Abstract:Artificial rainfall simulator is a very effective experimental device for studying the impacts of rainfall on infiltration,runoff,soil erosion,and sediment transport,because it can simulate natural rainfall without temporal and spatial limitations.A trough rainfall simulator was designed,which could simulate similar rainfall characteristics to those of natural rainfall.To provide a guide for users to make and use the apparatus,an experiment for calibrating simulator's rainfall intensity was conducted with single nozzle raining and multiple nozzles together at the height of 2.5 m.Results show that the rainfall intensity simulated by this simulator ranges from 11.3 to 132.5 mm/h.Single nozzle raining has a rectangular rainfall area of 5.4 m²,2 m width parallel to simulator and 2.7 m length perpendicular to simulator.Combined multiple nozzles are needed to generate a uniform rainfall intensity distribution.The combining experiment indicates that the optimal distance between two close nozzles is 1.1 m in the swing direction and 1.5~1.6 m in the perpendicular swing direction.The homogeneity coefficient of simulated rainfall intensity is more than 0.89.One trough rainfall simulator is composed of five nozzles and the distance between the two close nozzles is 1.1 m,which direction is called swing direction.According to the experimental area,users can choose the number of nozzles and simulators themselves and the suggested distance between two simulators is from 1.5 to 1.6 m.

Abstract:Runoff and its relationship with rainfall factors are impacted by factors such as vegetation and tillage.Understanding the impact is the base of soil and water conservation and erosion models.4 types of soil ad water conservation measures were investigated in 9 runoff plots, and rainfall was recorded synchronously.Runoff from different plots is compared and regression equations are constructed between runoff and precipitation, rainfall intensity, and rainfall duration, respectively.Results show that the 4 measures can reduce runoff significantly.Rainfall?runoff relationship is affected by the four measures in the same way, which increases the correlation level between runoff and precipitation and rainfall duration and decreases the correlation level between runoff and rainfall intensity with two exceptions.Contour cultivation increases correlation level between runoff and rainfall intensity, and ground cover and contour cultivation decrease the correlation level between runoff and rainfall duration.

Abstract:Based on the observation in runoff plots and gully cross-section in the field, the relationship between runoff and sediment yield for different soil and water conservation measures under different rainfall character conditions was studied.The effects of prophase rainfall and rainfall characters on runoff and sediment yield were analyzed.Soil and water conservation benefits of vegetation were discussed.Results showed that runoff and sediment from runoff plots with the application of prophase rainfall were greater under the conditions of the same rainfall and soil and water conservation measure.The larger the difference in the character of two rainfall events was, the larger the difference in the amount of runoff and sediment yield from runoff plots was.For the different measures, the benefit of level terrace was the highest; vegetation measure combined with appropriate engineering measure also obtained a good benefit of soil and water conservation.In the initial stage of vegetation enclosure, engineering measure must be used to improve the environment of ecological recovery.Gully head protection measure can well protect gully head and control gully erosion.

Abstract:Zhifanggou watershed of typical erosion environment was regarded as a study area and the soil samples of planting orchard and building terrace were viewed as the objects.The interchangeable space-time method was adopted and a slope cropland was selected as a contrast.Several indexes were analyzed such as TOC, LOC, NLOC, and the evolution characteristics of carbon management index in the period of ecological restoration.The study indicates that the content of soil carbon for each group of soil samples was increased drastically with the increase in the time of conservation by building terrace.The carbon index and the carbon management index were increased steadily.The increasing range of the carbon index tended to balance and the carbon management index was declined gradually.Apparently, the content of soil carbon for each group of soil samples is increased by planting orchard.Soil management has been improved and soil quality has developed in a sound way.Moreover, correlation analysis shows that soil fertility factors have intimate relations to TOC, LOC, NLOC, carbon index, and carbon management index.The five indexes may be regarded as the indexes reflecting the evolvement of soil quality in the period of ecological restoration.

Abstract:With the aid of the rainfall erosivity model using daily rainfall and geographic information system ( GIS) software , ArcGIS 9.0 ,daily rainfall data from 21 weather stations in Da’ ning River watershed and its adjacent area , the Three Gorges Reservoir Region , were used to analyze the temporal2spatial variations of rainfall erosivity(R factor) for the watershed.R factor varied consistently with watershed elevation.R factor decreased rapidly in the upper reaches of the watershed from Gaolou station to Wuxi station , trended towards gentleness in the middle reaches from Wuxi station to Dachang station , and increased gradually in the down reaches from Dachang station to Wushang station(watershed outlet) .There was a great variation in year-toyear R factor with the maximum being three times greater than the minimum.The distribution of rainfall erosivity was highly seasonal with a single peak.Summer months from May to early September typically contributed 90.4 % of the yearly R factor.July and early August were the peak months with more than 38 % of the yearly R factor.

