Abstract:Taking sixteen forest types in the loess hilly area of eastern Qinghai Province as research objects,the main vegetation types and soil physical properties(soil bulk density and porosity)and chemical properties(organic matter,N,P,and K)are analyzed.The changes in soil water holding capacity and soil fertility are studied.Results show that mixed forest have the minimum soil bulk density and the largest soil capillary porosity,and the mixed forest soil is loosen and porous and has the higher capability of water conservation and soil conservation.The distributions of soil organic matter,N,P,and K for different vegetation types are consistent,following the order of mixed forestconiferous forestbroadleaf forestshrubbarren hills.In different forest types,soil in Larix principis-rupprechii forest has the highest N content,while P and K contents are relatively low.Soil in Populus cathayana has the highest P content,while N and K content are relatively low.Soil in Betula platyphylla Suk—Betulautilis—Sabina przewalskii—Ricea asrerata(5∶2∶2∶1)mixed forest has the highest K content,while N and P contents are relatively low.In terms of comprehensive comparison,mixed forest well promotes the increases in soil organic matter,N,P,and K contents,improves soil nutrient status,and helps to sustain soil fertility.

Abstract:Aiming at the problem of soil salinization existed inside oasis , grain-size of 84 typical samples in Ili Valley , Xinjiang Uighur Auto nomous Region was tested .Spatial variability of soil salinity in topsoil and its relationship with landscapest ructure were studied in combination of geo-stati stics methods .Results showed that mechanical composition of topsoil was mainly composed of silt and clay .Variation degree of silt and clay contents changed from the weak to the medium .Averaged diameter was gradually decreased and frequency curveex hibited a pattern with positive excursion , nearly symmetric excursion , and negative excursion from east to west .Structural factors like parent material and landform were the main factors which control the spatial dist ribution of surface soil particles .Random factors like irrigation and tillage intensified the spatial distribution of surface soil particles .It is the most important agro-ecolo gical problem that percentage content of silt was increased in mechanical composition of sag area .Soil hardening and secondary salinization were intensified in the sustainable utilization process of newly cultivated oasis resource .

Abstract:Under the different conditions of organic manure and ni trogen fertilizer , the dy namic changet rend of soil oxido reductases activities is studied .Results showed that compared with organic fertilizer or N fertilizer,soil catalase and dehy drogenase activities significantly increased under organic and N fertilizer conditions .With organic fertilizer of 22 500 kg/hm² and N fertilizer of 120 kg/hm², the activities of soil catalase and dehy drogenase were highest , being 1.1750〔0.1 ml/(g·20min)〕and 15.7931 ug/(g·d), respectively .Soil polyphenol oxidase activity decreased with the increase in the amount of organic and nitrogen fertilizer.

Abstract:To investigate actual evapotranspiration(ET)under different degrees of vegetation coverage,three plots of alpine meadow were established on the places where the topography was of the same slope,direction,and shape and where the degrees of vegetation coverage were 92%,65%,and 30% in the headwaters of the Yangtze River.The lysimeter method was used to calculate ET of alpine meadow under different degrees of vegetation coverage.The characteristics of ET and the dominating factors in four periods were analyzed.Results show that ET increased with the reduction in vegetation coverage in the per-growth period,while ET decreased with the reduction in vegetation coverage in the growth period,post-growth period,and the frozen period.The change of vegetation coverage influenced ET in the growth period very obviously.The dominating factors varied with different periods.Heat played a leading role in the per-growth period and the post-growth period and moisture played a leading role in the growth period.

Abstract:By taking ALOS as remote sensing information source and using supervised classification and human-computer interactive interpretation,the actual area of returning cropland to forestland project is extracted.Since complete measurement for the whole area is expensive and time-consuming,the map-spot area in remote sensing interpretation is selected as auxiliary sampling factor by using sampling methods of probability proportional to size(PPS).The total area of the project is estimated according to the areas of 30 engineering projects and the areas measured by GPS.The areas extracted from GPS and RS are then compared and the precision is up to 86.2%.This study is of importance in controlling the progress of project and its quality.

Abstract:Sentinel surveillance method was used to study patterns and means of nitrogen loss in sloping fields in the central Yunnan Province so as to reveal nitrogen loss characteristics.Results showed that the related coefficient between runoff and rainfall was 0.864 1,but soil erosion and rainfall did not show a good correlation.Under the same rainfall conditions,the amounts of TN,NO-3—N,and NH+4—N were generally increased with the increased amount of nitrogen in the order of CKN1N2N3N4N5 and under different rainfall conditions,the values of the three chemicals reached 5.57,4.36,and 1.30 mg/L,respectively.The NO-3—N concentration accounted for 21.02%～83.55% in soluble nitrogen and NH+4—N concentration was only about 1.02%～38.58% under natural rainfall conditions,indicating that NO-3—N was the main form of nitrogen loss.Rainfall runoff induced soil erosion and the amount of TN in sediment also showed irregular fluctuation.Nitrogen enrichment rate was about 1.02～1.58 in different treatments.When rainfall intensity was up to maximum,the enrichment rate of the overall trend increased and reached 1.23～1.53.Nitrogen enrichment rate was not significantly different with the increase of fertilizer under the same rainfall conditions and it decreased with time.

