Abstract:After two years' experiment in the west loess hilly and gully region with serious soil erosion,the effects of various tillage ways on soil water characteristics and soil erosion in slope farmland were studied. Results showed that (1) No-tillage with straw covering had good water conservation effect and its mean soil water content in a year was 1% higher than traditional tillage. There was no obvious difference between the no-tillage and traditional tillage. (2) Soil water content in cultivated layer kept steadily in the no-tillage,which benefits seedling emergence in early spring and crop growth after rainfall. (3) The effects of various tillage ways on soil water characteristics were related to the change of soil structure. Soil bulk density was increased by the no-tillage,the destruction ratio of soil aggregates was reduced,and the anti-erosion ability of soil was increased by the increment of the stability. Straw covering reduced soil bulk density and enhanced soil water retaining capacity. (4) The no-tillage might not reduce runoff on farmland,but it obviously controlled soil erosion. No-tillage with straw covering controlled soil and water loss efficiently and runoff and soil erosion were reduced by 8.35% and 88.11%,respectively.

Abstract:Five typicalland use types were chosen in the representative environmental immigrant region of Northwest Guangxi, China. Soil organic matter (SOM) and total and available nutrient contents were analyzed in the surface soil layer (0) 20cm). Results showed that in terms of the coefficient of the variation (C_V) of soil nutrients, the contents of SOM, total N(TN), total P(TP), total K(TK), available N(AN),and available K(AK) had a moderate variability(0.1V1.0), except that available P(AP) content had a high variability(C_V1.0). In general, SOM and TN contents were in a higher level, AN and AP contents were in a moderate level, TP and AK contents were in a low level, and TK content was in a lower level.Land use had an important effect on the change in soil nut rients. SOM,TN, and AN contents had a high level in shrubland and grassland and a moderate level in dry land and or char dland. SOM, TN, and AN co ntents had a high, moderate, and low levels in seco ndary forest land, respectively. TP, TK, A P, and AK contents had low and lower levels in five land use types except that AP had a moderate level in dry land and orchar dland. Land use change after immigration did not lead to obv io us soil deg radat ion due to effective soil and water conserv ation measures, but P and K nutrients were increased.

Abstract:Based on simulated rainfall experiment,hydraulic properties of shallow flow in the coarse sediment region in the middle reaches of the Yellow River were studied. The following results were obtained:(1) Shallow flow velocity increased with rainfall process under different rainfall intensities and slope gradients and it can be described with logarithmic equation. Shallow flow velocity was positively related to rainfall intensity and slope gradient. (2) The averaged shallow flow depth increased steadily with rainfall intensity under different slope gradients and it can be described with power equation. The averaged shallow flow depth was negatively related to slope gradient. (3) Under different rainfall intensities and slope gradients,Reynolds number of shallow flow increased with rainfall process. The influence of rainfall intensity on Reynolds number was more significant than slope gradient. Shallow flow was not the traditional laminar flow but in the state of instability. Froude number increased steadily with rainfall process,with the number being above 1. The influence of slope gradient on Froude number is more important than rainfall intensity. Shallow flow in the experiment was in the state of supercritical flow. (4) The resistance coefficient of shallow flow decreased with rainfall process under different rainfall intensities and slope gradients.

Abstract:Based on the map algebra function in ARC/INFO,precipitation erosivity is estimated by the simplified prediction model of daily precipitation using TRMM 3B42 data acquired between 2000 and 2008. The intra-annual and inter-annual spatiotemporal variations of precipitation erosivity are then analyzed. Results show that precipitation erosivity in the Tibet Autonomous Region shows a decreasing trend from the southeast to the northwest with significant spatial variation. The intra-annual concentration degree of precipitation erosivity shows an increasing trend from the southeast to the northwest. The lower precipitation erosivity is,the greater the concentration degree of precipitation erosivity is. The inter-annual variation of precipitation erosivity shows a decreasing trend from 2000 to 2008.

Abstract:Root-soil composites of four desert plants and pure soil were investigated by fast-shear test using direct shear apparatus to explore shear strengths of root—soil composites and the impacts of root diameter and vertical pressure on shear strength. Results showed that shear strengths of the root—soil composites for Caragana microphylla Lam.,Salix psammophila,Sabina valgaris Ant.,and Artemisia sphaerocephala Krasch. are higher than shear strength of pure soil within 1.5 m shallow layer(25 kPa). Equivalent friction angles of the root—soil composites do not change obviously as compared with pure soil. For the same diameter (1.25 mm),cohesive forces of the root—soil composites are greater than pure soil and the range of increased cohesion is 4.60%～46.23% and by the cohesion,the order of the plants is Caragana microphylla Lam.Sabina valgaris Ant.Salix psammophilaArtemisia sphaerocephala Krasch.. Shear strengths of the composites are increased to different extents when root diameter is increased.

Abstract:By employing soil core method,an investigation in the semi-arid loess hilly area was made on the vertical distribution of fine root characteristics and soil properties in the recovery of typical plantations. Results showed that fine root biomass,root length density(RLD),root surface area,and specific root length(SRL) decreased significantly as soil depth increased. In the 0—60 cm soil layer,the averages of the fine root biomass,RLD,and root surface area for 14 a Hippophae rhamnoides(HR) were the highest; for 30 a Robinia pseudoacacia(RP),less; and for 10 a RP,the lowest. The SRL of 10 a RP was the highest and the SRLs of 14 a HR and 30 a RP were the lowest. Dry layers obviously existed below soil depth of 150 cm in different plantations and the difference between arbor and shrub forests did not influence them significantly. Soil dry degree increased with the increasing of growth age. The improvement of tree forest to soil bulk density,which was greater than that of the two shrub forests,increased with the increasing of growth age. The vertical distribution of soil organic carbon was similar to roots. In the 0—60 cm soil layer,organic carbon contents of 24 a HR and 50 a RP were the highest and organic carbon content of 10 a RP was the lowest.

