Abstract:Water contents of sandy soil and loess in Jingbian County, Shaanxi Province are studied through the field investigations and measurements. Experimental results show that water content of sandy soil is less than 3% and water content of loess under poplar trees, about 7%. Severe dried layer occurs in sandy soil and moderate dried layer under poplar trees, in loess. All the dried layers are above 6m in depth. The degree and depth of dried layer indicate that natural arid climate is a dominant factor causing dried layers in the area, with the tree species being an important factor. During ecological and environmental construction, different types of vegetation should be recovered in view of the different levels of dried layer development. Grass and bush should be planted in the sandy soil area and grass and drought tolerant bush with trees should be plan-ted in the loess soil area. Where dried layers develop severely, afforestation is unsuitable because it can not bring environmental and economical benefits, but can cause excessive consumption of deep soil moisture and underground water.

Abstract:Tuanshangou unit watershed was selected to be the sediment yield source. The ratio of transported sediment modulus from a medium or small watershed to erosion modulus of the unit watershed was defined as sediment delivery ratio. Temporal and spatial variations of sediment delivery ratio from a single rainstorm and integrated effects of rainfall hydrological factors and topography factors were studied systematically. Re-sults showed that from a long-term perspective, soil erosion and sediment yield of watersheds may reach a balance, but from a single rainstorm or one year perspective, watersheds were characterized by alternative deposition,erosion and transportation of sediment. Rainfall, runoff coefficient, rainfall duration and average sediment content in runoff can well express sediment delivery ratio for a single rainstorm in Chabagou water-shed. After topographic factors were incorporated, an integrated expression of rainfall hydrological factors and topographic factors was founded for sediment delivery ratio from a single rainstorm in Chabagou water-shed.

Abstract:During desertification processes, change of plant community is closely related to spatial variation of soil nutrients. This research, conducted in a degraded hilly rangeland in the Ordos Plateau, aims to investi-gate spatial variation of soil nutrients for Stipa bungeana and Cynanchum komarovii communities at small scale using geostatistics methods. Results show that in spite of absence of shrub encroachment, fertile islands are distributed in two typical communities.Their development is not resulted from shrub encroach-ment, but from accelerated soil erosion due to vegetation damage. Hence, shrub encroachment cannot be considered as an assessment indicator of rangeland degradation. Multiple variable indicator Kriging method is also proved to be an alterative for integrated evaluation of soil nutrients.

Abstract:Nutrients and particle size composition in surface sediments in the Guangzhou section of the Pearl River were measured. Granularity effect and distribution characteristics of nutrients were studied.Results showed that all of the nutrients appeared the distribution characteristics of "low-high-low" on longitudinal distribution in trunk stream on whole. There were significant positive correlations among organic matter, to-tal nitrogen,and total phosphorus.Total nitrogen was highly linearly correlated with organic matter,with regression coefficient reaching 0.950. Nutrients were significantly negatively correlated with sand fraction and positively correlated with powder sand fraction. However, nutrients were not significantly correlated with clay fraction.The correlations between nutrients and particle size composition would enrich the content of granularity effect of pollutants in sediment.

Abstract:A Pinus tabulaeformis plantation in western Miyun Reservoir of Beijing city was observed and ana-lyzed to study canopy interception, throughfall,and stemflow.Results showed that the relationship between the amounts of canopy interception and precipitation was the power function, but the relationship among throughfall, stemflow and precipitation displayed a linear correlation.Contributions of canopy interception, throughfall, and stemflow to total flux of rainfall were 7.23%～87.39%,12.56%～91.58% and 0.007%～1.77%, respectively. The differences of environmental aspect,meteorological condition,and characteristics of rainfall were a major factor which caused the discrepancy of atmospheric precipitation chemistry in the same area.When the precipitation passed through the canopy, the content of chemical elements in through-fall and stemflow increased in comparision with that of the precipitation.There was a positive correlation be-tween the individual element content in throughfall and the interval of precipitation, but a negative correla-tion with rainfall intensity and its amount. The correlation between the phosphorus and potassium contents in stemflow and characteristics of precipitation was the same as throughfall except for nitrogen element.

