Abstract:Construction site of rocky slope surrounding Zhujiajian airport of Zhejiang Province was selected as the study site.Synthetic soils were constructed by adding chicken manure(CM) and peat soil(PS) with 12 different ratios.Based on the analyses of soil texture and aggregate composition,11 anti-erodibility parameters,which can be further classified into four groups including inorganic clay,micro-aggregate,water-stable aggregate and organic colloid,were calculated and compared.Principal component analysis was then applied to determine the contribution of each anti-erodibility factor.Furthermore,the anti-erodibility of the synthetic soils with organic amendments was evaluated.The results showed that the anti-erodibility indicators should be re-grouped into three categories: microaggregate,inorganic clay,water-stable aggregate,in which aggregation degree,aggregation status,dispersal rate were the best indicators for assessing anti-erodibility.As the PS group could not meet the minimum requirement of principal component analysis,no quantitative evaluation of anti-erodibility was conducted for the synthetic soils with different mixing ratios.Linear function analysis of the principal components and composite indicators showed that synthetic soils of the CM group have the best anti-erodibility with soil∶CM ratio of 2.41(weight basis).

Abstract:The aggregate movement during hillslope erosion process reflects the interaction among the aggregate breakage,raindrop impact and runoff transportation.The simulated rainfall experiment was designed to quantify movement characteristics of variously sized aggregates on hillslope farmlands of the black soil region,Northeast China.The results showed that the content of 0.25 mm water-stable soil aggregate was about 52%,24% lower than the contents obtained through dry sieving,while 1 mm soil aggregates contents was 83.8% lower.The majority of the water-stable soil aggregates was 0.25 mm aggregates.Under rainfalls of 50 and 100 mm/h intensities,0.25 mm aggregates contributed most of the aggregate loss,accounting for more than 80% of the total aggregate loss.The micro-aggregate loss rates were found significantly positively correlated with sediment concentrations under both rainfall intensities.As the rainfall time extended,the loss rate of micro-aggregate rapidly increased from the initial stage and then decreased in a short period of time and reached a relatively stable stage under 50 mm/h rainfall intensity;while under 100 mm/h rainfall intensity,the micro-aggregate loss rate increased quickly and increased slowly after the peak value was reached.The proportion of 0.25 mm aggregates loss and MWD of aggregates losses decreased with the increase of rainfall intensity,indicating that raindrop impact had played a great role in separating aggregates.

Abstract:To examine the effects of soil warming on carbon dynamics in the wetland ecosystem,a field-warming experiment was conducted under flooded and regular conditions in a typical meadow﹝Calamagrostis angustifolia(TMC) wetland﹞of the Sanjiang Plain,Northeastern China.Electrical cables were used to simulate soil warming.Warming caused significant increases in aboveground biomass on most measuring dates,accounting for 85.12% and 49.37% more than the control under the two water conditions,respectively.Meanwhile,the root biomass also increased by 43.27% and 54.39%,respectively.Elevated temperature tended to improve soil nitrogen availability through the growing season,which was significantly correlated to the increase of aboveground biomass and root biomass.Compared to control,CO₂ andCH₄ fluxes of the average growing season increased by 30.55% and 31.39% respectively,and were positively correlated with 5 cm soil temperature.However,flood condition significantly reduced the aboveground biomass while increased the root biomass.However,it had no significant effect on soil NH₄-N contents and CO₂ and CH₄ fluxes.The results indicated that soil warming would have direct effects on the fluxes of CO₂ and CH₄ and indirect effects on the biomass accumulation of C.angustifolia through improving soil NH₄-N availability in TMC wetland ecosystem.However,little interaction between carbon sequestration and emission processes was found under soil warming conditions.

Abstract:Water conservation capacity of the different plant communities were compared in north region of Yanshan mountain.The results showed that the interception by litter contributed most in the total interception of the aboveground layers.For total interception of aboveground vegetation layer,the plant communities were ranked in a descending order as follows: larch plantation(4.39 mm)natural secondary poplar and birch forest(3.81 mm)Corylus heterophylla shrub(1.7 mm)Spiraea pubescens shrub(0.18 mm).Both soil water holding capacity and total soil porosity of Corylus heterophylla shrub were the biggest,followed by natural secondary poplar and birch forest,larch plantation,and Spiraea pubescens shrub.In terms of soil infiltration,natural secondary poplar and birch forest had the highest rate,larch plantation and Corylus heterophylla shrub had similar intermediate rates,and Spiraea pubescens shrub had the lowest.The total amount of water conservation of the plant communites in a descending order was Corylus heterophylla shrub(272.52 mm)natural secondary poplar and birch forest(239.61 mm)larch plantation(221.53 mm)Spiraea pubescens shrub(194.85 mm).The amount of aboveground vegetation layer interception accounted only a very small portion of the total water conservation for all the communities,showing little importance in their overall water conservation capacity.It is concluded that Corylus heterophylla shrub and natural secondary poplar and birch forest are of critical values in water balance of the region,while the water conservation value of Spiraea pubescens shrub is low owing to frequent human and animal disturbances.As Spiraea pubescens shrub is widely distributed,some reasonable measures should be carried out to improve overall water conservation in this region.

Abstract:Combined with field survey,comparative analysis was conducted on long-term monitoring data collected in the Dongyizhigou gully and the adjacent contrast gully,which is located in the soft rock area in the upper and middle Yellow River basin.A clear trend of sediment grain-size distribution that sediment grain-size cumulative curve and total grain diameter became finer from the upper to lower stream was found in the Dongyizhigou gully,where seabuckthorn vegetation was planted and almost covered the whole gully.In contrast,the sediment grain size distribution showed no regularity at all in the control gully where no vegetation was planted.Specifically,the content of sediment with diameter larger than 1 mm was 2.0% on the gully bed of the Dongyizhigou gully,whereas it was 9.93% on that of the control gully.The analysis results showed that sand-fixing capability of seabuckthorn vegetation imposed a sediment sieve effect on the sediment transportation in the gully bed.

Abstract:A data set,which includes soil losses from field standard runoff plots established in red soil region during 229 rainfall events,was used to calibrate and validate the physically based soil erosion model(water erosion project,WEPP model).Meanwhile,sensitivity test and elastic coefficient analysis methods were applied to determine the major influencing factors of soil erosion and runoff on red soil slopelands.The results showed that erosion sediment yield is extremely sensitive to the input parameters including rainfall amount,intensity,rill erosion threshold,critical shear stress,slope length and gradient.Surface runoff is regulated strongly by the rainfall amounts,while is weakly sensitive to rainfall intensity,initial saturated hydraulic conductivity and effective hydraulic conductivity.In conclusion,all parameters aforementioned are the major controlling factors of soil erosion and runoff on red soil slopelands.