Abstract:In order to understand the photosynthetic characteristics of Chinese seabuckthorn , Russian seabuckthorn , and Russian seabuckthorn× Chinese seabuckthorn , research on the 3 species and their influence factors were conducted with Portable LI26400 Photosynthesis System in the loess hilly and gully region of Northern Shaanxi Province.Results showed that diurnal courses of photosynthetic rates , stomatal conductance , intercellular CO₂ concentration , and transpiration rate of the 3 species were the doublepeak type curves.Midday depression of Chinese seabuckthorn was light , and diurnal photosynthetic rates and afternoon photosynthetic rates were significantly higher than Russian seabuckthorn and Russian seabuckthorn× Chinese seabuckthorn ( p < 0.01) .Stomatal conductance , intercellular CO₂ concentration , and transpiration rate in afternoon for Chinese seabuckthorn were significantly higher than Russian seabuckthorn and Russian seabuckthorn×Chinese seabuckthorn ( p < 0.01) .Optimum stomatal conductance , air CO₂ concentration , and air relative humidity for photosynthesis of Chinese seabuckthorn were lower than Russian seabuckthorn , and optimum intercellular CO₂ concentration , transpiration rate , air temperature , and photosynthetic active radiation were higher than Russian seabuckthorn.Under the conditions of optimum stomatal conductance , intercellular CO₂ concentration , transpiration rate , and air CO₂ concentration , photosynthetic rates of Chinese seabuckthorn were higher than Russian seabuckthorn.Under the conditions of optimum air temperature , air relative humidity , and photosynthetic active radiation , photosynthetic rates of Chinese seabuckthorn were lower than Russian seabuckthorn.Midday depression of Russian seabuckthorn×Chinese seabuckthorn was lower than Chinese seabuckthorn and higher than Russian seabuckthorn , and photosynthetic rates were similar to Russian seabuckthorn in afternoon.Optimums stomatal conductance and air CO₂ concentration for photosynthesis of Russian seabuckthorn× Chinese seabuckthorn were higher than Chinese seabuckthorn and Russian seabuckthorn ; its optimum intercellular CO₂ concentration was lower than Chinese seabuckthorn and Russian seabuckthorn ; and its optimum transpiration rate , air temperature , air relative humidity , and photosynthetic active radiation were between Chinese seabuckthorn and Russian seabuckthorn.Under the condition of optimum stomatal conductance , photosynthetic rates of Russian seabuckthorn× Chinese seabuckthorn were higher than Chinese seabuckthorn and Russian seabuckthorn.Under the condition of optimum intercellular CO₂ concentration , transpiration rate , air temperature , air CO₂ concentration , air relative humidity , and photosynthetic active radiation , photosynthetic rates of Russian seabuckthorn×Chinese seabuckthorn were lower than Chinese seabuckthorn and Russian seabuckthorn.Photosynthetic rates of the 3 species had significantly correlations with stomatal conductance , intercellular CO₂ concentration , transpiration rate , air temperature , air CO₂ concentration , air relative humidity , and photosynthetic active radiation in forenoon , and their relationships might be described by a parabola.

Abstract:Response of the eco-physiological characteristics to simulated photosynthetic radiation intensity in Stipa bungeana , A rtemisia sacrorum , Stipa grandis , A neurolepidium dasystachys leaves was investigated.Results showed that with increasing irradiation , Photosynthetic rate( Pn) was increased in lower density irradiation , but was reduced in higher density irradiation.transpiration rate( Tr) rate was enhanced with increasing irradiation.WUE for Stipa bungeana rose with increasing irradiation at first and then declined despite the intensified irradiation.WUE for Stipa grandis , A rtemisia sacrorum , and A neurolepidium dasystachys were enhanced with irradiation gradually.With growth midseason , Pn and WUE of the four species reached a maximum in July and a minimum in September , while Tr reached a maximum in August.The species ranked in the descendant order of A rtemisia sacrorum , Stipa grandis , A neurolepidium dasystachys , and Stipa bungeana in terms of the max Pn ; in the descendant order of Stipa bungeana , A neurolepidium dasystachys , Stipa grandis , and A rtemisia sacrorum in terms of Tr ; and in the descendant order of A rtemisia sacrorum , A neurolepidium dasystachys , Stipa grandis , and Stipa bungeana in terms of WUE.The chlorophyll fluorescence parameter indicated that the conversion efficiency of primary light energy under light ( Fv’/Fm’) of PSII , actual PSII efficiency (PhiPSII) , and PhiCO₂ declined in line with the CO₂ concentration , but the nonphotochemical quenching coefficient (NPQ) ascended.