Abstract:Soil carbon pool is very important for the sustainable development of agricultural systems and the change of soil carbon pool is mainly related to soil easily oxidized organic carbon(EOC). Results show that long-term application of manure and chemical fertilizers results in the reduction of the EOC content with decreased soil layer except no manure or chemical fertilizers. In group A (organic manure),the EOC content in ANP(organic manure +nitrogen,and phosphorus fertilizers) is the highest,followed by ANPK(organic manure+ nitrogen,phosphorus,and potassium chemical fertilizers) and ANK(organic manure+nitrogen,and potassium chemical fertilizers). The EOC content in AN0 (organic manure without nitrogen fertilizer) is the lowest. In B group(chemical fertilizer group),the EOC content in BNP(nitrogen and phosphorus chemical fertilizers) is the highest and then is the BNK(nitrogen and potassium fertilizers) and BNPK(nitrogen,phosphorus,and potassium chemical fertilizers). Compared with the no fertilization treatment,long-term fertilization can increase the EOC content in 0—60 cm soil layer and the application of organic manure,as well as organic manure and NPK chemical fertilizers,is better than the application of non-organic fertilizer.

Abstract:The variation trends and spatial characteristics of annual precipitation,erosive precipitation,and rainstorm amount from 1961 to 2007 are analyzed using the data of daily precipitation observed from 24 stations on the Loess Plateau of Shaanxi Province. Results show that the spatial distributions of annual precipitation,erosive precipitation,and rainstorm amount are quite similar. The spatial distributions are characterized by greater magnitude in the north than in the south. The annual precipitation and erosive precipitation present a downward trend,whereas rainstorm amount has a rising trend. For the spatial distribution,precipitation is reduced little in the north of Yan'an City,but significantly in the south. The rainstorm amount is increased in the North Weihe Area,but decreased in the hilly and gully region.

Abstract:Leaf water content,daily change of transpiration rate,leaf water potential,and the correlation of transpiration rate and environmental factors for Viburnum rhytidophyllum Hemsl,Spiraea trilobata,Ostryopsis davidiana,and Syringa oblata were studied by using precision Electronic Balance with the accuracy of 0.001 g and dew point microvokmeter. Results showed that the leaf water content in the morning and evening was higher than that at noon and its minimum lowest point was observed between 10:00 and 14:00. By the daily variation amplitude (sunny—cloudy),the species were in the following descending order:Viburnum rhytidophyllum Hemsl (125.2%～114.2%)Syringa oblata (110.3%～59.8%)Spiraea trilobata (86.8%～46.9%),Ostryopsis davidiana (85.4%～35.2%). The relationship between fresh weight and leaf area can be fitted by exponential curve. By the daily maximum transpiration rate (sunny—cloudy),the species were in the following order:Viburnum rhytidophyllum Hemsl 〔4.017～3.226 mmol/(m²·s)〕Syringa oblata 〔5.628～2.918 mmol/(m²·s)〕Spiraea trilobata 〔3.742～2.908 mmol/(m²·s)〕Ostryopsis davidiana 〔3.174～2.035 mmol/(m²·s)〕. By the average transpiration rate (sunny—cloudy),the species were in the following order:Viburnum rhytidophyllum Hemsl 〔2.687～2.252 mmol/(m²·s〕Syringa oblata 〔2.652～2.058 mmol/(m²·s)〕Spiraea trilobata 〔2.215～1.649 mmol/(m²·s)〕Ostryopsis davidiana 〔1.864～1.423 mmol/(m²·s)〕. The diurnal variation of leaf water potential presented a waveform curve. Leaf water potential and transpiration were negatively related and the relationship between them can be fitted by logarithmic curve. The dominant factors affecting transpiration rate were different in different whether conditions.

Abstract:Based on the investigation and analysis of plot data,the community characteristics and litter hydrological effects of Quercus liaotungensis,Pinus tabulaeformis,and Pinus tabulaeformis f.shekannesis forests in Ziwuling region were studied preliminarily. Results from the study show that (1) the Quercus liaotungensis forest in Ziwuling Mountains is the single-priority community in general. The Pinus tabulaeformis forest and Pinus tabulaeformis f.shekannesis forest in Ziwuling Mountains are the single-priority community mixing with a small number of broad-leaved species. (2) The Pinus tabulaeformis species are abundant and evenly distributed,Pinus tabulaeformis f.shekannesis forest has the smallest species,and the plant diversity indexes of tree layer,shrub layer,and herbage layer are in the order from low to high. (3) The litter of Quercus liaotungensis forest accounted to 32.65 t/hm²; the litter of Pinus tabulaeformis forest,48.95 t/hm²; and the litter of Pinus tabulaeformis f.shekannesis forest,47.30 t/hm2. (4) The maximum water holding capabilities of the Quercus liaotungensis litter,Pinus tabulaeformis litter,and Pinus tabulaeformis f.shekannesis litter are 50.93,70.15,and 61.68 t/hm²,respectively.

Abstract:By maintaining the original conditions of undisturbed soil in typical profiles,tension infiltrometer(d=20 cm,h0=-5 cm)was used to measure soil infiltration under three different patterns of landuse in Qingmuguang karst valley. Results showed obvious differences in soil infiltration capability among three different patterns of landuse. Dryland behaved the best infiltration capability and wasteland,the worst. Unsaturated conductivity,stable infiltration rate,and accumulated infiltration in dryland decreased with soil depth,while the indicators behaved an opposite tendency in woodland. Furthermore,unsaturated conductivity,stable infiltration rate,and accumulated infiltration in the 15—30 cm soil layer were lower than those in the 30—45 cm soil layer in wasteland. Soil bulk density and soil porosity had significant correlations with the properties of soil infiltration,but initial soil water content solely significantly influenced initial infiltration rate,with the correlation coefficient being-0.825. According to the simulation infiltration experiments,an applicable result was achieved by Kostialov model in simulating infiltration process in karst valley under different patterns of landuse and the fitted value was 0.765.

