Abstract:Serious soil erosion in the purple hilly areas of Jialing River basin is the major source of soil and water loss in the lower and middle reaches of the river.Lizixi watershed in Sichuan Province was chosen as the study area.Land use data were extracted by RS and GIS technology from remote sensing images(Landsat TM/ETM+and Spot Images)in 1986,1999and 2001representing the conditions at the three periods before and after implementing the key control project of soil and water conservation in the upper reaches of the Yangtze River(referred to as the“Changzhi” project).The distributed hydrological model SWAT was used to simulate runoff and sediment yield based on the landuse data at the three periods.Based on the land use map in 1986,the impactsof land use changes and different climates on runoff and sediment yield inLizixi watershed were evaluated by making an assumption of 7different landuse conditions and 9different climate combinations.The simulated resultsshow that:(1)After the implementation of the“Changzhi” project,paddy fieldsand dry land area continued to decrease,and forest area continued to increase from 1986to 2001,which was mainly transformed from paddy fields and dryland.(2)The land use changes of increased forest area and decreased farmland had an obvious influence on runoff and sediment yield,which showed that the control measures,mainly in the form of returning farmland to forestry and afforestation,had effects on soil and water conservation.In terms of conserving water and intercepting sediment,forestry was better than grassland,and grassland was better than farmland.Taking the measure of returning farmland to forestry and grassland in>25°farmlands had more obvious effects on reducing surface runoff and intercepting sediment than 15°~25°farmlands.

Abstract:The spatial correlation between soil erosion and the elevation,slope,amplitude and surface roughness is analyzed based on overlay analysis of soil erosion in 2000and DEM with a resolution of 30meters.Results show that the main type of erosion in Wujiang River basin is water erosion.According to the strength,the erosion can be divided into five levels which are minor,slight,moderate,high and extremely-high.The minor and slight levels of erosion are the dominated erosion.The minor andslight levels of erosion appear a single peak with the increasing elevation,while the moderate and the other beyond the moderate show obvious double peaks.The distribution of the moderate and other levels of erosion below it decreases with increasing slope.The ratio of high erosion area to extremely-high increases with the surface rolling at first,and then decreases,with 15°as a threshold.The erosion increases with the amplitude at first and decreases later,with a threshold of 7～16meters.The surface roughness is negatively correlated to soil erosion.The rougher the land surfaces,the lighter the soil erosion.Soil erosion in the karst area is not sensitive to amplitude and surface roughness,while it is largely affected by elevation and slope.

Abstract:Soil physical properties,to some extent,determine the hydrological characteristics of soil layers.The influences of different vegetation types on soil physical properties can significantly change the functions of soil and water conservation in soil layers of different regions.We discussed the effects of different vegetation types on soil physical properties in Tianlaochi,a small watershed located in the upstream of Heihe River basin.An experiment was carried out under the five vegetation types of Picea crassifolia,Sabina przewalskii,subalpine meadow,shrubs and steppe.Results show that(1)Picea crassifolia had the minimum soil bulk density and the largest porosity.Particles were mainly composed of silt.Steppe and meadow steppe had the highest soil bulk density and the minimum porosity.For the same vegetation types,soil bulk density and total porosity were consistent at different slope positions.With the increase of the depth,soil bulk density increased and total porosity decreased.(2)In meadow steppe,physical properties of the 0-20cm soil layer were similar,and physical properties of the 20-50cm soil layer were with greater consistency.

Abstract:A study of rill evolution process and sediment yield characteristics is important for rill erosion prediction model.At different slopes(10°,15°,20°and 25°)and different rainfall intensities(1.5and 2.0mm/min),the indoor simulated rainfall experiment with pure water was conducted to study the specific rill evolution process.The relationships between rill development stages and influencing factors were discussed.According to the characteristics of sediment concentration and rill form,the rill development process was classified as the four states of surface erosion,initial rill form,rill development and rill adjustment.Results showed that the proportions of sediment yield to the total erosion were different for different stages.The proportion for the rill development was the largest,about 40% of the total erosion.The duration for each stage changed with slope.Increase in rainfall intensity had a promotion role in rill and interrill flow velocities. Rill flow velocity was 0.75～1.77times of interrill velocity.Rainfall intensity and slope had a great influence on erosion rate.The relationship between flow velocity and erosion rate was closer on the same slope,but the quantitative relationship should be explored further.

Abstract:Regarding the vegetation recovered for 3years on Beijing-Chengde third-phase freeway slopes as the study object,we conducted an investigation of soil nutrient status and analyzed the main factors affecting soil nutrients.Results showed that soil pH values were mostly about 6.5;soil organic matter contents on 86.73% of the slopes and total nitrogen contents on 88.78% of the slopes,in upper level;available phosphorus contents on 90.82% of the slopes,in rich level;and available potassium contents on 73.74% of the slopes,in low-middle level.This indicated that available phosphorus was the key nutrient factor for plant growth undere the current construction techniques and curing conditions.Slope material,slope direction and construction techniques had more effects on total nutrient content on the slopes.

Abstract:The effects of controlling wind erosion by strip intercropping with stubble were studied to solve the problem of serious wind erosion in the ecotone between agriculture and animal husbandry in the north area of Yinshan Mountains,Inner Mongolia.Through the measurements of the wind,land surface roughness and the amount of wind erosion,the effects of different heights of stubble on controlling wind erosion in stubble field and neighboring bare field were revealed to provide a theoretical basis for controlling wind erosion.Results showed that with the increased stubble height,wind velocity near ground decreased and the effect of high stubble(30cm)was the best.With the increase of measured height,the effect of stubble height on wind velocity decreased.Land surface roughness increased with the increase of stubble height.Compared with the control,the surface roughness in high stubble(30cm)field and neighboring bare field of high stubble increased by 466.67% and 126.98%,respectively.Wind erosion decreased with the increase of stubble height.Compared with the control,the amount of wind erosion in high stubble(30cm)field and neighboring bare field of high stubble decreased by 90.21% and 65.51%,respectively.Crop stubble can enhance not only its effect in controlling wind erosion,but also the protection of neighboring bare field.The effect of high stubble(30cm)on controlling wind erosion was best,and it also had the best protective effect on neighboring bare field.

Abstract:The biomass,coverage and height of Disranopteris dichotoma,as well as topography,soil nutrients and soil erosion degree in Changting County,Fujian Province,were investigated using quadrat methods.The differences of the biomass were evident in different slope directions.The total biomass for the quadrats on east slope was with the maximum of 1 967.65g/m² and for the quadrats on south slope,with the minimum of 1 230.28g/m².The coverage and height decreased with increased slope position.The total biomass,coverage and height were positively correlated with soil organic matter and total nitrogen.Soil erosion degree was significantly negatively correlated with the biomass,coverage and height.The Dicranopteris dichotoma growth was apparently influenced by soil erosion degree,soil organic matter and total nitrogen.Dicranopteris dichotoma plays some important roles in controlling soil and water loss and therefore,it can be used as pioneer vegetation in soil and water conservation and ecological restoration of the study area.