Abstract:Ecological greening is an important way of highway greening.Community stability and species diversity are the two essential characteristics of highway ecological greening.By taking Populus tomentosa communities in the Shunyi section of Shunping Road (S305) , Beijing , as a research object and applying WinSCANOPY produced by Regent Instrument of Canada in taking photos , light environment over and under the canopy and community structure characteristic indexes , such as photosynthetic photon quanta flux density (PPFD) , gap fraction , leaf area index(LAI) , and mean leaf angle(MLA) , are analyzed by data analysis and field investigation.Results show that the gap fraction of Populus tomentosa communities decreases with the diameter at breast hight(DBH)increasing and MLA decreases with the DBH increasing.Although LAI fluctuates in some degree , it also presents an ascending tendency.The study provides a basic analysis and a reference for highway ecological greening to establish a stable plant species diversity and a multi-layer structure.

Abstract:Infiltration process in the typical soils in the upper and middle reaches of the Yangtze River where is suffering from severe soil erosion are systemically studied based on field experiments in 37 counties with double -ring method.Results show that the fitting precisions with Jiang Ding -sheng formula and Horton Equation are much higher than that with Philip and Kostiakov Equation.Steady -state infiltration rate decrea - ses with increased soil bulk density, but increases with increased total porosity, water stable aggregates, soil humus, and the ratio of silt to clay.Infiltration rates change significantly with soil type due to different soil characteristics.Steady - state infiltration rate varies regularly in different regions.This implies that changes in steady - state infiltration rates in Sichuan basin and Bijie region are the most rapid; in South Shaanxi, South Gansu, and the Danjiangkou Reservoir area, secondary; and in the lower reaches of Jinsha River and the red soil hilly region of South Jiangxi and East Hu.nan, the lowest.The regional differentiation matches with the major sediment source areas in the middle and upper reaches of the Yangtze River.

Abstract:The transpiration rates of Pinus sylvestris L.var.mongolica Litv., L arix gmelinii , Populussimonii×P.nigra , and Populus alba× P.berolinensis , the main tree species of farmland shelterbelts in the semi-arid region in the wesTheilongjiang Province of China , were studied by using the method of rapid weighting.Results showed that the monthly variations of the transpiration rates were different and the transpiration rate of Pinus sylvestris L.var.mongolica Litv.was the slowest.The monthly variation of the transpiration rate of Pinus sylvestris L.var.mongolica Litv.was the least and the transpiration rates of other structures showed a parabolic trend.The transpiration rate of farmland protection forest was seriously affected by atmospheric temperature and solar radiation in a variety of environmental factors in combination , and the transpiration rate showed the positive correlations with atmospheric temperature , solar radiation , and soil water content , but the negative correlations with relative humidity and wind speed.

Abstract:In the semiarid loess hilly and gully area of Southern Ningxia Hui Autonomous Region, the small watershed of Zhongzhuang in Pengyang County was chosen in view of the management effects of soil and water conservation.By using a light rainfall simulator and double-ring infiltrometers, infiltration rate was measured in the spots with different ecological restoration and reconstruction measures ( level trench, scale pit, level terraced field, artificial forage grass, and natural pasture) and different landforms ( slope aspect, slope position, and slope grade) in the whole watershed.Results show that infiltration rate presents the dis- tinct vertical variation along slope.With slope degree increasing, steady-state infiltrating rate increases.Steady-state infiltration rate on shady slope is higher than that on sunny slope, but its initial rate is smaller than that on sunny slope.The influence of slope position on steady-state infiltration rate is that steady-state infiltration rate is gradually increased from the upper slope down to the bottom slope.For different landuse manners, infiltration rates also have significant differences.