Abstract:Soil and water conservation effects of the vegetation at different levels(aboveground and underground parts of shrub and herb layers) were investigated under field simulated rainfall of 0.5 mm/min rainfall intensity and successive 30 min rainfall duration on spoil slope with shrub-grass covered in Beijing Shouyun Iron district. Results showed that vegetation which plays an important role in soil and water conservation reduced surface runoff of 57.65% and soil loss of 93.55%. The effects of impoundment and erosion reduction by shrubs were 7.4 times and 30.9 times the effects by herbs,respectively. This was not only relevant to major ratio of shrubs in the vegetation,but also relevant to morphological structure of shrubs. The impoundment effect of the aboveground part of vegetation was 1.65 times the underground part of vegetation,which indicated that the aboveground part of vegetation played a great role in water conservation. While the erosion reduction effect of the underground part of vegetation was 1.52 times the aboveground part of vegetation,which illuminated that the underground part of vegetation played a great role in soil reinforcement.

Abstract:By the artificial rainfal experiment,the characteristics of surface runoff and sediment yield in loess and purple soil are contrastively studied under the same experimental conditions. Results show that loess slope belongs to the category of infiltration-excess runoff and deeper rills are developed on it. Purple soil belongs to the category of saturation-excess runoff,where rills are weakly developed or undeveloped. Erosion rate in loess is much greater than that in purple soil under the same conditions. When practicing soil conservation measurements,the appropriate methods combined with soil characteristics should be selected to achieve the ideal results.

Abstract:The research work is based on the original landuse map (1:10 000) of Hongmenchuan basin and combined with remote sensing images of the basin in 1990,1995,2000,and 2005. Landuse maps of the four periods were made with the support of GIS software and the change in the spatial pattern of shelter was found with the help of ArcView. At the same time,using the data of daily runoff of Hongmenchuan basin from 1990 to 2006,the response relationship between the change in the structure of shelter forest and the local runoff was studied. Results showed that the total area of shelter forest and the areas of various forest types did not change obviously. Shelter forest was dominated by highwood,accounting for more than 80%. With a little change of precipitation,annual runoff had a declined tendency from 3.00×107 m³ in 1990 to less than 1.00×107 m³ after 2000. The main reason was that shelter forest had played a role in flood reduction. However,the conclusion that the structure change of shelter forest had exerted an important influence on runoff can not be reached at present.

Abstract:Rosa chinensis Jacq and Euonymus japonicus L were grown in pots with different levels of water stress to evaluate the effects of soil water stress on photosynthetic physiological characteristics. Results are showed as follows:(1) According to the daily average of photosynthetic parameters,the Pn and Tr of the two plants gradually decreased with the increase in water stress. The WUE of Euonymus japonicus gradually decreased,but Rosa chinensis Jacq,increased first and then decreased. The Gs of Rosa chinensis Jacq gradually decreased,while Euonymus japonicus L had higher value in moderate water stress (W2) than in mild water stress (W1). The Ci of Rosa chinensis Jacq first decreased and then increased,while Euonymus japonicus L gradually increased. (2) The chlorophyll fluorescent parameter,Fo,increased,while Fm,Fv,Fv/Fm,and Fv/Fo decreased due to water stress,but Euonymus japonicus L had greater change than Rosa chinensis Jacq. (3) The diurnal variation curves of photosynthetic parameters of the two plants were significantly different. The diurnal variation curves of the Pn and Tr of Rosa chinensis Jacq were the double-peak type and Euonymus japonicus L,the single-peak type in normal water supply (CK) and mild water stress (W1). (4) The changes of fluorescent parameters and photosynthetic parameters of the two plants under water stress revealed that Euonymus japonicus L was more sensitive to soil water stress than Rosa chinensis Jacq.

Abstract:This study was conducted in the Beigou forest farm of Mulan Forestry Authority in Hebei Province. In a field investigation,detailed measurements were made for the different densities of Larix principis. Results show that as the stand density increases,both stand diameter at chest height and crown width decrease,which have an exponential relation to the density. Single-tree volume decreases progressively,while stock volume increases progressively. The single timber volume and store are also related to the density.

Abstract:Soil physical characteristics and its spatial variation were studied in Pailugou watershed located in Qilian Mountains Forest Ecology Monitoring Station belonging to the State Key Field Scientific Experimental Station. Results showed that (1) Soil physical characteristics changed with soil depth and the change extent was in the order of sub-alpine shrub meadow soilforest gray-brown soilchestnut soil. (2) Total soil porosity varied dramatically with different vegetation types. The total soil porosity of sub-alpine shrub meadow soil was higher than forest gray-brown soil,and in turn,chestnut soil. There was no significant difference in soil capillary porosity under different vegetations. For soil non-capillary porosity,there was significant difference among chestnut soil,sub-alpine shrub meadow soil,and forest gray-brown soil from the viewpoint of geographical spatial difference (P0.05). (3) The soil water holding capacity of forest gray-brown soil was higher than sub-alpine shrub meadow soil and chestnut soil. As for soil capillary capacity,sub-alpine shrub meadow soil was the highest,followed by forest gray-brown soil and then chestnut soil. Soil non-capillary porosity varied dramatically with different degrees of vegetation cover. As for natural moisture content,sunny slope is significantly different among all vegetation types. Sub-alpine shrub meadow soil is the highest,followed by forest gray-brown soil and chestnut soil. Sub-alpine shrub soil had good structure and texture and greater potentiality for water conservation. Natural moisture content of all the soil types was increased with elevation.

