utilization rate of SOC, increased emission content of CO₂ and decreased preserving rate of soil carbon.

Abstract:An experiment of consolidation and permeability in undisturbed soil was carried out to test and verify the membrane performance of cohesive soil. Undisturbed soil samples were collected from 65 m underground in Tangshan coastal salty area and then size composition, pore characteristics and clay mineral content were tested. The undisturbed soil sample was pressured into ring knife for saturation and consolidation, permeation under stable osmotic pressure was tested with 10 g/L saline, and water flow and Cl^- and Na⁺ concentration of the aqueous solution were regularly monitored. When the permeability experiment came to end, inflow fluid concentration and ion concentration on the surface of the undisturbed soil were tested separately. Results show that Na⁺ and Cl^- concentration almost synchronously increased, and were still rising after reaching the initial infiltration solution concentration. At the end of the experiment, inflow liquid concentration was 1.1 times the initial value of the inflow liquid, and the solution concentration on the surface of the undisturbed soil was 1.5 times the initial value of the infiltration solution. The phenomenon of concentration polarization testifies that the undisturbed soil has certain membrane performance, but cannot play a role in intercepting salt under the experimental conditions.

Abstract:Based on measurements of soil bulk density and organic carbon content, this paper studied the characteristics of soil organic carbon density in degrading Achnatherum splendens communities around the Qinghai Lake. Results showed that soil bulk density under the heavily degraded Achnatherum splendens communities was apparently greater than that in the moderately degraded communities. Soil organic carbon content in the moderately degraded Achnatherum splendens communities was generally higher than that in the heavily degraded. Especially, there existed an extreme apparent difference in surface soil organic carbon content between them. In the 0-100 cm soil profile, soil organic carbon content showed a decreasing trend in the moderately degraded Achnatherum splendens communities and however, the heavily degraded communities displayed two kinds of trend, i.e., decreasing trend and the trend of first increasing and then decreasing with soil depth. Soil organic carbon density showed the same trend as its content. Soil organic carbon was mainly distributed in the 0-30 cm soil layer. Soil organic carbon densities in the layer in the moderately and heavily degraded Achnatherum splendens communities were 7.35 and 2.92 kg/m², respectively, occupying 57.45% and 63.06% of the total soil organic carbon densities in the whole soil profile. In the profiles, soil organic carbon densities in the moderately and heavily degraded Achnatherum splendens communities around the Qinghai Lake were 12.79 and 4.63 kg/m², respectively.

Abstract:The effect of soil physical and chemical properties, soil aggregate and its characteristics of planting ramie and peanuts in red soil were studied by dry, wet sieving method. Moreover, the relationship between soil aggregates and surface runoff and soil erosion were also analyzed. The results indicated that: (1) After three years by planting ramie, soil organic matter, field capacity, total porosity, grains of sand were increased 28.44%, 10.06%, 5.65%, 28.44%, soil bulk density, silt, and clay were reduced by 7.20%, 14.85%, 34.95%(p<0.05); (2) Mean weight diameter(MWD), stability index(ASI) of soil aggregate by planting ramie were significantly higher than that of planting peanut, soil aggregate stability of planting ramie was better than that of peanuts; (3) 0.25~1 mm aggregates is the best chance of preservation of the red soil, and the resist-erosion ability also the strongest. (4) Surface runoff and soil erosion, with soil organic matter, sand content, >1 mm dry aggregates, >0.5 mm water stable aggregates, MWD, ASI were negatively correlated(p<0.01), but were significantly positively correlated with silt, clay content, <0.25 mm,dry aggregates, and <0.053 mm water stable aggregates.

Abstract:Hydrodynamic dispersion theory studies the temperoral and spatial changes in groundwater soluble substances and predicts the trend of groundwater pollution. This article carried out a dispersion test in the new Huamei factory site of Baotou City, and measured the longitudinal dispersion degree of the shallow aquifer. The results showed that the longitudinal dispersion degree was 1.19~1.28 cm, the transverse dispersion degree experience value was 0.24~0.26 cm. It provides a sound basis for formulating effective measures to prevent and control groundwater pollution.

Abstract:Net primary productivity(NPP) is a material basis of ecosystem services. NPP plays a key role in the eco-security assessment and ecological risk assessment. The data of SPORT-NDVI, meteorology and landuse from 2000 to 2010 were used to estimate the temporal variation and spatial distribution of the NPP in Southern Shaanxi Province with improved CASA model. Results indicated that the annual average NPP of various landuse types all showed an upward trend from 2000 to 2010. The land-use types, in order of decreasing NPP, were forestland, shrub land, grassland, cultivated land and other types. During the years, the NPP of various landuse types increased in February and reached a peak in July. The NPP significantly declined in November and the minimum value appeared in following January. For the spatial distribution, the annual average NPP increased significantly in western Hanzhong City and the eastern and western regions of Shangluo City, increased steadily in the center of Hanzhong City and the most parts of central Ankang City, declined obviously at the juncture of Chenggu and Xixiang Counties, but did not change obviously in other regions of Southern Shaanxi Province. The NPP differences between monthly and annual change trends were apparent.

Abstract:The experiment was performed with the two cultivation modes of solar greenhouse(G) and rain protection shed(S) in two soil moisture levels(soil relative water contents of 60%~70% and 90%~100%). The No.4 Jinchun cucumber was selected to investigate the effects of cultivation modes and soil moisture on yield and quality of cucumber and its water use efficiency. Results showed that: (1) Water consumption increased with increasing soil moisture content. Lower soil moisture was helpful for improving water use efficiency(WUE). Under lower soil moisture, the root-shoot ratio was higher, but plant biomass and crop yields were lower. The root-shoot ratio in solar greenhouse was lower. Plant biomass and crop yield in solar greenhouse were higher than those in rain protection shed. (2) Lower soil moisture was beneficial to improving cucumber quality, and vitamin C(V_c), soluble sugar, protein content and soluble solid content were higher. As for the nutrition quality, rain protection shed gave a better quality than solar greenhouse.