Abstract:In order to understand the dynamics of soil water-stable aggregates and the relationship with soil physico-chemical properties on abandoned arable land in the eroded hilly area of the Loess Plateau, 11 aban- doned arable lands with different ages of Robinia pseudoacacia in Zhifanggou watershed were selected for a systematical study through the approach of substituting the temporal serial with spatial serial.In addition, the correlation between soil water-stable aggregates and physico-chemical properties were examined.Results showed that the content of soil water-stable aggregates increased promptly in the early abandoned stage, in- creased slowly with the extension of the abandonment, and then kept a relatively stable content in the follow- ing years.The content increased by 253.45% in the first 10 year abandonment, but by only 16.42% in the following 40 years.> 0.25 mm aggregates were significantly correlated with soil organic carbon, total nitro-gen, available P, CaCO₃, and CEC, but not with total K and available K.It is necessary to close and manage hillsides, as well as keep soil organic carbon in a good balance in order to improve soil structure on abandoned arable land in the eroded hilly area of the Loess Plateau.

Abstract:The characteristics of forest floor in Liupan Mountain was studied.It was found that the herbage diversity in the forest of Larix principis- rupprechtii, Betula platyphylla, and Pinus tabulaef ormis was abundant.Due to the fleshy leaves of Quercus Liaotungensis forest, litter layer was rather loose after litter was decomposed, so that litter depth was the greatest and litter biomass was lower than that in Larix p rincipis- rupp rechtii forest.Furthermore, the leaf litter was the main configuration.Ratio of litter biomass to litter depth in undecomposed layer was greater than that in half?decomposed layer, while in September, the ratio in needle forest was the greatest.There was more complicated forest structure in Quercus Liaotungensis as litter can be supplied continuously but be decomposed rapidly.This supplied soil nutrients and at the same time, a looser litter layer formed in soil surface.The most evident change occurred in the litter of Quercus Liaotungensis forest.

Abstract:According to the located observation for the artificial Haloxylon ammodendron forest in Northwest Xinjiang Wei Autonomous Region , we analyzed its ecological value and economic functions.Results indicate that the air current resistance of forest belt to close stratum may increase 1.2～6.6 times.Moreover , the wider the belt , the more notable the effect.The 130 m wide forest belt can block and intercept about 95 % of drift-sand.The observation shows that the better width of forest belt is more than 130 m in order to make drift-sand to be blocked and intercepted effectively in the oasis periphery.The inner temperature of forest belt has the closer correlations with its width and plant coverage degree , so there is an important significance to improve its inner air humidity by keeping forest belt with a certain coverage degree and width.

Abstract:In order to resolve soil water deficiency in Pingshan County , Heibei Province , the application of the technology of water-holding agent was studied.In this experiment , acacia was used as an example of forest species and absolute random design was used to investigate the effect of water-holding regent on growing items (height of plant and diameter of stem) and ecological item (photosynthesis) and the effect of waterholding agent on soil water content and soil nutrients.Results showed that the direct applying model of mixing soil with water-holding agent was better than that of mixing soil with water-holding agent absorbing water beforehand.The diameter of stem and the height of plant were promoted by 19.70 %～34.0- % and 41.41 %～48.04 % by this applying mode , respectively.Soil fertility level was improved after - year application (Total N was increased by 41.80 %; available P , by 130.77 %; available K, -4.86 %; and Microelements , by 41.37 %～67-.16 %) .64 g/ plant was the best amount of application and water-remaining effect was still significant after applying water-holding agent 3 years later.

Abstract:The loess hilly region is a specific and fragile zone of ecological environment.An evaluation of ecological security is particularly important to the agricultural development in the region.By using hierarchical analysis process,an indicator system is set up to assess the agricultural ecological security of typical county in the region.By taking Baota District in Yan'an City and Ansai County for an example,a mathematical model is used to calculate the index of agricultural ecological security in the two places and then the index is used to characterize agricultural ecological security status in the loess hilly region.Finally,in view of the ecological safety problems of this region,some recommendations are given.

Abstract:T hrough investigating the main species of different communities in the wind-sandy grass shoal area of Yulin Region, 5 representative areas were selected according to vegetation, site factor, and soil water content.Species richness, species diversity, and the evenness of community were comprehensively calculated by using richness index ( R1) , Shannon - Weiner index ( H ) , Simpson index ( D) , and evenness index ( E 1) .Meanwhile, the relations of the important value of the main species and soil water content to species diversity were studied.The communities in the wind -sandy grass shoal area of Yulin Region, in terms of the species diversity, rank in the descendent order of Amorphaf raticosa community, Caragana intermedia community, H edysarum scop arium community, Salix cheilop hila community, and A rtemisia arenaria community.However, they, in terms of the evenness of community, rank in the descendent order of Salix cheilophila community, A morp ha f raticosa community, Caraganaintermedia community, Hedysarum scop arium community, and A rtemisia arenaria community.They, in terms of soil water content, rank in the descendent order of A morp ha f raticosa community, Artemisia arenaria community, Caragana intermedia community, and H edysarum scoparium community.