Abstract:In combination of field investigation with laboratory analysis,the relationships between multiple cropping and soil and water loss in the purple soil region were analyzed using soil erodibility Kvalue,runoff and erosion amount as indicators.Results showed that:(1)In contrast to single cropping pattern,the different cropping modes enhanced the sensitivity to soil and water loss,increased soil erodibility Kvalue and made soil to be eroded more easily.(2)The K value had a significantly negative correlation with sand content,with a correlation coefficient of-0.957.It was negatively correlated with clay content and organic C content,with correlation coefficients of-0.191and-0.637,respectively.The Kvalue had a significant positive correlation with silt content,with a correlation coefficient of 0.986.The levels of organic matter content and clay content were the sound indexes reflecting the resistance to erosion for purple soil.(3)Compared with the grapefruit pure cropping pattern,the runoff interception efficiency by multiple cropping was significant.The multiple cropping pattern of grapefruit and Pachyrhizua angulatus has the best effect in controlling soil erosion and thus is most suitable for application.

Abstract:The influences of mineralization degree on infiltration characteristics of coastal saline soil and brown soil were investigated by an indoor experiment of one-dimensional water ponding infiltration,using infiltration duration,infiltration rate,accumulative infiltration and average water content increment as indexes.Results show that compared with fresh water,saline water increased soil infiltration ability significantly.The abilities for the two soils reached the highest value as the mineralization were 12and 3g/L,respectively.As wetting front reached 25cm,infiltration duration for saline water was less than that for fresh water by 32.5% and 38.2%.Under the same mineralization degree,the infiltration ability for saline soil was usually stronger than that for the brown soil.Under the different mineralization,however,the infiltration ability for the saline soil did not show a big difference.Philip model could accurately simulate the infiltration process for the short-duration salty water and the deviation was within the range of±0.19%.With different mineralization degree levels water,the mean water content increment for the saline soil varied between 36.64% and 37.82%,while that for the brown soil ranged from 36.64%to 37.82%.

Abstract:Laboratory experiment with different kinds of treatments on texted brown soil,namely original soil+calcium silicate(CaSiO₃),original soil+1mmol/L citric acid+CaSiO₃ and original soil+2mmol/L citric acid+CaSiO₃,was conducted to investigate the characteristics of soil phosphorus(P)adsorption and desorption in the presence of citric acid and silicon fertilizer by Langmuir,Freundlich and Temkin equation fittings.The OECD Guideline106batch equilibrium method was used for adsorption and desorption experiments.Results showed that the brown soil P adsorption fitted Langmuir and Temkin models better.The soil added calcium silicate and 1mmol/L citric acid treatment had the maximum adsorbed P,with the maximum adsorption capacity of 500mg/kg.The soil with calcium silicate and 2mmol/L citric acid treatment had the greatest desorption rate of P,with the maximum desorption rate of 45.2%.Therefore,the soil added calcium silicate and 1mmol/L citric acid treatment had the strongest storage capacity for P,and the soil added calcium silicate and 2mmol/L citric acid treatment had the strongest activation ability and supply capacity of P.

Abstract:Minqin oasis-desert ecotone,located in the northwest arid area of China,was selected to conduct a comprehensive evaluation research on the differences of soil nutrients and soil fertility under different land cover types.8transects and 221sampling points were made,including Minqin desert botanic garden,Dongba township and Suwu Mountains.Results showed that:(1)Soil organic content varied in the order of oasis area>oasis-desert ecotone>desert.Discrete degree of soil nutrient content for different transects was large as the CVchanges from 16.67%to 410.68%,as affected by human activities and desert landscape characteristics.The variation of soil nutrient with different land cover types tended to increase from desert to desert-oasis ecotone and then to oasis in the transects.(2)There were differences in the contents of soil N,P and K among grassland,shrub land,forestland and wasteland due to different human activities,soil types,soil textures and vegetation types.(3)Soil fertility quality index varied in the order of grassland(0.552)>shrub land(0.057)>forestland(-0.642)> bare land(-0.677),which shows that grass and shrub has a good improvement effect on soil fertility.

Abstract:Soil physiochemical properties for 7different landuse types were investigated in the typical karst rocky desertification area of Lingyun City,Guangxi Zhuang Autonomous Region.Results showed that different landuse systems had significant effects(p <0.01)on the bulk weight,water content,total porosity,capillary porosity and non-capillary porosity,as well as the organic matter,total N,P and K,effective N,P and K,and exchangeable Ca²⁺.Compared with the soil in broad-leaf forest,the degrees of soil degradation in shrub land,coniferous forest land,fallow terrace farmland,grassland,fallow sloping land and farmland became serious in turn.Among them,soil quality was he worst in farmland and it was in middle in coniferous forest land,grassland,fallow sloping land and fallow terrace farmland,while it was better in shrub land and broadleaf forest land.Human disturbances were the dominant factor affecting soil physiochemical properties. Hence,the degrees of soil degradation were changed with disturbance intensity.It is significant to control unreasonable disturbances and restore good vegetation for soil quality improvement in the region.

Abstract:From a water conservation perspective,the cumulated mass(CM)and water-holding characteristics of litter were studied at different thinning intensities of Larix principis-rupprechtii forest in Xiaowutai Mountains based on field investigation and indoor experiment.Results showed that there were significant differences in the CM of different layers(un-decomposed and half-decomposed)before and after thinning.The ratio of the un-decomposed layer to the CM was smaller than the half-decomposed before thinning,but contrary after thinning.In all the sample plots,the CM and the maximal water holding capacity(MWHC) varied in the same order of light thinning>control>medium thinning>heavy thinning>super-strong thinning.There were significant differences in the CM and MWHC at different thinning intensities(p <0.01),but insignificant differences in the maximal water holding rate(p >0.05).The modified interception rate showed the maximum of 162.41t/hm² at the thinning intensity of 600 plants/hm²(reserved trees),which was equivalent to 16.241mm precipitation.

Abstract:The variation of soil moisture content of different thicknesses in the western Qinghai Lake was investigated based on the measurements of soil moisture content.Results showed that the soil moisture contents of thick and thin soil layers in Jiermeng area gradually decreased with the increased depth.In the same soil thickness,the soil moisture content in short grass land was higher than that in tall grass land.Under the same vegetation conditions,the soil moisture content of thick soil layer was higher than that of thin soil layer.A soil dry layer appeared at 80cm depth in thick soil layer,indicating the local moisture deficiency in the lower part of the soil layer.The soil moisture content of thin soil layer(30cm thickness)presented a drying phenomenon,with less than 11% of the moisture content at the 21cm depth in tall grass land and 24cm depth in short grass land,respectively.Soil moisture in Jiermeng area was outstandingly characterized by the higher moisture content in the upper part of soil layer,implying that there was a gather characteristic in the upper part.The outstanding characteristic was mainly caused by longer freezing period and less transpiration and evaporation,and it was beneficial to develop grassland vegetation.Because of the local moisture deficiency in the lower part of soil layer,the region is suitable for the development of drought-resistant and low water consumption vegetation and is not suitable for the development of vegetation with deep root and high water consumption.

Abstract:In the semiarid loess hilly region,the condition of soil moisture under different land use patterns is of importance to agricultural production,vegetation restoration and rational land use.Results from the analysis of soil moisture data under different land use patterns in Sunjiacha watershed show that soil water content on the north-facing slope was higher than the south-facing slope.Soil moisture contents at different depths in the enclosed land of the hill top zone were higher than farmland.The average moisture content in farmland of the gentle slope zone(<15°)was higher than the abandoned field.Soil moisture content of surface layer(0-80cm)in shrub land was higher than the abandoned field,but of the deeper layer(80-180cm),was lower than barren slope.The average soil water content in pine woodland was higher than apricot forest.These indicated that in the semiarid loess hilly region,terrace's water conservation benefit is the best;apricot forest has higher water consumption than pine woodland and thus,is not suitable for the large scale planting without irrigation conditions;Caragana microphylla can significantly improve surface soil water status and sufficiently use the deeper soil moisture;and in the gentle slope zone,planting crops can enhance soil moisture better than the abandonment.