Abstract:Split plot design experiments were conducted to study the effects of irrigation amount and timing on onion water consumption and yield on lands graded with laser guidance.The results showed that the yield decreased with increasing water,the yield of the optimal irrigation amount(420 mm) varied between 12.6 and 13.1 ten thousand kg/hm²,4.1%-4.8% higher than the treatments with irrigation amount of 840 mm.This indicated a water-saving rate of 50%.The onion yield with 7 times irrigations was higher than that with 14 times.With the irrigation quota decreased,the onion water consumption was also reduced,while the corresponding yield increased and the efficiency of water was improved.The onion water requirements showed a parabola trend,i.e.,low in the early and final growth stages and high in the middle growth stage,which was consistent with soil moisture variations.

Abstract:Water flow resistance is one of the important hydraulic parameters.Elucidating the variations of rill flow resistance coefficient is critical to understand the hydraulic properties of rill flow and the mechanisms of dynamic rill erosion process.The flow resistance involved in rill erosion processes on loess hillslope was studied by a multi-plot experiment under simulated rainfall with addition of steady in-flow through the tops of the plots.The results showed that rill flow resistance coefficients for different rainfall intensities showed a consistently increasing tendency increase with runoff duration.Fifteen minutes after the initiation of runoff,the increasing trend changed and could be well described by an exponential equation.The resistance coefficients for different slopes exhibited the exactly same trend.The average resistance coefficient of rill flow decreased with increasing rainfall intensity,which can be described by a logarithmic equation,while it increased slightly with increasing slope steepness,which can be described by an exponential equation.A dual exponential equation can be used to describe the variations of the average resistance coefficient with various rainfall intensity and slope steepness.

Abstract:The variations of hydro-dynamic parameters(Reynolds number,Froude number,average flow velocity,water depth and resistance coefficient) of overland flows were characterized under different flow discharge,slope gradient and roughness based on flume experiments.The research results indicated that Reynolds number,Froude number,average flow velocity,water depth and resistance coefficient of the overland flows increased with flow discharge for the artificial beds with same roughness and slope gradient.Under the conditions of same gradient and flow discharge,Reynolds number,Froude number and average flow velocity of the overland flows decreased with increasing roughness,while resistance coefficient and flow depth increased.Flow discharge and slope gradient were found closely correlated with the hydraulic parameters such as average flow velocity,water depth,and resistance coefficient,which could be well described by simple power functions.Furthermore,the influences of flow discharge were dominant.

Abstract:Based on the field investigation and laboratory analysis,soil organic carbon was compared between upper and lower slope positions of Cunninghamia lanceolata stands with the aim of understanding the effects of slope position on carbon fixation of Cunninghamia lanceolata stands.The results showed that organic carbon storage of litter layer were 0.9 and 1.1 t/hm² in upper-slope and lower-slope,respectively,indicating a 32% increase from the former to the latter.Soil organic carbon storage was 149.9 and 174.2 t/hm²,respectively,in the upper-slope and lower-slope.The surface(0-40 cm) layers accounted for 55% and 56% of the total carbon storage(0-100 cm) for upper and lower slopes,respectively.Organic carbon contents decreased with increasing soil depths in both upper and lower slopes.In each layer,the content and storage of organic carbon of the upper slope were greater than those of the lower slope.

Abstract:The forest at Maolan National Nature Reserve of Guizhou Province(MNNRG) is the largest karst primal forest area along similar latitude in the world and of great hydrological significance to the region.Its major hydrological effect,according to the tracer technology of hydrogen and oxygen stable isotope,is to increase precipitation in summer and to supply ecological water need in winter.In 2010,the precipitation was 1 710.0 mm within the reserve area and 1 066.5 mm outside.The increased rainfall in the forest mainly came from evaportranspiration of epi-karst water.The epi-karst water cycle demonstrated distinct seasonal variations including a three-month wet season and two-month dry season,suggesting the epi-karst hydrodynamics might be affected significantly by forest growth cycle.

Abstract:The methods of comprehensive pollution index,double weight index,and Spearman′s rank correlation coefficient were used to evaluate the spatiotemporal variations in water quality of Weihe River in Shaanxi Province.According to the water quality data collected at 26 monitoring sections from 2005 to 2010,the temporal and spatial trends of COD and NH3-N and the driving forces were analyzed respectively.The results indicated that the overall water quality has improved certainly as shown by the reduction of COD.The water quality of Baoji section was classified as of the third grade.However,the pollution level in the section from Xianyang to Weinan City was still quite high.The polluted tributaries and drainage outlets in the areas of Xi′an and Xianyang City contributed mainly the pollution in the mainstream.

Abstract:The effects of freezing-thawing cycle on soil penetration resistance were studied on a black soil in Northeast China.The tillage experiment was established in Dehui City,Jilin Province since 2001.We compared soil penetration resistance before and after the freezing-thawing cycle under both no tillage(NT) and mouldboard plow(MP) treatments.Furthermore,we analyzed the relationship between soil penetration resistance and soil moisture content.The results showed that there was a significantly negative logarithmical correlation between soil penetration resistance and soil moisture content(R₂=0.838 8).Compared with MP treatment,NT led to a significant increase of soil penetration resistance before the freezing-thawing cycle,especially in the layer of 2.5-17.5 cm(p<0.05),while resulted in reduction of soil penetration resistance of 2.5-17.5 cm after the freezing-thawing cycle,especially in the layer of 2.5-10 cm(p<0.05).Soil penetration resistance was obviously less after the freezing-thawing cycle than before(p<0.05).Soil penetration resistance was greater under continuous corn system than under corn-soybean rotation system.However,even with the maximum soil penetration resistance,no restriction was found on the crop growth before and after freezing-thawing cycle of both NT and MP.

Abstract:The correlation between biodiversity and soil physiochemical properties were analyzed under four stand types in Great Xing′an Mountains,which were restored since burned in 1987,using the gray relational analysis.The results showed that the biodiversity varied substantially among four different stands,demonstrating a descending order of biodiversity as Pinus sylvestris var.mongolica plantationLarix gmelini plantationPobulus davidiana natural forestBetula platyphlla natural forest.The soil physical and chemical properties also varied;Pinus sylvestris var.mongolica plantation was found under the poorest condition.The grey relational coefficient between biodiversity and soil environment exceeded 0.5 for all the four stands,showing different correlations.Shannorr-Wiener index,evenness index and species richness index correlated closely with soil bulk density under Pinus sylvestris var.mongolica plantation and Pobulus davidiana natural forest,whilewith non-capillary porosity under Larix gmelini plantation and Betula platyphlla natural forest.The three indices were also found correlated closed with available phosphorus under the Pinus sylvestris var.mongolica plantation,Larix gmelini plantation and Betula platyphlla natural forest,except for Pobulus davidiana natural forest.

Abstract:In order to understand the effects of slope aspect and human disturbances on the diversity and community regeneration,field and laboratory analyses were conducted on Pinus tabulaeformis artificial forest in loess hilly region.The results showed that the community similarity coefficient of undergrowth was 74%,74% and 38% between shady and sunny slopes,between the natural and litter removed conditions,and between natural and timbered conditions,respectively.The indices of richness(R),Shannon-Wiener(H),and Simpson(D) of the shrub layer on the shady slopes were larger,while Pielou(J) in the shady was smaller than those on the sunny slopes.For herbaceous layer,R,H,D and J on the shady slopes were larger than those on the sunny slopes.The values of R,H and D in shrub layer were the highest under litter removed condition,then followed by natural state and timbered land;however J showed the exactly opposite trend.The values of R,H,D and J in herbaceous layer were the highest under litter removed,then followed by timbered and natural forests.The best regeneration of seedlings was found in the timbered land and on the shady slopes,respectively.