Abstract:By taking Xiaobazi town in Fengning Man Nationality Autonomous County of Hebei Province as a case study area, data of weather and socio-economic development in the past 50 years were collected and ana-lyzed. The results such as the change, period and leading trend of temperature, rainfall, evaporation and wind were presented. Meanwhile, intensity, situation and trend of human disturbance were recognized. The inner relations and impactions among climaate change, human disturbance, and land desertification were ana-lyzed and discussed in association with the process of land desertification in the past 30 years.

Abstract:Based on soil moisture data from September 2004 to April 2005, the dynamic change of soil mois- ture and the influence from a typical rainfall were analyzed under three types of landuse (cropland, grassland and black fallow) in the peak-cluster depression areas of karst region in Southwest Guangxi Province. Re-sults showed that soil moisture in surface layer (0-20cm) was the lowest, but fluctuated violently in all lay-ers. Down to deeper layers, soil moisture increased and became steady. Surface soil moisture of grassland was lower than that of cropland for the absorption and transpiration of grass.Soil moisture was obviously in-fluenced by typical rainfall, but the time responses for three types of landuse were different. Surface soil moisture increased obviously in cropland and grassland one day after rainfall,whereas bottom soil moisture reached the peak value 6～8 days after rainfall.Soil moisture of the 0-30 cm layer in black fallow reached the maximum 3 days after rainfall. The time stability of soil moisture in grassland was the worst.Precipitati- on, land use types (vegetation),and soil texture were the main factors influencing soil moisture in the area.

Abstract:This paper takes Taihu Basin as a study area since it has highly intensive land use and is subject to rapid urbanization. Historical landuse scenarios in 1985 and 2000 are analyzed to track landuse changes by in-terpreting TM/ETM images. The L-THIA (Long-Term Hydrologic Impact Assessment) model is applied to estimate hydrological effects of landuse changes from 1985 to 2000, based on daily precipitation records span-ning 30 years (1971-2000). Results show that the main trend of landuse change is the urban expansion in the basin,which results in an increase of runoff volume of 1.14×10⁸m³, about 2.9% of the runoff volume from entire basin. Hydrological response varies with the extent of landuse changes in different parts of the basin. In Su-Xi-Chang and Pudong-Puxi sub-regions,with larger extent of landuse changes, the landuse changes result in runoff volume increases of 6.01% and 3.91%, respectively. In Hu-Su-Xi-Chang city zone, with intensive urbanization, the urban area expands as much as about 635.2 km² and the runoff volume increases by 6.5%.Based on runoff simulation and hydrological risk evaluation, the low, middle, and high risk areas are identified, which account for 37.5%,50.0% and 12.5%, respectively.

Abstract:In recent years, many middle/small cities grow up rapidly, which greatly spurs the economy devel-opment in Southeast China. However, the deterioration of environment it causes has had obvious impacts on the economy to continue to grow, and a threat to survival surrounding of people in the area.Therefore, the TIN pollution load in the Xikou basin of Southeast China is estimated using the L-THIA (Long-term Hydro- logical Impact Analysis) model and integrated GIS technique. The spatial distribution of the TIN pollution load is simulated and displayed. The result is visualized so that the simulating is easier to understand and is more helpful in the prevention of pollution and making control measures for the basin.

Abstract:This study aims to reveal the spatial distribution of water resources and meet the various demands for geological survey, geological disaster prediction, facility agriculture,and constructions of industrial and agricultural bases, as well as the development and utilization of precipitation resources.Twenty-four spatial distribution models of water resources in Hulun Buir City are constructed by using GIS techniques and Pu Baofu theory on climate resource simulation. Water resources in the city are manipulated in a number of "3×3" mini grids.Thirty-four out of the 41 models pass the very significant test, and 7, the significant test. The average relative errors of tests for the models are between-5% and 5%. In this way, the rapid and accurate calculation of water resources has been accomplished.Accordingly, the spatial distribution of water resources is analyzed. The study lays a scientific foundation for the sufficient and rational use of water resources in the region.