Abstract:The study aimed to analyze the niche dynamics of the populations of vegetation communities in natural restoration succession process on sloping land with purple soils in Hengyang basin by the quantitative analysis method. First,by using the space series to replace time courses,four typical sample plots standing for four different successive stages were chosen. Then each investigation quadrate was used as the synthetic resource state including multi-dimension resources. The niche breadths of all the populations in different succession stages and the niche overlaps among all the populations in the same succession stage were measured using the formula given by Levins and Pianka and their ecological senses were further analyzed. Results showed that (1) In each stage,community was dominated by the dominant species with the largest niche breaths,which reveals their stronger capacity to adapt to environment and higher efficiency to utilize resources. (2) The dynamics of niche breadths of the populations in community process properly manifested the dynamics of corresponding populations and habitats,especially the replacement between dominant species. (3) In general,the niche overlaps were higher between the species that have greater niche breadths than between those that have relatively narrow niche breadths. The niche overlaps were also higher between two species that have more similar ecological characteristics. (4) With succession process,the average niche overlap of populations in communities increased first,reached tiptop in middle anaphase,and then decreased little in anaphase,which is mainly caused by interspecific and intraspecific competitions of populations in communities. This study,to some degree,may enrich and broaden the vegetation ecology and restoration ecology of the area and provide a theoretical basis for the vegetation recovery and reconstruction of ecosystem on sloping land with purple soils in Hengyang basin.

Abstract:Root distribution characteristics have special ecological meaning as they reflect the utilization of trees to the environments.Soil drilling method is applied for the root distribution characterist ics of Vitex negundo var.heterophylla and Lespedeza bicolor Turcz. in two slope gradients( 12^。and 28^。) and two slope aspects(south and north).Results show that the d ≤1 mm root biomass of Vitex negundo var. heterop hyl la is more than Lespedeza bicolor Turcz . . The d≤1 mm root biomass of the two shrubs in south slope is more than that in north slope. The d≤1mm root biomass of Lespedeza bicolor Turcz. is more than Vitex negundo var. heterophylla in three site conditions, including two slope gradients in south slope and 12^。 slope in north slope. The d> 1mm root biomass of Lespedeza bicolor Turcz. is more than Vitex negundo var. heterophylla at 0.2 and 0.4 m from trunk in south and north slope,while the d ≤1 mm root biomass is on the contrary. It is showed that ef fective root( d≤1mm) of Vitex negundo var.heterop hy lla is st ronger than Lesp edez a bicolor Turcz . in horizontal distribution. Root s of the tw o shrubs are distributed mostly in 0-60 cm soil layer. By the d> 1 mm root density, the order of shrubs in the two slope aspects is Lespedeza bicolor Turcz. (south slope) > Vitex negundovar. heterop hylla( south slope) > Vitex negundo var. heterophylla(north slope) > Lespedeza bicolor Turcz . ( north slope) . By the d≤1 mm root density, the order of shrubs in the two slope aspect s is Vi tex negundo var. heterophylla( south slope) > Vitex negundo var. <>iheterophylla( north slope) > Lespedeza bicolor Turcz. ( south slope) > Lespedeza bicolor Turcz. ( north slope) .

Abstract:Through the analysis of nearly 50 year annual runoff data of Tarim River,the evolution trend of runoff under changing environment is investigated. Possible impacts on the runoff process are discussed in the two aspects of climate change and human activities. Results show that under changing environment,the runoff process of Tarim River in nearly 50 years has been significantly changed. Under the influence of climate change characterized by temperature rising and precipitation increasing,runoff in headstream zone of Tarim River generally has an obvious increasing tendency. Temperature variation has little effect on regional evapotranspiration,but increases glacial meltwater runoff. There are some differences in the effect of precipitation increasing runoff among different headstream zones of Tarim River. However,human activities are the dominant influencing factor to runoff changes. The construction of hydraulic engineering and the increased amount of water use have significantly changed the runoff process of Tarim River and comprehensive management engineering of Tarim River has positive effects on the whole basin.

Abstract:In August,2008,the wetlands in the Yellow River Delta,covered with different plant communities,were selected as the study objects to investigate the spatial distribution characteristics and the reserves of phosphor(P) and sulfur(S) in wetland soils. Results showed that different plant communities could affect the contents of P and S differently. Total phosphorus(TP) content had no significant variation with the succession,while total sulfur(TS) content,varying in the "S" mode,was affected obviously by the period of plant community succession. As for the characteristics of vertical distribution,TP content was not remarkable,showing that TP in soils depends on parent material. However,the vertical distribution of TS was significant(CV10%) and its distribution was based on soil organic matter. Besides,the reserves and distributions of the two elements were also affected by plant communities differently. Both the reserve and the distribution of phosphorus varied little,fluctuating around 0.32 kg/m² (0—60 cm). The reserve of S varied significantly from 0.17 kg/m²(the last stage of succession,0—60 cm)to 0.33 kg/m² (bare beach,0—60 cm),fluctuating in "S" mode with the succession,while the distribution of S was not clear. Result from the research shows that the distributions of P and S in wetland soils are affected by plants and thus,right plants can be selected to apply in ecological rehabilitation of wetland. The research may provide a theoretical basis for the ecological rehabilitation of wetlands.

Abstract:Taking Xuzhou City as a study case,normalized difference vegetation index (NDVI),soil-adjusted vegetation index(SAVI),and land surface temperature(LST) are derived from Landsat TM/ETM+ remotely sensed data and then used to monitor drought status. The spatial characteristics of the vegetation indices and LST are built,by which the temperature vegetation dryness index (TVDI) is calculated from the remote sensing images obtained on April 3,2001 and May 14,2007. The analyses of TVDI,LST,and rainfall show that TVDI can be used to monitor drought largely and the result of TVDI based on SAVI is better than that based on NDVI.