Abstract:In order to understand the status of soil water under perennial woodlands in the water-limited regions,soil moisture were observed using the neutron probe in the soil profile under Caragana microphylla shrubs in the semi-humid region of the Loess Plateau during April to November from 2002 to 2006.A compartment model was used to study the vertical changes of soil water.The results showed that the characters of vertical variations of the moisture in the profiles were described well by the model with the specifically calibrated parameters and the goodness of fit met the statistical requirement,suggesting a great potential applicability of the model to the similar areas.

Abstract:The relationship between soil macropore and preferential flow was analyzed in different citrus land in Jiangjin District of Chongqing City using brilliant blue dye method with image processing techniques,water breakthrough curve,and the Poiseulle equation.The results showed that the steady effluent rate of the dye-stained area was 1.48 times higher than that of the dye-unstained area.The radii of soil macropores ranged from 0.3 mm to 1.7 mm.The path of preferential flows were mainly found in the macropores with radii larger than 0.7 mm.

Abstract:Using micro-lysimeter,we observed the condensed water in the soils of variously degraded alpine meadows in Fenghuoshan basin of the Qinghai-Tibet Plateau.The formation mechanism of condensed soil water was further analyzed according to the observation data.The results showed that condensed soil water came mainly from two sources: water vapor in the air and in the vadose zone migrated upward under the action of the geothermal gradient.The water vapor from the vadose zone was significantly greater than that from the air.The condensation mainly occurred during night from 20:00 pm to 8:00 am in the next day,and the largest amount of water was condensed in early morning between 6:00 am and 8:00 am.Meanwhile,the condensation mainly occurred within the upper 5 cm of the soil profile.The amount of condensed water decreased with the degradation of alpine meadows,and the occurrence of condensation was of great significance in maintaining the balance of alpine meadow ecological system.

Abstract:Soil microbes in the root zones of cucumber were investigated.Three major micro-groups,major functional groups and the soil microbial biomass carbon(MBC) were addressed with various fertilization treatments.The study aimed to further understand the effects of different fertilization on microbial composition and MBC in cucumber root zone soil.The results showed that the fertilizer could be ranked in a descending order in terms of the total amount of soil bacteria,fungi and actinomycetes of the root zone as following: compost50% compost+50% chemical fertilizercommon fertilizerordinary organic fertilizerCK.For the diversity,soil actinomycetes of the compost treatment had the highest Shannon-Weiner index and the greatest amount of soil ammonifying bacteria,nitrogen-fixing bacteria and cellulose decomposition bacteria,while the treatment with 50% compost+50% chemical fertilizer had the greatest amount of soil nitrifying bacteria.Furthermore,soil MBC increased after applying both fertilizers containing compost.These results indicated that compost fertilizer could increase the amount and diversity of soil micro-organisms and subsequently improve the soil fertility.

Abstract:Aeolian activities,precipitation and human activities are the main factors affecting the delivery of the coarse sediments(0.05 mm) from the transition zones of arid and humid areas into the Yellow River in Northern China.The variations of coarse sediment transportation are determined by the total sediment yield and the percentage of coarse sediment.Based field collected suspended sediment yield,grain size of suspended sediment,precipitation,events of sand-dust storms and areas of soil and water conservation measures,the relationship between coarse sediment yield and its influencing factors were investigated in the basin of Wudinghe River.Both total sediment yield and proportion of coarse sediment in the total yield were used to describe the dynamics of coarse sediment transportation.Effects of physical process,referred to as the interactive fluvial-aeolian process,and human activities on the generation of the coarse sediment were studied,and the relationships between the two parameters and the influencing factors were investigated using geographic information system(ArcGIS) and statistical software(SPSS 12.0).The contribution of fluvial-aeolian changes and human activities to coarse sediment ratio and the total suspended sediment yield was analyzed using multivariate regression.The results showed that total suspended sediment yield correlated closely with the amount of precipitation and the area of soil and water conservation measures.The coarse sediment ratio was linked closely with aeolian factors and the area of soil and water conservation measures.It was also found that the contribution of precipitation to total suspended sediment yield was almost equal to that of human activities,while the contribution of human activities to the reduction of coarse sediment ratio was higher than that of aeolian activities.

Abstract:In order to understand soil reinforcement mechanisms of nitrogen-fixing plants,we chose five Leucaena trees with similar ages in Jiangjia Ravine of Dongchuan area of Yunnan Province,near which soil samples were collected on profiles of 2 m deep and 1 m wide.Soil and roots of Leucaena trees were taken for tri-axial experiments to determine the relationship among shear strength,cohesion,friction angle,root amount,and root diameter.It was found that both shear strength and cohesion related positively to the amounts and diameters of the roots.Meanwhile,the amounts and diameters of the roots negatively related to friction angles,to less extent.The results of tri-axial experiments agreed well with the cohesion principles.The cohesion of soil was enhanced by the roots;however,the friction angle of soil was degraded at the same time.According to the quantitative assessment on the roots of Leucaena trees in improving shear strength of soil,more attention should be paid to applying biological engineering measures to ecological restoration of this region.

Abstract:A study was conducted to investigate the distribution of total soil organic carbon,soil microbial biomass carbon and organic carbon in different size soil aggregates in three typical grasslands that were dominated by Panicum virgatum,Bothriochia ischaemum,Stipa bungeana in hilly-gully region on the Loess Plateau.The results showed that total soil organic carbon,soil microbial biomass carbon and organic carbon content in soil aggregates was higher in the soil surface than in other layers.The organic carbon contents of different grasslands in a descending order were Panicum virgatumBothriochia ischaemumStipa bungeana.A clear relationship was found between the organic carbon contents and the sizes of soil aggregates.2-1 mm aggregates had the highest soil carbon content.The total organic carbon content and organic carbon content in soil aggregates in Panicum virgatum grassland were higher than those in Bothriochia ischaemum grassland and Stipa bungeana grassland,while the microbial biomass carbon content was lower than that in Bothriochia ischaemum but higher than that in Stipa bungeana grassland.

Abstract:AN Le-ping,ZHAO Li-yi,XIN Ying,XIE Deng-ju(Tianshui Soil and Water Conservation Experiment Station,YRCC,Tianshui,Gansu 741000,China) The hilly-gully loess area is composed mainly of the fifth sub-region,involving parts of the second,third,and fourth sub-regions of the Loess Plateau.The major ecological environment problems in the region are short of rain,extremely dry,vast hilly gully area and intense soil and water erosion,which directly lead to the low quality of the local environment.Loss of soil and water,drought,low productivity and poverty are the prominent ecological,social and economic problems.We selected Dongshan village as a demonstration site,which is located in the Zhongshan river basin in the third sub-region of loess hilly-gully region.In addition to soil erosion control,rainwater harvesting and water saving irrigation techniques were deployed on the site as well.Meanwhile,many measures including cultivating and developing the featuring produces like grape,promoting water-saving agriculture,decreasing application amount of chemical fertilizers and pesticides were carried out to reduce non-point source pollution.We established a comprehensive monitoring index,and at the same time,set up a special monitoring and evaluating index system for demonstration benefit using analytic hierarchy process method based on field observation and interactive interview.