Abstract:The Xi he River demonstration district, as an ecological project of soil and water conservation in the Yellow River basin,is located in the third sub-area of hilly gully area on the Loess Plateau.Its topogra-phy is typical of numerous valleys and gullies, where gully erosion is one of the main erosion processes. Con-struction of check dam is an important engineering measure for gully management in the region. In practice, many regional experiences of check dam construction have been developed, such as small reservoir capacity with high dam, high standard against flood, huge invest, and single form of construction. In planning, some technical methods-single dam dominated,relaxing technical indexes moderately, arranging main projects reasonably, and increasing standard against flood moderately-have been popularly used. Check dam plays an important role in promoting social economic development in the area.

Abstract:Arable land gradation, a further step of the finished agricultural classification,has a great signifi-cance to the evaluation of arable land quantity and its quality, as well as the protection and utilization of land resources. High resolution QuickBird images are used and a novel strategy different from the traditional gra-dation of farmland is proposed by adopting high-pass filtering fusion method in spatial domain and geometric correction. Accordingly,object interpretation symbols and screen vectorization classification are established to make a real time land utilization map. The effect of large-scale mapping is improved and a map of arable land quality gradation is made at a scale of 1:2000.

Abstract:Slope length is an important topographic factor.There are various methods to extract the slope length factor of a watershed. Both of grid based direct calculation method and fast calculation method based on the ridge line have been used in practical research in China. Based on the DEM data of the Danangou wa-tershed in Shaanxi Province, this study attempts to make a comparison of precision for the two methods, and analyze the problems that may exist. Results show that direct calculation method has the eligible ratio of 86.9% and model efficiency of 0.520, whereas fast calculation method has the eligible ratio of 69.7% and model efficiency of-0.150. It can be seen that direct calculation method is superior to fast calculation method. This study can serve the further research work on slope length calculation and other related fields.

Abstract:Based on the analysis of eroded red soil deterioration processes, research on evaluation index sys-tem of red soil deterioration is carried out. Influenced mainly by time and biological factors, soil fertility has been restored gradually with the reclamation of eroded soil. The process of soil restoration can be promoted with much longer time and forest plantation. Correlation and factorial analyses are used to reduce the iterated information and simplify soil indexes. Six indexes are selected to indicate more than 90 percent information of all 16 soil indexes, and thus soil fertility status can be expressed by fewer indexes.

Abstract:Based on meteorological data from 11 weather stations during 1970-2000 and data of soil moisture from 5 agro-meteorological observation stations during 1981-2000, the frequency of heavy rain and storm and the variations of soil water content and potential soil water content were analyzed. The index used to as-sess possibility of debris flow had been created. Results showed that under heavy rain, the possibility of deb-ris flow in Xihan River valley is greater than that in Bailong River valley, while under rainstorm, the possi-bility of debris in Bailong River valley is greater than that in Xihan River valley.

Abstract:This study determined infiltration into soils on black farmland under different tillage systems by long-term experiment. The moldboard plough and rotary tillage being representative of conventional tillage systems induced a lowest bulk density in ridge. Surface stable infiltration rates under moldboard plough and rotary tillage were 9.20 and 7.31 mm/min, respectively, which were higher than the others. Although no-tillage induced a higher bulk density in ridge and furrow, it had a relatively high stable infiltration rate. Re-duced tillage could significantly increase stable infiltration rate in furrow because it loosed the furrow in sum-mer. These indicate that no-tillage and reduced tillage are effective tillage systems of soil and water conserva-tion.

Abstract:Ten kinds of Panicum virgatum originated in USA were introduced on hill slope and valley plain in the Ansai research station from 1992 to 1998.The data observed for 7 years illustrate that Panicum virga-turn in 3 to 5 year growth fastigium stage particularly requires soil moisture and gives the highest yield. In view of the change in soil water content, Panicum virgatum helps form a dried layer between 80 and 200 cm from soil surface and it can not be compensated by rainfall in growing season, as well as rainfall and snow in leisure time.The problem is resulted from the maintenance for a higher productivity.Panicum virgatum has a strong adaptability in semi-arid hilly and gully region of the Loess Plateau, which is of importance to artifi-cial grassland construction and natural grassland improvement.Through comparing the productivity of Pani-cum virgatum cultivated in the region with the characteristics of soil moisture, the effects of Panicum virga-tum's eco-adaptability on its aboveground biomass formation may be understood.The results offer a scientific basis and an important reference to rational utilization of local herb resources and improvement of grassland productivity.