Abstract:Soil organic carbon(SOC)and its correlations with soil properties were studied under the four stand types of Larix olgensis natural forest,Larix olgensis plantation,natural mixed broad-leaved forest,and natural mixed coniferous and broad-leaved forest in the eastern part of Changbai Mountains.Results showed that the SOC contents had significant differences among different soil layers under the four stand types.The SOC content gradually decreased with the increase of soil depth,and SOC was mainly distributed in the topsoil(0-20cm).The average SOC content under the stand types followed the order of natural mixed coniferous and broad-leaved forest(33.64±17.48g/kg)>Larix olgensis natural forest(25.30±15.09g/kg)>natural mixed broad-leaved forest(22.13±13.74g/kg)>Larix olgensis plantation(19.23±12.35g/kg).The SOC density in 0-60cm layer under natural mixed coniferous and broad-leaved forest was 21.44±8.31kg/m²,higher than that under the other three stand types.In different soil layers,the correlations between the SOC density and soil physiochemical properties were different.The SOC content had significant negative correlations with soil bulk density,but positive correlations with soil moisture,soil total N and P,and available K.For different stand types,SOC had positive correlations with soil total N,but had great differences in correlation with soil properties.

Abstract:Pot and filed experiments were conducted to study the Pb and Cd contents in soil and plants during soybean growth periods under the treatments of different residual amounts of mulching plastic film.Results showed that during soybean growth periods,the Pb and Cd contents in soil and the plants for high residual mulching film samples were higher than those for low.The Pb contents in soil were 49～188mg/kg;the Cd contents in soil,0.7～2.4mg/kg;the Pb contents in plants,0.022～0.097mg/kg;and the Cd contents in plants,0.001～0.0032mg/kg.By the secondary limit of China Environmental Quality Standards for Soils(GB15618-1995),the Pd content in soil was less than the limit and the Cd content in soil was higher than the limit.By the China Maximum Levels of Contaminants in Foods(GB2762-2005),the Pd and Cd contents in seeds were less than the level and the Cd content in seeds was much less than the level.

Abstract:This paper explores the water level changes of river networks under the changes of underlying surfaces represented by urbanization based on water level duration curve(LDC)method,taking the Taihu Lake basin as an example.According to the result from LDC analysis,the LDC slope of the 1980sand 1990sis steeper than the other decades.Then the study period is divided into two periods:1950s-1970sand 1980s-2000s,and normal years are selected to make further investigation.Results indicate that the LDC slopes of all the gauges in the1980s-2000sare steeper than those in the 1950s-1970s,and the LDCs of the former are also above those of the latter.What's more,the relative variations between the two periods are significant in the high water level end,and the variations are the least in the low water level end.Analyses of the precipitation and water level trend in the study area indicate that the significant increase of average water level is not consistent with the trend of precipitation.It is concluded that the above results are due to the influences of urbanization,i.e.,changes of underlying surfaces cause the slope of LDC to increase,thus the changes of water levels respond more quickly to rainfall,and the high water levels increase more significantly as well.

Abstract:The potential evapotranspiration were calculated based on the data of temperature,precipitation,relative humidity,sunshine duration,and wind speed from 12weather stations located in the upstream of the Weihe River and the data of runoff from the Beidao hydrometric station from 1971to 2008.The characteristics of regional climate change and runoff in the upstream were discussed and their relationship was studied using the methods of Mann-Kendall and climate inclination rate.Results showed that the mean temperature had increased by 0.3℃every ten years in the area since 1971and the catastrophic point was in 1994.Precipitation varied with periodicity and its catastrophic points were in 1994and 2004.The potential evapotranspiration had increased by 23mm every ten years in the area since 1971and catastrophe point was in 1993.This indicated that the monthly runoff varied with precipitation.The runoff had decreased by 2.57×10⁸ m³ in every ten years and catastrophic point was in 1991.The runoff had significant correlations with temperature,precipitation and potential evapotranspiration and the model for simulating runoff with precipitation and potential evapotranspiration was set up.Because of the raised temperature,potential evapotranspiration increased and precipitation decreased,which caused the expenditure of surface water increased and the income of surface water decreased in the upstream.The runoff in the upstream of the Weihe River decreased in recent years.The dropping of runoff in the upstream would bring about stress for water resource safety in the downstream of the Weihe River.

Abstract:A sustainable development strategy was put forward based on low impact development(LID).An experimental study of surface temperature monitoring on spot was implemented through the different road surfaces(granite road,cement road,permeable pavement and green ground)with the traditional flat roof and ecological roof.The performances of permeable pavement,green ground,ecological roof and other LID measures to alleviate the urban“heat island” were quantitatively described.The experiment showed that permeable pavement and green ground could cool the surface temperature more obviously.Ecological roof,especially planting shrubs roof,brought a significant decrease in temperature,as compared with the traditional flat roof.As time goes on of the day,all the underlying surface temperatures showed a parabolic trend from low to high and then high to low,and the maximum surface temperature occurred at 12:00.The heating rates of flat roof and granite road were higher than those of green ground,permeable pavement and ecological roof.

Abstract:The remote sensing monitoring of geological hazards on the Moxi Platform in Luding County,Sichuan Province,China,was carried out using remote sensing data from the multi-temporal and multiplatform satellite.Evolution trends and stability of geological hazards were obtained,and a scientific basis for prevention of geological hazards was provided.Results from the remote sensing monitoring reveal that during the period of nearly four years from January 2,2006to December 21,2009,new debris flows and avalanches did not occur at the platform,which means that there were no recurrence of debris flows and avalanches,debris flow were intermittent,and avalanches and most of landslides were in a steady state.There was only one new landslide still in developing and precarious state,which is subject to further development and needs to be monitored.Slides and collapses induced by river erosion and shallow debris flow on margins of the Moxi Platform are always developed continuously,which will threaten the stability of bank and reduce the area of the platform and hence needs handling at early date.

Abstract:Two karst soils(terra fusca and rendzina)and a contrast soil(red soil)were selected to study soil carbon fluxes in typical karst soils.The daily and seasonal soil carbon fluxes on different interfaces(soil surface and soil stone surface)were tested to indicate the transformation of soil organic carbon.Results shows that soil carbon flux in rainy season was higher than that in dry season.Soil carbon flux in red soil was steadier than that in terra fusca of both shrub land and forest land.Soil carbon flux in terra fusca was more sensitive to temperature and humidity than that in red soil.Soil carbon fluxes in rendzina of shrub land(soil surface and soil stone surface)were less than that of forest land.Soil carbon flux in rendzina of forest land was higher than that of the shrub land.The maximum values of soil carbon flux on soil surface occurred in July(3.0μmol m²/s)in both the shrub land and forest land,while on soil stone surface,in June(1.5μmol m²/s).In shrub land,the maximum value of soil carbon flux on soil stone surface occurred in June(1.9μmol m²/s).This implied that soil carbon flux differed in soil types in karst area.Climate,season and vegetation were the most important factors which influence soil carbon flux in karst area.Soil carbon fluxes of soil surface and soil stone surface were greatly impacted by them.