Abstract:In order to study the roles of meadow brome in soil and water conservation, 6 runoff plots were established on a 25 sloping land in Yanqing County.Soil loss, soil water content, soil compaction, and the root system were measured.Results showed that the effects of meadow brome planted on the slope were evident in preventing soil loss.Soil and water loss descended with the coverage increasing.When the coverage was 90% , the yearly amount of surface runoff and soil erosion modulus were 14 233.19 m³/ km²and 57.82 t/( km²! a) , respectively, and the capabilities of water conservation and soil conservation were 67.8% and 98.31%, respectively.Meadow brome planting effectively increased the compaction within 30 cm of surfacesoil.Especially at 10 cm soil depth, the compaction was 1.72 times of CK.The water dynamic change of the soil covered by meadow brome was gentle in comparison with that of CK.Meadow brome maintained the water content in the soil obviously.The root system was mainly distributed in the soil layer of 30 cm, accounting for 98.1%.

Abstract:By the environmental characteristics and conditions , there are 3 first grade areas , 5 second grade areas , and 7 third grade areas in the mining areas of Liaoning Province.Those are the water erosion mining area , waterwind erosion mining area , and wind erosion mining area; water erosion mining area with surface matter similar to soil , water erosion mining area with surface matter similar to rock , water-wind erosion mining area with surface matter similar to soil , water-wind erosion mining area with surface matter similar to rock , and so on.In addition , regional area , characteristics , and the key of vegetation reconstruction are considered.

Abstract:Based on the adaptive cycle model,the evolvement mechanism of social-ecological system was explored in a case study of Wangdong Village,Changwu County,Shaanxi Province.The dynamic adaptive cycles of Wangdong Village were identified by integrating key variables from social,economic,and ecological aspects.The social-ecological system of Wangdong Village has experienced a total adaptive cycle(1949—1961),then fell into a poverty trap(1961—1980),and now is in the exploitation phase of a new adaptive cycle(1980-).The institutional changes,especially the adjustment of land use policies,are the main driving force for the adaptive cycles.The technical innovation maintains the current system in the exploitation phase.Climate change such as drought is a strong disturbance to the social-ecological system and may lead the system into a releasing phase.

Abstract:The characteristics of alfalfa growth in the semi-arid sandy area for different buried depths of underground drip irrigation are studied.Effects of the buried depths on alfalfa planTheight, root collar diameter, branch number per plant, root length, weight density, and yield are investigated experimentally.Principal component analysis is used for comprehensive evaluation.Results show that the dropper installed at different depths affects the indexes of various alfalfa growth characteristics.In the seedling stage, the 10 cm laying depth treatment is conducive to alfalfa growth.From the branching period, the 30 cm laying depth treatment is superior to other treatments.T hroughout the growth period, the buried depths rank in the descendant order of 30, 20, 10, and 40 cm in terms of the comprehensive evaluation for the effects of different laying depths on alfalfa growth characteristics.

Abstract:With the clear physical meaning of parameter structure and the full reflection of spatial heterogeneity,a distributed hydrological model can describe and simulate the real process of runoff induced by rainfall in a basin,accurately and sufficiently.The model is widely needed and concerned recently.Non-point source pollution,land surface process,and climate change impact assessment have a wide range of applications in the simulation of land use,land cover,soil erosion,and other changes in hydrological responses.Accuracy and error are critical to model forecast,which determine the application and extension of the model.On the basis of the analysis of model construction and verification process,the four kinds of model error sources are identified as follows: error caused by the factors being excluded,random or systematic error in a measured historical record,parametric error,and error caused by model structure.The analysis of each error and its calculation method are discussed and a basis for the model development and growth is provided.

Abstract:The causes of soil and water loss in opencast coal mine are analyzed based on No.1 coal mine of Shengli diggings in Inner Mongolia.The cells and periods of soil and water loss forecast are classified.The contents and means adopted for the project are introduced.The degree and quantity of soil and water loss are found.The harm of soil and water loss in opencast coal mine are illuminated by analyzing the results, and a base for the following measures is established.