Abstract:A simulated rainfall experiment was conducted to detect the response of forest soil respiration to precipitation change in the Jiufeng National Forest Park, Beijing City. Platycladus orientalis was chosen as the representative tree. Soil respiration rate in different stand ages was measured in conditions of 5, 10, 20 and 50 mm rainfall depths and consecutive identical frequency. Results indicated that there was significant variation(p<0.05) in the impact of stand age on soil respiration rate of Platycladus orientalis, and the soil respiration of 30-years-old Platycladus orientalis generally exceed that of 10-years-old. Compared with control group, 5,10 and 20 mm rainfall tests all had auxo-action effects on soil respiration of 30-years-old Platycladus orientalis and 50 mm rainfall and consecutive identical frequency were suppressive on 30-years-old Platycladus orientalis' soil respiration. 10-years-old Platycladus orientalis needed less water than 30-years-old Platycladus orientalis and hence, only 5 mm rainfall could promote soil respiration rate, while the others presented suppressive effect.

Abstract:The debris flow in Zhangmu gully is a great threat to Zhangmu treaty port, which is the only national level 1 treaty port in Tibet. In order to design a program to prevent debris flow, the study analyzed the forming conditions and dynamic characteristics of the debris flow gully, then evaluated the possibility of the occurrence of debris flow through quantitative and comprehensive method and fuzzy mathematic comprehensive evaluation method respectively. The result showed that Zhangmu gully is prone to has slight debris flow, but also has a possibility of moderate debris flow. In addition, monitoring results of the water flow showed that the running water in Zhangmu gully is the mainly supply source of groundwater in loose layer under Zhangmu town. This may has negative effect on the stability of Zhangmu landslide group.

Abstract:In order to explore the influence of the desert wind velocity on wind velocity distribution in forest and windbreak effect, this article observed in multi points, using traditional statistical analysis, surfer software, geostatistics and other methods to analysis wind velocity distribution in forest and windbreak effect when the desert wind velocity is 5.4, 7.2 and 10.3 m/s. The results showed that the leeward side of primary forest formed a wind down district under all 3 kinds of desert wind velocity; The average wind velocity reduced by forest is 26.1%,23.3% and 25.7% under 3 kinds of desert wind velocity. The average effective protection area ratio is 50.8%, 41.7% and 47.7%. The overall effectiveness of forest protection is maximum with a wind speed of 5.4 m/s and minimum with a wind speed of 7.2 m/s; forest wind velocity spatial variability functions under 3 kinds of desert wind velocity can be a good fit as a spherical model, the ratio of nugget to sill under 3 kinds of desert wind velocity is small, and all were less than 25%, and forest wind velocity has a strong spatial autocorrelation. The influence of the wind velocity of desert on wind velocity distribution in network of forest and windbreak effect is complex, it does not increase or decrease with desert wind velocity but strongly influenced by forest structure and porosity.

Abstract:According to two-factor quadratic regression rotation design, effects of water and nitrogen fertilizer coupling on yield and quality of Chuzhou Chrysanthemum morifolium were studied by a pot experiment and the suitable water and nitrogen management modes were investigated. Results showed that remarkable effects of water and nitrogen coupling on flower yield, total flavonoid content of leaf or flower, chlorogenic acid content of leaf or flower of Chuzhou Chrysanthemum morifolium were displayed, and there was a significant interaction between water and nitrogen. Effects of water on flower yield, total flavonoid content and chlorogenic acid content were more significant than those of nitrogen fertilizer. When soil water and nitrogen fertilizer were at 0.2841 and 0.4037 levels, respectively, namely, keeping 80% of the field water capacity and 0.257 g/kg nitrogen fertilizer, flower yield of Chuzhou Chrysanthemum morifolium reached a maximum up to 18.09 g/plant; and when both of soil water and nitrogen fertilizer were at -1.414 level, namely, keeping 50% of field water capacity and 0 g/kg nitrogen fertilizer, total flavonoid content and chlorogenic acid content of Chuzhou Chrysanthemum morifolium flower were maximal. Considered from the field of flower yield and quality, a suitable management mode of water and nitrogen is to keep middle level in the beginning stages of growth of Chuzhou Chrysanthemum morifolium and low level in the squaring stage and flowering period.

Abstract:The quantitative calculation and evaluation for soil and water conservation schemes of 106 expressways are made using soil and water loss impact index(SWII). The weight of each indicator is calculated by consulting experts about the weights of 9 indicators and applying analytic hierarchy process(AHP). The key factors for soil and water loss in different eroded areas are then analyzed by applying principal components analysis(PCA). According to the calculated SWII, the expressway projects can be divided into three types: high-influencing project with a value of SWII higher than 0.387, medium-influencing project with a value of SWII between 0.258 and 0.387, and low-influencing project with a value of SWII lower than 0.258. Based on the influencing degree of soil and water loss on expressway projects, some technical requirements are presented from the aspects of prevention criteria, engineering grades, allocating requirements of soil and water conservation measures and construction techniques.

Abstract:Comprehensive evaluations of soil and water conservation may provide principles and a theoretical basis for the policy development of soil and water conservation and the feasibility assessment of technological scheme. An index system was built based on the two factors of the basic situation of soil and water loss and the protective efficiency of soil and water conservation. An evaluation model was constructed based on factor weighted sum, and the factor weights were determined by using AHP and entropy weight method. By taking the typical power transmission projects in Jiangsu Province for examples and using the evaluation model, the study made a comprehensive evaluation of the soil and water conservation benefits and a comparative analysis of the soil and water conservation benefits for different types of soil and water conservation areas. Results showed that, as for the soil and water conservation benefits in power transmission engineering projects, the hilly area had the greatest beneficial result, followed by the general plains area and the sandy plain area. For the fluctuation of soil and water conservation benefits, the general plain area was the first, the hilly area was the second, and the sandy plain area was the third in a descending order.