Abstract:Using TM satellite image data in 1989,2000,and 2005 as remote sensing information source,dynamic changes of sandy desertification in Pishan area of Xinjiang during 1989—2000 and 2000—2005 are analyzed by establishing a scientific system to classify the types of sandy desertification land,calculating the areas of these lands in different years and examining the conversions among these types of land during the periods. The features of the range,speed and spatial variation of various types of sandy desertification land are revealed. The evolution characteristics of sandy desertification land in the area are also clarified. Result shows that in Pishan area,the areas of severe sandy desertification land and non-desertification land are all increasing,yet the increment of the former is greater than that of the latter and sandy desertification is still rapidly progressing.

Abstract:Security monitoring is one of the most important ways to investigate and control landslides and displacement monitoring is the most common way to monitor landslides. The analysis of landslide displacement monitoring data is generally based on flat files. A different approach based on data warehouse is proposed,which analyzes in depth the time series data from landslide displacement monitoring and build a multidimensional model of landslide displacement monitoring using CASE tool Power Designer. By the approach,a multidimensional model is designed and applied in Baishuihe landslide in the Three Gorges Reservoir area. Data mining process is then implemented using the algorithm of Microsoft Time Series in SQL Server 2005 Analysis Services. Results show that the predicted value is approximately in accordance with the measured value and the algorithm is applicable in short-term prediction.

Abstract:Based on hydrogeologic conditions and geomechanics model of highway slope in mountainous areas,a new catastrophic model on slope stability is established in consideration of the static water pressure of top splay fracture. Equations for calculating the critical water highness in the splay fracture and the critical rainfall intensity are developed by adopting cusp-catastrophic theory. The meteorological criterion of highway slope failure is put forward. At the same time,it is illustrated using the landslide on the No 316 national road in the southern Shaanxi Province. The results calculated by above model agree well with the observed ones,providing a new approach for the prediction of highway landslide.

Abstract:Based on the monitoring data of groundwater level and its quality in Karamay artificial carbon-dioxide-capture forest,the characteristics of groundwater dynamic change were analyzed. Meanwhile,the reasonable ecological water table of groundwater in the artificial carbon-dioxide-capture forest was discussed. Results show that buried groundwater depth in the artificial carbon-dioxide-capture forest was regularly distributed and it was reduced from 7.8 m in 2005 to 4.6 m in 2009. Groundwater mineralization changed from 22.67 g/L in 2005 to 5.35 g/L in 2009. Statistics of groundwater physicochemical properties indicated that the spatial variation of water-soluble salts in groundwater was obvious. According to relationship between the main forest vegetation growth conditions and buried groundwater depth,the reasonable ecological water table of groundwater in Karamay artificial carbon-dioxide-capture forest was 2.5～5.0 m.

Abstract:Based on the land use change data obtained from TM images in 1997 and 2006,the land use/cover changes on the Loess Plateau of North Shaanxi Province were studied and ecological effects of land use/cover changes were evaluated with the help of RS and GIS technologies. Results showed that land use patterns changed considerably during the period from 1997 to 2006. 50.37% of farmland was transferred into woodland and grassland and the total ecosystem service value was increased by 7.67×106 yuan,with the annual increase of 0.2%. The overall environmental quality index was increased from 0.145 to 0.157. The index of eco-contribution of land use and land cover changed remarkably and the overall eco-contribution index was 1.239. The environmental ecological quality has been improved,which means that the ecosystem in the area tends to develop healthily on the Loess Plateau of North Shaanxi Province with the development of the conversion of farmland to forest project.

Abstract:By using the raster data of landuse and soil types,this paper builds a raster-based SCS model,which in turn enables the improved model to make a better consideration of the heterogeneity of watershed underlying surface and the heterogeneity of rainfall. In addition,this paper applies the new model in a real watershed,result from which shows that simulation accuracy can be significantly improved by the raster-based SCS model,compared with the original SCS model. Among the 44 rainfall events in total,the number of the rainfall with a runoff simulation accuracy of above 85% increases from 12 to 26. What's more,runoff distribution maps are obtained using the improved model,which help provide more accurate runoff information on the water management of watershed.

Abstract:Due to complex geological,geomorphic,and hydro-meteorological conditions,numerous geo-hazards occur in Huili County. The "8?30" earthquake induced a large number of new geo-hazards,as well as the intensification of old hazards in Huili County. With the help of sending geo-hazard census list,remote sensing,and expert inquiry,55 new geo-hazards triggered by the "8?30" earthquake are identified,including 8 rock-falls,25 landslides,2 debris-flows,and 20 unstable slopes,which are mostly in the south of the county,particularly in the region of Chinsha River. Based on the results from survey,the zoning on susceptibility level of geological disasters in Huili County is made in a unit grid of 2 km×2 km. The areas of high-susceptibility,mid-susceptibility,and low-susceptibility occupy 42.4%,37.1%,and 20.5% of the total area of the county,respectively. Additionally,some countermeasures are proposed,including setting a network of disaster prevention and mitigation,making the emergency treatment of some sudden hazards or the comprehensive treatment of important geological hazards,and enhancing the preventive management of geo-environmental disasters.

Abstract:Water and sediment samples from surface runoff in the coal mine areas of Guizhou Province were collected and analyzed to investigate pollutant migration from gangues and its impacts on water quality of rivers. Results showed that the pH value of runoff was 2.64～6.38 and the main pollutants in runoff were SO₂^4-,Fe,and Mn. Their concentrations were affected by gangue type and rainfall intensity. After runoff sediment was immersed for 3～28 days,the pH value of upper water reached 2.78~3.71 and the contents of SO₄^2-,Fe,and Mn reached 27～160,0.3～3.9,0.6～2.8 mg/L,respectively. The impacts of surface runoff on water quality of rivers were the acidification of water bodies and serious pollution of Fe and Mn.