Abstract:The differences of growth and total soil mass water amount among different tree species were studied by large-scale weighing lysimeter in the whole process of rainstorm in Beijing from 21to 22July in 2012.At the same time,soil moisture content was measured in different depths of soil mass by soil three-parameter determinator and dynamic changes of the moisture content of every layers in soil mass were analyzed in the whole rainfall process.Results showed that soil mass water content in lysimeter presented the trend of slow growth after a jump under the rainstorm conditions.Soil mass water content for Acer elegantulum gained the most and leakage was the least,while for Pinus tabuliformis,just the opposite.The soil mass water content decreased in the order of A.elegantulum>Platycladus orientalis>space>P.tabuliformis.In different soil layers,they had a jump of moisture in rainstorm process.The jump in topsoil occurred earlier and increased more,while in deep soil layers,the opposite.At the end of rainfall,the soil moisture content of every layer for A.elegantulum was the most and P.tabuliformis was the least.The soil moisture content decreased in the order of A.elegantulum>space>P.orientalis>P.tabuliformis.

Abstract:The scarcity of undergrowth vegetation has already become a common but outstanding problem,existing in a large portion of Pinus massonianaforest ecosystems in the eroded red soil area of southern China.Accordingly,making every effort to restore the undergrowth vegetation in degraded masson pine community is of great significance for reversing regressive succession of inefficient Pinus massonianaforests and improving local ecological environment.This paper analyzed the main causes leading to the problem of undergrowth vegetation scarcity in some Pinus massoniana ecosystems and then presented a comprehensive discussion on the limiting factors to undergrowth vegetation recovery from several aspects,such as soil nutrient status,soil physical properties,high summer temperature,seasonal drought,soil acidification and human disturbances.Several effective countermeasures and successful recovery models,which had already been proven by practices,were put forward to solve the problems of how to control soil and water loss in woodland,improve degraded woodland and reduce human disturbances.It is expected to provide references for future research on the transformation and restoration of degraded Pinus massoniana forests in the eroded red soil area of southern China.

Abstract:Hydro-thermal factors is a key factors affecting the greening on highway slope.By using self-recording hygrometer,self-recording soil thermometer and other instruments,solar radiation,soil temperature and soil moisture were observed on sunny slope,ground,shady slope and central isolation belt along the Langfang-Zhuozhou highway from June 2009to May 2010.Results show that:(1)The diurnal variations of solar radiation under different terrain conditions meet a quadratic curve.There was no significant impact of terrain on direct solar radiation.(2)The monthly variations of soil temperature are in a“cosine curve” shape under different terrain conditions.The soil temperature at 40cm depth was the highest under different terrain conditions;and the soil temperature in central isolation belt was the highest from March to August,whereas the soil temperature on sunny slope was the highest from September to December and from January to February.(3)The monthly variations of soil moisture are in a wave shape under different terrain conditions.The soil moisture in 20-40cm soil layer was the highest under different terrain conditions,and the soil moisture in central isolation belt was the highest at different depths.

Abstract:Effects of different soil amendments on soil compaction and growth status of oat were studied.Results showed that all the soil amendments could reduce soil compaction;the order of them was potassium polyacrylate+potassium humate>polyacrylamide+potassium humate+potassium humate>potassium polyacrylate>polyacrylamide>potassium humate> CK;and soil compaction increased with the increase of soil depth.Soil amendments significantly increased plant height of oat and dry matter weight,and the height for the mixed use was higher than the single use.Grain yields under the amendment treatments were significantly higher than that under the control.The yields for potassium polyacrylate+potassium humate and polyacrylamide+potassium humate were higher than that for the single use,being 4 694.2and 4 566.9kg/hm² with the increments of 21.66% and 18.36%,respectively.Biological yield had the same effect as grain yield.The WUE under the amendment treatments was significantly higher than that under the control,and the WUE under mixed amendment was higher than that under other soil amendments.

Abstract:Ryegrass,hairy vetch and milk vetch were selected as green manures to study their effects on soil fertility for growing spring corn in Southern China.Results show that compared with the control,three green manures increased the organic matter contents and available nutrients of rhizosphere soil,while ryegrass and hairy vetch showed better effects than milk vetch.Furthermore,hairy vetch was better than ryegrass and milk vetch as for improving the available nutrients,and hairy vetch was about equal to ryegrass regarding the effect on improving the organic matter in rhizosphere soil.Preliminary tests prove that the ryegrass and hairy vetch can be used as the predominant green manure species of winter fallow field.

Abstract:According to the agricultural non-point pollution problems in Yitong River,a model of agricultural non-point pollution in this area was constructed using SWAT model with the support of GIS technology and watershed foundation database.The model was used to simulate the temporal and spatial distributions of N,P and sediment,as well as the total nitrogen delivered into groundwater in the study area.Results from the calibration and verification for the model showed that the precision of the model can meet the requirements.Through the calculation of model simulation,sediment yields in 1985and 2008were 7.031 6and 3.458 7million ton,respectively.In 1985,total nitrogen and phosphorus outputs were 20 400and 2 300ton,respectively,and in 2008,was about half of that in 1985.For one year,pollution output from June to August took up90% of the total amount.The simulation result showed that the amount of nitrogen delivered into ground water by infiltration was considerable in 1985and 2008,the amounts of nitrogen delivered into groundwater were 2.4and 5.5times of those in other forms of output.

Abstract:Based on daily precipitation data of 53meteorological stations over the North China Plain during 1961-2010,the extreme precipitation thresholds were determined for different stations by centesimal value method.Then,the three indices of annual amount,frequency and intensity of extreme precipitation events were counted and their spatial characteristics and temporary trends were analyzed.Results showed that most stations in the North China Plain had no significant monotonic trend by each selected index of extreme precipitation events and however,the annual amount,frequency and intensity tended to reduce.Furthermore,the variation trends of extreme precipitation events exhibited similar spatial variability.Specifically,there was a positive trend of extreme precipitation events in Hebei Province and the southeast coast of Shandong Province,while a negative trend,in He'nan Province.Each index fluctuated during 1961-2010,and basically showed a significantly decreasing trend in the 1960s.The annual amount and frequency showed abrupt changes around the year of 1965.However,the intensity did not show an abrupt change.

Abstract:The stationarity of streamflows over the past 50years were investigated for well/poorly forested watersheds in the Beiluohe River basin on the Loess Plateau,using concentration degree and concentration period methods.The change trend and change point were checked with nonparametric M-K,Pettitt and Rank-sum tests.Results show that all the five watersheds studied were characterized by the high fluctuation of annual streamflow and the double peaks of inner-annual hydrograph.Forested ones presented mild slopes and less forested ones,steep shapes.In contrast,the streamflows were better distributed in well forested watersheds where the concentration period was 1month behind the poorly forested counterpart.Different components of the streamflow in forested watersheds did not show a significant trend or change point,while significant decrease and change points were detected in annual streamflow and the components in summer,fall and flood season for less forested watersheds in the past 50years.In both annual and inner-annual scales,the streamflow in forested watersheds was considered more stable than that of the less forested,which implies that less forested watersheds still demands a long-term construction and conservation for the eco-environment to recover.