Abstract:By taking nine typical wind power sites built in the Jiuquan gobi desert for an example, impacting index of soil and water loss for wind power site construction in the gobi desert area was calculated and a range of impacting indexes for the gobi desert areas in China was determined through the calculation, analysis and grading of the impacting index of soil and water loss. The data like engineering properties, cover area, excavation and embankment volume and construction technology involved in the project were obtained by combining data collecting with in-situ monitoring. It follows from the calculation that the impacting index of soil and water loss for wind power site construction in the gobi desert area was 0.3140.

Abstract:Based on the monitoring experiment of pollutant production from a typical scale pig farm in three pig feeding stages(sows, fattening pigs and piglets) in the Taihu Lake region, Jiangsu Province, the contents of pig manure pollutant and the coefficients of the pollutant production from pigs were estimated. In addition, discharge of animal manure pollutant and the water equal standard pollution index in the region in 2011 were estimated using animal manure discharge rate and equal standard pollution method. Results showed that the total discharge amount of total nitrogen(TN), total phosphorus(TP) and chemical oxygen demand(COD) from livestock and poultry breeding industries was 218.9 thousand tons, and the water equal standard pollution indexes of Changzhou, Suzhou and Wuxi Cities were 11.54, 5.70 and 6.10, respectively. However, differences were observed for the water contamination degree in different areas. The primary pollution source of livestock and poultry breeding industries was poultry and pigs whose load ration in equivalent standard reached 49.52% and 44.47%, and the primary pollutant was TP whose load ration in equivalent standard reached 67.87%. A great attention should be paid to the pollution of P.

Abstract:A new kind of super absorbent polymers(SAP, superabsorbent) for agriculture and forestry, HA-CMC compound superabsorbent, was prepared by surface cross-linked reaction with humic acid and carboxyl methyl cellulose to improve the shortages of current SAP. The appropriate proportions of different stuffs and the best reacting conditions were optimized, and the characteristics of constituent and surface texture of the compound were studied by the infra-red spectrum and electron microscope. The abilities of water absorption and repeated water absorption of the compound were then compared with other four SAP. The results showed that the most appropriate mass ratio of CMC, MBA, HA, AM and KPS was respectively 1:0.015:0.2:6:0.2. The HA and CMC reacted well and form a kind of powerful-water-holding surface texture which can provide a high water absorption ability. Compared with other SAP, the compound performed well in water absorption and repeated water absorption. The water absorption ability of the compound was better than other three SAP and had no significant differences with Dijin polymers. The repeated water absorbency ability of the compound was significantly better than others.

Abstract:The degree of soil and water loss in Guangdong Province was studied by using GIS technology. Factors relating to the degree of soil erosion, such as slope steepness, slope length, soil, rainfall and geological lithology, were considered. By the method of spatial overlay analysis, the potential danger degree of soil and water loss in Guangdong Province was measured and assessed, and finally a map of its distribution was generated. Analysis results show that most of the soil erosion potential danger areas in Guangdong Province were no risk or light risk areas, which covered more than 80% of the whole province area, mainly distributed in the plains. It is worth noting that the heavy risk areas are the key prevention and protection areas in soil and water conservation, which covered 18.3% of the whole province area and was mainly scattered in hilly areas with higher relief and larger rainfall. Once the vegetation in these areas is destroyed, they are prone to erosion.

Abstract:Ecological footprint is one of the important methods to assess regional sustainability, and current researches usually adopt nationwide equivalence factor and yield factor. This paper, taking Shaanxi Province as a case study, estimated independently the equilibrium factor and yield factor for each year, and improved the traditional evaluation methods. The results indicated that there were big difference between factors of Shaanxi Province and nationwide unified factor. From 1995 to 2011, Shaanxi Province was general unsustainable, and the ecological deficit and ecological pressure index changed between 0.1389~0.4978 hm²/cap and 1.1703~2.6137 respectively, and kept relatively stable. compared to the result calculated by the global unity factor, the data form the present study were smaller than normal study and more closely to regional reality. Being good for the negotiations on global ecological problems, it is necessary to establish a set of ecological footprint calculation factor and method conform to national condition and regional characteristics.

Abstract:Intensive utilization of rural construction land is an important part of rural land use, and is one of the important measures to solve the contradiction between supply and demand of land. The paper constructed a set of evaluation indexes to evaluate the intensive utilization degree of rural construction land in Beiyuan area of Linxia County in Gansu Province, using the information on land use intensity, input intensity, and output results, the socio-economic situation and the regional terrain conditions. Then factor analysis method and analytic hierarchy process(AHP) were used to bestow weighting using combination of objective and subjective methods, and sorted the order of the intensive utilization of rural construction land in Beiyuan area using the improved TOPSIS method. The results showed that Tuqiao Town, Xianfeng Township, Hexi Township have the highest land use intensity; Lianhua Town, Beiyuan Township, Anjiapo Township and Qiaosi Township have higher land use intensity while Nanyuan Township and Potou Township have lower land use intensity. The causes of differences were analyzed with the consideration of land utilization, economic and social factors.

Abstract:The pollution by heavy metals of Hg, Cd, Cr⁶⁺, Pb, As, Cu, Zn and Se in the Weihe River of Xi'an section were analyzed using the methods of single factor water quality assessment and heavy metal pollution index(HPI). The health risks of these metals were evaluated by the method documented by USEPA. The results indicated that Pb and Cd were undetectable in all water samples, but the water was contaminated to certain degrees by Hg while all other metal contents were within the limits of the categoryⅠor Ⅱ of surface waters based on the Environmental Quality Standards for Surface Water (GB3838-2002). The HPI of the water of the river in the region was 32.74, which was lower than the threshold value of 100, indicating that the pollution is within the acceptable level. The results also showed that the non-carcinogenic risk and the carcinogenic risk of the investigated metals are acceptable, and the highest carcinogenic risk was from As in the water body, with the risk index being at 8.50×10^-5. It suggests that As in water of the region should be of specific concern for the local environmental monitoring and management authorities, since its health risk index was almost close to the upper acceptable limit(10^-4).