Abstract:The water absorbency and releasing characteristics of several water-retaining agents were analyzed in regard to their influences on soil water contents and survival rates of Haloxylon ammodendron seedlings,and further summarized the critical afforestation techniques of Haloxylon ammodendron under desert condition with application of water-retaining agents.The results showed that under the condition of fully saturated,the agents can be ranked in a descending order of water absorbency ability as HongsenHaimingJinyuanyiWote.Considering both water absorbency and water release rate,Haiming showed the best water-saving effectiveness.Dry application of water-retaining agent decreased enormously its water absorption ability under the natural conditions.In contrast,wet application of water-retaining agent significantly increased the soil water content in 20-30 cm depth of the soil and the survival rate of Haloxylon ammodendron seedlings(p0.01).Wet application of 60 g per stem was the best treatment.We concluded that in the afforestation of Haloxylon ammodendron in desert condition,the application of water-retaining agent should follow the procedures: soaking agent fully with water first(60 g per stem),applying under wet condition,and then burying and mixing the agent into the soil at the depth of 20-30 cm and near the roots.

Abstract:With rapid development of the resources and social economy in Xinjiang Uygur Autonomous Region,some provisions,especially the compensation standard,are not suitable for the new situation and needs.Therefore,we should explore further in practice and establish new collecting standards of soil and water compensation in Xinjiang region to promote the harmonization between economic and social development and ecological environment associated with soil and water conservation.Incorporating the practices of soil and water conservation administrative divisions,this study described the connotation and denotation of soil and water conservation compensation,analyzed the present status and risks of soil erosion in the region,compared the approaches to estimating the values of ecological service function,and especially assessed the soil and water conservation function values of Xinjiang region.By calculation,the soil and water conservation function value in Xinjiang region was approximately 123.1 billion/a.The result could be used as reference to determine soil and water loss compensation in coal,oil and natural gas development projects.

Abstract:Heihe River is the second largest inland river in the northwest of China.Its wetland has played a significant role in the natural ecological environment and social economy of the Hexi corridor.In order to expedite the recovery process of the degraded wetland,ecological restoration practices including planting Phragmites australis and Tamarix chinensis along with enclosure was experimentally tested.The results showed that by the coverage 1 and 2 year after Phragmites australis planting increased 36.8% and 49.6% respectively.With top-pruning(10-12 cm aboveground parts retained),the average growth(in height) and new stem numbers of Tamarix chinensis increased 67.8% and 30.8% more than the control without top-pruning,respectively.In addition,top-pruning of Tamarix chinensis led to 16%-22% more increases of vegetation coverage.The vegetation coverage increased from 45.7% to 77.2% for the enclosure treatments,with 40.9% increase in height and 73.1% increase in average total aboveground biomass.

Abstract:Concave-down green space is a simple rainfall collection technique in urban setting.It has advantages such as simplicity,low investment and high efficiency.The storage and infiltration efficiency can be improved with increases of the depth of concave and the area of green space.According to the actual situation in Tianjin City,the experimental tests and theoretical calculations suggested that the depression depth should be 100 mm in the environmental setting of Tianjin City.With 30% green space rate,the storage-infiltration efficiency could reach up to 70% for the storms with recurrence interval of 1 or 2 years,which will reduce the flow peak and at the same time,minimize effectively the water demands of green oases and increase ground-water resources.

Abstract:Debris-flow valleys in Southeast Tibet were found distinct in their channel structure.The source area of debris flow usually extends to the middle reaches,with cross and confluence of the channels.The traditional method based on the full-valley parameters is inadequate to provide accurate parameters for engineering designs.We proposed a new method to calculate the peak discharge of debris flow.Based on field survey in Shannan Prefecture of Tibet,a traditional valley was measured.We calculated the hydrograph with the triangle model and concentration time of sub-basins with large areas(25% of full-valley area),and then obtained the converged hydrograph and corresponding peak discharge,which is amended by the concentration times of two sub-basins.Comparing the results of the full-valley method and the proposed new method,we concluded that the proposed method accurately captured the contribution of dynamic sub-basin discharges and is of greater applicability.

Abstract:Salt content in the top layer of soil is one of main factors that should be taken into account in soil salinity classification.This study analyzed three saline soil reflectance spectral database which include soils with various salt and soil moisture contents.With the help of statistic analysis,the relationship between soil salt content and five hyperspectral indices was analyzed and contrasted.The optimal hyperspectral index and spectral predicting models for soil salt content was developed.The results showed that the most sensitive wavelengths for soil salt content were in the NIR and SWIR domains,indicating possible sensitivity of the characteristic features associated with salt minerals in the VNIR-SWIR region.The selected ND index can be calculated easily and is insensitive to soil moisture,and therefore has wide applicability for large-scale soil salt content mapping.

Abstract:In this study,topographic information(e.g.,elevation,slope degree and aspect) and land use in Huangling County,Shaanxi Province were extracted from DEM and land use map of the county with ArcGIS software.The distribution of various land use types regarding different elevations,slope degrees and slope aspects was analyzed by overlapping the topographic features and land use information.The results showed that most farmlands,garden lands and residential lands were located in the areas with slope degree lower than 3° and lower altitude.In contrast,forest lands were concentrated in the areas with slopes degree greater than 8° and elevations lower than 1 000 m.From the perspective of slope aspect,the flat lands have been commonly used while the lands with other slope aspects were used to various extents.

Abstract:Flood level is important information for flood control decision and flood loss evaluation.Based on the principles of trend surface analysis and field survey of flooded areas of Mabu Town in Wenzhou City during typhoon Matsa,a simple and quadratic trend surface model of flood level was developed and validated.The results showed that the prediction of the model matched the field data of the flood levels quite well,indicating the strong coefficients of determination of 0.95 and 0.96 for the first and second order surface simulation(p0.01),respectively.The average absolute error of the first-order model was 0.1 m in validation,while that of the second-order model was 0.3 m lower.

Abstract:In order to establish rational use of ASTER GDEM and SRTM elevation datasets,the slope and slope length have been extracted from the datasets that were downloaded from the website and have been preprocessed.Furthermore,the extracted features were compared with Hc-DEM derived variables.The results showed that:(1) the Hc-DEM derived features were much better than the SRTM and ASTER GDEM derived in terms of all the topographic variables including elevation,slope,and slope length.(2) the variables extracted from ASTER GDEM were unrealistic for the areas with gentle slope,owing to the abnormally void values and irregular sinks,but in steepy area it is useful;(3) the topographic variables extracted from SRTM and Hc-DEM showed similar patterns,while the SRTM based variables featured reduced slopes and extended slope length,suggesting down-scaling may be required if it is applied in hydrological or erosional modelling.