Abstract:Forced by energy shortage and environmental degradation, recently, wind power as a clean and nonpolluting renewable energy has rapidlydeveloped in China.Implementation of wind electric power project mayinduce severe soil erosion because soil and vegetation may be destroyed or disturbed in construction period.For effective soil erosion control, the article makes a brief analysis of the characteristics of soil erosion in project construction and presents a series of arrangements of soil and water conservation measures.Soil and water conservation measures in Bojiagou wind electric power project in Liaoning Province are also analyzed.The study is hoped to make a reference for the similar project by the combination of botanic measures and engineering measures.

Abstract:公路建设过程中产生的水土流失非常严重。在标定人工降雨器降雨参数的基础上,研究了华北地区公路土质边坡水土流失规律。结果表明,土体硬度、前期土壤含水量、降雨强度相同条件下,土壤侵蚀量随坡度的增大而增加,在25°附近达最大值,之后随坡度的增加侵蚀量略有下降并渐趋稳定;土壤侵蚀量随土体硬度的加大而减小,且降雨强度越大这种影响愈显著;前期土体含水量愈大,土壤侵蚀量呈增大趋势。本研究可为科学评价工程土质边坡的水土流失提供依据。

Abstract:In view of pipeline engineering design and construction, the application of soil and water conservation techniques may perfectly display the ecological benefits of soil and water conservation measures with satisfying the demands for refined oil transportation.The pipeline project has a long distance, is large in scale, and covers various types of landforms.It involves with various means of construction and faces various types of soil and water loss.The amount of soil and water loss in the local area is large in total quantity.The prevention and control system of soil and water loss includes three aspects of engineering measures, plant measures, and temporary measures, among which the measure of temporary retaining and protection is a major control measure.

Abstract:Taking Xi’ an City as an example and using statistical data from 1996 to 2005 , the landuse change of Xi’ an City during its accelerated urbanization is studied.Firstly , the landuse change of the city is analyzed from different stand-points.The area of cultivated land during the 10 years , as well as that of pasture and idle land , is found to decrease.Moreover , the areas of garden , forest land , population centre , industrial and mining field , traffic field , and water body increase.Therefore , the landuse of the city is in the duration of development and adjustment.After that , by bringing in an index and setting up a regression equation , the correlation between landuse change and urbanization of the city is studied on the ground of analyzing the urbanization.The analysis indicates an increased index , which elucidates that the expansion of population centre , industrial and mining field , and traffic field is quicker than the urbanization.As a result , the lack of land resources has severely retarded the urbanization and will impede it in the future.At last , some suggestions are proposed.

Abstract:SWAT model was used to calculate the agricultural non-point source pollution in Daninghe watershed.The runoff and the sediment data series from 2000 to 2004 were used to calibrate the parameters and validate the model.Results indicated that SWAT model was appropriate for Daninghe watershed.Then the calibrated model was used to calculate the spatial distribution of non-point source pollution.The calculated result indicated that the west part of the watershed was the serious soil erosion area , which is the same as the spatial distribution of organic nitrogen.In one word , the production of non-point source pollution in the west is more than that in the east , while in the south , more than that in the north.The measures for the prevention of non-point source pollution were presented according to the simulated results.

Abstract:With the population increasing and industrial development of Guiyang City , Nanming River has been seriously polluted.The self-purification of pollutant in river and self-restoration of river become weak , and the ecological system and survival environment are seriously damaged.In order to control the pollution in Nanming River , bioremediation , aeration technique , and sediment eco-dredging engineering are used.At the same time , controlling the pollution source is found to be a necessary way to control the river pollution.By developing the self-restoration capability of ecology , applying technical means , and controlling the pollution source , Nanming River’ s ecological system can be restored to its natural state.By restoring the internal structure , system function , and inner relationship of Nanming River’ s ecological system , the ecological environment of harmonious coexistence between man and nature can be available.

Abstract:By comparing the differences of plant diversity between artificial measures ( enclosed land for reforestation, thinning and renewal) and contrast area ( natural way) , the effects of different measures for soil and water conservation ecological rehabilitation in vegetation rehabilitation are analyzed.It is showed that the diversity by artificial measures is higher than natural diversity.Variance analysis and multiple comparisons show that for shrubs, the effect between artificial measures and natural ways has significant difference.The diversity index for artificial measures is higher than that for natural ways, but the measures of enclosed land for reforestation, thinning and renewal have no significant difference; and for herbs, the effect between artificial measures and the natural way has no significant difference.The change in evenness is almost consistent with that in the diversity index and ecological dominance is almost opposite.In short, soil and water conservation ecological rehabilitation may increase plant diversity.