Abstract:Ecological security assessment is important for poverty reduction and environmental protection in large poor areas in Lipan Mountain in Ningxia Hui Autonomous Region. Based on data from 2001 to 2011, press-state-response(PSR) model was used to construct index system which consists of 19 indicators in this research and entropy method was used to calculate ecological security index value of seven poverty counties in Liupan Mountain area. The results were as follows: (1) On the time scale, it can be classified as three phases: during 2001 and 2006, ecological security index value slowed down and to be lowest in 2007 and 2008, and then began to rise slowly, showing that the study area had taken a turn for the better after a period of deterioration. (2) On the space scale, it can be classified as four areas: ecological security index values of Pengyang, Longde and Jingyuan County are higher and stable; while ecological security index values of Xiji and Haiyuan County remained at a low level; ecological security state of Yuanzhou District improved gradually, and its ecological safety in 2011(0.5282) was only next to that in Pengyang County(0.6194); Moreover, ecological security index value of Tongxin County decreased, but still kept higher than that of Xiji and Haiyuan County.

Abstract:Taking Qinzhuanggou Watershed in the dry upland to the north of the Weihe River for an example, terrain factor data and land use data were overlaid and extracted based on the map of the terrain, with the support of ArcGIS software. The relationship between land use distribution and terrain factors was studied by land distribution index. Results showed that there is a close relationship between spatial distribution of land types and the terrain data of elevation, gradient and gully density. The predominant area of farmland are 900~1100 m above sea level, 5°~25° slope and 0~4 km/km² gully density; the predominant area of garden plot, 800~1200 m above sea level, 0°~15° slope and 0~2 and 4~6 km/km² gully density; the predominant area of woodland, 1100~1250 m above sea level, 15° ~25° and >25° slope and 2~6 km/km² gully density; the advantages of bare land, 800~1000 and 1100~1200 m above sea level, >25° slope and 4~8 km/km² gully density; and the predominant area of rural residential land use, 900~1000 m above sea level, 0°~5° slope and 0~2 km/km² gully density.

Abstract:The correlations of soil physicochemical parameters with the total content of arsenic(As) and the available content of arsenic were analyzed based on the measured contents of arsenic, total phosphorus, organic matter and soil moisture in soils around a mine in Inner Mongolia area. There were two mixed samples consisting of coal gangue and local natural topsoil. Arsenic was separated out from the mixed samples through leaching process at different pH values according to rainfall amount and characteristics. Results show that there was a significantly positive correlation between the available arsenic and the total arsenic content. Total arsenic content had a certain positive correlation with pH value and total phosphorus, but insignificant correlation with organic matter and hydrolysable nitrogen. The available As content had a positive correlation with organic matter, but a negative correlation with pH value. The arsenic leaching decreased with the increasing pH value of leaching solution. The lower pH value was, the higher arsenic leaching was.

Abstract:Two ecological restoration technologies, i.e., vegetation-growing concrete base material spraying technology(CBS) and the external-soil spray seeding technology(ESS), were applied in ecological restoration area of the Guandi Hydropower Station on the Yalong River to study soil fertility in the preliminary stage of ecological restoration. Six soil fertility indexes were measured by selecting four ecological restoration slopes and one contrast slope. Then the method of standard comprehensive assessment on fertility grade was employed to analyze the variation of soil fertility. Results showed that the contents of soil organic matter, total nitrogen, total phosphorus, available nitrogen, available phosphorus and available kalium on the four ecological restoration slopes were larger than the contrast slope. The soil fertility on the four slopes was also significantly higher than the contrast slope. The slope on right riverbank with CBS applied had the highest soil fertility. Therefore, the two ecological restoration technologies can improve soil quality in the study area, but the benefits of using CBS were better than ESS.

Abstract:This paper used gray correlation analysis method to evaluate the water quality of Haihe River basin. However, the traditional grey correlation analysis has drawbacks due to subjectivity in calculating relatedness. To overcome this defect, this paper chosen two kinds of improved gray correlation analysis methods for the water quality evaluation, and compared the advantages and disadvantages of the two methods. The combined application of improved gray correlation analysis method and correspondence analysis method can reach to scientific and reasonable evaluation conclusions.Meanwhile, this paper predicted water quality using grey prediction model. The results showed that: (1) Combination of the improved AHP weights of gray relational analysis and correspondence analysis can provide a nice way to understand basin water quality and reach to a rational evaluation result; (2) The main sources of pollution in the Haihe River basin is agricultural non-point source pollution and sewage pollution.

Abstract:A pot experiment was conducted to study the measurements of plant volume and leaf area of Ptadtyctadus orientates and their relations to plant height, crown breadth and leaf area index(LAI). Results show that physical volume increased with the increase of cuboid and cylinder volume and had linear and extremely significantly positive correlation with cuboid and cylinder volume. With increasing crown width, physical volume and total leaf area presented linearity(R=0.572) and downward opening parabolas(R=0.450). When crown width was 73 cm, cylinder lateral area was 0.546 m² and cylinder cross sectional area was 0.329 m², corresponding total leaf areas reached the maximum values of 3581, 3639 and 3523 cm², respectively. With increasing total leaf area, leaf and branch volumes and physical volume presented downward opening parabolas, which all showed a significantly positive correlation with total leaf area. With increasing leaf volume, leaf area index presented an upward opening parabola. When leaf volume was 338 cm³, leaf area index reached a maximum value of 6.1.

