Abstract:The dynamic processes of soil water movement and interflow occurrence mechanisms for Camellia oleifera ecosystem on red soil sloping land were analyzed based on environmental isotope technologies,soil science and hydrological experiments in terms of morphology and energetics.Results showed that in the initial stage of rainfall infiltration,soil water in the upper layer（0-40cm）was affected obviously by rainfall infiltration and evapotranspiration.The 40-90cm layer was a transitional layer and soil water moved alternately upwards and downwards in rainfall infiltration process.Compared with wild grass ground,Camellia oleifera ecosystem with deep roots was easier for the occurrence of interflow.In the same soil layer,the amount of interflow in Camellia oleifera ecosystem was higher,whereas the peak value of interflow was lower and the progress of interflow occurrence lasted longer.Rainfall on the surface of wild grass ground with shallow roots was mostly lost as surface runoff,so it was difficult for infiltration and storage to occur.With the same vegetation coverage,interflow production,peak,lag and trailing in the upper layer（0-40cm）were less than those in the lower layer（40-110cm）.The dynamic change of stable hydrogen and isotope of soil water indicated that a relatively saturated layer was one of basic conditions for the occurrence of interflow and the interflow was mainly from the displaced initial soil water.

Abstract:Infiltration process,in general,is closely related to surface runoff,soil erosion,loss of soil fertility and non-point source pollution.Two series of soil column experiments were performed to study the characteristics of one-dimensional vertical infiltration into a purple clay soil.One was the simulation under the condition of continuous water supply at different ponding water depths and the other was that under intermittent water application at the same water depths.Results indicated that there was no significant effect of ponding water depth on infiltration rate and cumulative infiltration when ponding water depth is between 1and 10cm.Soil bulk density and initial water content had great impacts on the infiltration characteristics underthe condition of continuous water supply at some ponding depth,which means that infiltration rate and cumulative infiltration increase with the decreased soil bulk density and initial water content.The curves of infiltration into the purple soil are discontinuous under intermittent water application at some water depth.The process in the first period was the same as that under the condition of continuous water supply,and however,infiltration rate and cumulative infiltration were both less than those under the condition of continuous water supply in the second period.The characteristics of infiltration into the purple soil under intermittent water application show significant relation to the cycle and rate of water supply.

Abstract:In a case study of Xifeng City on the Longdong Loess Plateau,climate change trends and its effects on soil moisture,as well as the evolution of soil moisture were analyzed based on the 50-year climate data and the 20-year observation data of soil moisture.Results show that temperature increased and rainfall decreased in the recent 50years.From 1991to 2010,soil moisture in Longdong presented a downward trend on the whole.In spring,soil moisture decreased more severely and in summer,soil moisture had a similar trend,but the rate of change was significantly lower than that in spring.In fall,soil moisture in shallow soil layer showed a downward trend,while the deep soil presented a rise trend.For topsoil,soil moisture in each season was negatively correlated with temperature and positively correlated with precipitation.For deeper soil layer,the correlations of soil moisture with temperature and precipitation depended on season.The effects of potential evapotranspiration on soil moisture were characterized by an antiphase monthly and annually,and the basic trends were synchronized.The analyses of soil moisture evolution and its influence factors may provide some references to the decision making for understanding soil moisture evolution,rationally using climatic resources,adjusting agricultural and ecological patterns and positively coping with climate change

Abstract:In order to investigate the influences of root diameter,root length and tensile rate on stress-strain curve,four common arbor root systems,i.e.,Pinus tabulaeformis,Betula platyphylla,Quercus mongolica and Larix gmelinii,were selected to perform tensile experiments.Results show that the overall stress-strain curve of every single arbor root system is the single-peak curve and does not have the apparent sizeshrink phenomenon.Stress-strain curves for the four trees present elastoplastic material characteristics. Under the same loading condition and with the same diameter size,Betula platyphylla performs the tensile mechanical properties close to Quercus mongolica,both of which have larger elastic modulus and tensile strength and smaller elongation;Pinus tabulaeformis and Larix gmelinii have similar mechanical properties,with smaller elastic modulus and tensile strength and larger elongation.With the increase in root length,elastic modulus of Larix gmelinii manifests a downward trend,whereas elastic moduli of the other three trees manifest an increasing trend.Both of the ultimate elongation and tensile strength are negatively correlated with the root length.For Betula platyphylla and Larix gmelinii,the increase in tensile rate makes roots to be failure more easily;elastic modulus and tensile strength are negatively correlated with tensile rate;and ultimate elongation is positively correlated with and the tensile rate.

Abstract:Effects of tillage modes and straw return on soil organic carbon（SOC）and rice yield were studied in direct seeding rice field.Results showed that straw return significantly increased SOC contents,and soil tillage modes had significant effects on the vertical distribtion of SOC.There was a significant positive correlation between SOC content and rice yield（R2=0.712 9**,n=6）,and significant positive correlation between SOC and TSN（R2=0.860 9**,n=43）.These evidenced that straw return promoted SOC content,stabilized crop productivity in direct rice field,and achieved the win-win effect of grain safety and environmental safety.

Abstract:Spatial heterogeneity of soil salinity in the typical area of Yutian oasis was analyzed by using geostatistics.Results indicated that soil salinization in Yutian oasis was severe and soil salinity accumulated in surface soil layer.The variational amplitude of soil salinity in surface soil layer was the highest because of the disturbance of human activities.The spatial correlation of soil salinity in the 0-5cm soil layer was strong;in the 5-30cm soil layer,in the second place;and in the 30-70cm soil layer,relatively low.In the horizontal direction from east to west,soil salinity in the 0-30cm soil layer manifests an increase and decrease trend,while soil salinity in the 30-70cm soil layer gradually declined.Soil salinity was high in the northern and southern parts of the study area and low in the interior part.In vertical direction,soil salinities in saline land,highly coved grassland and medially coved grassland were relatively high and gradually decreased from soil surface to lower soil 20.5 468. layer.Soil salinity in saline land was the highest,the variational amplitude of soil salinity in highly coved grassland was greater than that in medially coved grassland,soil salinities in farmland and lowly coved grassland were relatively lower with low variational amplitudes.The main factor for the spatial heterogeneity of soil salinity in the oasis was the difference of soil and water movement in different landforms and land uses.

Abstract:Three species of Stipa seeds（S.bungeana,S.grandis and S.sareptanavar.krylovii）in Ningxia Hui Autonomous Region were taken as a test materials,the effects of drought stress on their germination were studied under different gradients of polyethylene glycol（PEG-6000）.Results showed that as the drought intensifiedc2北，seed germination rate,vitality index,seedling fresh weight and drought resistance index of the three species declined.Especially,the declinations for S.grandis were most significant（p<0.05）. The low concentration of PEG（5%PEG）had a certain improvement to seed germination and seedling growth of S.bungeana.Compared with the control treatment,the low concentration of PEG did not significantly reduce the seed germination rate and seedling fresh weight of S.sareptanavar.krylovii,which indicates that S.sareptanavar.krylovii has a certain drought resistant potential.PEG had a greater inhibiting effect on the seedling growth than that on the root.The drought resistances of the three species declined in the order of S.bungeana>S.sareptanavar.krylovii>S.grandis.