Abstract:The aim of this study was to evaluate the efficiency of different vegetative restoration settings on mining wasteland.Vegetation species,quantity,coverage,species diversity and biomass were surveyed by standard plots on different treatments deployed on the mining wasteland of Zijinshan gold-copper mine in Fujian Province.The results showed that the number of vegetation species was rapidly increased at almost all the treatments,and the species number of the herb layer were significantly greater than the control after 5 year restoration.Species quantity at Pinus massoniana +Lespedeza bicolor+ Vetiveria zizanioides+ local flood turf(mode B) was the most.There was 25 species of those.Diversity index at Liquidambar formosana + local beach turf(mode D) and Eucalyptus robusta + local flood turf(mode E) were bigger than others,these two vegetation allocation modes could rapidly increased the species diversity of the community.The vegetation coverage also increased greatly.There were above 85% apart from Pinus massoniana+Lespedeza bicolor(mode A).The biomass of herb layer at Pinus massoniana +Lespedeza bicolor+ Vetiveria zizanioides+ local beach turf(mode B) was the largest,it was 15.81 times to the control.The treatments of Pinus massoniana+Lespedeza bicolor+Vetiveria zizanioides+local beach turf(B),Liquidambar formosana+local beach turf(D) and Eucalyptus+local beach turf(E) performed considerably better than the other ones and therefore can be promoted for larger areas in the vegetation restoration of the mining wasteland.

Abstract:Simulation of the changes of land use structure is one of the most important components in land use planning.In this study,a dynamic model of land use change was constructed based on dynamic modeling theory,and the thorough knowledge of the land use change and the driving forces.Taken Jiangning District of Nanjing City as an example,the scenarios of land use were simulated between 2006 and 2020.The simulation results showed that the model predicted well the past and future land use structure change in the study area.

Abstract:With the staggering development of computer and graphics sciences,stand visualization technology has become a solid foundation and guarantee for digital and meticulous forestry in the 21st century.Beginning with the basic principles of stand visualization system(SVS),we demonstrated the operation and outputs of SVS based on the forest survey in Mulan Weichang state-owned forest farm.In addition,we illustrated the technical process of individual tree simulation and mixed plantation visualization via SVS.The simulation outcomes were analyzed and discussed as well.The results of the this study indicated that SVS could provide successfully an intuitive,three-dimensional picture with substantial statistical data of forest stands,including species and DBH distribution,height structure and forest canopy.In the fictitious forest environment,SVS can be used to design and modify various forest management plans,and to simulate the entire process of forest management.We concluded that SVS is an ideal tool for visualize forest management.In the end,the paper discussed the current limitations and possible future needs in development.

Abstract:Infiltration,as one of the fundamental physical properties,is closely related to many processes including rainfall-runoff,soil erosion and non-point pollution.It is critical to measure soil infiltration rate quickly and accurately.Soil infiltration rates were measured using four methods of double-ring,single-ring,disc permeameter,and Hood infiltrometer on the loess-derived soil with planted soybean at the Ansai Research Station of Soil and Water Conservation,which is located in the hill-gullied area of the Loess Plateau.The results were evaluated based on the measured steady infiltration rate by double-ring method and saturated conductivity by Hood infiltrometer.The results showed that the steady infiltration rates of single-ring,disc,and Hood methods were 116%,111%,and 225% of that of double-ring method,respectively.The saturated conductivities of double-ring,sing-ring,and disc method were 65.8%,75.1%,and 105% of that of Hood method,respectively.The times of reaching the steady infiltration were quite different,approximately 100,80,and 30 minutes for double-ring,single-ring and disc method,respectively.The disc permeameter was more suitable to measure soil infiltration on hillslope for not only the savings in time,labor and water,but also the accuracy in estimating the steady infiltration rate and saturated conductivity.

Abstract:To understand the movement of solid particles in micro-channel and improve the anti-clogging ability of emitters,we observed the movement of solid particles of different diameters and the different densities in labyrinth channel using particle image velocimetry(PIV).The trajectories of solid particles showed that water in zigzagging channel flew in sine wave,and formed mainstreams near the tips of the spikes and turbulence at the bottoms.Particles of small diameter(65 mm) or low density(1 740 kg/m3) exhibited apparent following behaviors.With the increase of the diameter or density,water flew more turbulently,particles moves slower and became more easily to be trapped and caused clogging.Comparing to the diameter,the density of the particles affected less their movement trajectories,path lengths and velocities.

Abstract:China National Experimental Sustainable Communities(CNSCS) are of great importance as the experimental and demonstration bases regarding the sustainable development strategy carried in China.Evaluating the sustainable development level is one of the key topics of CNSCs study.Based on the concept of emergy,we established an assessment index system considering emergy total,emergy intensive degree and emergy efficiency,and proposed three indices including emergy sustainable index(ESI),sustainable development index(SDI),and urban eco-efficiency index(UEI).Taking the CNSCS of Yulin City as an example,we evaluated the sustainable development level using the established approach.The results showed that,from 2000 to 2008,the ESI was much larger than 10 but kept reducing continually,indicating that the economic development level of Yulin City was still underdeveloped.The SDI decreased year by year,implying reducing social and economic benefits under the environment pressure.The UEI also decreased gradually,suggesting that the self-organizing capacity,the development potential and the recycling capacity of Yulin City still needed to be improved.Emergy analysis method provides a new ways to assess the sustainability of CNSCS,which generates more objective assessing results.The method can be used to evaluate and compare the sustainable level of CNSCS of different levels and different sizes by eliminating the obstacles induced by the differences of research objects.It has a direct significance for identifying the development problems and optimizing development strategies of the CNSCS.

Abstract:Special projects such as highway construction,surface mining,and the devastation of mountains often cause surface exposure of bed rocks as side slopes.Owing to the special needs of oil reserve and chemical repository,it is important to consider the special habitat and ecological environmental management on these rock slopes.In this study,the habitat characteristics of these artificial slopes and sites were analyzed,and appropriate environmental management practices of these special habitat conditions were proposed based on the ecological theory.The findings of this study are expected to provide theoretical foundation for similar ecological environmental management plans.

Abstract:The Holocene sediment profile was surveyed in detail and sampled systematically at the Liaowadian site on the first river terrace in the upper Hanjiang valley.Its sedimentological and hydrological characteristics were observed in the field.Particle-size distribution,magnetic susceptibility and loss-on-ignition were analyzed in laboratory.An integration of the results showed that the palaeoflood slackwater deposits of the profile are very typical,recording an extreme flood event that might occur during A D 100-300 according to stratification comparison.Based on flood level information recovered using sedimentological and palaeo-hydrological methods,the palaeoflood peak discharge could reach 65 420 m3/s.The methods were further validated by the reconstruction of the modern flood event(20110919),with a very low error less than 1%.