Abstract:The effect of water retaining agent on growth and development of maize was studied by a field experiment under the condition of sowing with water,a water-storing absolved irrigation,in Minqin Oasis. Results show that the technology of sowing with water and the application of water-holding agent enable early emergence,enhance leaf area index,promote the accumulation of dry matter,improve the ratio of panicle dry matter distribution,and improve maize grain yield and biological yield. Compared with the CK,applying water absorbent of 2.5 g/m² and using sowing seed dressing can increase yield by 17.77 % and 15.13%,save water by 13.92% and 18.76%,increase farmer's income by 15.73% and 26.37%,and increase water use efficiency by 3.33 and 3.07 kg/m³,respectively.

Abstract:Through the summarizing and analysis of the previous researches,we put forward the principles and requirements in designing substrate for extensive green roofs,present a new type of substrate mixture which has higher content of fine particle matter and suits for the regions with the climate of summer drought,and investigate how to design the substrate mixture and check the application effect of our newly-invented additive for the green roofs. We firstly design orthogonal experiments with clay(A),distillers' grains(B),expended clay(C),and cement(D) as the 4 factors(3 levels for each factor),and treat germination rates of Bermuda grass and Ryegrass as dependent variables to find out how the factors and levels influences germination rates of Bermuda grass and Ryegrass by pot culture experiments. Then,we compare the germination rates and growths of Bermuda grass and Ryegrass and growth of Stringy Stonecrop Herb between the most adverse substrate mixture and the substrate mixture added with additive for the green roofs. Results show that:(1) by the significance influencing the germination rates of Bermuda grass and Ryegrass,the orders of the factors are D→A→C→B and D→C→A→B,respectively,and the best substrate mixtures for the two grasses are A2 B3 C1 D3 and A2 B2 C3 D2,respectively. (2) The content of cement in substrate mixture influences significantly the germination rates of Bermuda grass and Ryegrass and the cement-clay ratio should not exceed 18% for the germination of Bermuda grass and 23% for Ryegrass. (3) Stringy Stonecrop Herb indicates good alkali endurance and can survive in substrate mixture with 23% cement-clay ratio. (4) When our newly-invented additive for the green roofs is added into the most adverse substrate mixture of A3 B3 C2 D1 with 23% cement-clay ratio,the pH value of the A3 B3 C2 D1 drops significantly. The pot cultured Bermuda grass and Ryegrass with this improved substrate gain much better germination rate and the pot cultured Stringy Stonecrop Herb grows much higher.

Abstract:The urban permeable surface is an effective practice to conserve rainwater. This study presents a method to calculate the areas of the urban permeable surfaces and assess the benefits of the rainwater retained by them. As a case study in the Xigang District and the Zhongshan District of Dalian City,the areas of the urban permeable surfaces in 2005 were calculated based on the data from aerial photographic survey. Then the volume of the collected water in the year was obtained according to the annual rainfall amount,retaining ratio of the runoff,and infiltrating ratio of ground water. At last,the benefits of the rainwater retained by urban permeable surfaces were estimated using the economic and ecological benefit indexes. The main results from the study can be summarized as follows:(1) The total area of the permeable surfaces was 3 663.30 hm²,which was 51.5% of the total area of the study region. The area ratio of forestry land,grassland,and porous pavement was 6.5:1.3:1.0. (2) In virtue of the urban permeable surfaces,runoff was reduced by 1.69×107 m³,of which 5.0×106 m³ rainwater infiltrated into groundwater layer. Consequently,the total economic benefit of the retained rainwater was 1.4×106 RMB and the ecological benefit was 5.52×107 RMB. Moreover,great social benefit was generated due to controlled soil erosion and improved urban residential environment.

Abstract:Conventional super absorbent resin is less salt-tolerant. In practice,its application,particularly in agriculture,often results in the result far less than water absorbency measured in laboratory conditions. An experiment was conducted for a new kind of super absorbent resin performance in soil. Calcium lignosulfonate contains a large number of hydrophilic groups,such as sulfonic group,and carboxyl. Calcium lignosulfonate can not only reduce the cost of the water-absorbent resin,but also improve water absorbency. Results showed that water absorbency of the new water-absorbent resin was 230 g/g. Compared with the traditional super absorbent resin,water retention time was extended 10 days,water absorbency was increased by 50%,and soil permeability was increased. The new water-absorbent resin has a repeatedly absorbent function. At the same time,it has a good expansion and can reduce evaporation. Particularly,it plays important roles in enhancing soil available water-absorbency,increasing soil temperature,and improving soil permeability.

Abstract:Agricultural non-point source pollution is mainly induced by the excess matter accumulated in soil,when the exogenous substances are beyond soil environmental capacity and nutrients are beyond the need of plant growth. Based on the analysis of soil physical and chemical properties in different land uses,clay particle content,pH,organic matter,total nitrogen,total phosphorus,hydrolysis nitrogen,and available phosphorus were chosen as indexes and forest soil was taken as control. Grey relation principle and method were used to analyze soil pollution and its distribution in different land uses,different planting patterns,and different distances from residential areas. Analyses indicate that by soil pollution ratio,cultivated lands are in the order of paddy fieldvegetable landupland and soils are in the order of farmland pollution with two-maturity per yearsignal harvest. The shorter distance from a residential area,the heavier soil pollution is.

Abstract:Up to now,soil and water conservation has already achieved significant benefits in China. However,the benefit assessment for soil and water conservation is far behind and remains in the stage of qualitative description and theoretical exploration. Some deep-seated issues have not been involved yet,such as the relationship between the control models of soil and water loss and their benefits,the regulations and indexes of benefit assessment,the relationships among measures,benefits and control aims,and the connection between point and area benefits of conservation. Researches and investigations on those issues will greatly push forward the construction of the theory system of benefit assessment and thus,prompt the applicability and scientific meaning of benefit assessment for soil and water conservation.