Abstract:Groundwater level dynamics is a complicate nonlinear system due to the effect and limitation of its natural and human factors.It is important to predict the change of groundwater level exactly in exploiting water resources of an irrigation area.Groundwater level change of typical well in Weibei irrigation area is predicted by artificial neural network(ANN) according to its high nonlinear function of parallel distribution processing.Result from the study shows that ANN may give a high precision and has a great value of extension and application.

Abstract:Supported by RS and GIS,the landscape types in the study area are charted based on the landscape classification using remote sensing images obtained in 1994 and 2003.Landscape patterns in the Chang'an River basin,apart of the water source area of the middle-route of the South-to-North Water Diversion Project,are analyzed in view of landscape patch characters,landscape diversity,and landscape fragmentation by selecting the indices of patch number,diversity,dominance,evenness,fractal dimension,and fragmentation.The analysis of the ecological landscape patterns indicates that the patch number in the basin increased obviously from 469 in 1994 to 1518 in 2003.Disturbed by human activities,landscape diversity index increased by 0.61 from 1994 to 2003,but the level of landscape diversity was low.The landscape fragmentation index in the basin increased from 1994 to 2003.Among the landscape patch types,the fragmentation index for the three landscape patch types(artificial woodland,dry land,and grassland) was high and was easily disturbed by human activities.

Abstract:The SWAT model is a distributed hydrologic model with the ability of evaluating the hydrologic responses to climate change.Its ArcView interface version AVS2000 is applied to analyze 2000-2004 basic data observed from the Zhangweinan basin on medium scale.Based on the current climate,24 kinds of climate scenarios are set to simulate the hydrologic responses to climate change.Runoff,evapotranspiration,and water yield are selected to quantitatively analyze climate change impacts on hydrologic responses.Result from the research shows that runoff,evapotranspiration,and water yield of the basin are affected greatly by climate change.Runoff,evapotranspiration,and water yield also increase with increasing precipitation.When temperature rises,evapotranspiration increases,but runoff and water yield decrease.The research may be helpful to water resource management under climate change.

Abstract:Based on TM images (path 127 , row 036) acquired in August , 1990 and May , 2000 respectively , five types of landuse were classified with the support of remote sensing and GIS.Using the theory of landscape ecology and geographic information images , we made quantitative analyses of the quantity and spatial feature changes of landuse in Xi’ an region in the period of 1990 to 2000 , and a series of ecology environmental effects.Landuse change/ cover in Xi’ an region can be listed as follows: Urban construction land increased sharply , while water-body , arable land , and forestland decreased apparently.Arable land and water-body were more fragmentary and interspersed than ever before.The increase in the area of urban construction land was at the cost of encroaching a wealth of arable land.Landscape became more and more fragmentized and the shape of landscape became more complex.The predominance index decreased as well.The Shannon diversity index increased from 0.90 to 1.02 , while the Shannon evenness index increased from 0.48 to 0.56.It indicates that the landscape is getting more and more diversified and balanced , but poor to withstand the interference.It also indicates that human activities disturb the landscape more and more seriously.The results suggest that the trend that all the other land types translated into construction land appears much more dominantly than any others in the study region.In the meantime , the results also show that the Xi’ an City is in a fast developing stage of urbanization to a certain extent.

Abstract:The images of Naimanqi in the year 1975,1985,1995,and 2005 were interpreted and the land use change in typical area of Horqin sand land during recent 30 years was analyzed by using 3S technology.Results showed that the area of landscape types of sandy land was reduced obviously.The reduced extent of fixed dune was significant,decreasing from 44.79% in 1975 to 6.18% in 2005.The areas of cultivated land and woodland increased prominently,especially the woodland with the net increase of 29.72%.The areas of other landscape types did not change obviously.The transfers among the main land use types were from mobile dune and semi-fixed dune to fixed dune,cultivated land,and woodland;from fixed dune and pasture to cultivated land and woodland;from cultivated land to woodland;and from woodland to cultivated land.In view of the change space pattern,the number of woodland patches was the most,being 191 in 2005.The index of the largest patch of cultivated land was the greatest and its numerical value was 43.12 in 2005.The mean patch area of fixed dune was more than other landscape types,being 1 896.50 hm² in 2005.The connect index was reduced continually from 2.62 in 1975 to 2.13 in 2005.However,the patch density(PD) index changed oppositely,increasing continually from 0.15 in 1975 to 0.44 in 2005.The Shaanon's diversity index(SHDI) and Shannon's evenness index(SHEI) presented the similar changing trend of increasing first and then decreasing.