Abstract:Seasonal dynamic variations and vertical distribution characteristics of preponderant groups of soil microbes and their correlations with soil enzymatic activities were studied in Betula luminifera forest, Pleioblastus amarus forest and cropland(control). Results indicated that there were six preponderant species of soil microbes: Micrococcus, Bacillus, Streptomyces, Actinoplanes, yeast(the genus was not identified) and Trichoderma. The amounts of dominant groups of soil microbes had difference between two models of forest rehabilitation: the ratio in P. amarus forest was the largest in spring, summer and autumn, and the ratio of B. luminifera forest was the largest in winter. Seasonal variations of dominant groups of soil microbes in two forests and cropland were that amounts of Micrococcus and yeast were higher in summer and winter than spring and autumn; Bacillus was the highest in autumn and the least in summer; Actinoplanes and Trichoderma were less change than other dominant groups with season; Streptomyces was the highest in summer and the least in winter. Vertical distribution characteristics of dominant groups were that amounts of Micrococcus, Actinoplanes, Trichoderma were reduced gradually with soil depth, but Bacillus and Streptomyces were opposite to them; and change of yeast was not significant with soil depths. Rhizosphere effects showed that R/S values of Streptomyces and Trichoderma were more than 1; R/S value of yeast was less than 1; and R/S value of Micrococcus and Actinoplanes was more than 1 in Betula luminifera forest, but opposite in Pleioblastus amarus forest. There were significant positive correlations between Micrococcus and invertase, Bacillus and cellulase, Actinoplanes-Trichoderma and catalase, and yeast and urease.

Abstract:Spatial variability of soil moisture on micro-topography is an important factor influencing the distribution and restoration of vegetation on the Loess Plateau of China. Soil moisture of different size of platforms in loess hilly-gully region was investigated and analyzed. The results showed that: (1) The size of platform had a significant impact on soil moisture content. Overall, the larger platform showed a better soil moisture condition; (2) The variation coefficient of soil moisture in 0-60 cm soil layer of platforms ranked as follows: small size platform(<100 m²)> large size platform(>1000 m²)> medium size platform(100~1000 m²); (3) Within the large size platform, the variation coefficient of soil moisture along the up and down slope direction(parallel to slope) was higher than that along the contour. Geo-statistics was used to analyze the spatial heterogeneity of soil moisture(0-60 cm) in large size platform. A spherical model was used to fit the change of semi-variance with separated distance. Kringing interpolation showed that within the large size platform, soil moisture on the joint part of platforms and the scarp on upslope was higher than other parts.

Abstract:On the basis of defining the meaning of the health of land use system, the evaluation index system for the health of land use system was constructed based on the press-state-response(PSR) model, then an empirical analysis was conducted in China by entropy method and grey prediction model. The results showed that: (1) The health level of land use system had been gradually improved from 1999 to 2008 in China, with the comprehensive index increasing from 0.3935 to 0.5331. The health of land use system generally experienced two stages, i.e., unhealthy and critical state. (2) The pressure index showed a downward trend, while status index and response index showed a rising trend. (3) The growth rate of fixed asset investment, per capita cultivated land, land reclamation rate, extent of soil erosion and per capita GDP were proved to be key constraints for further improvement of the health of land use system. (4) The health level of land use system show a steady upward trend from 2009 to 2015, and the health degree of land use system reaches the sub-health state in 2014. Finally, some measures was proposed for the further improvement of the health of land use system.

Abstract:Based on multi-spatial information, analytic hierarchy process(AHP), principal component analysis and grid GIS technology are applied in gridding the indicators of ecological vulnerability evaluation system at 10 m×10 m scale and achieving the spatial data about the ecological vulnerability of grassland in Changshun County, Guizhou Province. The ecological vulnerability of karst grassland is divided into 5 levels according to ecological vulnerability index(EVI). The analysis shows that the area of heavy vulnerability region is 36.32 km², taking the largest proportion; the areas of moderate and extreme vulnerability regions are 28.09 km² and 24.99 km², respectively; and the areas of slight and potential vulnerability regions are 16.54 and 8.60 km², respectively, taking smaller proportions. Overall, the ecological vulnerability of grassland in Changshun County is at a higher level and the ecological vulnerability of karst grassland is resulted from the special geological background and frequent human activity interference.

Abstract:In order to study the distribution characteristics and causes of heavy metals(HMs) in river sediment, six kinds of HMs(Cu, Zn, Cd, Cr, Pb and Ni) in sediment of the Xiaohe River were measured with atomic absorption spectrophotometer(AAS). The characteristics and causes of HMs pollution were analyzed and the potential ecological risk index method was used to assess the potential ecological risk coefficient and harm index of HMs in the river sediment. Results indicated that the content of HMs in sediment of the Xiaohe River was higher in the upper and middle basin, and lower in the lower basin under normal accumulation conditions. Under the non-normal accumulation conditions, such as channel fluctuation and new pollution sources, the content of HMs was higher in the lower basin than in the upper basin. The content of HMs in the river sediment was easily affected by water quality, and their relationship was analyzed by principal component analysis(PCA). Besides, the content of HMs in the river sediment was also affected by sediment size composition. Result from composite pollution evaluation for heavy metals in surface sediment of the Xiaohe River showed the order of Cd> Pb> Ni> Cu> Cr> Zn.

Abstract:Soil moisture is an important refereed index for controlling desertification, breeding sand fixing plants, restoring and reconstructing degraded ecosystem. Soil moisture dynamics(0-80 cm) under different underlying surfaces(7-year-old Pinus elliotii, 4-year-old Pinus elliotii, grassland and bare sandy land) in the sandy land of the Poyang Lake were measured and analyzed. Results are as follows: (1) The underlying surfaces, in order of decreasing average soil moisture content, were 4-year-old Pinus elliotii(5.22%), grassland(4.88%), 7-year-old Pinus elliotii(4.01%) and bare sandy land(2.95%). (2) All of the annual soil moisture contents at different depths under different underlying surfaces showed moderate variation. The variation coefficient under the 4-year-old Pinus ellioti was the highest, while that under the bare sandy land was the lowest. (3) There were seasonal changes in the vertical variation coefficients of soil moisture content under different underlying surfaces. The variation coefficients in August were the highest, followed by those from October to December. The smallest variation coefficients were observed from Match to June. Apart from August and October, the vertical variation coefficients for the underlying surfaces with vegetation coverage were lower than those of the bare sandy land.