Abstract:Semi-arid loess regions are the key areas of returning cultivated land to forest and eco-forestry projects in our country.As a result of the special climatic conditions,rainfall is relatively short and potential evapotranspiration is relatively great.Transpiration can cause considerable loss of plant water which leads to water deficit and dehydration and great difficulties in artificial afforestation.Spraying anti-transpiration foliar fertilizer on leaf surface can not only provide the necessary nutrients required for plant growth,but also inhibit plant transpiration,improve plant water potential,reduce plant water evaporation,and improve the survivability of plants to some degree.The study uses Xanthoceras sorbifolia Bunge,Amorpha fruticosa,and Rhus typhina in the arid and semi-arid area of the Loess Plateau as the main research object and two self-made anti-transpiration foliar fertilizers and the foliar fertilizer which has been promoted on market as the main basis,to explore the effects of self-made fertilizers on reducing the plant transpiration by orthogonal experiment.Results show that the best formulation is self-made C + Xanthoceras sorbifolia Bunge or Amorpha fruticosa + 800～1200 times diluted + 12%～22% soil moisture,which reduces plant transpiration rate most obviously.

Abstract:Ecological experiments on soil moisture in poplar-wheat complex and wheat monoculture(CK)pattern were conducted in the reclamation areas of Ili River basin.Results showed that(1)1～2 days after irrigation,soil humidity in plough layer(0—44 cm)in the two systems was increased by 5% and the increase of soil water content in lower layer(110—154 cm)in poplar-wheat complex system was greater than that in the CK.(2)There was less root distribution at the S2 spot in parallel direction in poplar-wheat complex system and the most of wheat and poplar roots were distributed in 20—30 cm soil layer in vertical direction,which have greatest competition for water and nutrition from soil.(3)The 1 000-grain weight in the CK was 4.56% more than that in poplar-wheat complex ecosystem and the 1000-grain weight of wheat at the S12 spot was 1.11 times that at the S2 spot in the poplar-wheat complex pattern.(4)Compared with the CK,diurnal mean value of transpiration rate in poplar-wheat complex system was 30.8 g/(m²·h)lower,diurnal evaporate amount was 1.07 g/d lower,diurnal average of air temperature was about 0.46 ℃ lower,and soil temperature was 0.24 ℃～1.20 ℃ lower.In view of water use,this study provides a theoretical support for feasibility and continuity of poplar-wheat complex ecosystem in the water and soil development areas of Ili River basin.

Abstract:Decomposition of litter and the dynamics of the major elements in litter in Taihang Mountainous area were studied by using litterbag method.Results showed that mass losses of different vegetation types were different,which was in the order of Robinia pseudoacaciaPunica granatum LLeptodermis oblonga shrub bushesVitex negundo shrub bushesgrass.The changes of mass losses during decomposition were consistent with temperature and rainfall.During decomposition,there were significant net releases of K,Mn,and N,while a significant net accumulation of Na.Ca was firstly accumulated and then released,while Zn and P were firstly released and then accumulated.By the release rate of the elements from litter after 12 months of decomposition,the elements were in the order of KNMgPMnZnNaCa.K had the maximum amount of nutrient returned in the process of litter decomposition,while the amount of Ca was negative.By the amount of nutrient returned,the elements were in the order of KPMgMnNZnNaCa.According to soil nutrient analysis,the change of each element content in soil accorded with the nutrient returned of litter.

Abstract:Soil quality,soil moisture and fertilizer preservation ability,and soil nutrient uptake ability are closely related to soil physical properties.In this study,42 soil samples were collected respectively in the 0—20 and 20—40 cm soil layers from seven desert sampling plots along descending precipitation gradient in Hexi Corridor region(from Minle County to Gaotai County).Saturated soil hydraulic conductivity was measured with the tension infiltrometer in field,and bulk density,porosity,and soil particle composition were determined by general methods in lab.Results show that physical properties of the desert soils are gradually degraded.With precipitation decreasing from 360 to 100 mm,silt and clay contents are reduced and sand content is increased.Increase in soil particle size may definitely result in soil dispersion and structure destruction,further increase soil bulk density,and reduce soil porosity and water holding capacity.The variance coefficients of saturated soil hydraulic conductivity in the surface and subsurface layers are 70.0% and 86.3%,respectively,both of which are the highest among the Cv values of all the physical properties.

Abstract:4 945 earthquake-induced mountain hazards in Wenchuan Earthquake were identified by field investigation and interpretation of remote-sensing images.GIS techniques were used to finish the statistical data analysis for the relationship between distribution of mountain hazards and environmental factors,including distance from middle faults,seismic intensity,and lithology.Research on the geological structure effects on the development of mountain hazards in earthquake was then conducted.The main results are summarized as follows:(1)The zonal distribution of mountain hazards was consistent with strike of middle faults and seismic energy was mainly released along the middle faults which caused the attenuation of energy obvious in the minor axis perpendicular to middle faults.The high density of hazards was distributed within the distance 12 km from middle faults.The density in hangingwalls of middle faults was obviously higher than that in footwalls because the middle faults belong to reversed thrust faults.The density appeared as reduction-increase-reduction in the footwalls of middle faults because of the combined action of middle faults and front faults which both belong to reversed thrust faults.(2)The mountain hazards,well developed at Ⅺ and Ⅹ seismic intensities,were obviously responsive with seismic energy,and about 99.29% of the mountain hazards were distributed in the areas where seismic intensity was greater than Ⅶ.(3)The density appeared in the order of calculous rocksolid rockloose rocksoft rock.Calculous rock was easy to disintegrate,especially the alternative distribution of calculous rock and soft rock by the effect of seismic wave.Many collapses were well developed in calculous rocks and landslides were well developed in loose rocks.