Abstract:The structure characteristics of the communities under manmade forests were surveyed at three different attitudes in Jiuzhoutai District of Lanzhou City based on typical sampling strategy.The characteristics of species diversity were then analyzed based on the survey results.The results indicated that the communities on the midslope(altitude1 760-1 840 m) had the highest species diversity indices(DHJ),the most species,and the best recovery degree.The layers of shrub and herb on the upslope(1 900-1 970 m) showed the lowest richness index,while the layers of shrub and herb on the downslope(1 590-1 730 m) showed the highest.The development of herbaceous layer was apparently better than the layers of shrubs and woods on the north mount according to the richness index,the species composition and biodiversity.The succession of communities was still at their early stages at all the slope positions,as implied by the dominant sunny species under the woody layer.The research on the biodiversity of manmade ecosystem at different altitudes was the extension of eco-afforestation project carried out on the north and south mounts;the findings from this study is of great importance for evaluating the effectiveness of vegetation recovery and reconstruction on the north and south mounts.

Abstract:An improved growth model was established by adding a stressing factor to classical Logistic model.The growth data of Caragana microphylla shrubland was collected in semi-arid loess hilly region,Guyuan City of Ningxia Hui Autonomous Region,to which the new model was fitted.The result showed that the improved model is highly sensitive to the planting density.The optimal density of caragana in the study area should be limited in the range from 51 to 71 clusters per one hundred square meters.

Abstract:Standard runoff plots were built in Jianshan small watershed of Fuxian Lake watershed in Chengjiang County,Yunnan Province.In addition to the control,two types of soil and water conservation measures were set up on the sloping farmland,i.e.,reverse-sloped terraces with 1.2 m interval and grass strips with 2.0 m interval.Surface runoff and sediment yields were monitored after each rain events to compare the water and soil conservation effects of these two measures.It was shown by the study that both surface runoff and sediment yields differed significantly between the two measures.The runoff depth for the reverse-sloped terrace was 113.64 mm during the year,which was 61.9% less than that of the control,while the observed soil loss was 714.7 t/km²,approximately 77.4% less than the control.For the grass strip treatment,the runoff depth was 82.76 mm,72.2% less than the control,whereas the soil loss was 370.1 t/km²,88.3% less than that of the control.Apparently,both measures showed significant benefits in reductions of both surface runoff and soil loss.The average index values of runoff and soil loss reduction were 0.57 and 0.97 for constructing reverse-sloped terrace,and were 0.79 and 0.76 for building grass belts,respectively.The total N and P losses in surface runoff and sediment were also reduced remarkably,by 81.9% and 44.3% for reverse-sloped terrace,and by 74.7% and 83.7% for grass belts,respectively.

Abstract:Basing on pressure-state-response(PSR) model,we screened indices including ecological pressure of railway construction,nature reserves status and countermeasures response effectiveness,determined weights of each index by AHP,and then constructed an evaluation system based on triangular fuzzy numbers.The results showed the impact rank of the proposed railway on the environment of Shapotou Nature Reserves could reach as low as grade Ⅰ,suggesting reasonable route selection and scheme design,effective protection recovery measures and acceptable influences on the environment.More importantly,the method of combinating AHP and triangular fuzzy number could overcome the shortcomings of single factor evaluation,the difficulty quantification of assessing indices,and poor comparability.The evaluation results were found consistent with field survey and expert review conclusions,which implies that the proposed evaluation system is of good feasibility and applicability.

Abstract:Based on the statistic data of crop yield,planting area,effective irrigation area,fertilizer usage and agricultural machinery power of Hebei Province from 1989 to 2008,the carbon source and sink of the farmland ecosystems in Hebei Province were estimated.Furthermore,the temporal and spatial variations and the influencing factors of carbon source and sink were analyzed.The results showed that the total carbon sequestration and emission of the farmland ecosystems in Hebei Province showed a gradually rising process in the last 20 years,and more carbon was sequestrated than emitted.Overall,the farmland ecosystem of Hebei Province was a carbon sink.Spatially,the density of carbon sink declined from southeast to northwest.The carbon sequestrated by wheat and corn plants accounted for the largest proportion.In addition,the process of agricultural irrigation was the main controlling factor for carbon sequestration.The carbon emitted from fertilizers contributed the biggest proportion among the three major carbon emission sources of the farmland ecosystems.

Abstract:Through the collection,reorganization and analysis to the historical data and materials,the time and grade of the drought and flood disasters has been compiled for Ankang City.In addition,we tried to correlate the natural disasters with the location,migration,and reconstruction of Ankang City in the history.The results showed that,from 500BC to 2000AD,drought disasters altogether occurred 79 times during these 2 500 years,averagely one time per 31.65 year,while flood disasters occurred 140 times,approximately one time per 17.86 year.During 500BC to 1000AD,the natural disasters were rarely recorded,and more were found since 1000AD.The highest frequency of the recorded natural disasters was found during the period from 1400AD to 2000AD.The extreme flood disaster was the reason for the migration of Ankang City from the old city to a new site for twice.However,the return of Ankang City back to its old site was a synthetically action effected by many factors,such as water transportation,farming and cultural psychology of the residents.

Abstract:Estimation of soil erosion is of great importance for ecological protection and erosion control in the major grain producing areas of the North China Plain.Based on geographic information system(GIS),the revised universal soil loss equation(RUSLE) was employed to assess quantitatively soil erosion in the North China Plain by incorporating the interpreted data from remote sensing images,digital elevation model(DEM),soil map and rainfall data.Furthermore,the spatial distribution of the soil erosion intensity has been obtained.The results indicated that the annual average soil erosion modulus was 2 674.26 t/(km²·a) with the maximum of 8 302.11 t/(km²·a),which can be classified as overall moderate according to the national standard.The areas which under the mild range accounted for 82.94% of the study areas,suggesting that the soil loss was under control.Approximately 7.33% of total area was still on the severe range,especially in the rocky mountainous areas along the Taihang Mountains,Yanshan Mountains,Tai Mountains,and Dabie Mountains,the key areas where soil erosion are yet to be controlled.

Abstract:We analyzed land use changes of Chongqing City during the last 10 years,and then built a landuse evaluation system,considering both regional geographic characteristics and the requirement of quantitative evaluation.The results showed that the area of farmland decline sharply between 1999-2008,accounting for a net decrease of 293 679.7 hm².Meanwhile,the area construction land increased substantially by a total of 74 334.1 hm².Both the structure of landuse configuration and the degree of land utilization decreased,from 0.713 2 and 0.114 3 in 1999 to 0.294 2 and 0.038 7 in 2008,respectively.Land use conflicts highlighted the low intensification degree of landuse in the study area.Land use efficiency and utilization benefit increased significantly from 0.065 5 and 0.046 7 in 1999 to 0.447 2 and 0.301 1 in 2008,respectively.However,the overall efficiency is still relatively low,indicating that the land productivity can still be improved potentially.Landuse performance value was still relativity low,but its trend was keeping increasing steadly,similar the changes of social economical development and natural environmental condition.Chongqing City is moving towards in a development direction of reasonable and sustainable land use.

