Abstract:Modelled tests on a key dam show that, under nappe flow over three different slopes on a stepped over-flow structure,unit energy in the flow cross section before the hy draulic jump increases with increasing slope,and H_dam/y_c similarly increases.As H_dam/y_c approaches a certain value, the rate of increase in the unit energy in the flow cross section slows.The pressure y_pat the bot tom of the cross section before the hydraulic jump in stilling basins demonstrates a posi tive linear correlation with critical water depth y_c to the water crest,with the number N of the steps not affecting y_p.Comparison of energy dissipation ratios at λ>1 and λ=1 (λ is the correction factor for pressure at the cross section before a hydraulic jump)reveals that the relative error amounts to about 7 %w hen H_dam/y_c=10, with this error decreasing to 1 %when H_dam/y_c ≥70.Experimental results also show that λ has a very strong linear correlation with y_p/y1(r =0.9999).

Abstract:The land use change graph from 1982 to 2003 of Xiaojiang watershed in typical karst region was analyzed by GIS based on 2 times spatial data.The results showed: (1) the cultivated land increased was the most important changes, which was transformed from unused land. 610. 12 km² land use had been changed, of which 268.5 km² or 44. 01% of the total was changed into cultivated land during the past 20 years in Xiaojiang watershed.(2) The annual change rate of regional land use was 2. 95%, while the annual change rate of cultivated land, unused land and forest land were 10. 55%, 4. 08% and 5. 95%, respectively.(3) The spatial pattern of land use in Xiao jiang watershed changed from composed of large and scatter patches mosaic to compose of middling and scatter patches mosaic,and the types of dominating patch have also been changed, which changed from unused land and forestland patch to cultivated land and forest land patch. (4) When the spatial pattern of land use in Xiaojiang watershed was analyzed quantitatively by introducing the diversity index,dominance index, homogeneity index and broken index,a clear picture of the interference degree caused by human activities can be made. As the increasing of disturbances from human, the diversity index,the homogeneity index and the broken index all increase,especially the broken index increased by 84.6%.(5) By analyzing of the change of the land use gravity center, the change of land use spat ial pat tern was very obvious during the past 20 years in Xiaojiang watershed.The land use gravity center has changed in different speed. Finally, analyzed quantitatively by introducing society and economy data, it was clarified that the rapid growth of population and the economic development for survival were the main driving forces of land use change in Xiaojiang watershed during the past 20 years. Furthermore,macro-policies such as ecological protection were also important human driving forces of land use change.

Abstract:Based on comparative analysis on spatial temporal distribution characteristics of soil nutrients of typical dam land in Beigou small watershed of Yan. an City. The results showed that imbalance of soil nutrients was very serious in experimental area, and most soil nut rients were very poor, especially, soil organic matter, total Pand available P, but total K and available K were rich. The insignificant spatial and temporal differences in the soil organic matter, total N and total P were found, yet available nutrients were high-low-high from upper to lower and spatial temporal differences were significant on profile.In the light of these results, the theoretical evidences for balancing fertility of dam land are put forward.

Abstract:The spatial distributed characteristics of soil erosion on straight hillslopes before and after erosive rainfall are studied with ⁷Be trace method and field investigation. The results showed that within 20 m of slope length,⁷Be inventory at 0～2 cm deepth of soil profile in different sloping locations was not significant before occurrence of erosive rainfall,but after occurrence of erosive rainfall in 2004, ⁷Be inventory in different sloping locations was great significant.⁷Be inventory at 0～2 cm deep after occurrence of erosive rainfall and difference values of ⁷Be inventory before and after erosive rainfall occurrence decreased as slope length increased with 20m slope length. This indicated that soil erosion increased generally as the increase of slope length. There are great differences in detachmentor deposition process at different sloping locations. At 0～5 m slope length of the upper slope,deposition process was dominant; but at 8～15 m of slope length, detachment was dominant, where soil erosion was very severe.