Abstract:Soil water diffusivity is a significant parameter for water and salt transport in saline soil.Horizontal soil column method is used to study the relationship between soil water diffusivity and soil water content in different saline soils.The relationships among soil water diffusivity,soil water content,and Boltzmann parameter are determined.Soils with different salt contents are found to have different soil water diffusivities.Soil water diffusivity increases with increased salt content under the same condition of soil water content.Soil water diffusivity increases with increasing soil water content as well.When soil tends to be saturated,soil water diffusivity approaches infinity.The empirical relationship presented in the paper may better reflect the relationship between unsaturated soil water diffusivity and soil water content.

Abstract:Responses of seed germination of 4 desert vegetation species﹝Zygophyllum xanthoxylum Bunge.,Ammopiptanthus mongolicus(Maxim.)Cheng f.,Reaumuria trigyna Maxim,and Amygealus mongolica Maxim﹞to soil moisture were studied.Results showed that soil moisture had a significant effect on the seed germination and seedling growth.At 6% soil moisture content,germination rate and germination index of Z.xanthoxylum seeds reached peak value,vigor index and seeding biomass were the greatest,and seedlings of Z.xanthoxylum grew well.Germination and growth of A.mongolicus seeds behaved very well at 12% soil moisture content and those of R.trigyna and P.mongolica seeds behaved also well at 16% soil moisture content.The seed germination strategy of the 4 plants reflects different adaptation mechanisms to desert moisture condition and affects population regeneration and expansion.

Abstract:In order to investigate the relationship between vegetation diversity and soil factors,a vegetation survey was made on the highway side slopes in the tourism segment and near rivulet in Yanqing County.There were 39 families and 120 species of plants in the sections,of which there were 18 species of arbor,17 species of shrub,and 85 species of herb.By the ecological dominance index in the community,the layers of plants were in the order of tree layershrub layerherbage layer.In the sections,the vegetation ecological dominance index of Gulong Road was the greatest.The diversity and richness of herb layer were greater than canopy layer and bush layer.The vegetation diversity and richness on Luanchi road were greater than those on Songyan Road and Gulong Road.The relationship between vegetation diversity and soil factors was analyzed by applying grey incidence analysis.Results indicated that the relation degree between vegetation diversity and soil pH value was the biggest,the relation degree between vegetation diversity and available K was the second,and the relation degree between vegetation diversity and soil bulk density was the third.The total nitrogen was one of the plant diversity restricting factors on Guyaju road completely covered by nature plants.

Abstract:Dy namics of soil moisture in root layer , water use efficiency , crop yield, and economic benefit sunder different types of conservation tillage were studied with the triple crops of wheat-maize-sweet potato in the southwest China .Results indicated that different types of conservation tillage had significant effects on cropyield and water use efficiency .Straw mulching (TS), film mulching (TM), straw mulching plus film mulching (TSM), and ridge plus straw mulching plus film mulching (RSM)increased soil water storage and soil moisture in 0—60 cm soillayer in July and October , while ridge (R), ridge plus straw mulch (RS), and ridge plus film mulching (RM)can not remarkably affect the indexes .RSM , RM , RS , TSM , TM , TS , and Rincreased average yield by 0 .52 %, 6 .11 %, 6 .77 %, 4 .59 %, 5 .12 %, 3 .15 %, and 1 .24 %, respect ively ,compared with CK .T he comprehensive effect of ridge plus straw mulching plus film mulching was the best in view of water use efficiency , rainfall use efficiency , cropyield , and economic benefits.

Abstract:In order to reveal the driving mechanisms of Robinia pseucdoacacia plantation and the responses of ecological characteristics of soil moisture to plantation degradation,the soil hydrologic-physical characteristics,infiltration,and water-holding capacity in degraded R.pseucdoacacia plantation in the Yellow River Delta area are studied using the methods of representative field investigation and laboratory analysis.Results showed that with the degradation of R.pseucdoacacia plantation,soil hydrologic-physical properties such as soil organic matter,soil porosity,and void ratio decreased with increased soil density and soil hydrologic-physical properties in the 0—20 cm layer was better than those in the 20—40 cm layer.Soil porosity in slightly,medially and badly degraded stands increased by 3.68%,9.56%,and 14.71%,respectively,compared with normal stand,and however,total soil porosity decreased by 2.38%,4.86%,and 9.57%,respectively.Horton infiltration model can better describe the infiltration process in the degraded R.pseucdoacacia plantation.With the degradation of R.pseucdoacacia plantation,initial infiltration rate and stable infiltration rate decreased greatly.Similarly,stable infiltration rate decreased by 25.62%,55.47%,and 85.07%,respectively,compared with normal stand(4.02 mm/min).Total water-storage capacity deceased by 2.37%,4.85%,and 9.56%,respectively,compared with normal stand(195.78 mm).Soil capillary and non-capillary porosity,water-holding capacity,total soil absorption precipitation,and effective precipitation decreased greatly.Soil water-holding capacity in the 0—20 cm layer was better than that in the 20—40 cm layer.