Abstract:This article regards the data of the World Bank loan project in Yanhe watershed as a sample and makes a path analysis for the project investment so as to explore the primary and secondary factors. Results show that the development of agricultural mechanization is an important condition for promoting agricultural development,but the effect of agricultural mechanization on the project investment in Yanhe watershed is not significant. It is necessary to raise level of agricultural mechanization in the region.

Abstract:There is a close relationship between arable resource and urbanization level. This paper takes all regions in He'nan Province as the research units,and separately constructs the indexes of arable land and urbanization level. Then the paper carries on the mathematical quantification for the arable land index and the urbanization level index of all regions in He'nan Province in 1990,1995,2000 and 2005,adopting principal component analysis. Using the coordinated model,the paper carries on the quantitative analysis for the indexes of arable land and urbanization level,and divides the types of coordinated development. The results show that the regional distribution of arable land index basically consistent in the four years. The entire province urbanization level presents the obvious rise phenomenon. The coordinated development degree is decided by the two indexes and the difference between of them. In the earlier research period,the traditional agriculture regions are usually imbalance between arable land and urbanization. But in the later research period,the regions are mainly imbalance where are in the good industry foundation and high urbanized level area.

Abstract:The effects of the application of different soil conditioners (sulfur,organic,gypsum,fertilizer,and PAM) on soil structure were studied by pot experiment with alkali-saline soil in Pingluo,Ningxia Hui Autonomous Region. All of the four soil conditioners reduced soil bulk density and increased soil total porosity. The improvement of soil physical structure,in combination with water use,promoted the improvement of local alkali soil. The best amount of sulfur was found to be 30.45 g/pot. Great attentions should be paid to soil aeration and prevention of the occurrence of anti-vulcanization. Among the four soil conditioners,PAM showed the best effect,followed by gypsum and S3 treatments.

Abstract:Qingshuihe watershed was appointed to be the research object for ecological restoration models of soil and water conservation in the rainstorm center area by the Huaihe River Commission of the Ministry of Water Resources in 1986. In order to achieve both ecological benefits and economic benefits from soil and water conservation in the small watershed,ecological restoration models were explored and their features were analyzed. Furthermore,a comprehensive assessment on the models was given. Some harnessing models were found for the ecological restoration of other small watersheds in the rainstorm center area.

Abstract:The evaluation index of ecological security system was built using the PSR(pressure—state—response) model,entropy method was applied to define the weights of seventeen assessment indexes,and the Excel software for data processing was used to evaluate the ecological security of Shengzhong Reservoir. Results showed that the ecological security situation from 2004 to 2007 was improved. At last,several environmental protection measures for reservoir ecosystem were discussed,such as banning cage farming fertilizer,strengthening the solid waste and wastewater treatments of reservoir residents,controlling soil erosion,reducing point source and non-point source pollution by nitrogen and phosphorus,preventing the spread of water hyacinth,focusing on the management of water eutrophication,and maintaining the reservoir storage capacity in a reasonable level. At the same time,it should be noted that the new factors such as reservoir fishing or other factors affected the ecological balance of Shengzhong Reservoir.

Abstract:Grain production is one of the most important income sources for rural households in the gully area of the Loess Plateau. In order to reveal the input-output conditions and stability of main grain crops production in the area,this paper used 10 years data surveyed from 30 rural households in Wangdonggou valley,Changwu County and mainly analyzed the input and output of wheat,maize,and soybean. Results from the cost-benefit analysis showed that soybean had the highest production stability and its variation modulus of output was 14.2%; maize had the second high production stability and its variation modulus of output was 17.2%; and wheat had the lowest production stability and its change in output was comparatively large. From 1999 to 2008,the output value and production cost of the three grain crops were all increased. Maize had the highest profit,followed by soybean and wheat. Finally,according to the results,some suggestions were given,such as increasing investment in science and technology,enhancing government control power in the prices of agricultural production materials,so as to reduce the cost of grain crops,increase farmers' income,promote stable grain production,and insure regional food security.

Abstract:The eco-environmental protection in the mountainous rural areas in their economic development has focused the concerns of numerous scholars and public communities in recent years. This study investigated the eco-environmental status and civil environmental consciousness of Reshui Town,Heping County,North Guangdong through face to face interviews with a questionnaire. Results showed that the economic development level in the study area was low and the area did not have any industry pollution. The solid waste pollution was insignificant,but random disposal of domestic rubbishes was ubiquitous. The energy utility method was primordial and the clean energy use rate was low. The excessive use of fertilizers and pesticides was quite serious and the resulted pollution could not be ignored. According to the investigated results,the following suggestions were arrived:firstly,facilitating the construction of rural environmental protection infrastructures such as sewage treatment system,rubbish collection and disposal system,and improvement of lavatories and drinking water; secondly,facilitating the construction of eco-agriculture and characteristic villages; thirdly,spreading the use of clean energy; and lastly,strengthening the environmental protection education and establishing environmental monitoring and forewarning systems in rural areas.

Abstract:The purpose of this study was to analyze the land use structure and its change,industry structure,and economic return after the Grain for Green Project,as well as grain supply-demand and input-output in 2007 in Wuqi County,by the investigation of households' product management in the county. Results showed that in the county,land was mostly used for arable land and growing trees and grass. Industry avocation and the subsidies of the Grain for Green Project were the main sources of income. There was a significant difference in industry structure among different rural households. For high level income households,the proportion of industry avocation was 81.8%. For low income level households,the proportion of industry avocation was similar to crop production,but the subsidies of the Grain for Green Project accounted for 46%,showing a certain dependency. The difference in income level was related to the conditions of land and the labor productivity across households. It was found that in the county,grain yield basically met the self-supply need of households and the input was nearly equal to the output,so there was no big problem of grain security. Accordingly,the suggestions are presented that the county should adjust its agricultural structure more efficiently,continue popularizing agricultural techniques,and construct prime cultivated land.