Abstract:Water storage pitirrigation method is a new method suitable for orchard irrigation in gully area in the North China. Water infiltration is under varying-head condition. Considering the study lateral horizontal inf iltration of water storage pit,the experiments of infiltration in different heads were studied by horizontal column. The results are shown that infiltration head has significant effect on infiltrate coefficient,and has smaller effect on infiltration index,and the infiltration coefficients and inf iltration indexes both vary alternately between relative-stable and obvious variation as infiltration head increasing.The research result swill have an important value for studying further vary ing-head infiltration and soil moisture characteristic of water storage pitirrigation.

Abstract:Soil nutrients of different land using in gully region of the Loess Plateau is analyzed. The contents of nutrients,such as organic matter,P and N,were low.The content of N was very poor.The contents of K were higher than others.By comparing the nutrients,it is found that the contents of soil nutrient in forest-grass land were higher than in orchard land and agriculture land.

Abstract:The system of rainwater harvest ing for affovestation(SRHA) are analyzed based on soil water resources.The system focused on rainwater harvesting and improvement of rainwater use efficiently.Model of SRHA was established using water balance equation of the planted area to solve water shortage for afforestation in the arid and sem+iarid regions. Taking Tamarix ramosissima as an example, we explored main problems in the SRHA. The model has a reliable theoretical base and provides guidance for affroestat ion in the arid and sem+iarid regions.

Abstract:The phenomenon of rocky desertification presents a serious obstacle to rural economic development.Control of rocky desertification is drawing increasing academic attention and is an increasing urgent problem for local government.This study focused on the appropriate st ructure and species diversity of artificial vegetation in rocky desertification areas,established as a means of control. It was concluded that artificial vegetation with a spatial structure and species disposition dominated by pricklyash peel is suitable for desertification control,and that this assemblage has an advantageous community structure, which develops uniformly and with ecological dominance,which increases with latitude and as the rocky desertification process identities. It is proposed that rocky desertification areas can be managed, with ecological and economic benefits,with the establishment and management if such well st ructured artificial vegetation.

Abstract:Loess is a typically structured soil.The study on loess soil structure is an important aspect of soil structureresearch,contributing to the broader understanding of soil structural properties. This paper draws on primary data collected from confined compression tests of unsaturated loess, including intact loess and anthropogenic modified loess, and discusses the key influences on changes in the st ructural properties of unsaturated loess. Research results indicate that increasing vertical pressure, increasing water content and increasing soil density promote gradual structural weakening of unsaturated loess; and the structural integrity of the loess is reinforced in some instances by the increasing of cementing agents. Other important findings are that the key influences on loess structure are not uniform across loess regions, and that achievement of higher loess structural integrity is difficult under very high and very low clay content.

Abstract:People are increasingly paying much attention to the serious effect of non-point sources pollution from livestock and poultry to water environment.The formation,damage to eco-environment and loading calculation of non-point sources pollution from livestock and poultry are discussed. The progress of non-point pollution and its control measures,some methods and critical problems have been brought forward about control of livestock and poultry pollution,focusing on three parts:regional proper layout,best management practice (BMP) and ecological engineering technology.

Abstract:Levee building,river pollution control and water landscape development have become dominant management techniques for urban rivers. This research assessed environmental control engineering on the Weihe River in Baoji City. It is argued that the implementation of this engineering not only guarantees the safety of flood-prevention, but also optimizes the utility of the river’s resources, raises Baoji City’s status, increases it s green character,develops the water landscape, beautifies environment and encourages further investment in the environment.These outcomes notably improve socio-economic performance and the urban ecological environment.This creates a good foundation for the sustainable development of the city.

Abstract:In order to analy se the deg ree of the sustainable development of the ecological construction, we choose some suitable indice and set up the index system.Then use the gray relational method to analyze the index system and calculate the gray relational grade and the gray relational coefficient.In accordance w ith the results,the standard and the t rend of the sustainable development have been measured.The sustainable development of the ecological region has been given the quantitative and the qualitative basis.With the suggestion brought forward,the goal of the sustainable development should be smoothly achieved.