Abstract:Based on the data observed in fixed location,the variation of soil moisture and its influences on potato yield in the mountainous area of South Ningxia Hui Autonomous Region was investigated.Experimental results indicate that the annual variation of soil moisture content presents a positive parabola shape,which is high in spring and autumn and reaches a bottom in early summer.Dynamic change of soil moisture is mainly dependent on the balance process between the seasonal distribution of annual rainfall and evaporation.Dynamics of soil moisture varies from 9.95% to 21.6% in the whole growth period.The soil moisture content in 0—100 cm soil layer is most remarkably correlated with potato yield.The most remarkable correlation with potato yield is observed in branching period and fruit period which are the peaks of potato water consumption.In this stage,10 mm increase of soil moisture in the layer may increase potato yield by 135~270 kg/hm².

Abstract:The evolution of soil quality in orchard with different growing years was studied.Soil studied was alkali at the beginning,but finally was seriously acidified.With growing years prolonging,organic matter showed a declining trend,but nitrogen and phosphorus showed an enriching trend.A decrease-increase trend was presented for both bacteria and fungi,while the actinomycetes showed a linearity increase.The percentage of bacteria over microbe number increased,but fungi and actinomycetes decreased.Soil quality was classified based on principal component analysis.The 9 year orchard had the most excellent quality,the 5 year and 9 year were in good-quality,the 17 year and 23 year were poor,and the 1 year was the worst.After apples were planted in cultivated land,soil quality in orchard became good in full fruit period,soil nutrients and enzyme activity were the highest in the 9 year orchard.The apple trees were in a decline stage after 14 years and a severe degeneration stage after 17～23 years,with soil quality declining as well.

Abstract:In order to maintain the sustainability of Tarim Desert Highway shelterbelts,the change of soil water-salt environment of the outer edge of the shelterbelts in a complete irrigation cycle was monitored.Results showed that(1)soil water content on the outer edge of the shelterbelts began to decline when irrigation finished.After the sixth day in the irrigation cycle,it gradually decreased within 90 cm outside of the outer edge and reached a basic balance beyond 90 cm outside of the edge.(2)Because of a comprehensive influence of saline water irrigation and evapotranspiration,soil salt outside of the edge was accumulated in soil surface and 120 cm soil layer and the accumulation decreased in root layer.(3)The relative change of slat content in groundwater on the outer edge presented a V-type change and the change was the weakest 90 cm outside of the edge.Groundwater parameters had a greater change with decreased distance to shelterbelts.

Abstract:Burma reed (Neyraudia reynaudiana) is a perennial grass which has the capacity of strong tolerance to drought, leanness, high temperature, and acid. It is a pioneer plant in natural vegetation restoration in the deserted area resulted from water erosion, mining area, stone pit , and slope. In order to explore the feasibility of ecological restoration with burmareed in various mining areas and the heavy metal contaminated area, germination ability of burma reed seed stressed by different concentrations of Hg²⁺, Cr⁶⁺, Cd²⁺, Pb²⁺, Zn²⁺, and Cu²⁺ , as well as different pH values was studied by labg ermination test . Results showed that burma reed seed can well germinate between pH 5.0~ 9.0. Inhibiting effect of the heavy metals on burmareed seeds increased with increase of heavy metal concent ration. The order of the heavy metals, by the lowest concent ration which leaded to inhibition, was Cd²⁺ < Cu²⁺ < Hg²⁺, Zn²⁺ and Cr⁶⁺ < Pb²⁺. The concent rations of the heavy metals which affected obviously burma reed seed vigor were lower than the concent rations which affected obviously burma reed seed germination percentage, germination vigor, and germination index . This indicates that seedling is more sensitive to the heavy metals than germination.

Abstract:Analysis of dynamic change in desertification is the foundation of desertification prevention.Multi-temporal TM image data of Kubuqi Desert in recent years were analyzed and different periods of desertification grade distribution maps were obtained by image interpretation using RS GIS software.Dynamic desertification process was discussed in terms of desertification area change and spatial changes of desertification levels.Results show an obvious downward trend of total desertification area after 1989.In view of the spatial variations of desertification levels,desertification is reversed in most areas along the main course of Yellow River,but increased in southeastern part,southern desert hinterland,and the surrounding of lakes.In addition to general engineering and biological measures,irrational human activities should be eliminated in order to maintain the dynamic balance of ecological systems and human environment.

Abstract:Through the investigation of soil,topography,and vegetation in the forest lands of Miyun County,different site types are analyzed.According to the principle of key factors and the principle of practicality,evaluation,slope orientation,soil thickness and so on are selected as the key factors.Site types in the county are classified into 3 small site-type districts,9 site-type groups,and 15 site types and then the potential of accumulation is calculated.Moreover,the map of the site type classification is made by using GIS.It can provide a scientific reference for the allocation and plant management pattern of water conservation forests in Miyun County.