Abstract:Agriculture is an important part of the economic development in the northwest arid area. Research on the cultivated land change is particularly important to the development of the economy in Northwest. Based on the data from landuse change survey and socio-economic statistic data in Gansu Province in nearly two decades,the situational development of cultivated land resource and spatial patterns were analyzed under the support of GIS and remote sensing and the grey correlation analysis was made to find the main factors to cultivated land change. Results showed that the correlations of the change in cultivated land and the factors of economic development level,two tertiary industries,and agricultural structure adjustment were as high as 0.898,0.892,and 0.883,respectively. Finally,each impact factor was deeply analyzed and some comments and suggestions were given for sustainable utilization of cultivated land resource in Gansu Province.

Abstract:The scientific analysis of wetland eco-environmental water demands is the important foundation for wetland management and protection. In the case study of Hengshuihu wetlands natural reserve in Haihe basin,we set up a 3-level ecological conservation target system according to the present situation in the study area,adopt classification and grading method,and select 8 indexes in evaluating and grading the eco-environmental water demands of Henshuihu wetlands,based on which the minimum,optimal,and maximum eco-environmental water demands are estimated,respectively. Analysis indicates that the Hengshuihu wetland water supply can merely guarantee the minimum level which confirms to the actual situation of Haihe basin basically. The result provides a scientific basis and support for water resource allocation and dispatch in Haihe basin,while the research method can be used as a reference for the computation of wetland eco-environment water demands in arid zone.

Abstract:Previous studies on riparian zone in a reservoir focus mainly on eco-environmental changes and routine economical usage. In China,one of the main utilizations on riparian zone caused by the construction of large-scale hydropower project is the tourism development. However,little attention has been paid to the potential and long-term influences of riparian zone on tourism. This paper takes the riparian zone in Three Gorges reservoir for example,which is the largest one both in area and fluctuation in China. The authors point out the passive influences of riparian zone on tourist attraction,tourist environment,and tourist management and the possible use opportunities,and stress that tourism development in reservoir area should circumvent the passive influences and take rational use of riparian zone.

Abstract:At small spatial scale,the study on relationship of vegetation with climate change to find key climatic factor affecting vegetation changes has important significance for vegetation reconstruction and ecoenvironment restoration. The temporal evolution of vegetation and the dynamic changes of climate were analyzed using the Normalized Difference Vegetation Index(NDVI) obtained from the NASA/AVHRR sensor (1982—2006) and corresponding meteorological data at four stations in Huangnan Tibetan Autonomous Prefecture. Further,the relationships between the NDVI and climatic factors were calculated. Results indicated that from 1982 to 2006,the NDVI in Jianzha County slightly decreased. In Tongren County and Zeku County,the trend of decline was significant,while in Henan Mongolian Autonomous County,the NDVI increased. The drier and warmer tendency was very obvious and the air temperature averaged over the four counties remarkably increased by 0.67 ℃ per decade over the past 25 years. Precipitation in Tongren County slightly decreased,while in other counties,rapidly decreased,with an average of 24.82 mm per decade. In Jianzha County and Tongren County,the most important climatic factors influencing the variation of the NDVI were precipitation and temperature; the relation between the NDVI and precipitation was positive; and the correspondence between the NDVI and temperature was contrary. In Zeku County,the NDVI was jointly affected by pan evaporation,hail weather process,and frostfree days. The increased NDVI was primarily caused by increase of sun hours in Henan County. The climate warming was of advantage to the NDVI growing in Zeku County and Henan County. In the process of vegetation restoration,Jianzha County and Tongren County should focus on moisture insulation works. For the similar studies at small scale,the results have great significance as well.

Abstract:Thi spaper reviewed the development of the thought of sustainable development and the theory of ecology and analyzed the change of energy value in the agro-ecosy stem of Dezhou City between 1998 and 2007 and the sustainability of the agro-ecosy stem .Results showed that the total energ y usage of agro-eco system of Dezhou City kept increasing during the study period , so did its dependence on non-renew able resources .Its enviro nmental loading ratio kept grow ing and its sustainable development was under g reat pressure .The agro-ecosy stem manag ement in the future should develop water-saving irrigation , int roduce advanced technology actively , increase the input of energy value of intellectual resources , adjust the input of indust rial supporting energy to improve the benefit ratio of energy value , and explore the ways of establishing a multi-level and high-function ecological agriculture .

Abstract:Research on ecosystem service value is a hot spot in ecology at present. Based on the Costanza's ecosystem service value theory and combined with the landuse change traits in the past 30 years in Chongqing urban,the impacts of landuse change on ecosystem service value are analyzed. The remote sense images in 1975,1987,1995,2000,and 2005 are interpreted and the landuse drafts are obtained. Single dynamic landuse degree and landuse extent index are used to indicate the landuse change. According to each type of landuse and its single ecosystem service value,the ecosystem service value is calculated,which is used to analyze the whole change in ecosystem service value and the change in the structure of ecosystem service value. In view of the influence of landuse on ecosystem service value,ecosystem effect index and ecosystem effect degree are introduced to ascertain the influence extent and absolute influential power resulting from the landuse change. Results indicate that,firstly,the expansion speed of constructive land in the area should be controlled properly and the intensive degree of constructive land in mountainous city should be promoted. Secondly,in the scale of controlling economic rising,the increasing speed of landuse extent should be slowed down. Lastly,the planning of eco-water and eco-forestry should be strengthened in order to enhance ecosystem service value in mountainous city.