Abstract:This study is based on the differences in development stage features of resource-based cities and their natural resources.Incorporated with currently existed sustainable development index system, a new sustainable development index system with dynamic, personality and common unified is reinvented for the cities.Some practical evaluation methods are then discussed.Accordingly, the effectiveness of sustainable development and transition of the cities is evaluated.

Abstract:In order to improve inversion accuracy for soil moisture and enhance the research on quantitative soil moisture, a method combining finite element with Genetic Algorithms is proposed. Affected by precipita-tion, irrigation, wind speed, and so on, there exist complex material and energy exchanges on the interface of atmosphere and soil, which lead to very complex boundary conditions of coupled moisture and heat flow equation. Then, Genetic Algorithms are applied to calculating the boundary conditions of the equation. Sur-face initial condition of the equation is obtained by remote sensing technique. Finally, the finite element method is applied to solving the equation. Thus, monitoring of soil moisture is fulfilled. The tested results show that the method is feasible and satisfactory by comparing with observed data of soil temperature and soil moisture.

Abstract:The circular slice method is one of the normal methods for analyzing slope stability, which assumes that the stabilities of individual slices are equal and equaled to that of whole slope and belongs to an imprecise limit equilibrium method of rigid body with some irrationality. In this study, a simple slope was used as a model to study the features of force transferring between individual slices,discipline of slippage and compati-bility condition of acceleration with improved slice method when the slope is in destabilization and the stabili-ties of individual slices are not equal. A theoretical formula for calculating interaction forces and the stable coefficient of individual slices under instable states was then deduced. The calculation of practical sample demonstrates that this method can be used to analyze accurately the stability of whole slope,as well as to re-veal the stable circumstance of part slices within a slope. It maybe possesses some important referential val-ues for practical construction.

Abstract:To dynamically monitor soil and water conservation in H ubei Province, the three factors of vegeta-tion, slope, and landuse are incorporated in the fast estimation of soil erosion using MODIS images and other investigated information. First, a vegetation coverage map is extracted from MODIS images. Second, a land-use distribution map is obtained from TM images. Third, a slope map is created from DEM. Finally, based on the standards of soil erosion grading, a soil erosion distribution map is obtained by overlaying the maps of landuse distribution, vegetation coverage, and slope. Based on geographic information system(GIS), the de-gree and distribution of soil erosion in Hubei Province are quantitatively analyzed using MODIS images in 2004 and 2005 and the change of soil erosion from 2004 to 2005 is analyzed.

Abstract:The medium-and-long-term prediction of precipitation is not only difficult in meteorology,but also an important issue in hydrology. The logarithmic Markov chain model is established to predict precipitation, which can compensate the uncertainty of peak point in precipitation prediction by the traditional Markov mod-el and raise the prediction accuracy. At last,precipitation data of 43 years from the hydrological station in Yanchi County are used to verify the model,and prediction accuracy is found to be satisfied. So,the loga-rithmic Markov chain can provide an oversimplified channel to the medium-and-long-term precipitation predic-tion in the semi-arid sandy region.

Abstract:Stream network structure in Xunhe watershed is simulated using GIS methods for the buffering area construction. NDVI in 1997 and 2004 is calculated to examine its relationship with stream order. Results indicate that stream network in mountain area can be well simulated,stream order and NDVI are closely re-lated,and the NDVI in 2004 is higher than in 1997. These suggest that the eco-environment in Xunbe water-shed has been improvement in recent years.

Abstract:By means of the field investigation combined with site survey and the soil and water conservation plan for the Yingmaili Gas Fields project, the paper comprehensively evaluates precaution and protection of soil and water loss, engineering and vegetation measures, land reclamation measures, implementation of in-vestment funds, and supervising and monitoring of soil and water loss. Some proposals concerning the prob-lems with soil and water conservation measures such as lower quality and lagging behind the principal part of project are put forward. It is very important to enhance environment protection and carry out the soil and water conservation system in the manner of the simultaneous design, construction, and operation.