Abstract:This study was conducted based on the data of TM/ETM+,combined with the DEM and soil type of Xi'an City,and supported by RS and GIS technology.By taking soil erosion dynamics and its countermeasures as study object,factors of slope,vegetation cover,and land use,as well as other factors in 1988,1997,and 2002 were extracted.According to soil erosion interpretation,a soil erosion map was drawn by the ARCGIS and spatial characteristics of soil erosion and its trend in future were analyzed.Results are shown as follows.(1)The area for light erosion presented a decreasing trend from 1988 to 2002 and the area for moderate erosion increased from 26.83% in 1988 to 37.03% in 2002,showing a significant upward trend.(2)Spatial distribution pattern of soil erosion in Xi'an City changed little in the past 14 years.Compared to 1988,the most obvious change in 1997 was the soil erosion around the city.The expanded area of light and moderate soil erosion in 2002 was greater compared with 1988 and 1997,mainly in Bailu Plateau,Shaoling Plateau,and the periphery of the city.(3)Combined with spatial variations of soil characteristics in Xi'an City,five measures restoring ecological environment,such as scientific planning and comprehensive management,were proposed to provide a reference to soil erosion control.

Abstract:Affected by steep landform,complex lithology,intensive geotectonic movement,and unreasonable economic activities,about 280 geological hazards including collapses,landslides,debris flows,and potential unstable slopes are distributed in Shimian County,Sichuan Province.The occurrence of the geological hazards are closely related to rainfall.According to field investigation,debris flows usually breaks out just on the day when intraday precipitation is supreme and however,slope hazards such as collapses and landslides usually occur 2~5 days later.In this study,6 geological regions were zoned firstly based on landform and lithology.Then their occurrence and rainfall process were analyzed respectively and a certain warning line was set up according to the rainfall indexes including intraday rainfall and antecedent rainfall.Finally,meteorological warning grade was confirmed and a series of warning system including 18 warning maps were established.This research can provide a scientific guideline for the warning and mitigation of geological hazards in Shimian County.

Abstract:Irregular soil and water loss crisis incident with sudden abno rmal high-degree characteristics and the regular one with cumulative effects have great negative impacts and threats to both production and people's life .Compiling the emergency plans of soil and water loss crisis incident at all levels is effective in the prevention of the crisis incident .Among them , provincial emergency plan of soil and water loss crisis incident is the representative one .Some key issues about how to accomplish the emergency plan of soil and water loss crisis incident are analyzed and discussed , including the concept , classif ication and grading of soil and water loss crisis incident , prevention and management objects , plan composition, organizational system, and emergency response flow chart .Some reasonable and feasible so lutions are put forward .

Abstract:The development of information techniques brings the advance methods for soil and water information management and its knowledge dissemination.It is important to develop the system to manage the data of slump-gully,which has the functions of information and knowledge querying.The whole framework,function,database design,and implementation are discussed by taking slump-gully information querying system of Hubei Province as an example.

Abstract:The landuse database of Bachu County in Xinjiang Uygur Autonomous Region are obtained from remote sensing images of two periods by using the interpretation method combined with correlated census data for correction.Results show that cropland in Bachu County has continuously expanded since 2004 and the reclaimed land gradually spreads into forestland and grassland.Land reclamation damages the shelter forest system that protects the ecological safety of oasis,aggravates land desertification trend,and threatens local biodiversity.Meanwhile,large-scale farmland reclamation exacerbates water shortage.

Abstract:Spectral knowledge method and spectral angle mapper(SAM)are used to extract the desertification information,including flow sand,semi-fixed sand,fixed sand,and sandy plantation by taking Mu Us sandy land as a typical area and CBERS-2 as the source of data.The extracted precision of the different methods are analyzed and compared.Results show that the summarized precision of spectral knowledge method is 76.04% and SAM is 83.21%.This indicates that the extracted precision of SAM is higher than spectral knowledge method for extraction of the desertification information on CBERS images.

Abstract:A hybrid form of rainfall-runoff models integrating artificial neural networks(ANNs)with conceptual models is proposed.The integrated model is a semi-distributed form of conceptual rainfall-runoff models,in consideration of the spatial variation of rainfall,the heterogeneity of watershed characteristics and their impacts on runoff.Genetic algorithm is used to optimize the parameters of the conceptual model and GIS software and DEM data are used to divide the whole catchment into sub-catchments based on the spatial distribution of rain-gage stations.As a result,in each sub-catchment,runoff generation is simulated in consideration of the spatially distributed model parameters and rainfall inputs.In runoff routing,instead of a linear superposition of routed runoff from all sub-catchments as traditionally performed in a semi-distributed form of conceptual models,artificial neural networks as an effective tool in nonlinear mapping are employed to estimate runoff.The feasibility of the new approach is demonstrated in Dapoling watershed,the upper tributary of Huaihe River basin,and the results of coupling model are compared with those of the Xinanjiang model.Verified results of the model indicate that the approach integrating artificial neural networks with conceptual models presented in this paper can achieve the promising results with acceptable accuracy for flood event simulation and forecast.