Abstract:Understory plants and soil characteristics of Acacia auriculiformis plantations with three densities were studied.Results showed that the total coverage degrees of understory plants were in the order of lowdensity stand(1 667trees/hm²)> middle-density stand(4 444trees/hm²)> high-density stand(10 000trees/hm²).The total biomass of understory plants were in the order of low density stand> middle-density stand>high-density stand,and the shrub biomass of low-density stand and the grass biomass of middledensity stand were the greatest among the three stands.In the low,middle and high density stands,Simpson diversity indexes for shrub layer were 0.679,0.935and 0.708,and for grass layer,0.904,1.228and1.064;Shannon-Wiener diversity indexes for shrub layer were 1.657,0.535and 1.171and for grass layer,0.904,1.228and 1.064;and Pielou evenness indexes for shrub layer were 0.691,0.333and 0.654,and for grass layer,0.504,0.886and 0.594,respectively.Except the available P,the soil characteristics of the low and middle density stands were better than those of high-density stand.

Abstract:Sap flow of Eucalyptus urophylla×E.grandis in Guangdong Province was measured from July to August in 2010using thermal dissipation probe method.The relations of sap flow to ambient environmental factors were analyzed in combination with environmental factors collected from the micro-meteorological station.Daily sap flow had significant circadian variation with weak sap flow activities at night.The velocity in the north was higher than the south and the correlation between them was significant.There were marked correlations between sap flow and ambient environmental factors〔photosynthetically active radiation(PAR),relative humidity(RH)and wind speed〕,and the correlated degree was in the order of PAR> RH > wind speed.The equation set up with stepwise regression shows that it reaches an extremely significant level.Sap flow at night was mainly associated with water storage in the trunk and had no significant correlation with ambient environmental factors.

Abstract:A typical parabolic dune in the south margin of the Hobq Desert was taken as the research object.GIS spatial interpolation was used to generate DEM that was obtained by on-site RTK GPS measurement and the topographical factor and morphological parameter were collected.High resolution images were then used to obtain environmental background information.Form changes of parabolic dune can be analyzed by referring to relevant meteorological data.Results show that the flat form of the dune is U-shaped,with its arm pointing to the west.The windward slope is gentle,while the leeward one is steeper in the long section.However,the cross section is dissymmetrical.The average moving speed is 11.69m/a.The axes of the crest move toward WNW-ESE,in the same direction as the prevailing wind or the resultant sand drift.Artemisia ordosicashrub is distributed on the arms as well as the plain area between them.There is an annual decrease of 0.95%in vegetation coverage.Under long-term resultant wind,the dune moves forwards,while the Artemisia ordosica shrub between the arms recover periodically and spontaneously.

Abstract:Taking an abandoned quarry watershed in Beijing City as the research object,the parameters of watershed and landform were extracted and analyzed using the raster DEM at the different resolutions from 0.3to 7 m.Results showed that the morphological structure of drainage networks extracted from the different resolution DEMs had significant differences.The structures of drainage networks had significant differences between the two sets of gird size:one was with 7,4and 3mand the other was with 2,1,0.7,0.5,0.4and 0.3m.Positions of the two main channels changed dramatically.But there was no marked qualitative difference among drainage area,channel length and gradient,average slope and elevation.The difference was obvious between the total channel length and drainage density.According to the results,the optimal resolution of DEM was estimated to be 0.5m.The main components,i.e.,elevation and slope,were obtained using the PCA(principal component analysis).By se tting four runoff plots of 20°,25°,30°and 35°in the research area,the relationships among rainfall,slope,runoff and soil erosion were analyzed and obtained.Then,the average runoff and soil erosion of the whole drainage basin were computed for different slope grades and rainfall levels.The research results can provide reference for the restoration and ecological reconstruction of abandoned quarry.

Abstract:Impulsive wave generated by high-speed landslide on reservoir bank often result in serious disasters.At first,a sliding block model is developed for predicting the movement of high-speed landslide,while the fluid movement is solved by SPH(smoothed particle hydrodynamics)method in accordance with the incompressible continuity equation and Navier-Stokes equation.Then the basic principle,kernel function,discretization scheme and boundary treatments are introduced.Coupled with landslide and fluid movement,the SPH model is developed to simulate impulse wave.The initial impulsive wave height and climbing height are compared with those by other methods.Results show that the model can simulate the movement of waves generated by high-speed landslide,and the SPH method can well simulate the mechanics problems with instantly large deformation.

Abstract:On a basis of understanding the domestic and foreign theoretical researches on ecological restoration engineering and related evaluations,the quality characteristics of slope protection engineering by vegetation were summarized and an evaluation index system was established in combination with the systematic engineering theory by threading structure stability &functional continuity as a guidance.This system contained three main evaluation indexes:mechanical protection quality,slope plant community quality and base material quality.Analytic hierarchy process(AHP)was conducted to determine the weight and order of each index.Meanwhile,according to the grey system theory,a low-cost hierarchy grey comprehensive evaluation model was constructed to evaluate the slope vegetation protection engineering handled with three different engineering measures in Pengzhou City,Sichuan Province,China.Results showed that the grades for all the slopes were ranked as good and the grades that slopes with the injection technoogy of thick layer base material mixture were better than those disposed with seed grilles or vegetation nets,which coincided with the factual account.All these outcomes indicated that the evaluation index system and its grades could objectively and accurately reflect the quality and grade of the slope vegetation protection system,which means that it has good practical values.

Abstract:In the karst regions of Southwest China,rocky desertification is one of the most serious problems of land degradation.Because of the inherent merits of macro scale,frequency,efficiency and synthesis,remote sensing is the promising method to monitor and assess karst rocky desertification.However,existing remote sensing methods can not directly be exploited to extract the information on karst rocky desertification owing to the high complexity and heterogeneity of karst environments.Based on NDVI,karst rocky desertification synthesis indices(KRDSI)and lignin-cellulose absorption index(LCA),this study compared the feasibility and accuracy of indicator extraction for the assessment of karst rocky desertification with Hyperion and simulated ASTER images.Results showed that Hyperion imagery can be used to efficiently and directly extract the information on the fractional covers of photosynthetic vegetation,non-photosynthetic vegetation and bare soil,while the proportion of exposed bedrock was not so good due to the different types and weathering processes of carbonate rocks.As for multi-spectral image,ASTER can be used to estimate the fractional cover of photosynthetic vegetation and bare soil,but could not be utilized for accurate estimation of the fractional covers of exposed bedrock and non-photosynthetic vegetation due to the limits of spectral bands and spectral resolution.

Abstract:According to plants investigation with the combined method of uniform distribution with typical sampling area,the plant species and diversity along four provincial roads in Xuzhou area were studied by using significant value,richness index,Shannon-Wiener index,Pielou evenness index and similarity index.Results showed that(1)there were 31kinds of arbor,17kinds of shrub and 40kinds of herbage along the four roads.Populus,Ligustrum lucidum,Juniperus chinensis cv.kaizuk and Trifolium played important roles,and their significant value and frequency of occurrence were at the top.(2)The species of arbor and shrub occurred mostly in S323and the species of herbage,mostly in S253.Artificial trees and shrubs inhibited the growth of weeds to some extent.Comprehensive Shannon-Wiener index was in the order of S323>S322>S253>S251.Richness index,Shannon-Wiener index and Pielou evenness index were all in the order of herbage>arbor>shrub along every provincial road.(3)The similarity index was between 30%and50% and herbage species had the greatest contribution to it.During road greening,we need consider the community as a whole,especially increase the diversity of herb to inhibit weed growth.