Abstract:An analysis has been undertaken to develop basic rules for the establishment of an index system to assist the evaluation of the environmental and economic capability of land resources on the Loess Plateau. The result of the analysis is a general framework for such an index system including four assessment layers and three ecological,economic and social indicators. The general framework prov ides a basis for the further development of a dependable,science-based evaluation method.

Abstract:Soil and water conservation is an important ecological service of forest systems.To determine the effectiveness of forests in soil and water conservation,the loss modulus of soil and water is often employed.However,this is an imperfect concept.The authors advanced a new theory for the assessment of soil and water conservation,specifically presented an analysis of not only soil loss rate and water loss rate,but also soil and water loss rate.

Abstract:Several new-style soil consolidator are int roduced according to the loess properties of Guanzhong area in Shaanxi Province.The capacities of the soils mixed with stabilizers were tested,including compaction,unconfined compression strength,seepage and frozen-thawing.The results indicated that their optimal water content decreased;maximum dry density increased;and the compression characteristics had significant effects after the soils were mixed with soil consolidators;the intensities of the soils inundated in water,after 28 days, were separated from 0～3.37 MPa;the seepage modulus is between 8.59×10^-6～1. 81×10^-7cm/s;and the frozen-thawing times were also different,the ultimate up to 20 times.In short, when stabilized soil is directly used as channel face seepage cont rol material,its endurance is worse than concrete, but it is possible to be used as secondary grade seepage control of canal.

Abstract:It is very significant of land use coordinated development degree evaluation to instruct land resource use.As an example, Quzhou county of Hebei province,the indices system and the model of evaluat ion of coordinated development degree of land use was established according to the level of society-economy development and the quality of environment.Then the degree of coordinated development deg ree of land use in Quzhou County was evaluated integrativly.The result of this research indicated that it is of the type of intermediate coordinated development and economy-lagged,and the level of society-economy development is in perfect harmony with the quality of environment of land use in Quzhou County.But the level of land use integrative benefit is low,society-economy benefit is lagged appreciably, compared with environment benefit.Then according to the Kuznet scurve in economics,the land use mode choice is analyzed.The result indicated that the NSFYPW track mode of land use in Quzhou County should be chosen.

Abstract:Drought can severely reduce agricultural productivity.Since the risk of drought is likely to intensify with projected global warming and increases in evaporation potential, it is critical to identify methods for minimizing the manifestat ion of drought condit ions and reducing agriculture's vulnerability to drought.The vulnerability of landbased product ion systems to natural disasters is a funct ion of the systems underlying ecological integrity. Therefore,ecological improvement and reconstruction may reduce agriculture?svulnerability to drought.Hengyang,an important agricultural area in China,experiences severe drought from time to time.This study demonst rates the close correlat ion between agricultural losses in the area during drought and certain environmental and social factors,under particular space-time considerations.Factors cont ributing to agricultural vulnerability,such as local weather conditions, vegetation and soil conditions, irrigation works and the level of economic development were analyzed in detail.The vulnerability of agriculture to drought in the area is assessed based on a long time series of meteorological data and economic stat istical data, and by the use of a mathematical model and a correlation optimization method. The results of this assessment are used to determine optimal methods for ecological improvement and reconstruction to reduce agriculture svulnerability to drought.

Abstract:The recently man-land relationship in the Three Gorges Reservoir Area are analysed.It is evident that land lessening,water and soil erosion,the decline of the natural forests,natural casualty, environment pollution are the main causes for incoordinand man-land relationship.Therefore more attention is being paid to finding the means to adapt to the unfolding gradually impacts of human activities.The resumption and rebuilding of eco-environment;the conversion of agricultural methods of production;the renovation administ rant system should be taken as the main countermeasures to the sustainable development in the Three Gorges Reservoir Area.