Abstract:The area for soil erosion modeling at watershed scale is large,usually dealing with more than one types of climate.Single type of runoff mechanism can not describe runoff generation exactly.A long term soil erosion model at watershed scale is built by taking a grid of DEM as simulating unit and a day as time interval.Dynamic runoff mechanisms are used in the model,which consider runoff as a dynamic process depending on weather and subsurface conditions.The sub-processes of precipitation,infiltration,surface storage,flow velocity,snow melt,and evaporation are incorporated in the regional soil erosion model.RUSLE model is used to calculate soil detachment.Monthly vegetation coverage is used to calculate C factor,so that the C factor is dynamic in the long term simulation and may describe the hydrologic process more exactly.The model is then applied to Linyi watershed for simulation and validation.Results show that the model is applicable in the watershed.Elevation is found to be the main factor to soil erosion.Sediment from the watershed mostly comes from the upstream and midstream and is distributed in the zone of 200～500 m elevation.Therefore,the zone is the main region for the prevention of soil erosion.

Abstract:Riparian zone is a buffer zone between river ecological system and land ecological system for exchange of matter,energy,and information with apparent marginal result.Through introducing protection technologies of riparian zones in the United States and studying concepts of ecological design,the designing process,methods,and principles suitable to the situation of riparian zones in China are presented.Several measures commonly used in riparian zone engineering are introduced.

Abstract:According to the survey data of forest resources in Beijing mountainous areas by CCA analysis,the relationships between distribution of forest landscape patterns and environment factors were analyzed with the help of ArcGIS.Results showed that in Beijing mountainous areas,exposure,position,and soil thickness were not the dominant factors controlling landscape pattern.The first impact factor of the landscape distribution pattern was elevation and the second was slope.Distribution of plantation was in low altitude,while the distribution of natural forest was in high altitude.This was the same as the distribution of the landscape type in the CCA diagram.

Abstract:The vertical percolation of soil water under different rainfall inputs is calculated using a semi-empirical analytical equation and the numerical solution from HYDRUS-1D model.Results from both methods are compared to assess the relative accuracy of the analytical equation.It is found that both methods can capture the response of soil water leakage to the rainfall conditions.The soil water percolation rate is highly correlated to rainfall intensity.The analytical solution of soil water percolation is a little greater than the numerical solution for low rainfall intensity and the result is the opposite for high rainfall intensity.Major differences from the two methods are shown in terms of the time when the peak percolation rate occurs and the time when the water initially starts to occur at the bottom of soil column.It is also found that the accuracy of the analytical solution is improved with the decrease in the thickness of soil column.Therefore,it is suggested that soil column be divided into sub-columns when the analytical solution is used to achieve a better accuracy in the calculation.

Abstract:Dynamic modeling of hydrologic and soil erosion processes in catchment needs appropriate simulation methods to handle the water and sediment transfer on hillslope and in channel,as well as the initial and boundary conditions.Soil erosion in watershed,as a spatially and temporally coupled process,is divided into soil erosion in channels and soil erosion on hillslope.Soil erosion in watershed is partitioned into a surface-line system to deal with the hillslope-channel relation and a line-line connection for soil erosion in channel.The governing differential equation with initial and boundary conditions was outlined for watershed erosion modeling.The comparison of laboratory experimental results with model outputs indicates that the simulation accuracy is above 80%,which demonstrates the feasibility of the method.The simulation method presented in this study may supply a basis and reference for the simulation of soil erosion in watershed.

Abstract:As power market demand becomes increasingly pronounced,the 110 kV power network develops rapidly in the recent years.The power network building increases soil loss from the construction area.The causes and characteristics of soil loss caused by overhead power transmission lines construction were analyzed.Combined with the project case,prevention zones were divided based on the features of the project area and project construction.Soil and water conservation measures were then proposed based on the divided zones.Result from the study is helpful to give a supplement and perfection to soil and water conservation in overhead power transmission lines construction and provide construction unit with scientific references to effective soil and water conservation.

Abstract:In consideration of the high sediment concentration in Jinghe River and the complexity of the power station operation,the characteristics of water and sediment in Jinghe River and their effects on power generation were studied by analyzing the hydrological data of water intake of power station from 1994 to 2009.Results showed that annual runoff and sediment yield presented a significant trend of decrease,which was closely related to the construction of soil and water conservation in Jinghe River basin.Runoff and sediment were unevenly distributed during a year,mainly in the flood season,and the amounts accounted for 64.6% and 92.6% of the whole year,respectively.However,sediment concentration in flood season was still high.Based on the change characteristics of water and sediment in Jinghe River,the effects of water and sediment on power generation were further discussed and several countermeasures ensuring the normal operation of the power station under high sediment concentration were preliminarily given.

Abstract:The regionalization and construction of eco-economic functional areas were made based on land uses and their functions in Shanghuang demonstration area.The ecological characteristics of landscape,functions,models,and indexes for the ecological protection area,dryland farming area,and efficient eco-agricultural area were presented.After 5 years of the construction of the functional areas,per capita income and per capita grain production capability in the demonstration area reached 4 470 RMB and 480 kg,respectively.Vegetation coverage and soil erosion module in 2010 reached 70.3% and 500 t/(km²·a),respectively.The initial targets for the three functional areas have been accomplished.The models and their technological systems of suburb eco-agriculture and eco-homeland established in Shanghuang demonstration area may be useful to the regionalization and construction of eco-economy functional areas at town and village scales in the loess hilly-gully region of southern Ningxia Hui Autonomous Region.