Abstract:Non-point source pollution is the main origin of water pollution in the Taihu Lake basin.Quantitative study of non-point source pollution load can provide decision supports to its forecast,prevention and treatment.In traditional study,GIS and non-point source pollution models were integrated in the loose coupling way that has the defects of a large amount of data management and transform works.An estimating system for non-point source pollution load in the Taihu Lake basin was designed and developed using mosaic integration.Structure of the system and its functions were introduced and the realizing flows of three main function modules were discussed,including modules of SCS,USLE and non-point source pollution load models.Using the system,non-point source pollution load of total N in Wuxi City in 2005was estimated to be 8 014.43t, which originated mainly from agricultural production and waste water drainage of daily life.Application of the system showed its practicality because the calculating procedures of non-point source pollution models were simplified and the result reflected non-point source pollution situation and its relationship with land use in the study area objectively.

Abstract:Landslides,mudslides,avalanches and other secondary geological disasters,triggered by“5·12”Wenchuan earthquake,have severely damaged vegetation in the region.Maoxian County is one of the earthquake disaster areas.Identifying changes of Maoxian County's vegetation coverage can provide a reference for vegetation restoration and is helpful to control soil erosion and geological disasters.Landsat-5TM remote sensing images for Maoxian County before and after the earthquake are selected as a data source and the normalized difference vegetation index and dimidiate pixel estimation model are used to analyze the vegetation coverage changes.Through the study of the data,the vegetation coverage is divided into high vegetation coverage,moderate vegetation coverage,low vegetation coverage and no vegetation coverage areas.Statistical analysis is made for the coverage change in each area.Results show that the earthquake has severely affected Maoxian County's vegetation coverage,with the high vegetation coverage area being most seriously affected and the low vegetation coverage area being least affected.The more seriously damaged area is mainly distributed in the slope of more than 40°。

Abstract:The spatiotemporal trend of vegetation coverage in Beiluo River watershed was analyzed to understand the eco-environmental evolution and runoff-sediment behaviors on the Loess Plateau.TM images of 1987,1995and 2007with a spatial resolution of 30mwere employed,the normalized difference vegetation index(NDVI)was then calculated,and the dimidiate pixel model was used to get vegetation coverage degrees and its classification.Results showed that(1)under the double influences of climate change and human activities,the vegetation coverage in Beiluo River watershed experienced the process of slow to rapid increase from 1987to 2007.The vegetation coverage degrees for the whole watershed were 41.12%,46.43% and 63.43%in 1987,1995and 2007,respectively.(2)The vegetation coverage both in the hilly-gully and tablegully regions showed a slow to rapid trend from 1987to 2007,and the rocky-mountain region kept the relatively stable forest coverage.The intense vegetation restoration mainly occurred in Wuqi and Zhidan Counties and Luochuan tableland in the watershed.

Abstract:The spatial and temporal characteristics of land use change and its driving factors in Zhengzhou City in 1998-2008were analyzed based on visual interpretation results of three TM/ETM⁺ and SPOT fused images in 1998,2002and 2008,Spatial analysis module in ArcGIS software and statistical analysis.Results showed that:(1)Non-agricultural land increased rapidly over the past 10years,characterized by increases of 124% and 158%in the construction land and industrial storage land,respectively,while farmland was reduced by 40%due to the conversion to construction land,industrial storage land and garden.(2)In 1998-2002,agricultural land,including woodland,vegetable land and garden,changed more quickly;but in 2002-2008,non-agricultural land,including construction land and industrial storage land,changed more quickly.(3)The districts with more rapid economic development and industrialization showed a quicker land use change.(4)The land use change and expansion of urban area were mainly affected by the development of traffic network and the growth of population and economy,while the intensive use of urban land was promoted by the adjustment and upgrading of industry structure.

Abstract:Effects of eco-environmental construction projects on soil and water loss from 2000to 2009were studied by taking the Huangshui River basin as the study area.Landsat TM/ETM data of 2000and 2009 were used to derive the data of land cover and vegetation in combination with the Aster DEM.The study was conducted by the“Standards for Classification and Gradation of Soil Erosion” (SL190-2007)and with the support of GIS techniques.Results showed that soil erosion on slope in the Huangshui River basin was reduced somewhat in the last ten years.The intermediate and above soil erosion in 2009was reduced by 309.11km² as compared with that in 2000,but gully erosion tended to increase,with a net increase of 706.87km².This illustrates that the engineering measures are effective to soil erosion on slope,but insignificant to gully erosion.

Abstract:Based on Landsat TM images of 1990,2000and 2006and“HJ-1”Satellite image of 2011,land use/cover changes from 1990to 2011in Qingdao City were analyzed using a system dynamic model.There were significant changes on land use/cover in Qingdao City in the past 21years(1990-2011).The areas of farmland and grassland decreased,while the areas of rural,urban,mining and residential lands increased.Forest area was reduced first and increased later,and water area and unused land went to the other way.The degree of land use became greater year by year,which indicates that Qingdao City was in the stage of land use development and the strength of land use was enhanced to a higher level.Spatially,distinct changes took place in the middle and eastern areas of the city,and a relatively small change,in the north and south-west areas.The conversion of land use type was complex,but it mainly changed into the rural,urban,mining and residential areas.

Abstract:Calculating the investment benefits of soil and water conservation(SWC)is an important part in SWC project evaluation.Using the existing methods of benefit calculation,however,is difficult in eliminating the contributions of other factors except SWC and estimating the comprehensive benefits of system.By taking Changting County for an example,an analysis on the contributions of SWC investment to local agricultural economy was made based on the Cobb-Douglas production function theory.Results reveal that the contribution of agricultural investment was highest in the features of output,butlower in technology and system innovation.From 1999to 2009,5.20% of agricul tural GDP were derived from SWC investment and the ratio of output to input was 5.9in Changting County.With the rapid growth of physical capital investment in agriculture,the contributions of SWC investment to agricultural GDP were being reduced year after year,which may restrain farmers'investment enthusiasm for SWC.

Abstract:The risk gradation of soil erosion is an important approach to study soil erosion hazard degree.To find a suitable approach to the gradation of soi erosion and its hazard degree in practice,soil erosion degree and its potential risk for the scientific investigation area in the red soil region of Southern China,as well as sediment delivery ratio for the main lakes within the basins in the region,were gradated according to the MWR(Ministry of Water Resources)Standards for soil erosion classification and gradation and the data from the scientific investigation by the MWR.Results showed that there were light,moderate,intense and extremely intense soil erosion degrees in the investigated area.The moderate erosion and intense erosion were the main soil erosion types and accounted for 84% of the whole area,while the light erosion and extremely intense erosion accounted for 16%.The types of no risk,light risk,risk and extreme risk were all found in the potential risk gradation.The light risk and risk were the main risk types and accounted for 84% of all the risk types,while the no risk and extreme ris accounted for 16%.Soil erosion was harmful to the places nearby.Sediment delivery ratios in 60% of the lakes were greater than 0.5,which indicates that soil erosion occurred in the upstream of the lakes is dangerous,even extremely dangerous to the places nearby.Results from the study may offer reference for soil erosion gradation and control in the whole red soil region.

Abstract:Effects of ecological de-farming on farmers'income,industrial structure and cultivation structure were analyzed based on the agricultural statistic data from 1980to 2007in Ansai County of Shaanxi Province.Grey relational grade analysis method was used to investigate the rural industrial structure adjustment process and agricultural structure adjustment direction.The purpose of the study was to explore the influences of the de-farming and reafforestation project implement in the county,especially for the agricultural and rural economic development,and find the path for rural economic transition after the ecological de-farming.The conclusions are as following:(1)The ecological de-farming program has markedly increased farmer's per capita income and promoted the agricultural structure adjustment and rural labor transfer.(2)At the present stage,purpose of rural economic transition in Ansai County is to consolidate the results of the ecological de-farming and realize the sustainable development of rural economy.The fundamental task is the agricultural industrial structural readjustment.(3)Key point of rural economic structure adjustment in Ansai County is to promote secondary industry.In the process of interior agricultural structure adjustment,the development of crop farming,animal husbandry,forestry and fruit industry should be treated as a key point.(4)The crucial problem of rural economical transition is to increase farmers'income and realize the reliable transfer of rural surplus labors.