Abstract:Taking Bayan County in grain producing areas of Northeast China as the study area, with "3S" technology, Logistic model is used to indentify the driving forces of cultivated land resources change. Single factor index method and path analysis are used to explore the impact of single factor and composite factors on food production. Results showed that: (1) The driving forces of cultivated land resources change mainly included slope, soil type, average land GDP and other 8 sensitive factors, and the driving mechanism of each driving factor was different. (2) The changes in the classification of single driving factor index might lead to changes in food production. The maximum change occurs in soil organic matter content with a level of 1-2 while the minimum change occurs in policies and regulations with a level of 2-3. (3) The impact of complex factors on food production was that 0.1 changes in the driving forces may lead to a change in food production around 950 kg/hm². Both single factor and composite factors had a great impact on food production. Therefore, specific measures need to be formulated to enhance food production according to the different characteristics of the driving factors.

Abstract:According to the consolidation practice and the special characteristics of land in the saline area with high soil salt content and less nutrient content, this article selected salt separating material(A), the depth of the salt separating layer(B) and ameliorants(C) as factors to design a 3 factors by 3 level orthogonal variance experiment. The results showed that after soil improvement, the soil bulk density, pH value and salt content decreased significantly, and the content of available nitrogen, phosphorus and organic matter increased but a slight decline in available potassium. Compared with the control group, the soil properties, main nutrients, crop biomass and yield of the test groups were significantly improved, and the indicators were significantly different. The best improvement program is A₂B₂C₁, in which the slag and straw are selected as the salt separating material, and the depth of the salt separation is 60 cm and organic fertilizer can be used as ameliorants.

Abstract:Yeniu gully is a representative debris flow gully in the middle reaches of Dadu River. The ample source of materials and terrain change create appropriate conditions for the formation of next debris flow. Based on the study of solid material discharge, and the gully-bed condition of fan by debris flow from Yeniu gully under three different frequencies, the conventional empirical blocking formula was revised. The revised formula was verified by the study on debris flow in the Jintang River in Yeniu gully. The results showed that Jintang River will be completely blocked when P=1%, and partially blocked when P=2% and never blocked when P=5%. The test indicated the generality of the revised formula, which can be applied in the middle reaches of Dadu River.

Abstract:Analyzing the interactions between environmental or agricultural policies and farmers' behaviors has been widely considered to be very important for the sustainability of agro-ecosystems. Based on the economics theory, the goal-project-risk-decision(GPRD) model was constructed, and the process and change of the land use decision-making by farm household were revealed. With the help of hierarchical linear model(HLM) software, the farm households' landuse behaviors were analyzed. The conclusion is as follows: (1) The off-farm was widespread due to the lower comparative advantage of agriculture, and the majority crops were potato, corn and fruit tree. (2) The decision-making for cash crops was affected by the characters of farm household and the distance between parcels and roads, and for cereal crops, by the natural conditions.

Abstract:The comprehensive evaluation and analysis of land resources utilization in Shaanxi Province from 2001 to 2010 were made by using analytic hierarchy process(AHP), variation coefficient method and specific gravity method and selecting 18 indicators from economy, society and ecology. After determining the weight of each indicator and calculating the indicator value, the general level of land resources utilization of Shaanxi Province in the past 10 years was evaluated. Results show that the change of land resources utilization structure in Shaanxi Province was consistent with the sustainable development of economy and society from 2001 to 2010. Meanwhile, economic and social benefits of land resources utilization increased steadily and the average annual growth rates were 58% and 21.5%, respectively. However, the ecological benefit of land resources utilization showed a linearly decreasing trend.

Abstract:Groundwater resources are the most important source to life and industrial water use in Southwest China karst-mountains and provide an important guarantee for the all-side sustainable development of social, economic and ecological construction. The present status and characteristics of groundwater pollution were analyzed based on the analysis of groundwater resources use in Southwest China karst-mountains. Results indicate that the groundwater pollution in Southwest China karst-mountains mainly comes from four aspects: urban economic activities, industrial and mining exploitation, the "three wastes" emission, agricultural non-point source pollution and rural living garbage pollution. On this basis, several measures were discussed and put forward: strengthening investigation and monitoring of groundwater in karst region; strengthening water environmental protection publicity and education and improving villagers' water environmental protection consciousness; adjusting industrial structure and promoting rural waste treatment; developing organic ecological agriculture; and promoting the prevention and controlling countermeasures of rural ecological environment and groundwater pollution controlling. Prevention is recognized to be the key to control karst groundwater pollution.

Abstract:Based on the data observed from 11 meteorological stations in Ningxia Region from 1960 to 2012, the characteristics of climate change were analyzed and the trends of droughts and floods were forecasted with methods of linear regression, Z index, Mann-Kendall mutation test and Markov model. Results indicated as follows: (1) Ningxia regional climate changes experienced the three periods of cold-wet, warm-wet and warm-dry during the recent 52 years. The temperature fluctuations showed a significant upward trend with a rate of 0.36 ℃/10 a, far higher than the average warming rate(0.2 ℃/10 a) in Western China. The precipitation fluctuations showed a downward trend with a decreasing rate of 9.94 mm/10 a. (2) The frequencies of droughts and floods and temperature changes occurred with a certain synchronicity: from the 1960s to 1980s, the change of temperature was not significant and the tendencies of droughts and floods were stable; from the mid-1980s to 2006, temperature increased substantially and droughts and floods increased simultaneously; and from 2006 to 2012, warming trend occurred and the occurrence of droughts and floods was reduced correspondingly. (3) The state of droughts and floods in the next 5 years was forecasted using the Markov model. From 2013 to 2017, the probability of normal precipitation will be larger in Ningxia Region. In the backgrounds of warming and drying climate, the frequencies of droughts and floods are likely to increase further in the future.