Abstract:Based on the theory of ecology and the contents of ecological city , the three concepts of health , safety , and development were introduced into the evaluation of ecological city .The index system for comprehensive evaluation model of ecological city for Xiamen City was constructed through the analysis of geog raphical environmental characters.Then Principal Component Analysis was used to calculate the target hierarchy of ecology healthy , ecology safety, and ecology development .At last , the comprehensive evaluation index of ecological city fo r each dist rict of the city was scored .Results are showed as follow s :(1)The urban planning was led to the process of nature construction and protection in aspects of ecology healthy , ecology safety , and ecology development by the comprehensive evaluation and analysis of ecological city based on ecology oriented .(2)There was a remarkable gap between districts inside island and out side island in the ecological city evaluation of Xiamen City .The evaluation indexes of Siming and Huli districts inside island were remarkably higher than those of Jimei , Haichang, Tongan , and Xiang an districts outside island .(3)The natural and human impacts were integ rated into the complex system of harmony and balance by the ecological city based on ecology oriented .The const ruction mode of the city should be led by urban layout of ecological function oriented and ecological function regionalization in urban planning , so tha tecological concepts were better integrated to urban construction .

Abstract:The Wenchuan earthquake area is one of the typical vulnerable areas in our country.Its vulnerability is quite evident on account of the seismically triggered geo-hazards like debris flow and landslide,variable geography remarkably different in height and wet climate,and human activities.In the light of the analysis which involves the factors,16 indexes including productivity of water,land use ratio,farmland area per person,topography and geomorphology,geological hazard degree,social economic development level,etc.are selected in order to set up an assessment index system.The system consists of four grades by DARE(decision alternative ratio evaluation)method and weighted ecological frangibility degree in evaluation index.Results show that ecological vulnerability is the strongest in the core of Longmen Mountains fault zone and Qinba Mountains,the stronger in the western plateau,moderate in piedmont plain,and the weakest in east hilly region.The influences of the landuse status and the distribution of earthquake induced disasters on ecological environment are analyzed.Result from the evaluation is important to guide economica1 development and ecological environment construction in the Wenchuan earthquake area.

Abstract:In 2005—2008,Zhejiang Province made an inquiry and evaluation to the debris flows in 42 mountainous counties of the province.It was found that there were 486 debris flows at various scales in the whole province,among which there were about 347 gully debris flows and 139 slope debris flows.From the analyses and studies of debris flow types and their distribution characteristics,gully debris flow is the main type of debris flow,characterized by small scale,large damage,and landslide-collapse changing into debris flow.The distribution of debris flow is mainly controlled by landform,rock nature structure,and precipitation and it is mainly distributed in the volcanic area along big fractures.Debris flows have the obvious bimodal distribution form due to plum rain and typhoon.

Abstract:On the basis of matter element analysis theory,the grade,evaluation indicators,and characteristic values of comprehensive land consolidation benefit are taken as matter elements and then the sutra field,controlled field,and matter element for judge are determined.A matter element judge model for comprehensive land consolidation benefit is established using correlation function of extension set and matter element.The model is applied to land consolidation projects in Wangguantun and Xiajingshen Towns,Yanggao County,Shanxi Province for a case study.The grade of comprehensive benefit belongs to degree Km(P)=(-0.101,0.037,-0.431),being a general grade,and it has a result similar to fuzzy comprehensive evaluation and accords to the conditions of project area.It is an attempt that matter element model is applied to evaluate comprehensive benefit of land consolidation.A new idea is provided for quantitative evaluation of land consolidation comprehensive benefit.

Abstract:The indexes of vegetation restoration degree,vegetation coverage,qualified control measurement rate,dreg blocking rate,reduced soil erosion rate,soil and water loss control ratio,sediment concentration,soil and water loss control degree,and disturbed land remediation rate are significant in the evaluation of soil erosion control effect.The 9 evaluation indexes are thus selected to construct an index system using the method of analytic hierarchy process and synthetic index method for the evaluation of soil loss control effect in Jinanqiao hydropower station project.In the five levels of very poor,poor,general,good,and very good,soil loss control effect in the project is in the "general" level,being low in vegetation restoration degree and low coverage,but high in sediment concentration.Result from the evaluation can provide further improvement in soil erosion control measurements of the hydropower station and a reference to similar research works.

Abstract:The middle and lower reaches of Fenhe River is in the arid and semi-arid area of the Loess Plateau of China and shortage of water resources and eco-environmental issues are very prominent.In views of the eco-environmental problems in development and utilization of water resources,this paper aims to construct a calculation model of ecological water demands in the middle and lower reaches of Fenhe River.Because the demands change with time and river sections,the middle and lower reaches of Fenhe River are divided into five sections according to hydrological stations for the calculation of ecological water demands with different hydrological frequencies.Ecological water demands are classified as river ecology surface evaporation,seepage demand,self-purification demand,sediment transport demand,and base flow demand.According to the relationship among them,total eco-environmental water demand is defined.Annual ecological water demands with the 4 hydrologic frequencies of 25%,50%,70%,and 95% are 617.43,377.94,236.93,and 158.56 million m³;the percentages over annual ecological water demand by channels are about 55.43%,61.97%,61.27%,and 88.15%;and the percentages over total flow averaged over years are 73.68%,45.10 %,28.27%,and 18.92%,respectively.It is necessary to take effective measures to control water resources for the sustainable management of Fenhe River basin and make use of water resources in different periods and reaches.