Abstract:The grain for green project,as a major measure for vegetation construction,plays a very important role in accelerating eco-environment restoration on the Loess Plateau.Based on the arable land pressure index,the effects of the grain for green project on food security were evaluated by taking the Yan'an demonstration area of soil conservation and eco-environmental construction as a study object.Results showed that the grain for green project has achieved the purpose of“food for ecology”.Arable land pressure decreased by 75.5%in northern forest-meadow region and remained balance basically in southern forest region to a large extent.However,arable land pressur rebounded and reclamation occurred sometimes due to the ending of the project and the change of food subsidy policy after 2003.Arable land pressure from 2004to 2009was 1.8～4.8and 1.1～1.7times of that of 2003in the north and the south,respectively.Among them,arable land pressure for the south was greater than 1after 2007,which should be paid more attention.Longevity and stability of food subsidy should be ensured in future,so as to insure the sustainable development of ecological restoration.

Abstract:In order to predict and evaluate the ecological service values under different land use types in Yanchi County,Ningxia Hui Autonomous Region,a research on the changes of land uses and ecological service values was conducted for six types of land uses(farmland,forestland,grassland,saline land,desert and other lands).Results showed that from 1999to 2004,the amount of transferred grassland and farmland was greater than other land uses,with farmland being mainly transferred to grassland.From 2004to 2010,the transferred farmland and grassland were still more than other land uses,and the conversion between grassland and farmland still occurred in this period,with a small portion of grassland being turned into desert.In these years,the total ecological service value of 2004was the highest and the overall trend first increased and then decreased.In the first class service,the values for regulating services and support services were greater than others,but the annual changes were insignificant.Soil conservation,biodiversity conservation and climate regulation dominated in the second class service.Generally,the contribution from forestland and grassland was the largest in these years.

Abstract:An assessment index system of land use suitability in the Shanghuang experimental area was established based on the characteristics of the area and the experts'advices,and the quantitative grade and weight of each index for the land suitability assessment were acquired using expert scoring method.The experimental area was divided into 185units,and the spatial and attributive database of the 185units were established using ArcView 3.2software.The land use suitability of each unit was analyzed using spatial overlay analysis function and comprehensive index method.Results showed that the largest area in the experimental area was the land suitable for grassland,about 419.04hm2(52.31%);the second,for agriculture,about 195.35hm2(24.39%);and the smallest,for woodland,about 46.8hm2(5.84%).the area of the land suitable for both grassland and woodland was 139.86hm2(17.46%).Result from the assessment could provide a data basis for determining the best land use plan of the experimental area.

Abstract:The Ulmus glaucescens woodland is the largest vegetation type in the Helan Mountain natural reserve areas.Research on the organic carbon storage of the woodland is useful for evaluating ecological service functions of the area.The biomass,vegetation carbon content and soil organic carbon of the woodland were sampled and measured on the east side of Helan Mountains and the carbon storage was evaluated.The carbon contents varied in the different parts of Ulmus glaucescens.The trunk carbon content rate was higher than other parts and average carbon content of Ulmus glaucescens was 437.78g/kg,lower than other forest species.The carbon density of understory and roots was 276.61g/m².The soil carbon content was 15.82g/kg,higher than other soil type,and the carbon density was 3.76kg/m².Average organic carbon density of the woodland was 4.72kg/m².Carbon storage per hectare was 47.2t.Soil carbon storage was significantly higher than vegetation carbon storage.In the sparsely vegetated arid area,soil conditions are of benefit to the organic carbon accumulation.Soil organic carbon in arid zone is an important organic carbon pool.

Abstract:Based on the detailed survey data of landuse change from 1996to 2008in Zhangjiakou City,many models and methods including the contribution rate of landuse change,dynamic degree of landuse change,information entropy,equilibrium degree,degree of dominance,diversification and centrality degree were used to analyze the landuse structure characteristics and its dynamic change.Results show that:(1)The main landuse types in Zhangjiakou City were arable land,forestland,grassland and unutilized land,which accounted for about 92% of the total land area.(2)The landuse change was obvious in the city from 1996to 2008.The areas of arable land,unutilized land and water body had a drastic reduction,while the areas of forestland,orchard,grassland,construction land and traffic land increased.In terms of the maximum dynamic degree of landuse change,the landuse types from high to low were in the order of forestland,arable land,orchard,unutilized land,traffic land,grassland,construction land and water body.(3)The informationentropy,equilibrium degree of land use for Zhangjiakou City increased,while the degree of dominance decreased,which indicated that land use structure was changing to be disordered and equalization.(4)The centrality degree of landuse increased along with the diversification decreased,which shows that the landuse structure of Zhangjiakou City tended to be diversified.

Abstract:An evaluation index system of sustainable urban land use was established from the three aspects of resource environment,economic development and social harmony and the improved grey relational analysis was adopted to evaluate the sustainable urban land use in Hu'nan Province.Results show that:(1)The status of urban land sustainable use experienced from a lower level to a higher level in Hu'nan Province from 2000to 2010,but there was still a large space for improvement.(2)The most important factor affecting sustainable urban land use was the resource environment,followed by social harmony and economic development.(3)Overall,the gray relating degree for the three sub-goals increased,but the sub-goal of social harmony fluctuated greatly.To improve the level of sustainable urban land use,people should further accelerate the economic development,explore the potential of urban land use,optimize the structure of urban land use,strengthen environmental protection,speed up the urban traffic and infrastructure construction,and increase the proportion of land for public facilities.

Abstract:A series of issues such as resources exhaustion,soil degradation and environmental pollution caused by rapid population growth,accelerated urbanization and unreasonable development and utilization to natural environment have brought great challenges to the eco-security situation.In consideration of the social,economic and environmental characteristics,we attempted an integrated assessment of the ecological security in Zhangjiakou Rigion of Hebei Province by employing the pressure-status-response model(PSR).An integrated assessment model of regional eco-security and corresponding indicator system were given according to the levels of socio-economy and environment of the study region.Through determining 29indexes,building sample matrix,using dimensionless processing and determining the index weights with AHP method,each index value was computed by comprehensive index method and then the integrated eco-security index for each index was obtained.Results suggested that overall the eco-security index for every county increased by 0.035 6between 1987and 2009.The average eco-security index for Bashang Plateau region was 0.006 0higher than that of NW Hebei depressed basins.The evaluation result fits well the actual situation and can reflect the regional ecological problems and eco-security status.

Abstract:A comprehensive evaluation of water footprint,water resources utility and urban and rural residents'virtual water consumption diversity index in Wuwei City from 1995to 2009was made based on the calculation of water footprint by introducing the concept of water footprint.A dynamic analysis of water resources utility was made according to the co-integration analysis model in dynamic econometrics.Results showed that water resources utility in Wuwei City was poor and it had a stable relationship with water resources utility,water footprint and urban and rural consumption structure.Therefore,some effective measures of water resource management must be taken as soon as possible.However,as the interaction between water use efficiency and other indexes is dynamical,people should consider the influences of water footprint and urban and rural consumption structure variables while taking the measures to improve the efficiency of water resources.