Abstract:The measured data of annual precipitation and runoff during 49years（1955-2003）for the small watershed of Zhifanggou located near Pingliang City,Gansu Province,were statistically analyzed in order to understand and quantify the contributions of human activities,and precipitation change to the variation of runoff on the Loess Plateau.It was found that although annual precipitation did not change significantly,annual runoff showed a tendency of significant reduction from 59.1mm in the 1950′s to 12.2mm in the early of the 21th century,a relative reduction of 72.4%.Based on the double-mass-curve of accumulated annual precipitation and annual runoff,the variation of precipitation-runoff was divided into five stages:1955-1964,1965-1976,1977-1985,1986-1995and 1996-2003.Then the stage of 1955-1964was chosen as the base stage for comparisons,and the contributions of human activities and precipitation change to annual runoff variation were separated and quantified for each stage.Besides the obvious contribution of annual precipitation decrease to annual runoff reduction in dry stage,the variations of annual runoff in other stages were mainly caused by the human activities,and the absolute contribution of human activities showed an increasing tendency.All these indicate that a rational planning of human activities is an important approach to solve the water problems on the Loess Plateau

Abstract:Based on the data of Beijing forest resources inventory,biodiversity and carbon storage of different forest ecosystem types in Beijing mountainous areas were evaluated by using InVEST（the integrated valuation of ecosystem services and tradeoffs tool）model.The relationship between them was also discussed.Results showed that the highest biodiversity was 0.76in natural birch,while the lowest one was 0.49in artificial Chinese pine.The total carbon storage of Beijing mountain area was 49 193 742t,with the highest one being 10 402 900tin artificial economic woodland and the smallest one being 423 132tin natural coniferous.The average carbon storage per unit area was relatively high in all of the forest types.In general,the carbon storage of one forest type is higher when the biodiversity is high.Biodiversity has a certain correlation with carbon storage,but the correlation is not very significant.

Abstract:Research on soil contamination and plant absorption of toxic elements at coal gangue site can provide a scientific basis for pollution control and vegetation restoration.Soil pollution and heavy metal content in herbaceous plants are studied at Sanlidong coal gangue site in Tongchuan City.Moreover,soil pollution and the enrichment capacity of heavy metals in herbaceous species are analyzed and evaluated using geo-accumulation index and complex accumulation coefficient.Results show that all the elements of Cu,Cd,Zn,Mn,Ni,Pb and Cr in both of the soil and plants obviously exceed their background values and the Cu,Cd and Ni elements in herbaceous species are beyond their normal range.Heavy metal element Cd in soil is in the most serious pollution grade and the elements of Ni,Cu,Zn,Pb and Cr are in the slight pollution grade.For the different plants,the heavy metal enrichment capacities of Conyza canadensis（L.）Cronq.,Artemisia sacrorum Ledeb.and Artemisia lavandulaefolia D.C.are the strongest,followed by Artemisia scoparia Waldst.et Kit and Datura Stramonium Linn.The enrichment capacity of Cynodon dactylon（Linn.）Pers.is the worst.

Abstract:In order to explore the influences of different water treatments on evapo-transpiration and the growth of common green hedge tree Ligustrum quihoui Carr in the cities of North China,small plot and pot experiments were carried out in the Shingle economic area of Horinger County and Hohhot City.Pot experiment had nine water treatments and small plot experiment,four drip irrigation treatments.Results show that more the irrigation amount is,the greater the evapo-transpiration will be.The maximum evapo-transpiration occurs between 75%and 100%field capacity（FC）and the minimum evapo-transpiration,between 35%and 45%FC.The relationship among plant height,crown diameter and evapo-transpiration may be described by a downward quadratic parabola.The maximum evapo-transpiration occurs between 65%and 100% FC and evapotranspiration under different water treatments is positively correlated with aboveground biomass.The water use efficiency（WUE）of Ligustrum quihoui Carr tends to decease with increasing evapo-transpiration.The maximum evapo-transpiration occurs at 35%～45%FC,but biomass of Ligustrum quihoui Carr is the lowest in the above range and drought stress becomes most obvious to its growth and development.The better drip irrigation mode for Ligustrum quihoui Carr under the condition of small plot drip irrigation is that water dropper is 4or 5L/h and the irrigation amount is between 415and 470mm.

Abstract:The research was carried out in Xiaoyi open pit coal mine.Soil bulk density,pH value,organic carbon and total nitrogen,as well as the seasonal variations of soil respiration,temperature and water content,were measured under Lotus corniculatus,Medicago sativa,Salix matsudana,Sabina chinensis mixed forest and Pinus tabulaeformis plantations.In addition,the relations of soil respiration to temperature and water content were simulated.Results show that significant differences in soil bulk density,soil organic carbon,ratio of carbon to nitrogen and average annual soil respiration are found under different vegetation types,but not significant in soil pH value and total nitrogen.Seasonal variation of soil temperature shows a single curve over season and correlation for Guassian fitting is significant.Soil water content fluctuates with season.Seasonal variation of soil respiration approximately manifests a single peak,but correlation for Guassian fitting is not significant.Higher regression coefficient is found for the relationship between soil respiration and temperature when fitted with Guassian equation and for the relationships between soil respiration and the two variables of temperature and soil water content with linear and nonlinear equations in M.sativa. And a stronger exponential relationship between soil respiration and water content is found in both L.corniculatus and P.tabulaeformis.

Abstract:Soil hydrological characteristics were studied for four typical forest ecosystems located in Beijing mountainous area.Results showed that soil bulk density increased with the increase in soil depth,while total soil porosity and capillary porosity decreased.There was no regular trend for non-capillary porosity.Soil water potential at all levels increased with soil water content for all forest stands and 100kPa was found to be the cutoff value of the characteristic curve of soil water.The transient phase of infiltration occurred in the first five minutes,the gradual phrase occurred between the fifth minute and the sixtieth minute,and the stable phrase occurred after 60minutes.Infiltration capacity of coniferous forest soil was significantly higher than that of broad-leaved forest.Jiang Dingsheng formula best fitted the infiltration process determined by double-ring method.

Abstract:In order to choose proper sand-fixing shrub species and vegetation water management in Mu Us sandy land,stem sap flow of Atraphaxis bracteata was measured by using heat-balance packaged stem sap flow measuring system and simultaneously,related environmental impact factors were observed with automatic weather station system in Yanchi County,Ningxia Hui Autonomous Region from May to September in 2009and 2010.Results showed that:（1）Diurnal dynamics of the sap flow of Atraphaxis bracteata presented a significant regularity.Changing course of the sap flow velocity presented a multi-peak curve with obvious diurnal change.（2）In the growing season,the sap flow velocity of Atraphaxis bracteata changed with its growth stage.In the early growth period of Atraphaxis bracteatain May and June,the sap flow velocity was relatively low because of low soil moisture;in the vigorous growth period of Atraphaxis bracteata after rainy season in July and August,the sap flow velocity reached its maximum due to the increased cumulative soil water content;and in September,physiological process of Atraphaxis bracteataslowed down and consequently,the sap flow velocity decreased gradually.（3）The effects of environmental factors on the sap flow velocity were analyzed by using partial correlation method.Solar radiation was found to be the most important factor for the sap flow of Atraphaxis bractea,followed by atmospheric temperature,air relative humidity and wind speed.