Abstract:To study the farmers' income as affected by the areal change of cultivated land resources in the poverty areas around Beijing and Tianjin Cities, statistical data of seven poverty-stricken counties in Baoding City from 1997 to 2011 were used to verify the relationship between the two. The seven counties were zoned to be three regions using cluster analysis method, the relationship between cultivated land resources and farmers' income was analyzed, and the regional differences were studied using panel data model. Results indicate that in the three regions(mountainous area, Beijing's surrounding area and Beijing's nearby area), there exists a long-term equilibrium relationship between the cultivated land area and the rural per capita net income. In the mountainous area, the rural per capita net income and cultivated land area are positively correlated, while in the Beijing's surrounding area and Beijing's nearby area, negatively correlated. Moreover, the relationship between the two indicators is different within every region, and there are also differences in the growth rate of rural per capita net income in different areas. The positive or negative relationship between the amount of cultivated land and farmers' income are closely related to farmers' income source and income structure, and also related to regional resource endowments, geographic conditions and socio-economic conditions.

Abstract:The research on ecological safety, especially that of regional land use/cover is a hot issue, which is of great significance to the protection of regional ecological environment and the sustainable development. This paper, using TM images in 1980, 2000, 2010 as the data source, developed a comprehensive index method to evaluate the ecological security of land use, analyzed the temporal and spatial variation of the ecological security in Songnen Plain during 1980 to 2010, and predicted the ecological security pattern in the next 40 years. The results showed that: (1) The risk of ecological security in land use increased from the northeast to the southwest. (2) The lower risk area proportion is the largest, accounting for more than 50%. From 1980 to 2000, the other risk areas were reduced and transformed to lower risk area. This indicated that ecological environment pressure has been decreased. However, from 2000 to 2010, The conversion of low and lower risk areas to higher risk areas is obvious. (3) The prediction showed that during the period from 2020 to 2050, the area of moderate risk, high risk, and higher risk levels will increase gradually, and the ecological environment will deteriorate seriously.

Abstract:Desertification is not only one of the most serious ecological environment problems but also the limiting factor of the development of agriculture in arid areas. This paper took the area of 150 regiment in Shihezi City of Xinjiang Uyghur Autonomous Region as the study area, and used TM images to derived the normalized difference vegetation index(NDVI) and surface Albedo, and to classify desertification grade of study area by establishing NDVI-Albedo feature space. Desertified land in the study area can be divided into very severely desertified, severely desertified, moderately desertified, and mild desertified. The accuracy of the monitoring was tested with the ground investigation, and the result showed that the accuracy meet the requirement of the study. With the same method, we classified desertification area in 2000, 2005 and 2010, and analyzed the dynamic changes of desertification three periods. The analysis showed that the development of desertification has been effectively controlled after 10 years.

Abstract:Soil water condition for vegetative growth in Loess Plateau presents a gradient change from Southeast to Northwest. Quantitative analyses of spatial distribution and temporal change of fractional vegetative cover(F_c) can offer an important indication for evaluating the regional environmental changes after the implementation of returning farming land to forestry and grass land. The MODIS/NDVI images with 250 m×250 m spatial resolution were used as the data source to estimate F_c in the central precipitation gradient zone of Loess Plateau based on a dimidiate pixel method, and the spatial distribution and temporal change of F_c were obtained for the period from 2000 to 2010. The spatial characteristics and temporal trend of F_c were analyzed, while the relationships of F_c with climatic factors were discussed. Results showed that: (1) The F_c in the studied zone presented a decreasing trend from southeast to northwest. The maximum F_c value in southeastern region was 82.6% and the minimum F_c value in northwestern desert was only 38.6%; (2) The average F_c value in the studied zone appeared an increasing trend from 2000 to 2010 due to implementation of the project of returning farming land to forestry or grass land. The maximum average F_c value of 65.3% occurred in 2007 because of the maximum annual precipitation during the studied period; (3) The F_c value in the studied zone was affected by the precipitation and the temperature during the period of April to August in each year, the regression analyses of time series proved a significantly positive correlation between F_c and total precipitation and between F_c and average temperature.

Abstract:Using the meteorological data, vegetation distribution data, water resources data, we calculated the minimum and appropriate ecological water requirement of existent forest and grassland in growing season in the Central and Southern Ningxia Hui Autonomous Region. Through the analysis of equilibrium between the eco-environment water demand and rainfall resource, the results showed that in Longde County and Jingyuan County, which locate in the south area, with an average rainfall of 350~550 mm, the minimum and appropriate ecological water requirement both can be met by precipitation, and the vegetation grow well. In Pengyang County and Yuanzhou County, which locate in the south area, with an average annual rainfall of 350 mm or so, the minimum eco-water demand can be satisfied, but appropriate ecological water demand cannot be met. So reasonable grass planting structure should be considered in the area. In Haiyuan, Yanchi and Tongxin Counties in the central arid area and Xiji County in the south area, with an average annually rainfall between 175 and 280 mm, both minimum and appropriate ecological water demand can not be met, it is unreasonable to develop forest and grassland in this area.

Abstract:Traditional statistics, combined with geostatistics, were applied to analyze the spatial distribution of nitrogen(N) in plant and soil on a Stipa bungeana slope in the water-wind erosion crisscross region of the Loess Plateau. The spatial characteristics of the plant-soil system at different spatial scales were studied to reveal characteristics N distribution in the region grassland. Results showed that plant biomass, plant N content, and N stock increased gradually with the decrease of slope position. Soil organic carbon and nitrogen content in the upper and middle positions were similar, lower than those in the bottom position. Soil nitrate nitrogen and ammonium nitrogen contents performed a V-shaped change, with the highest content being on the upper slope. Except nitrate nitrogen and ammonium nitrogen contents, the variation coefficients of those variables measured to be the lowest on the bottom slope, which indicates that N distribution of plant-soil system was uniform on the bottom slope. Furthermore, the best fit models for each variable were precisely consistent at the three scales. Nugget effect increased, while spatial dependence between different sample points and spatial correlation weakened gradually with the increase of analysis scale. These results indicate that N in plant and soil have relatively stable spatial structures at different spatial scales and are characterized by medium or strong spatial correlation, and its spatial variation is mainly caused by structural factors.