Abstract:As the industrialization and urbanization of China are accelerated in recent years, soil and water loss resulted from development and construction projects has become a severe problem and aroused common concern of the whole society.The projects not only have some inherent connections with soil and water loss, but also possess their own particularities.This paper summaries and analyzes the situation and trend of soil and water loss resulted from the projects, reveals their nine characteristics, analyzes their formation, and provides the theory and basis for us to further take precautions against the loss.

Abstract:In resent years, the development and construction projects have been initiated everywhere, and the soil and water loss has been aggravated with the rapid development of national economy. However, there are some weaknesses in implementing the projects, such as monitoring, supervision, and acceptance of soil and water conservation. The technical assessment route of soil and water conservation facilities should be devel-oped immediately. Present works concerning the technical assessment should be focused on examining dis-turbed lands, checking cinder pits, dump and service roads, following the principle of planting trees and grass suitable to local conditions, assessing systematically soil and water conservation facilities, and so on.

Abstract:Supported by the RegionManager software, the land utilization condition before and after compre-hensive management in the Jianshanhe small watershed is investigated, and its land quality is assessed using the comprehensive index method and AHP. The result from the investigation shows that the areas of forest-land, shrub land,fruit land, and terrace land are increased by 423.5, 299.9, 17.6 and 32.0 hm², respective-ly. The areas of new open forestland,sloping farmland, and bare land are decreased by 487.4, 164.3 and 164.5 hm², respectively. Conservation land and economic forest land are two new land types. Irrigated land, water-land,unutilized land and difficultly utilized land are balanced.The result of assessment indicates that the 3rd and 4th grade lands account for 67.20% of the whole area before restoration, while the 2nd and 3rd grade lands account for 71.37% of the whole area after comprehensive management. In one word, the land quality rises one grade, and gets a remarkable effect after management.

Abstract:According to present conditions and characteristics of regional fragile eco-environment and analyses of the factors influencing fragile eco-environment, a quantitative assessment index system for Gansu Province is set up and the weighting value of each index is confirmed.By calculating fragile degree of eco-environ-ment, the major problems and causes in different fragile eco-environment regions are analyzed to provide a scientific gist for protection of eco-environment.The study is helpful to the sustainable development of socie-ty and economy in Gansu Province.

Abstract:The study of comprehensive treatment of shelterbelt system and its benefit evaluation in Yulin sandy area has been accomplished by using the analytic hierarchy process (AHP).The characteristics of the shelterbelt and its management status, as well as the social economic situation in the area were investigated. Twenty indexes in the 3 categories of ecology, economy, and situation were selected.The result indicated that ecological benefits, economic benefits and the comprehensive benefit were improved significantly from (bad) grade in 1995 to better grade in 2005, but social benefits were kept in general grade.Ecological bene-fits were improved from had grade in 1995 to better grade in 2005. Economic benefits were improved signifi-cantly from bad grade in 1995 to best grade in 2005. However, social benefits in 2005 were kept nearly in the same stage as in 1995. So environment construction is still a primary mission of economic construction and social development in Yulin sandy area.

Abstract:Soil and water resources are the natural conditions on which the human rely for existence, and also important elements of eco-environment. Soil and water loss can directly result in soil and water resources de-stroyed and make the local eco-environment deteriorated. In order to control soil and water loss efficiently, a full investigation on the current conditions of soil and water loss and their control were conducted in Luo-chuan County, Shaanxi Province. Some suggestions on further control of soil and water loss in the county were put forward based on the combination of the investigation and the author's experiences of many years.

Abstract:Based on the data of temperature and precipitation at 54 meteorological stations in Shaanxi Province from 1961 to 2004, and the calculation for accumulated temperature during winter, influences of thermal and water resources on winter wheat were analyzed. Results indicated that seasonal and annual mean tempera-tures changed obviously in the mid 1980s, decreasing before the mid 1980s, increasing after the mid 1980s, and increasing rapidly after 1990s. Precipitation showed a reducing tendency. Thermal resource increased and the planting area of winter wheat expanded northward after 1980s. Serious drought and water shortage ap-peared in 1990s. The negative impact of climate change on winter wheat was greater than the positive.