Abstract:Through field investigation and experiment analysis,the soil nutrient status under three types of forests including artificial pure forest,mixed forest and natural forest of Pinus koraiensis and at different levels are analyzed.Results showed that there was significant difference among the nutrients in different foresttypes.For the same forest type,the nutrients all declined with the increase of soil depth,and the organicmatter content as well as the total and available contents of nutrients reached highest value in soil layer of 0- 15cm.As a whole,the nutrients in natural forest of Pinus koraiensis were highest,followed by mixed forestand pure forest.In the three forest types,the kalium content was rich and the total phosphorus contentmaintained a low level.The pH value declined slowly and the soil in pure forest of Pinuskoraiensishad anacidification trend,with pH values ranging from 5.08to 5.37.Therefore,regeneration in pure forest ofPinuskoraiensisshould be carried out in time to reduce and prevent soil nutrient loss.

Abstract:Characteristics of water consumption quantities for three nomal shrubs for urban landscaping,namely Ligustrum vicaryi,Berberis thunbergii and Euonymus japonicus Thunb,were studied by means ofpot weighing method.Meanwhile,the relationships between water consumption characteristics and environmental factors were analyzed under the conditions of four different soil moisture contents.Results indicated that the diurnal variation of water consumption of the three landscape shrubs presented a single peak feature.Under the same weather conditions,the three shrubs were in the order of Ligustrum vicaryi >Euonymusjaponicus Thunb>Berberis thunbergii,in terms of the single plant water consumption quantity.The waterconsumption quantities of the three shrubs showed an ordinal decrease with decreased soil moisture content.The soil moisture content of 35%～15%field capacity significantly influenced the water consumption quantities of the three shrubs（P<0.01）,which suggested that the soil moisture content resulted in a stress on thewater consumption quantities of the three shrubs.By correlation analysis,the main environmental factors forthe three shrubs were found to be air temperature and solar intensity.A multiple linear equation was established by stepwise regression,taking environmental factors as independent variables and water consumptionquantities as dependent variable,and the regression equation was fitted well.The regressionequation can beapplied to forecast the water consumption quantities of shrubs by using meteorological parameters.

Abstract:Three year experiment of 27kinds of alfalfa-crop rotation was conducted on the 10-year-old alfalfa grassland in the arid region of Southern Ningxia Hui Autonomous Region.Dynamic characteristics of soil nitrogen,phosphorus and organic matter during the three years of alfalfa-crop rotation were studied.Results showed that in comparison with continuous alfalfa planting,organic matter continued to decline during 3years of alfalfa-crop rotation.Potato in the first and third year planting and spring wheat in the second year planting influenced soil matter content obviously The pattern of potato succession cropping made soil matter content to decline most seriously. Change in soil total nitrogen under different alfalfa-crop rotations was obvious,comparatively.The sole rotation patterns of cereal grain planting,such as millet or spring wheat pattern,was in preference to consumesoil total nitrogen.As a whole,soil alkali-hydrolyzed nitrogen content under different rotation patterns tended to decline and was directly influenced by the level of rotation crop yield.Soil total phosphorus presenteddeclining at first,then rising,and again declining.The alfalfa-crop rotation pattern can improve soil nitrogen and phosphorus effectiveness.So,the reasonable alfalfa-crop rotation pattern should be adopted for a highly efficient,harmonious and sustainable utilization of soil water and nutrient.

Abstract:Through the study of individual tree growth of Pinus tablaeformis plantation under three different gradients of coal mining conditions,the impacts of coal mining on individual tree growth of Pinus tablaeformis plantation are primarily revealed from the three aspects of height,diameter at breast height（DBH）,andvolume so as to provide a theoretical basis for the study of regional vegetation rehabilitation and biological reconstruction.Results show that the impacts of coal mining on total growth of tree height,DBH and volume of Pinus tablaeformis are significant.Under the three different coal mining extents,all the tree height,DBH and volume of Pinus tablaeformis have a significant difference in total growth,which decreases withthe increase in mining extent.The annual successive growth of tree height and DBH of Pinus tablaeformis inrecent 30years has a significant fitting result（p<0.05）with the coal extraction during the same period.Thelatter can explain about 50%of the former inter-annual growth variation at least.

Abstract:Taking the microbial communities in the Shapotou deserted area of Ningxia Hui Autonomous Region as a research object,function diversity of microbial communities from fixed dunes crust（J1）,sub fixeddunes crust（J2）,semi-mobile dunes（L1）and sub semi-mobile dunes（L2）were studied using Biolog method.Results showed that physiological action of J1microbial community was the highest,followed by J2,L2andL1in turn.J1,J2,L1and L2had the same performance in utilization of carboxylic acids,polymers and aminoacid,but were different in utilization of sugar,amine/ammonia and parent compounds.The characteristicvalue contributions of PC1,PC2and PC3were 70.16%,19.23%and 10.61%,respectively.It can be concluded that（1）microbial community activity in fixed desert was significantly higher than that in mobile desert;（2）the differences of microbial community structure may result in the utilization of six types of carbonsources in different ways;（3）by principal component analysis,the utilization of acid,sugar and amino acidby desert microbial community was highest and carbon sources utilized were as many as 22types.

Abstract:Temperature and humidity characteristics of soil and air at different levels are analyzed based on theobserved data of typical forest ecosystem of Heihe River basin in 2008.Results show that:（1）Soil temperature at different depths is the lowest between February and March each year and the highest between July andSeptember.Annual temperature difference and minimum soil temperature decreased with the increase in soildepth.（2）The moisture of top soil is greatly affected by snowmelt in spring and rainfall,reaching its maximum value in the middle or last ten days of August.There is less impact of snowmelt in spring on the soilmoisture between 20and 40cm from soil surface.The soil moisture content between 80and 120cm is quitestable and is not influenced by snowmelt in spring.（3）Air temperature at different heights in forest presentsa declining trend from the middle of July to the last ten days of January next year and then increases continuously from the early of February to the early of July.Air temperature at 2mheight is a bit warmer than that at 10and 24mheights.The highest and lowest daily temperature peaks are observed at about 14:30and 6:30,respectively.（4）Air humidity in forest is lower between April and June and higher between June andOctober.The maximum and minimum relative humidity values are observed at about 22:00and 11:30,respectively.The humidity variation at 10or 24mheight is similar to that at 2mheight.