Abstract:In order to analyze the effects of grazing policies on animal husbandry in a farming - pastoral zone , changes of feeding manner , livestock output , and input of animal products in Ejin Horo Banner , Inner Mongolia Autonomous Region are analyzed and compared based on peasant household survey.After the grazing policies , some households abandon animal husbandry and others still work on in it at a lower level , which is unfavorable to the development of the local animal husbandry.The input of animal husbandry in 2006 was 111.3 % of that in 1995 , but the incomes from sheep and goats increased by 16.33 % and 33.15 % , respectively.For these reasons , the households must promote the development of the local animal husbandry by structural adjustment , change feeding manners , modify varieties , raise livestock breeding efficiency , and adopt other effective measures.

Abstract:The low foothill area in south central area is the most serious area suffering from soil and water loss in Shandong Province because of its steep slope and intense washout and cutting.The present situation and harms of soil and water loss are described and its causes are analyzed.By establishing the protection system integrated with engineering, biological and agricultural measures, effectively controlling soil and water loss, and improving ecological environment, the remarkable benefits of ecology, society, and economy have been obtained.

Abstract:Recent research conclusions about the causes and characteristics of soil pollution , pollution state in China and its relation to agricultural product quality are summarized.It is suggested that the relationship between people and the nature should be coordinated , controlling measures and remediation technologies should be further studied , and research on green product materials should be strengthened.Moreover , the way of developing green agriculture for saving resources , improving efficiency , and reducing pollution should be persisted in to insure the security of grain production and agricultural products.

Abstract:Yulin City is located in the north part of Shaanxi Province and is rich in mineral resources, so it is a base of national power and chemical industry.On the other hand, because it is in the transitional zone from Maowusu sandy land to the Loess Plateau, desertification and soil and water loss in the region are much more serious and its eco-environment is very fragile.The region is characterized by rich resources and fragile ecoenvironment that compose a pair of sharp contradiction.Therefore, developing eco-economy is the necessary choice.The priorities and existed problems are analyzed for developing eco-economy in Yulin City.The countermeasures of improving understanding, changing idea, developing recourse saving agriculture and characteristic agriculture, and carrying out industry financed agriculture are put forward.

Abstract:The characteristics of water resources and their exploitation status in Yan'an City are analyzed in order to solve the problems existed in water resource utilization,such as low level exploitation and utilization accompanied with serious shortage in water resources,high percentage of water use and low reuse efficiency in petroleum industry,and serious water pollution.Based on the concept of sustainability,the corresponding countermeasures are proposed: constructing a water-saving and anti-pollution society;making sound water resource development and utilization planning from a long-term and practical viewpoint;solving the problem of rural safety drinking water;and strengthening water resource protection and preventing water from pollution.

Abstract:The authors apply ecological footprint method to evaluate the sustainable development and ecological security of Zhejiang Province by the time series.The paper constructs the new evaluation index system of ecological security and introduces the model of ecological tension index , ecological occupancy index , and ecological economic coordination index.Taking Zhejiang Province as a case study area , the paper introduces the concepts of change rates and the scissors difference to quantitatively analyze the trends of ecological footprint and index system of ecological security in the province from 2000 to 2006.Results show that the per capita ecological footprint of Zhejiang Province increased reversely with ecological carrying capacity and the per capita ecological deficit increased steadily.Ecological tension index increased from 2.34 in 2000 to 3.22 in 2006.In the same period , ecological occupancy index increased from 0.67 to 0.90 and ecological economic coordination index declined from 0.286 to 0.277.The sustainable development model of Zhejiang Province is not optimistic , its ecological environment is at risk , and its social economic development does not go well with ecological environment.

Abstract:Based on the theory of H.T.Odum, a quantitative analysis of energy inputs and outputs of agri- cultural eco-economic system in Aba Autonomous Prefecture between 1952 and 2005 in Sichuan Province is given and an comparison of Aba with other regions is made.Results show that because of the over-exploitation of natural forest last century, ecological environment in the area has been seriously damaged.Along with the forest economy! ended and the rise of eco-tourism, Aba? s ecological and environmental conditions are gradually improved.But agricultural ecosystem still has such problems as serious shortage of modern assisted inputs, backward production model, and agricultural development on the basis of the excessive use of natural resources, so a sustainable development is difficult to achieve.It is therefore essential to enhance research and extension of agricultural science and technology, improve the quality of workers in order to make full use of local natural resources, increase the agricultural output capacity of ecological and economic systems, and achieve the sustainable development of agricultural economy.