Abstract:Xi'an is the city where is extremely short of water resource. Water resource supply is insufficient to meet the various demands. In order to improve the states of water supply, utilization of reprocessed water is an effective approach. On the basis of the study on the current situation of water resources, sewage and re-processed water used in Xi'an City, the authors put forward some reasonable proposals and measures for the problems faced in the utilization of reprocessed water resources. The problems that must be solved include the capital, prices, and market, as well as how to play the government's policy orientation, macro-control, and so on.

Abstract:Based on the definition of the connotation of ecological footprint (EF) and the overview of its back-ground and recent research advances,principle framework and computation method of the EF model are clari-fied. Then, the EF for Shaanxi Province in 2004 is calculated and analyzed by taking the province and its ten urban districts for example. Results indicate that the EF for Shaanxi Province is 2.60 hm²/cap, and the eco-logical deficit is 1.85 hm²/cap.This means that the EF's demand from human activities has already exceeded the carrying capacity of the regional ecological system and the present developing model is not sustainable.In terms of the average EF's demand per person in Shaanxi Province, the demand for farmland is the biggest and the demand for fossil energy use and grassland follows. The people's life consumption is dominated by staple food grain; the energy use, by coal; the biological resource use, by agricultural products. For the bal-ance between EF supply and its demand, the average EFs per person in Xi'an,Xianyang, Yulin, and Baoji are bigger than the whole province (2.60 hm²/cap), whereas the average EFs per person in Wei'nan,An-kang, Shangluo, and Yangling are smaller than the whole province. Accordingly, it is suggested that signifi-cant efforts should be made for the region to develop economy, positively improve ecological environment, and achieve sustainable development.

Abstract:This study is based on the investigations of basic geographical types, status and characteristics of land resources, situation of soil and water conservation in Shangluo mountain area, Shaanxi Province. The characteristics of growing environment, medicine uses parts, soil requirements, and land utilization allocation for 12 kinds of medical plants that are important to the development of Shangluo mountain area are prelimina-rily studied by the requirements for proper use of land resources and better eco-environmental management.

Abstract:Soil phosphorus as agricultural non-point source pollution is one of the main factors which lead to water pollution. By analyzing the status of soil phosphorus in Guangdong Province, we discovered that risk and quantity of soil phosphorus loss increase rapidly and it severely pollutes the aquatic environment. So we should adopt some control measures to reduce the environment pollution resulted from soil phosphorus loss.

Abstract:The concept and establishing principle of eco-agriculture with soil and water conservation have been briefly narrated. The eco-agriculture in Ansai County should be based on a great many works on soil and water conservation. During vegetation restoration, tree species and forest must match their sites, and local tree species should be selected as the major species. In order to attain grain self-sufficiency, construction of terrace and check dam should be strengthened, and minor crop production should be increased. Moreover, in order to develop the industries of commercial fruit, stockbreeding and facility vegetable, the orchard develop-ment and management, as well as stockhreeding development should be enhanced, and facility vegetable cul-tivation should be stabilized.

Abstract:The pollution of Tarim River may have negative effects on ecosystem stability and sustainable de-velopment in the area of the middle and lower reaches. Using the actual measured data from Longkou and Shi daqiao observation stations on Aksu River and the Alar and 14 Tuan observation stations on the main stream of Tarim River in 2001-2005, authors carry out a research on water quality assessment of Tarim River based on the statistic software STATISTICA, principal component factor analyses, and water pollutant synthesis index methods. The result shows that water quality of the Longkou and Xidaqiao observation stations be-longs to first degree(cleanness) water, and the water quality of Alar and 14 Tuan observation stations be-longs to fourth degree(middle pollution) and fifth degree(serious pollution ) water, respectively. The major pollutants in Tarim River are chlorides, total hardness, mineralization degree, sulphate, fluoride, etc.

Abstract:Eco-tourism has already become a new contest of tourism activity in Zhejiang Provimce. It deeply attracts tourists with the natural and primitive environments. Soil erosion is an important factor to attenuate the environments and eco-tourism resource quality. Therefore, soil and water conservation should be strengthened for the development of ecotourism. According to the different regional characteristics, the ways of soil and water conservation impact to eco-ourism in Zhejiang Province may fall into 4 categories of moun-tain and hill, river and lake, plain, and island. Different category has the different characteristic of soil ero-sion. The paper proposes some suggestions to strengthen soil and water conservation in Zhejiang Province.