Abstract:The effects of land use on carbon emission in Guanyuan City are analyzed.Coefficients of carbonemission of land use were firstly summarized.According to the data of land use,energy consumption and carbon emission coefficients,carbon emission related to land use from 1990to 2010 were then evaluated.Results are as follows:（1）carbon emission amount increased rapidly from 21 100thousand tons in 1990to 39 800thousand tons in 2010;（2）construction land was a major carbon emission source,whose carbon emission increased from 27 300thousand tons in 1990to 49 100thousand tons in 2010,accounting for about 99%of overall carbon emission;（3）woodland is a major carbon sink,absorbing much carbon from 1990to 2010,while grassland,water and unused land do not possess carbon sink ability;（4）in terms of the spatial carbonemission pattern,Lizhou district,the center district of Guangyang City,had the biggest carbon emission amount as compared with other places,reaching 16 000thousand tons per year.Based on relevant research results,some suggestions are presented for reducing carbon emission in Guangyuan City.

Abstract:In order to understand the degradation characteristics of polylactic acid（PLA）square sand barriers,the PLA square sand barriers paved for 3.5years were investigated in different slope directions and at different slope positions in the U Lan Buh Desert.Changes in the mechanical properties of the PLA sand barrierswere studied by means of yarn tensile test.Changes in loss ratio were weighed by electronic balance andchanges in surface morphology of sand barriers were described by environmental scanning electron microscope（ESEM）.Results are as follows:Compared with the original PLA sand barriers,yarn breaking tenacities of four positions of the PLA sand barrier decreased differently with slope position ascending,and the order from low to highwas windward side,top side,leeward side and ground side.Loss ratios gradually increased from the bottom to thetop of the slope.The degradation of exposed section of the sand barrier was more serious than that of ground section.Blastation and abrasion by wind flow is the most important factor to the degradation of the PLA sand barrier, ultraviolet irradiation is in the second place,and microorganism in sandy soil has the minimal impact.

Abstract:The watershed non-point pollution model AnnAGNPS and water quality model CE-QUAL-W2wereintegrated to apply.Outputting the non-point source pollution loads based on AnnAGNPS model and converting the loads as the inputs of CE-QUAL-W2model,this paper attempts to predict the water quality of Jinpen reservoir and study the impacts of the non-point source pollutions on water quality.Results show that: （1）non-point source pollutions have greater impacts on water quality of Jinpen reservoir in the flood periodthan in the non-flood period;（2）the impacts of non-point source pollutions on water quality make a greatdifference between longitudinal and vertical water qualities;（3）forests play a significant role in the reductionof non-point source pollution in the watershed;（4）when predicting the water quality of reservoir,non-pointsource pollutions should be treated differently in the flood and non-flood period.

Abstract:As the special equipment for collecting soil particles in wind erosion,research on sand sampler is ofsignificance.Sixteen sand samplers were designed with the difference in respect of position,area and meshsize of the screen,as well as position of opening for sand collecting.Through isokinetic tests and collectingtests in the wind tunnel,performance of the sand sampler with a 120-mesh screen on the top and a protrudedopening was considered to be the best of all sixteen.Its revised ratio of wind velocity at the opening to predetermined wind velocity is 0.870.Average collecting efficiency of soil with the particle size ranges of 0.10～0.25,0.075～0.10and<0.075mm were 83.58%,81.16%and 60.93%,respectively.It was suitable forcollecting the saltation particles and part of suspension particles.In addition,the sand sampler with simplestructure and simplified operation can collect wind erosion dusts at the different heights.It also meets the demands of indoor and outdoor researches if equipped with rotary apparatus.

Abstract:Plant-concrete grillage slope protection is a new technology for ecological slope protection.By taking asteep and bare slope located in Soil and Water Conservation Science and Technology Demonstration Park in Yanqing County of Beijing City as a research object,the applicability of the technology in Beijing City and itseffects in ecological restoration on slope were studied.Because of the existence of splash erosion,surface erosion,gully erosion and other types of soil erosion,the method combining plant cuttings and concrete grillage was used to restore bare slope near-naturally.After 3,15and 47months of construction,survival rate andcoverage degree of Salix metsudana were investigated and monitored,including the growth conditions,soilnutrients and biological diversity of 47-month-old Salix metsudana.It can be concluded that the growth ofSalix metsudana using this technology has reached a higher level.The average branch diameter of 47-monthold Salix metsudana was 2.02cm and the average stem height,317.2cm.Meanwhile,vegetation on sloperecovered rapidly,biological diversity increased obviously,and soil properties were improved somewhat.

Abstract:According to the characteristics of coastal saline soils in Jiangsu Province,the effects of four soilamendments were studied.Through single application of amendments and combined application of amendments and gypsum,soil salt content,soil pH value,and the output of crops were measured after the application of the amendments.The best amendment and combination suitable to the coastal soil in research areawere selected.Results from the experiment showed that the effect of humic acid on the coastal saline soil wasthe best and after the treatment of humic acid（300kg/hm2）,the relative amounts of salt content in the soillayers of 0-5,5-20and 20-40cm decreased by 38.2%,24.5%,and 13.9%,respectively.Gypsum couldsignificantly decrease the soil salt content and increase the outputof crops.After the treatment of gypsum（300kg/hm2）,the relative amounts of salt content in the soil layers of 0-5,5-20and 20-40cm decreasedby 18.8%,13.0%and 4.9%,respectively,and the yield of rape increased by 6.1%compared with that ofCK.The combined application of Humic acid and gypsum was the best combination to the coastal saline soil.After the treatment of humic acid（300kg/hm2）combined with gypsum（300kg/hm2）,the relative amountsof salt content in the soil layers of 0-5,5-20and 20-40cm decreased by 45.1%,38.9%and 25.7%,respectively,and the yield of rape increased by 18.6%compared with that of CK.

Abstract:Soil samples of two cultivated red soils developed from weathered parent materials of quaternary red earth and granite were collected in eastern suburbs of Changsha City.Soil particle composition and soilorganic matter were obtained by means of laboratory analysis.Then,soil erodibility factor Kvalue was calculated using Nomogragh model,modified Nomogragh model,EPIC model,geometric mean particle modeland Torri model.Finally,the calculated soil erodibility value was compared with the measured soil erodibility factor Kvalue by the Red Soil Ecological Experimental Station of the Chinese Academy of Science in Jiangxi Province.Results showed that Torri model and geometric mean particle model are more suitable for calculating the Kvalue of red soils developed from quaternary red earth in the eastern suburb of Changsha City,whereas EPIC model,geometric mean particle model and Torri model are suitable for calculating the Kvalueof red soils developed from weathered granite materials.

Abstract:Regional landslide hazards assessment is the basis of the research on regional landslide hazard risk.A “black box”method is proposed based on inverse distance weighted interpolation（IDW）theory consideringlandslide as a system and the factors as subsystems.This approach hypothesizes that existing landslides havelocal influences on the landslide risk to their surrounding areas according to the principle that the more closedthe distance of the things is,the more similar the characters of them are;it obtains the result of regional landslide hazard assessment by analyzing all the landslides with the IDW theory;and simultaneously,it analyzes the basis of theory why the IDW theory can be applied in regional landslide hazards assessment and thescope of its application.Finally,the feasibility of IDW Interpolation theory in regional landslide hazards assessment is verified by taking Cangxi County of Sichuan Province for an example.