Abstract:For evaluating,forecasting and regulating the health of Taiyuan City ecosystem,an evaluation system was established,which includes dynamics,organizational structure,resilience,ecosystem services and health status of population.Based on the evaluation system,dynamic change in the health degree of Taiyuan City ecosystem from 2000to 2009was analyzed using fuzzy synthetic method and its grey prediction model was established using grey system theory.Results showed that health degree of Taiyuan City ecosystem rose continuously.Its health status changed from unhealthy state in 2000-2006to critical state in 2007,which indicates that Taiyuan City ecosystem develops to a healthy direction.Furthermore,according to the grey prediction model,the city would achieve relatively healthy status in 2018and healthy status in 2049.

Abstract:The relationship between soil salinity in the top soil of nebkhas and annual litter-fall production of tamarisk shrub was analyzed to clarify the distribution of soil salinity patterns in and outside Tamarix nebkhas and their effects on oasis ecosystem.Results indicated that soil salinity in nebkhas surface soil(0-30cm)was lower than in internebkhas.Annual litter production was found to be an important factor reducing soil salinity in surface soil beneath the canopy according to correlation analysis.In contrast,soil salinity enrichment was observed in deeper soil layer(30-120cm)in the Tamarixnebkhas compared to internebkhas,which indicated the formation of salinity islands in nebkhas.K⁺,Na⁺,Cl^-and HCO₃ were the four important ions enriched in resource islands.The other three ions(SO₄^2-,Ca²⁺and Mg²⁺)were distributed evenly or randomly in deeper soil.These results suggested that the Tamarix nebkhas gathered soil salinity from internebkha spaces.The fate of Tamarixnebkhas will affect the stability of oasis ecosystem in the arid zone.

Abstract:The evaluation of regional land use performance and its obstacle indicator identification is the guarantee of sustainable land resources use.The paper takes the South Shaanxi as a study area,which is an important ecological fragile region.The data used is mainly from the statistics of socio-economy and land use structure in the region in 2009.An evaluation index system consisting of 16indices from the natural,socialeconomic and environmental factors influencing land use performance has been established.Related mathematical methods and econometric models are used to make a quantitative and comprehensive appraisal of land use performance in South Shaanxi Provnce.Results show that:(1)The land use performance of different counties(districts)in the region is at an intermediate level as a whole.And there is a significant special difference of land use performance among all the counties.The special difference of land use performance primarily corresponds with the urbanization process and the discrepancy of socio-economic development level.(2)The special differentiation of land use performance does not correspond with the special differentiation of land use structure information entropy in South Shaanxi Province.Hantai District is at the highest level in both land use performance and land use structure information entropy.The land use performance of Langao and Zhenping Counties is the lowest,as well as the information entropy of land use structure of Liuba and Foping Counties.(3)The percentage of forest cover,cultivation index,construction area per capita,multiple crop index,GDP of per hectare land,fixed asset investment per unit area,net income of per capita,unit of output value of construction land become the main limited factors to the land use performance.Finally,some measures are proposed to improve the land use performance in South Shaanxi Province.

Abstract:Regional difference of land use changes is a comprehensive reflection of land resources and economic development in an area.Analysis on regional differences and influencing factors of land use changes provides a scientific basis for sustainable use of land resources.Temporal and spatial changes of cultivated land,forest land,residential land,and industry and mining land in the three large regions of Northern Shaanxi Province,Guanzhong District and Southern Shaanxi Province from 1996to 2009were analyzed by taking land use dynamic degree,relative change rate,land use intensity and benefit as indicators.Results showed that the area of cultivated land continued to decline and the areas of forest land,residential land,industry and mining land increased in the recent 14years.With the implementation of the returning farmland to forestland/grassland project,the area of cultivated land in Northern Shaanxi Province declined most obviously and forest land increased fast.Construction of the national energy and heavy chemical industry base has driven a rapid increase of industry and mining land in the district.Rapid economic development lead to the rapid growths of residential land,and industry and mining land in Guanzhong District,which was also the main cause for cultivated land decreasing in the area.With the limits of natural conditions and economic development in Qinling-Bashan Mountains of Southern Shaanxi Province,all types of land changes were relatively slow,and land use intensity and benefits were significantly low as compared to Guanzhong District and Northern Shaanxi Province.

Abstract:This paper evaluated the socio-economic and eco-environmental benefits of land use during the urban expansion period of Nanjing City from 1990to 2008.Subsequently,their dynamic relationships were discussed based on the theory of co-integration.Methods of improved entropy,error correction model and variance decomposition were employed.Results showed that both of the indicators of socio-economic and eco-environmental benefits were increased and were integrated of order one.There existed an equilibrium relationship between them in long term,whereas things were different in short term.The magnitude of the adjustment from short-term fluctuation to long-term equilibrium was 45.36%.The eco-environmental benefits were the Granger's cause for socio-economic benefits,but the contrary was not true.The eco-environmental benefits were the main driving force that can be used to improve the comprehensive benefit of land use.The proportions of socio-economic and eco-environmental benefits could be represented as 85.27% and 93.89%,respectively,in twenty years later.Therefore,it is necessary to play the important role of eco-environment benefits by taking long-term and short-term strategies completely.On the one hand,the efficiency of environmental pollution management should be improved in the short term.On the other hand,the road of sustainable development should be taken in the long term,through conforming to the system of economic growth mode transformation and vigorously developing the low-carbon economy and green technology.

Abstract:A reasonable appraisement to the degree of intensive land use for cities and towns is an important means for advancing the managing level,improving the efficiency of intensive utilization and ensuring the sustainable development of city-and-town land.In view of the three dimensions of the investment,efficiency of land use and sustainable use of land resources,a sustainable development model based on intensive land use was constructed and the sustainable development of intensive land use was divided into the four types of sustainability,poor sustainability,nearly unsustainability and unsustainability.Result from the analysis based on the characteristics and existing data of land use for 15cities and towns along the railway in North Xinjiang Wei Autonomous Region shows that the type of sustainable development in the study area belonged to the sustainability.Scientific land use strategy was finally put forward for sustainable development from the perspectives of rational town-level expansion,i.e.,establishing land protection system including economical,administrative and legal means,optimizing regional and town-level land use structure and distribution,frugally and intensively utilizing town-level land and promoting friendly interaction between town-level land use and eco-environment with both prevention and control measures.

Abstract:The benefit of cultivated land use is an important measure of land productivity and sustainable agriculture development.By taking He'nan Province as the study area,19indicators were selected to build an evaluation index system of cultivated land use efficiency from the three aspects of economy,society and ecology.Entropy method was used to determine indicator weight;comprehensive multi-factor evaluation method,to evaluate the standards of cultivated land use efficiency from 1990to 2009;and the coordination degree model,to judge the mutual coordination degree for various subsystems affecting the cultivated land use efficiency.Results show that overall,the cultivated land use efficiency in He'nan Province presented an upward trend from 1990to 2009.The coordination degree of cultivated land use system was in an unstably fluctuated status in the 20years,from very uncoordinated status to basic coordination on a whole.To achieve a reasonable use of cultivated land resources in He'nan Province,we should exploit cultivated land use potentials,enhance land remediation and environmental protection,promote agricultural restructuring,develop agricultural science and technology,increase efforts to the concessions and support for agriculture,and control population growth.