Abstract:The distribution of desertification land in Ebinur Lake region in 1990 and 2010 was monitored by remote sensing and GIS technology. There was a large area of desertification land in Ebinur Lake region and it was mainly distributed in east of study area and the west bank of Ebinur Lake. The decrease of desertification land was obvious from 1990 to 2010. The desertification land decreased from 4426.49 km² in 1990 to 3789.16 km² in 2010, decreased by 3789.16 km². The study area experienced a development process from strong reverse of desertification to stability and development. From 1990 to 2001, the area of desertified land reduced from 4426.49 km² to 3713.25 km²; from 2001 to 2007, the total area of desertified land will remain basically unchanged, but the degree of desertification is slightly higier. In the past 20 years, the desertification is particularly serious due to climate change and irrational human activities, and the eastern part of the study area is more serious.

Abstract:Ecological footprint method is an effective approach for quantitative evaluatation of the regional sustainable development. Dynamic changes of ecological footprint(EF) and ecological capacity(EC) were analyzed based on ecological footprint method and land use sustainability was assessed using EF, EC and other indicators of Xuzhou City, Jiangsu Province from 1999 to 2008. The results showed that the per capita ecological footprint of Xuzhou City increased from 1.13 hm² in 1989 to 2.57 hm² in 2008, and the per capita ecological capacity decreased from 0.58 hm² in 1989 to 0.45 hm² in 2008. The per capita ecological deficit increased from 0.55 hm² in 1989 to 2.10 hm² in 2008. Intensification of land-use is low in Xuzhou City. The author used a linear regression model to predict the population, and predicted the ecological footprint of 2010-2015 by gray prediction model. The multi-objective linear programming model was built to optimize the land use structure in Xuzhou City, which minimizes ecological deficit and maximizes economic benefits as the objective function, and sets up seven variables and nine constraints. The land use structure was optimized in Xuzhou City according to optimal scheme.

Abstract:Regionalization of the key preventing and controlling area of soil and water loss is an important way to improve the effectiveness of prevention and controlling. By combining qualitative method with quantitative method and using technical means such as ArcGIS, a new round of regionalization of the key preventing and controlling area of soil and water loss in Jiangsu Province is carried out scientifically based on a comprehensive survey of the status of soil and water loss and obtained a map of regionalization of the key area. Results show that the key preventing and controlling area in the province consists of key preventing area and key controlling area, with a total area of 35 929 km² that accounting for 34.96% of the whole province. The two key areas are 21 934 and 13 995 km², accounting for 21.32% and 13.64% of the whole province, respectively.

Abstract:The optimal allocation of water resource is key to the sustainable development. By the qualitative analysis of the water shortages in Sanjiang plain due to hanging pump and local over-exploitation, a multi-objective water resource allocation model was set up based on the properties of water resource system with diverse targets. At the same time, paralleling choice GA with intrinsic parallelism and the ability of global search has been introduced to obtain a solution. Meanwhile, in order to realize the maximization of the comprehensive benefit in life, production and ecology, each calculation is converted into a unified economic benefit as a benchmark. The result showed that the combination of the model and the algorithm has optimized water resource use.

Abstract:Gross litter reserves and hydrological characteristic parameters, such as the maximum water capacity, maximum water holding rate and modified interception amount, were studied through the water holding experiment and litter reserves survey on Pinus tabulaeformis forest stands in the Miyun Reservoir, Badaling Forestry Center and Shisanling Forestry Center in Beijing City. Results showed that the three regions, in order of decreasing gross litter reserve and maximum water capacity, were Badaling Forestry Center, Shisanling Forestry Center and Miyun Reservoir. In addition, the maximum water holding rate, average water absorption rate and modified interception amount were the highest in Shisanling Forestry Center, followed by Badaling Forestry Center, and the lowest in Miyun Reservoir. However, the water conserving function of Pinus tabulaeformis litter was relatively poor in the three regions, especially in the Miyun Reservoir. When rainfall is less than the critical value, the water conserving function of litter was best in Badaling Forestry Center; when rainfall is larger than the critical value, the water conserving function was best in Shisanling Forestry Center. The water conserving function of Pinus tabulaeformis in Shisanling Forestry Center was better than other two regions.

Abstract:This article establishes a set of index system for evaluating the extent to coordinated development of environment-economy system in Jinhua City of Zhejiang Province, using mean square error method to determine the weight of each indicator and applying an evaluation model to calculate the coordinated development degrees of Jinhua City from 1998 to 2011. Results indicate that coordinated development of environment-economy system in Jinhua City has experienced four stages: elementary coordinated development and environment-economy synchronization(in 1998), medium coordinated development and environment-economy synchronization(from 1999 to 2002), medium coordinated development and delayed environment behind economy(in 2003), and better coordinated development and delayed environment behind economy(from 2004 to 2011). The coordination degree of environment-economy increased year by year. In Jinhua City, there is a larger gap between economic strength and environmental carrying capacity. Delayed environment is the dominant factor restricting best coordinated development and environment-economy synchronization in the city.

Abstract:Grain production is the most basic industry for the residence in soil and water loss area of Loess Plateau. Based on the data analysis in the representative counties of this region, the grain production potential is proved to be substantial in this region. The possible ways to realize the grain production potential were proposed accordding to the reconstruction of the low and medium production farm lands, climate and natural resources. To enhance the grain production, more efforts should be put on cultivating the good seed, improving the efficiency of soil water usage, popularizing the technology of reconstruction of low and medium production farms, and strengthening the farm infrastructure.