Abstract:SWAT（soil and water assessment tool）,which is based on physical mechanisms,is a distributedhydrological model developed to simulate and predict runoff in different underlying surfaces accurately.Thepurpose of this study is to simulate the monthly runoff from Yangou Watershed in the loess hilly area from2002to 2008by using SWAT model.Results indicated that the correlation coefficients in the period of calibration and validation were 0.96and 0.98with the Nash-Sutcliffe′s coefficient being 0.89and 0.76,respectively.The precision of SWAT simulation is higher than the evaluating criterion（Ens>0.5,r2>0.6）,whichdemonstrates that SWAT is applicable to simulate the runoff from Yangou Watershed and practical in floodmonitoring and forecasting in the loess hilly area.

Abstract:In order to solve the problem that there is no suitable platform to estimate ecological baseflow byusing different methods,a software to estimate ecological baseflow with friendly interface,simplicity ofoperation,and integrated 12hydrological and hydraulics methods is developed by using Visual Basic 6.0.Itnot only simplifies the estimation for ecological baseflow,but also easily makes comparison among differentmethods.A case study in the Weihe River basin was carried out by using this software.Results show thatecological baseflows estimated by using different methods are significantly different.Therefore,the averageof various methods,13.7m3/s,is selected as the ecological baseflow and the result of Texas method is regarded as the monthly ecological baseflow in the Weihe River. This software provides a great support for thedevelopment of the dynamic estimation of ecological baseflow in the future.

Abstract:Daily rainfall data of 1951to 2010obtained from Shapingba weather station was used to build simple algorithm of rainfall erosivity.Accordingly,the prediction accuracy of the simple algorithm was analyzed,the daily rainfall corresponding to the highest prediction accuracy was determined,and the temporalcharacteristics of annual rainfall erosivity and rainfall parameters were explored.The main results are as follows:（1）There is an exponential relationship between annual rainfall erosivity and annual rainfall.The annual rainfall with daily rainfall of≥25mm presents the closest relation with annual rainfall erosivity.Additionally,the accuracy for annual rainfall algorithm using daily rainfall of≥25mm in the prediction of rainfallerosivity is better than the algorithms using other levels of daily rainfall.（2）The changes of annual rainfallerosivity and rainfall parameters with time in the year from 1951to 2010are not significant.But for a certainperiod of time,the correlation coefficient between time and the annual rainfall with daily rainfall of≥25mm is similar to that between time and annual rainfall erosivity.The responses of soil erosion to climate changecan be analyzed by using the annual rainfall with daily rainfall of≥25mm as an alternative indicator.The results from the research can be used for reference in enhancing the prediction accuracy of the simplified modelfor annual rainfall erosivity and understanding the responses rainfall erosivity to climate change and regionalsoil and water loss control.

Abstract:Through the analysis of soil erosion factors,a comprehensive evaluation model for grade division ofsoil erosion based on the technique for order preference by similarity to ideal solution（TOPSIS）was established by selecting vegetation coverage,surface slope,area ratio of valley to slope,gully density,and arearatio of collapse to slope as evaluation indexes.The grade division of soil erosion was then made according tothe evaluation.An empirical study was conducted by taking the development and construction projects ofpower transmission for an example.Results show that the TORSIS model is simple and convenient,and theresult is reasonable.It provides a basis for the relevant departments to develop soil and water conservationplanning and its control measures.

Abstract:Improving the intensive use degree of urban land is of importance to alleviate the contradiction between human being and land resources and improve land use efficiency.According to the intensive use connotation of urban land,a set of indexes is established to determine the intensive use degree of urban land.Acomparative analysis is made to determine the intensive use degrees for the urban lands of 17cities in He′nanProvince using principal component analysis and matter-element method.Results show the two methods havegreater similarities in the order,classification and spatial distribution of evaluation results,despite of somedifferences.The cities in the northern,western and southwestern parts of the province have more intensiveuse degree of urban land than the cities in the eastern and southeastern parts.The two methods are quite different in the analysis of internal factors about intensive use of urban land.It is suggested that all the cities should increase land investment and improve land environmental quality in entire province in the future topromote the increasing intensive use of urban land.

Abstract:Based on land use data of Wuxi City in 2005,the GIS technology and the Minimum Cumulative Resistance Model（MCR model）are applied to analyze the spatial potential developing trends of the sources ofarchipelago type and network type and identify positional critical portion.Results are as follows:（1）InWuxi City,the critical portions of sources connecting type are arranged in three parts with amount of 23patches.The area of invasion in Yixing part is the biggest;Jiangyin part,in the middle;and Binhu part,thesmallest.The destroyed degree of invasion in Jiangyin part is the worst;Binhu part,in the middle;and Yixing part,the least.（2）The critical portions of network controlled type are arranged in two parts with amount of 40patches.From both views of area of invasionand destroyed degree of invasion,Biyi part are bigger or worse thanJiangyin part.（3）The positional critical portions are in amount of 56patches,which can be classified as twogroups and eight sub-groups.Among these portions,the portions with key importance are in amount of 13patches and the portions with common sense are in amount of 43patches.The spatial arrangement of positional critical portions has a close relationship with that of physical geographic traits of studied area.

Abstract:Based on the investigation of vegetation status in the hilly area of Taihang Mountains in NorthernHe′nan,six vegetation restoration models for the area are proposed according to the habitat and vegetationcharacteristics by applying ecological principle and methods.The models are the soil and water conservationforest model,ecological economy model,closing for afforestation model,vegetation restoration model in roadsides,nature reserve model and fire-resistant forest belt model.Specifically,vegetation restoration model inthe hilly area of Taihang Mountain is studied from the aspects of zonal plant communities,fire disaster reduction,landscape ecology,optimal location and so on.Results have a guiding significance for the vegetationrestoration in the hilly area of Taihang Mountains in Northern He′nan and overall Taihang Mountains.

Abstract:Runoff is the main power causing soil erosion.So,an accurate estimation of runoff in differentrainfall and underlying surface conditions is the key to predict soil erosion and control soil and water loss.The SCS-CN model developed by Soil Conservation Service of USDA is applied to the simulation of surfacerainfall-runoff processes in the Chaohu Lake basin.With the support of ArcGIS 9.2software,annual surfacerunoff in the basin from 2002to 2006is estimated and runoff yield capability under different land cover typesis analyzed.Results show that there is a greater inter-annual variation of runoff in the basin and runoff depthranges from 591.323to 1557.136mm.The runoff yield capabilities under different land cover types may beranged in the order of urban land>paddy field>unused land>dry land>rural areas>grassland>forest land>scrubland.

Abstract:By taking the Zhangjiachong small watershed in the Three Gorges Reservoir for an example,rainfall-runoff process simulation is conducted to provide references to the researches on soil and water lossand non-point source pollution process and scientific supports to control soil and water loss and non-pointsource pollution,to ensure water security,and to alleviate the growing pressures on ecological environment.Based on the observed data of hydrology and temperature and digital elevation model,TOPMODEL,a halfdistributed hydrological model,is used to simulate daily runoff in the study area.Nash-Sutcliffe coefficient,Root Mean Squared Error（RMSE）and correlation coefficient are taken as objective functions.Simulation results show that the measured values of runoff dynamics are roughly consistent with the simulated values.Simulation accuracy and fitting efficiency in wet season are better than those in dry season and they varygreatly.According to the“ hydrological forecasting standards” SL250-2000,runoff simulation accuracygrade is in C class in wet season and below C class in dry season.TOPMODEL is appropriate for the dailyrunoff simulation in wet season,but not appropriate in dry season.