Abstract:In order to evaluate soil remediation and to judge ecological and environmental risk of the reuse of the sites where soil is remedied,the method of human health risk assessment is applied.Based on the approaches that soil pollutants enter into human body and the specific assumption parameters,a site contaminated by organic chemicals was evaluated and the human health risks,which are caused by many soil pollutants entering into human body through various approaches in different land uses and harming human health,were calculated.Results indicated that in the different land uses,the integrated noncarcinogenic risk of benzene,nitrobenzene,and aniline decreased from 4.42～46.10 to 2.50×10-3～2.61×10-2 and the integrated carcinogenic risk decreased from 3.06×10-6～7.41×10-6 to 4.75×10-7～1.19×10-6 after soil remediation.The site after soil remediation is suitable to business and industry in the future.

Abstract:Xinzheng City of He'nan Province is located in the central plain of China with semi-arid and sub-humid climate.Per capital water resources is 200 m3,being comparatively scarce.The city belongs to the region where is seriously short of water resources.Groundwater is excessively exploited and surface water is seriously polluted at present.There is a series of serious problems of water resources in the city.Its economic development and well-off society construction are directly restricted with growing population,accelerating urbanization,economical development,and improvement of people' living standards.Three different economic development schemes are considered based on the regional characteristics.Then quota method is applied to predict the water demands at different levels.A reasonable scheme is determined after the analysis of actual water quantity and current water issues.Some suggestions and solutions are put forward at last,combined with the forecasted results of water demands and the situation of existing water problems in Xinzheng City,which can provide a support for decision-making and digital foundation for logical water resource allocation.

Abstract:This study was conducted to solve the environmental problems of Kenli County,based on environmental sensitivity theory.Vegetation cover,groundwater salinity,buried diving depth,soil texture,and physiognomy were selected as environmental sensitivity factors.Supported by GIS technology,each evaluation factor was evaluated,the weights were obtained through expert scoring method,and the environmental sensitivity of each unit was calculated using index-sum method.Results indicated that the extremely sensitive area occupied 37.4% of the total area,the highly sensitive area occupied 25.7%,the moderately sensitive area occupied 26.0%,and the sensitive area occupied 10.9%.From southwest to northeast,the sensitivity degree increased with the Yellow River extending to the Bohai Sea.The results can be a reference to make environmental policies in Kenli County.

Abstract:Huyu Valley is located in the Xishan area of Taiyuan City,Shanxi Province.The occurrence of debris flows in the valley directly threatens the security of the local people.To further identify the hazards of debris flows in the area,the geologic processes are studied through the investigation of potential debris flows in the valley,including tectonic activities in Xishan area,complex topography and geology formed from stream incision,loose deposit caused by natural weathering and human activities,and unbalanced distribution of rainstorms.A analytical approach to risk assessment is used to analyze debris flows in the valley.Results indicate that the risk degree of debris flows in the valley is 0.768,being a highly dangerous degree,and they may threaten the downstream if erupting.

Abstract:Relative stability of dam system and its layout planning optimization are currently a hot area of the dam construction in small watershed.In this paper,the present situation of research and application about relative stability of dam system and its optimization design are reviewed at first.Optimization models of dam layout and construction timing are then established for the optimizations of intercepting sediment reservoir capacity,flood detention reservoir capacity,and design of spillway discharge by the principles of system dynamics,empirical method,dynamic simulation method,and non-linear programming method.Moreover,a computer flow chart of automatic optimization is presented.The optimization models of dam system are verified in Jiuyuangou watershed in the loess hilly area and desirable results are achieved.The study has a valuable reference for watershed dam construction in the similar areas of the loess hilly and gully area.

Abstract:Based on RS and GIS,the data of land use changes in Lanzhou City were extracted from TM,ETM,and thematic vector data from 1990 to 2006.Land use changes during the 16 years were analyzed and ecological environment effects were quantitatively estimated.Results showed that great changes in the city happened from 1990 to 2006.The area of woodland was increased significantly,most of which was transferred from grassland and cultivated land.The next was city traffic land,transferred from cultivated land,woodland,and unused land.The most significant reduction in land use was grassland which was transferred to cultivated land,woodland,and city traffic land.The total ecological service value of Lanzhou City rose from 43 594.95 million yuan in 1990 to 44 084.16 million yuan in 2006.These indicate that the environment of the city is developing toward a healthy status.

Abstract:With the increased investments in infrastructure in China,tunnel construction is strengthened,its technology is improved,and its scale is increasingly large.These have some significant influences on ecological environment at the same time.The connotation of tunnel project and its effects on ecosystem are discussed and the effects of tunnel project,including physical effect,chemical effect,biological effect,and social effect,are analyzed.Ecological tunnel project is a logical choice to maintain ecosystem health.Ecological strategies of tunnel project are discussed from the aspects of survey and design,construction,and benefit operation.Ecological tunnel project can alleviate the interference and damages to structure and functions of ecosystem and the threats to ecosystem health.This study may provide some references to the coordination of tunnel construction with environmental protection.