Abstract:Taking Yancheng coastal wetlands as an example,we analyzed the spatial and temporal evolution characteristics of coastal wetlands landscape about two periods based on the years of 1987,1997 and 2007 landscape images.We used two landscape ecology indicators: transition probability and centroid,with the technologies of RS and GIS.The results indicated that both the landscape structure and centroid changed from 1987 to 2007.Firstly,the percentage of natural wetland dropped from 42.45% to 21.44%,but the artificial wetland rose from 18.19% to 58.88%.During the former decade,45.40% of the natural wetlands were transferred to the artificial wetlands or the non-wetland;while in the later decade,additional 37.91% of the natural wetlands were transformed,leading to an increased and then decreased landscape heterogeneity over the time.Secondly,both the natural and the artificial Landscape centroid shifted to the southeast from 1987 to 2007.From 1987 to 1997,the artificial wetland centroid moved 58.17 km and the natural wetland centroid did 6.15 km,while from 1997 to 2007,they shifted additional 12.67 and 7.15 km,respectively.

Abstract:In order to study the spatial and temporal evolution of the regional landscape in Hanjiang River in Shaanxi Province after the construction of hydropower system,remote sensing images of 1988,2000 and 2007 were interpreted and GIS buffer analysis was applied with widths of 500,1 000 and 5 000 m.The results indicated that water areas showed an increasing trend,while the arable land displayed a steady decreasing trend in the study area since 1988.During the sudied period,landscape pattern was in an unbalanced state with frequent two-way conversions,towards the direction that is beneficial for improving the regional ecology.According to the analysis on landscape fragmentation,landscape diversity and landscape shapes,the degree of landscape fragmentation pattern of the study area increased between 1988 and 2000,and the shape became more complex and landscapes was diversified.Between 2000 and 2007,the degree of landscape fragmentation reduced,the shape became more regular and the landscape diversity decreased.These evidences indicated that the landscape pattern experienced a regional ecological improvement.It can be concluded that the hydropower development has exerted great influences on the landscapes in the study area.

Abstract:The contents and potential pollution risks of Cd,Cu,Zn and Pb were studied in vegetable soil around Dongting Lake in Hu′nan Province.The results showed that the contents of Cd,Cu and Zn in top soil were higher than the background values,while Pb contents were lower.With single pollution index and comprehensive pollution index,the ascending order of the risks of heavy mental pollution was CdZnCu in vegetable soils.Pollution of Pb was not found in the whole study area.Based on the pollution index and comprehensive pollution index of soil heavy metals,the vegetable soil of Xiangyin County,Yuanjiang District,Ziyang District and Haoshan District belonged to polluted soil,and the soil of Huarong County exhibited warning pollution level,requiring immediate remediation or change in the pattern of land use.By contrast,the soils collected from Junshan District and Nanxian County were almost free to pollution,suitable for the cultivation of green vegetables.The relationship of soil Cd,Cu and Zn content was significantly positive,while the coefficients were low.

Abstract:In this study,we assessed the ecosystem service value of the second stage project of soil and water conservation deployed in Guyuan area of the Ruhe watershed according to the characteristics of ecosystems.The market value method,cost-alternative method,shadow-engineering method and opportunity-cost approach were applied to five indicators including soil conservation,water source conservation,carbon fixation and oxygen release,air cleaning and biodiversity conservation.The results showed that the ecosystem service value has increased by 852.93 million yuan since the project launched five years ago.The service of maintaining and improving soil quality contributed most to the total ecosystem value,accounting for about 48.86%.The service of water conservation contributed 30.16%,while carbon fixation and oxygen release and the other two accounted for 14.96%,3.7% and 2.31%,respectively.It is clear that the soil and water conservation measures played a significant role in environmental protection and soil erosion control in the Ruhe watershed.

Abstract:Based on the meteorological data collected in Inner Mongolia Autonomous Region during the past 50 years,we analyzed the characteristics of climate change in Inner Mongolia Autonomous Region since 1961 and attempted to establish the relationship between El Nino/La Nina events and the variables including annual precipitation,temperature and natural disasters.The results showed that compared to the normal years,annual precipitation of the El Nino years was 31.45 mm and that of La Nina years was 14.69 mm less by average,indicating a significant influence by the ENSO events on the regional climate.In contrast,annual temperature increased by an average of 0.12 ℃ in the El Nino years,and by an average of 0.22 ℃ than in the La Nina years,indicating that the ENSO events caused significant warming in the study area.Generally speaking,ENSO events increased the possibility of drought disaster,and moreover,the El Nino years had even higher possibility of drought than the La Nina years.Consequently,El Nino/La Nina events were often unfavorable for the agricultural and animal husbandry production of Inner Mongolia Autonomous Region.

Abstract:Soil microbes were collected from the root zone of dominant native plants Leymus chinensis and Stipa baicalensis on Hulunber meadow.The diversity and dominant species of microbes were analyzed based on isolation,culture and biochemical analysis.The results demonstrated that the treatments could be ranked according to the gross amount of microbes in a descending order as: Leymus chinensisStipa baicalensisControl.However,no significant difference was found among the treatment(p0.05).In the samples,bacteria had the highest species numbers,actinomyces had the intermediate,and fungi had the lowest(p0.01).Specifically,36 colonies of bacteria belonging to 7 genera,21 colonies of actinomyces belonging to 4 genera,and 17 fungi culturists of 3 genera were identified in the root zone soil of Leymus chinensis along.

Abstract:The technologies of RS and GIS were applied to obtain the five evaluation factors including annual precipitation,annual temperature,slope,elevation,and land cover within the Buhahe basin.With spatial modeling and analysis,we obtained spatial distribution of soil erosion within the basin and classified soil erosion into different classes.The results showed that in the study area,the total area of soil erosion was 14 337 km²,of which mild and moderate erosion were dominant,accounting for 54.88% and 20.51% of the total eroded area,respectively.A small portion of the basin has experienced severe erosion,accounts for 0.63% of the total eroded area.

Abstract:Spatial distribution patterns of nitrate nitrogen and ammonia nitrogen were studied in the tidal marsh soils of the Yellow River Delta by geo-statistical methods.The results showed that the NO₃^--N and NH₄⁺-N contents had significant horizontal variability in different soil layers,which was mainly correlated with their active physical transport characteristics caused by the better water conditions in the tidal marsh.The horizontal distribution of NO₃^--N in topsoil displayed significant spatial structure,which can be best fitted with Gaussian model and had moderate spatial correlation.The natural structure factors had significant effects on the spatial variability,while the effects of random factors were relatively low.The maximum spatial variability of NO₃^--N in topsoil was observed in the direction extending towards the low tidal marsh,showing a great effect by the ebbs and flows of tide.The spatial distribution patterns of NO₃^--N in topsoil were significant.The lowNO₃^--N contents in topsoil were generally observed on the sites close to low tidal marshes,while the high values appeared on the edges of the study area.This study indicated that micro-physiognomy characteristics and tidal micro-domain physical disturbance were the two most important random factors inducing spatial heterogeneity,while water and salinity conditions,soil types and tidal circulation were three important structure factors.