Abstract:Four representative models on viscous debris flow are introduced,including Bagnold′s model,Takahashi′s model,Fei′s model and Iverson′s model.Contrast tests for the four models are made using thedata observed from 23debris-flow surges in Jiangjiagou,Dongchuan City,Yunnan Province.The mean valueof velocities simulated by Bagnold′s model approximates to that of observations and however,simulated dispersion stress is not strong enough to sustain effective gravity of the solid phase.Simulated velocity byTakahashi′s model is less than observations.Hydraulic gradient can be simulated by Fei′s model,which isalso less than observations.Primary analysis with Iverson′s model shows that the liquefaction degree computed by stress balance equation can be achieved in Jiangjiagou watershed.Analysis of the sensitivity of each modelto some parameters indicates that Bagnold′s model and Takahashi′s model are sensitive to the maximum possibleconcentration,while Fei′s model and Iverson′s model are sensitive to the internal friction angle.

Abstract:The processes of water cycle in the middle and lower reaches of the Yellow River change under thecombined effects of climate change and human activities,which impacts flood disaster modes and evolutiontendencies.Status of flood disasters,as well as wet and dry cycle,frequency and intensity of precipitation inthe area are analyzed using Morlet wavelet and trend analysis.The variations of hazard inducing environment,disaster causing factors and vulnerability of hazard bearing body are analyzed in combination with social and economic development,relations between water and sediment and mechanisms of ice floods.Finally,new evolution tendencies of floods are identified:floods in the area will be more serious on the whole,especially in tributaries and small watersheds;floods with low peak discharge may result in heavy losses;and icefloods tend toward mitigation.

Abstract:Landform is the most important natural environment element and it has profound effects on thelandscape pattern of land utilization.Ansai County of Shaanxi Province located in the loess hilly-gully regionwas selected as the special case to conduct the research on landscape pattern of land utilization under differentgeomorphologic types based on the principles of landscape ecology using ArcGIS software package.Resultsshow that the combinations of landscape types are dissimilar in different geomorphologic types.Meanwhile,the patterns of different landscape types are distinct in the same geomorphologic area.The same landscapetype distributed in the different geomorphologic areas is dissimilar.Generally,the landscape in the valley terrace area shows higher spatial heterogeneity and greater> 类> ? diversity and evenness indexes,followed by thelandscape in the loess ridge ravine area.In the loess hilly and valley area,the landscape for grassland with ahigher value of dominance index is the substratum element,surrounded by other landscape types.In theloess flat-topped ridge area,the shapes of landscape types are complex and irregular,and many plaques risewith obvious difference in size.

Abstract:A 2-deimensional environment management model is established by comprehensively analyzing thecumulative environment impacts of the cascade hydropower development project group from a series of factorssuch as water body,resources,biology,society and economy.Based on the current construction projectmanagement procedures in China,the first dimension（environment management evaluation system）includes the project proposal or pre-feasibility study phase,feasibility study phase,design phase,construction phase, trial production and completion acceptance phase,and cooperation management.At the same time,the second dimension（5levels environment management maturity development model）is established,which includes“disorder level”,“simple level”,“standard level”,“improvement level”,and“lean level”from low tohigh,with the characteristics of each level being redefined.Group decision method is utilized to evaluate theenvironment management maturity of the cascade hydropower development project group and the four-quadrant analysis is made to improve the environment management maturity.Results from the analyses indicatethat for the purpose to improve the environment management maturity,the key improvement should be madein the second quadrant,while the first quadrant level should be maintained at the same time.A case study ismade to verify the model.

Abstract:Geomorphic features of a gully is an important slowly varying factor in the processes of debris flow,which determine the driving forces of debris flow,restrict the surface runoff converge among water source conditions and influence the ways of solid material supply.Therefore,debris flow occurrence can be analyzed by the geomorphic features of a drainage basin.By taking a rainstorm-induced debris flow gullies in the middle of Zagunao Riverbasin as the research object,the relationships among geomorphic information entropy in gully developmentstages,basin area,longitudinal channel bed gradient and debris flow disaster characteristics are analyzed.Geomorphic information entropy of the high frequency debris flow gullies is found to be 0.12～0.20and thelow frequency debris flow gullyondaryURI ,0～0.12and 0.20～0.30,respectively.When gully area is>15km2 andlongitudinal channel bed gradient is<300‰，debris flow is watery,and on the contrary,is viscous.

Abstract:The distribution of landslides in the twelve counties where Longmenshan faults pass through was investigated before and after Wenchuan earthquake.Then,the logistic regressive model was utilized to assess the landslidesusceptibility before and after the earthquake.Based on the susceptibility mapping and transformation matrix,thesusceptibilities showed a significant spatial variation before and after the earthquake.The high susceptible zones forlandslides were located along river valleys before the earthquake,while primarily along the Longmenshanfaults after the earthquake.The extreme high susceptible zones did not change.The areas with low susceptibility near the Longmenshan faults turned into high susceptibility level after the earthquake.

Abstract:The purpose of this study is to provide database and theoretical basis for the comprehensive controlof soil and water loss on the Loess Plateau of China by studying land use change and its driving forces inShanghuang small watershed based on land use change map.Methods employed include RS/GIS and statistical analysis.Results showed that land use changes in the small watershed can be divided into three phases according to the change in the landscape matrix whereby the dominant land use was grassland（1982-1990）,cropland（1990-2002）and forestland（2002-2008）.The land use in Shanghuang small watershed greatlychanged in recent 30years,mainly including substantial increase in forest and grassland area,decrease insloping arable land and expansion of orchard area year by year. It is concluded that land use change is an important factor to impact soil and water loss,and soil and water loss can be reduced by adopting rational landusestructure.

Abstract:Toshiko gully on the right bank of Dadu River is characterized by medium and high frequency debris flows,where several severe debris flow disasters occurred.Based on the history of disasters and development characteristics of the gully,formation conditions and development history of debris flow in the gully areanalyzed through detailed field geological engineering investigation,geological mapping for remained mudmarks in typical profiles,particle analysis and volume weight test.Combined with the development characteristics of the Dadu River terraces and glacial melting periods,phases of debris flow in the periods are analyzed and the prediction and assessment of debris flow are made.The research reveals that the formation ofdebris flow has a close relation with ice evolution. Using the historical analysis method,the conclusion canbe draw that Toshiko valley is in a decline phase and the scale of debris flow will be reduced successively.