Abstract:The area near Ebinur lake has become one of the deteriorating area in the Western China.The evolution of ecosystem services value was researched in the past 20 years in this area and the causes also were discussed.According to the ecological character of the research area,the research in China,and the research of Costanza were combined to build the estimating mode. Based on the multi-temporal remotely sensed data of TM, Geographical Information System(GIS),and the estimating mode, the value of ecosystem services were estimated in Bole-Jinghe oasis of Ebinur basin. The total value of the research area is: 85209.14×10⁴$in 1979, 77147.02×1010⁴$in 1991 and 81291.66×1010⁴$in 1999. The trend of evolution of the value of ecosystem services was that 1991 was the round turning point year, and the value was decreasing f rom 1979 to 1991 and st raightening up f rom 1991 to 1999,showing just a sunken curve.

Abstract:The present conditions,causes of sedimentation and impacts of sedimentation on the ecological functioning of a wetland in Xianhai town have been studied.Results indicates that human over utilization and poor management are the key causes of the sedimentation of the wet land.The ecological functioning of the wetland, for instance, in flood control, water purification, and habitat provision for waterfow land other birds, have been seriously affected.Management strategies and measures for wetland restoration and sustainable wetland and water resource use are put forward, with their primary aim being the control of sedimentation.

Abstract:Data on precipitation,soil,terrain,vegetation and management activities in the groundwater supply district of Ji' nan City were collected and treated in a geog raphical information system(GIS)to produce distribution grid maps of R,K,SL,C and P.These attribute maps were overlain and computations were undertaken using USLE.The results were used to produce a soil and water loss intensity map.From this map the present status of soil and water loss in the district was determined and the reasons for these conditions were assessed.The study area was then classed into three separate categories, namely urban area,three-valley area, Shahe area and corresponding soil and water loss management measures were determined.

Abstract:The concept of the"Ecological Footprint"(EF) is used to quantify the ecological sustainability of human development.It permitsest imation of the pressure and impact of human activities on ecosystems. The EF can be applied to urban ecological studies, to determine the impacts of concent rated human set tlement. This study calculated the EF of Xi'an in 2001 and compared the result with the EF of a few other countries and regions. The EF of the Xi'an area was estimated at 1.0 ha per person. The ecological carrying capacity of the Xi'an area is calculated to be 0. 13 ha per person. Therefore, the EF of the Xi'an area is 7. 9 times the area's ecological carry ing capacity.The EF of Xi'an City is 1.3 ha per person, which is 9.75 times more than the city's ecological carrying capacity.The EF of Xi'an City is slightly higher than the average EF of China, but it is lower than that of some other countries and regions.The results support an argument that EF increases with higher levels of development. The results similarly support an argument that Xi'an is relat ively underdeveloped. The need for further economic development should be balanced with improved ecological conditions and reduced development impact in order to ensure the sustainability of Xi'an city and region.

Abstract:Urbanization processes are having a profound effect on the character of large cities in China. Whilst playing an important role in economic development, urbanization also has deleterious effects on the ecology of the city environment.The present population and industrial settlement characteristics giving rise to the urbanizat ion of Xi'an City are analysed. The impacts of urbanizat ion on Xi'an's ecology are assessed, and possible countermeasures to be taken in urban planning and management are proposed for the purpose of urban env ironmental protection.

Abstract:This research considered st rategic tourism planning in four states in Xinjiang Wei Autonomous Region in order to examine the dialectical relat ion of tourism development and environmental protection in a fragile ecosystem.The environmental impacts of tourism development are analysed, and then the management actions is considered of focusing particularly on impact mitigation through project planning, construction and maintenance.The study can of fer support and means for promoting the sustainable development of the tourist industry in fragile ecosystems in western China.

Abstract:There are abundant coal resources in Maowusu sandy land. With the growing advancement of the resources exploitation,the ground collapsed and the level of underground water droped,the gangue occupied lots of land.This made large mineral area vegetation degenerated and mineral ecological environment deteriorated. According to this situation,countermeasures to protect vegetation and environment in coal mine area were proposed.