Abstract:The Maotiaohe River is the first river in China which has been completely developed for hydropower in a cascade manner.In this study,we systematically analyzed the regimes of hydrometeorological variables and detected their possible trends.Meteorological and hydrological observations on a daily basis were obtained at three weather stations in the vicinity of the Maotiaohe Basin for the period of the 1950-2010.Linear regression and the Mann-Kendall non-parametric trend detection technique were applied.In addition,daily reference crop evapotranspiration was calculated based on the FAO56 equation.The results showed that the mean annual precipitation ranged 1 000-1 300 mm/a in the watershed,while no statistically significant temporal trend was detected.The temperature of the watershed increased about 0.4-1.0 ℃ over the past 60 years,exhibiting a warming trend.The mean annul sunshine hour ranged 1 200-1 300 h/a,showing a decreasing trend at a rate of 8-10 h/a.Daily crop evapotranspiration was found to be 2.5-2.7 mm/d and mean annual reference crop evapotranspiration ranged 900-1 000 mm/a over the study period,displaying a decreasing trend over time.The decrease of evaportranspiration was closely correlated with the trend in sunshine hour.Overall,the Maotiaohe River watershed showed a slightly warming trend,which did however have not resulted in a significant impact yet on water resources of this watershed.

Abstract:Comprehensive assessment on the quality of soil and water resources provides a base for structure adjustment of agricultural planting and optimal allocation of soil and water resources.In order to promote the wise-use of soil and water resources and economic development in Heilonggang area,the comprehensive assessment was carried out at pixel scale on the ArcGIS 10 platform.The evaluation results showed that the quality of the soil and water resources in Heilonggang area was low,with quality values varying between 0.4-0.6.Only 2.5% of the total area had a quality score higher than 0.6.Spatially,the middle and southern regions had high quality resources,and the resources of the eastern and western edges of the study area were of lower quality.The results also showed that the soil resources that had relatively poor quality at present could be improved if water quality became better and at the same time,regional integrated quality of soil and water resources could be raised.

Abstract:Based on the water resource inventory and the socio-economic environmental data collected in Shaanxi Province,we developed a water ecological risk index system according to the concept of Pressure-State-Response(PSR) and the regional ecological risk assessment theory.Combined with GIS technology and the AHP and the composite index methods,we analyzed the economic and demographic carrying capacity,and assessed the temporal and spatial changes of the ecological risks of the water resources.The results show that the water resource pressure and integrated risks increased rapidly as the economy and the population grew.Overall,the state risk was the highest,pressure risk moderate,and the response risk the smallest.Central,northern and southern parts of Shaanxi Province exhibited ecological risks in a descending order from high to low,respectively;specifically,Xi′an areaXianyang areaYulin areaWeinan areaBaoji areaYan′an areaHanzhong areaTongchuan areaAnkang area Shangluo area.The vulnerabilities of local natural environments,such as uneven spatiotemporal distribution of water resources,fast societal development,rapid economic growth,unbalance water ecology,water environmental degradation,and unstable economic system were the main driving forces causing water resource risks in Shaanxi Province.

Abstract:Taking Jiangsu Province as an example,an index system of social-economic system was established based on the analysis on the time series of ecological deficit(ED) from 1985 to 2009.An ED dynamic prediction model was then developed using the conjunction of STIRAPT model,VIP value and the partial least square regression(PLS) method.The results demonstrated that the ED of Jiangsu in the plan period of "the 12th five-year plan" could increase from 1.156 1×108 hm² in 2009 to 1.418 4×108 hm² in 2015.ED per capita could also increase from 1.496 7 hm² to 1.768 8 hm² in the same time period,significantly higher than the global level(0.400 0 hm²).The classical environmental Kuznets curve(EKC) hypothesis could not explain well in the ED of Jiangsu Province.The VIP values showed that the many factors exerted strong influences,in an descending order of significance on ED as: ratios of primary and secondary industry in GDPtotal cultivated areaGDP per capitastudent to teacher ratio in higher educationbed number in health care unitsvolume of goods transportationtotal population.Based on these analyses,recommendations including transforming economic growth pattern,increasing total cultivated area,controlling the volume of goods transportation,and restraining rapid population growth,were proposed to slow down the increment of ED and to achieve the long-term development goals in Jiangsu Province.

Abstract:Taken Liangshan County,one of the key demonstration sites in the fifth initiative regarding soil and water conservation in upper Yangtze River as the study area,we analyzed the changes in ecosystem service values of Liangshan County,and developed comprehensive management practices and related models for assessing ecosystem service values in small watersheds,based on the published service values of Chinese terrestrial ecosystems and local grain yield and market price.The results showed that the land use type changed greatly from 1999 to 2003,as the areas of unused and cultivated lands decreased 36 038.67 hm² and 5 498.50 hm²,and the areas of forest and pasture lands increased 35 614.30 hm² and 5 889.53 hm²,respectively.Under the scenario that the proposed comprehensive management practices were carried out,the total ecosystem service value could increase from 1.37×109 to 1.85×109 Yuan.Except the value of food production decreased 3.31×105 Yuan,the other ecosystem service functions increased significantly but to various degrees.It was also found that only forest and pasture lands played positive roles in enhancing ecosystem service values,up to 89.4%.Their changes were the major reason for the increase of ecosystem service value.The average prediction accuracy of the principal component analysis(PCA)-radial basis function(RBF) model reached 94.8%,indicating that the model accurately reflected the influences of small watershed management measures on the ecosystem service values.

Abstract:Eco-environment sensitivity evaluation is recognized as the core issue of eco-environment of Tulasu area in Weastern Tianshan Mountain.The sensitivity of ecosystems in this area were analyzed with regard to soil,vegetation,climate,topography and other natural ecological factors.Based on the remote sensing(RS) technology,land use,pasture use and other information were extracted through image processing and interpretation.Based on GIS spatial analysis functions and the analytic hierarchy,the various factors affecting ecological sensitivity were combined by weights,and a synthesized sensitivity index was obtained.Based on the in-depth analysis of the ecological problems and their forming factors,some measures and suggestions were proposed to improve the ecological sensitivity.The results showed that the eco-environment sensitivity of Tulasu area could be divided into five categories,i.e.,non-sensitive area,mildly sensitive area,moderately sensitive area,highly sensitive area and extremely sensitive area.In addition,this study could provide scientific reference and technical support for the study of ecological environmental protection and the rational development of tourism resources and mineral exploitation.

Abstract:The input-output analysis method was applied to construct a water resource Input-output table on the basis of the data collected in 2007 in Gansu Province.This study focused on the impacts of water resources on the industrial and economic development of Gansu Province by analyzing water use rate,water multiplier and water consumption.Furthermore,virtual water transfer between industry and economy system virtual water transfer among different industries,and the flow direction of virtual water in economic system were addressed.The results indicated that agriculture(plantation for example) had the highest water use rate and total volume but had little contribution to the indirect boost of economic system by water resource.Some water resources virtually flew to manufacturing and then subsequently to construction and service industry.In addition,considerably amount of water flew to other provinces.During the process of promoting the water saving economic system,we should reduce the scale of agricultural production and improve the efficiency of agricultural water use.We should also readjust industrial structure,considering the relevance of water resource consuming between the industries.In addition,we should take into account the factors reducing the consumption of goods by the clients.