Abstract:In order to understand the characteristics of selenium（Se）distribution for environment-plant system in the Longfeng wetland of Daqing City,soil,water and reed were collected in the spring of 2011.Thecontent of Se was measured using hydride generation-atomic absorption spectrometry（HGAAS）and the relationship among the three samples was analyzed by statistical methods.Results show that the content of Se insoils was 129.63～142.18μg/kg,the mean of water Se content was 3.87～7.02μg/L,and the contents ofSe for reed root,stem and leaf were 50.17,18.29and 15.68μg/kg,respectively.The results show thatthere was a significant positive correlation in content of Se between soil and reed.Reed enrichment in Se fromthe environment was weak,and thergfor was a non-enriched Se plant.

Abstract:The responses of vegetation variation to global climate change have become a hot issue in ecologicalresearch recently.The Erdos Plateau is located in the eco-sensitive zone of West China and its vegetation variation responding to global climate change is of great importance.We used the NOAA/AVHRR NDVI datafrom 1982to 2006and local meteorological records during corresponding time of the Erdos Plateau to analyzethe vegetation variations and its relationship with meteorological parameters.Results showed that（1）from 1982to 2006,annual mean NDVI of the Erdos Plateau increased significantly（p=0.001 7）,with an increasing rate being 0.04%per year,and the mean temperature also increased significantly（p<0.001）while themean precipitation varied significantly with no clear trend（p>0.05）;（2）in the Erdos Plateau,the NDVI increment was mainly contributed from the typical steppe whose seasonal average NDVI in spring,summer and autumn allincreased significantly（p<0.001）;（3）in the growing season of the Erdos Plateau,the main driving factorfor the increment of NDVI was precipitation,while in the non-growing season,it was temperature.

Abstract:Pressure-state-response（P-S-R）model was used to perform the standardization of 21indexes,to determine index weights and to construct an ecological security evaluation model.By taking BaojiCity as an example,ecological safety problems in Baoji City from 1991to 2009were analyzed.Change of ecological security in the area was studied in detail by using dynamic ecological security model.Finally,grey system budget model GM （1,1）based on the grey system theory was used to forecast ecological security inthe next decade.Results showed that（1）ecological security value for the city in the past 19years was reduced year by year,specifically,the value was reduced from 0.650in 1991to 0.434in 2009,with an averagereduction by 0.01749%;（2）the pressure-state-response model was used to forecast ecological securitysituation in the next decade.From 2012to 2021,ecological security value will maintain the reducing trendand be reduced to 0.317by 2021.

Abstract:To evaluate the stability of gravitational erosion for small watershed on the Loess Plateau,the conceptual model of Wangmaogou watershed is explored with the aid of the finite difference software,Flac3D,and the numerical simulations for stress field,displacement field and plastic yielded zone are made as thewatershed system is in balance.The reliability is analyzed for the failure probability of gravitational erosion,combined with Rosenblueth moment estimation method.Results show that.The shear plastic zone is greatly located in the most area of slope and gully slope,and the tension plastic zone is mainly located on top andslope of barren hill.The gravitational erosion of watershed is in unaccepted risk level and effective engineering measures should be taken to improve its stability.Rosenblueth moment estimation method can effectivelycombine the conventional safety factor with probability distribution,which may offer a better approach to thebuilding of evaluation index system for watershed stability and gravitational erosion reliability.

Abstract:The Yellow River wetland plays an important role in the ecosystem of Lanzhou City.The plantdiversities of Lanzhou urban wetland was studied by the field investigation of three habitats in the YellowRiver wetland using belt transects and quadrats.Results show that:（1）Herb,particularly Salix babvlonicathat belongs to Salicaceae,is the dominant species in various wetland plant communities,while only one species of one family shrub is found.Wetland plant species in transition zone nearly cover all the species in otherhabitat systems.（2）The importance values for Leymus secalinus,Echinochloa crusgalli and Chloris virgataare 16.336,14.112and 11.723,respectively.Phragmites communis has been strengthened in transition zoneand its importance value in nearly natural wetland is 13.153.Common companions,such as Oenanthe clecumbens,Typha angustifolia and Beckmannia syzigachne,also have certain positions in wet environment.（3）Simpson and Shannon-Wiener indexes of wetlands′habitat follow the order of transition zone>nearlybare wetlands>nearly natural wetland,and however,evenness index does not have such a trend.βdiversityfor nearly bare wetland and transition zone is lower than that of nearly natural wetland and transition zone,which is consistent with the sequence of species dissimilarity among different habitats.

Abstract:In order to control soil erosion on hilly upland in Southwest He′nan Province,comparative experiments were conducted among Eulaliopsis binata,Amorpha fruticosa and secondary vegetation.Resultsshowed that Eulaliopsis binata and Amorpha fruticosa could significantly improve soil physical properties（p<0.05）:soil bulk density was lowered to 9.15%and 10.56%;total porosity was raised to 10.56%and12.28%;non-capillary porosity was increased to 38.64%and 42.93%;and capillary porosity was increasedto 4.78%and 5.98%,respectively.Planting Eulaliopsis binata and Amorpha fruticosa could remarkablyimprove soil water storage and conservation capacity（p<0.05）:moisture capacity was raised to 15.38%and19.57%;soil maximum capillary moisture capacity,18.14%and 19.57%;and saturated soil water content,4.10%and 4.42%,respectively.Soil permeability was apparently improved（p<0.05）:compared with secondary vegetation,artificially planted Eulaliopsis binataand Amorpha fruticosacould raise soil permeabilityby 2.09and 2.17times respectively.The water absorption rates of stem and leave were:Eulaliopsis binata>Amorpha fruticosa>secondary vegetation.In addition,results showed that the depth of surface runoff, the amount of soil erosion and the amount of soil nutrient loss in the areas with three years′Eulaliopsis binataandAmorpha fruticosa planting were lower compared with those with secondary vegetation only.

Abstract:Water and soil resource is an organic system of interactions and restrictions with each other,which is the main line throughout the coordination and sustainable development of regional society,economy,andenvironment.Shiyang River basin is a typical area lack of water resources in northwest arid zone.Oasis citiesrelying on the basin are the agglomeration centers of human production and life,and have a special and sensitive human-environment relationship.By taking Wuwei City as an example,and constructing LUCC ecological risk model,the dynamic and spatial changes in the ecological risks of land utilization were revealed withthe help of GIS and statistical method.Besides,identification and evaluation system for the ecological risksof water utilization were established by referring to the bulletin of water resources and statistic yearbook（2003-2009）of Wuwei City and the trends of the changes in water utilization risk were analyzed comparatively.The main conclusions are as follows:the ecological risk of land use cover in Wuwei City mainly concentrated on cultivated land,grassland and unused land which totally account for a greater percent in thewhole area;the integrated land use risk indexes for the counties and districts of the city increased during theresearch period and changes of land use patterns produced a certain degree ecological risk;the ecological risklevel of water resources utilization from 2003to 2009rose significantly,and the counties and districts shouldtake corresponding countermeasures to deal with the change in ecological risks of water and soil resources.

Abstract:Referring to the data of statistical yearbooks and peasant household questionnaires,the effects ofecological agriculture with commodity（EAC）implemented in southern,central,northern An′sai Countywere evaluated by using the evaluating indicator system and the weights.Results showed that in last 10years,the EAC in An′sai County experienced 3stages:economic system recession and ecosystem smooth transition stage,economic system recovery and ecosystem rapid development stage,and economic systemquick growth and ecosystem sound wave stage.The EAC development state was in the“fair”grade in 1998-2001,which evolved into the“good”grade in 2002-2009and is expected to achieve the“superior”grade by2015.During this process,the EAC system tended to be a coordinated development state,but there were also some uncoordinated problems in parts,such as resource-shortage in livestock husbandry and resourcewaste in vegetation,which constrains the EAC advancement in An′sai County.

Abstract:The border areas of Sichuan,Yunnan and Guizhou Province are greatly hit by landslides.There are 1.2million hidden dangerous points experiencing geological disasters,which have threaten more than 100million livesand property security,and have negative effects on production,livelihood security of local people and sustainable development.The five evaluation factors of gradient,relative height distance to active fractures,annual average rainfalland annual average number of heavy rain days are selected to calculate their contribution weights.With the support ofGIS,the map for landslide hazard evaluation in the area is drawn by using superposition method and the contributionrate model.Results show that:（1）The study area（about 19.18×104 km2）contains very highly dangerouszone（3.92×104 km2）,highly dangerous zone（4.34×104 km2）,moderately dangerous zone（4.58×104 km2）,slightly dangerous zone（3.92×104 km2）and stable zone（2.42×104 km2）.The areas of very highly,highlyand moderately dangerous zones account for 67.00% of the total area.（2）Very highly dangerous zone ismainly located in the two sides of deep fractures in Xiaojiang-Anning River and deep valleys of Jinsha Riverand Yalong River,which implies that active fractures and landform play a macro-control effect on landslides.（3）The population in very highly and highly dangerous zones is about 11.5231 million,accounting for32.17%of the total,and GDP is about 41.988billionyuan,accounting for 28.75%of the total.So,it is essential to strengthen the capacity of preventing and reducing the geological hazards in the area.

Abstract:The giant debris flow and flush flood that burst within Sanyanyu and Luojiayu gullies in the north side of Zhouqu County in August 8,2010caused tremendous losses of the local people′s lives and properties.Based on field investigation and survey,important roles of blocking projects in the treatment of SanyanyuGully were expatiated and the view of dominated blocking projects in combination with drainage projects wasproposed in terms of the analyses of geo-environmental conditions,formation and movement characteristics of the debris flow,storage and supply modes of loose materials,erosion and deposition in gully and disasterprevention of the county town,etc.To ensure enough storage capacity of sand hindrance and safe reliability,various types of blocking dams were analyzed and medium or high dams with high-impact strength werechosen to control debris flow disaster.According to the characteristics of supply and activity of debris flow inevery gully section,forms,types and functions of the blocking dams were analyzed,and blocking projectswere deployed systematically.

Abstract:12social factors,including population,GDP,agricultural mechanization level and urbanizationrate,were selected based on statistic data from 1996to 2009in Guiyang City.The change trend of arableland area in the past 14years and its factors were studied by using correlation analysis and principal component analysis with the aid of SPSS.Results showed that the general trend of arable land area presented a reduction in the study period,and the change of per capita arable land was consistent with that of total arableland quantity.By principal component analysis,the driving factors for the change of arable land area in GuiyangCity were found to be the economic development,population increasement and advanced agricultural technology.Finally,the measures for arable land protection were proposed to make the arable land resources used safelyand sustainably.

Abstract:Study on the dynamic characteristics of cultivated land plays a very important role in protection,consolidation and utilization of cultivated land.By taking remote sensing images in 1991,2006and 2009asdata source,the characteristics of amplitude and speed,roll-in and roll-out,spatial distribution,and landscape distribution of cultivated land changes were analyzed by means of spatial analysis function of GIS.Results show that the total area of cultivated land increased,but the net annual average speed declined in thethree years.Unutilized land,forest land and construction land were the main land use types transformed intocultivated land.Cultivated land was mainly transformed into forest land,unutilized land,grassland and construction land.Spatial differences of cultivated land change in Bayan County were remarkable,and newlyincreased cultivated land was mainly from the reclaimed floodplain along the Songhua River,deforestation ofnortheast hilly areas and construction land change in northwest.The number and density of cultivated landplaque tended to increase,human interference extent increased,and fragmentation enlarged.Landscapeshape index and fractal dimension tended to decrease and the shape of cultivated land landscape plaque becamesimpler and more regular.The high connectivity of cultivated land landscape indicated that the spatial distribution of cultivated land landscape had a high degree of aggregation.

Abstract:The lower reaches of Jinsha River are the area that has the most serious problem of mountain hazards.Debris flow is one of the main mountain hazards in the area and it may cause damages to the construction and running safety of large hydropower projects.The evaluation method for the influences of debris flowon large hydropower projects was established firstly and then four ways（construction road,ancillary facilityand resettlement,sand in reservoir area and engineering facilities in the dam area）of the influences were elaborated.Heishui gully,lying in the reservoir area of Baihetan hydropower station,was taken as a typicalarea to evaluate the influences of debris flow on the hydropower project.Results indicate that debris flow ofHeishui gully may block the main river and thus its blocked backwater and outburst flood can cause damagesto construction roads and some temporary facilities.In addition,a large quantity of debris flow materials canflow into the reservoir and the storage capacity of Baihetan hydropower station decreases consequently.

Abstract:The input-output condition,work efficiency and environmental load of the agro-ecosystem in theChangsha-Zhuzhou-Xiangtan urban agglomeration were systematically assessed based on the theory andmethod of emergy analysis.Results showed that the nonrenewable supplemental emergy dominated over theagro-ecosystem emergy input in the urban agglomeration and thus caused a high cost of the production.Themajority of emergy output was forestry and animal husbandry,while crop cultivation and fishery had a relatively low percentage.The environment load ratio was lower compared with developed countries and regionsand thus the agro-ecosystem had a large development space.From the perspective of emergy analysis,theChangsha-Zhuzhou-Xiangtan urban agglomeration should optimize its input-output structure ecosystem with multi-level,high function and low emergy consumption.

Abstract:Water environment security in rural areas around Poyang Lake has been threatened by increasinglysevere non-point source pollution（NPS pollution）.Combined with the features of NPS pollution in the areas,the structural best management practices（BMPs）are established in the demonstration area of Xingzi Countyto control the rural NPS pollution.Monitoring results show that in the monitoring period,the removalamounts of COD,TP and TN by the BMPs are 568.25,3.06and 26.90kg,respectively.Constructed wetland maintains the better and more stable pollutant removal capability and the removal amounts of COD,TPand TN per unit area are about 40,0.4and 3.0g/m2,respectively.The removal amounts of the pollutantsper unit area by ecological ditch vary greatly.Ecological ditch has better removalsecondaryU ability per unit area thanconstructed wetland,but has poor stability.In consideration of the advantages of ecological ditch and triclass surface flow constructed wetland（3-SFW）,the plants suitable to ecological ditch are recommended toimprove its stability in pollutant removal.