Abstract:[Objective] The urbanization in Hetao Oasis was monitored through remote sensing and the regional difference in the past 40 years was analyzed to provide a scientific base for urban plan and management, and for city coordinative and sustainable development. [Methods] Based on 6 term's scene of landsat MSS/TM/ETM⁺ remote sensing image in the years of 1975, 1989, 1995, 2000, 2006 and 2014, 7 evaluation indices of urbanization expansion were included and principal component analysis was used. [Results] (1) The expansion trends of Yinchuan, Shizuishan and Linhe cities had different expansive speed, strength and elasticity. (2) There were different space expansive patterns among the three cities. (3) The gravity transfer directions and distances of city center were different. (4) The real estate development investment and the tertiary industry were the major factors that affected the urban expansion of Yinchuan City, the first sector was the leading one for Linhe District while second sector was the pillar in Shizuishan City. [Conclusion] In recent 40 years, it was Yinchuan City that had the fastest annual expansion rate, the largest expansion intensity and more reasonable relationship between population growth and urban land. Yinchuan City and Linhe district urban expansion tended to be compact, stable and had decreasing complexity development; Shizuishan City had the tendency of discrete development and showed an increasing complex forms. In addition, the city center transferred to the southeast for Yinchuan City with the maximum transfer distance of 3 198 m; while Shizuishan City and Linhe District expanded toward to the southwest and northeast. Additionally, the dominating factors that influenced the urban expansion for the three cities were different.

Abstract:[Objective] The impact factors of urban water security in Guizhou Province were studied to provide basis for policy-making of local government. [Methods] A water security system model for Guizhou Province, China was established using system dynamics(SD) method. In the model, data of water security system from 2005 to 2025 were used and four scenarios(Guiyang model, Zunyi model, Bijie model and concerted development model) were analyzed. [Results] The major driving factors of the water security system in Guizhou Province included the agricultural irrigation water quota, soil and water losses area, ratio up to the standard of water quality and the investment of environmental protection. The concerted development model is the best solution for water security system by 2025 in Guizhou Province for the four scenarios. [Conclusion] In terms of water resource, water environment and water disaster, the concerted development model was proved to be a profitable solution both in economy and environment.

Abstract:[Objective] The purpose of this study was to analyze the flood susceptibility to land use type and mountain terrain condition in the upstream of Ganjiang River, and to provide theoretical support for the undertaking of non-engineering hazard mitigation efforts. [Methods] Based on GIS technology, data of land use types and Aster DEM were elicited from Landset images. Flood sensitivity was calculated in different slopes and land use types in a unit of small watershed. [Results] The construction of towns, farmland, and other artificial ecosystem components could increase floods disasters; whereas forests, shrub lands, grasslands and other natural ecosystems components could scale floods disasters down. The sensitivity of farmland and urban construction land in slopes over 25 degree significantly promoted the occurrence of floods disasters. [Conclusion] Disaster prevention and mitigation efforts should be carried out via ecological construction. The efforts should increase the coverage area of natural ecosystems. In addition, slopes more than 25 degrees are not suitable for development, where urban development and farmland reclamation were also not appropriate.

Abstract:[Objective] This paper studied the relationship between rainfall and runoff over upper Nyang river above Gongbo-gyamda Hydrological station to find the critical rainfall that will result to flood. We expected to provide reference for the meteorology pre-warning of mountain torrents. [Methods] Data of ground meteorological observation and CMORPH were used. The upper Nyang river watershed of the hazard critical rainfall was obtained according to the HBV rainfall-runoff model. [Results] After parameter optimization and calibration, the HBV model had a certainty coefficient of 0.91 and NASH efficiency coefficient of 0.89 in the phase of calibration during 2007-2011. Model was validated using the data of 2012-2014, in this phase, certainty factor was 0.86 and NASH efficiency was 0.85. For both the phases of calibration and validating, relative error was averaged as 3.1 %, which implied that the model was applicable. [Conclusion] The flood process in Nyang river basin was not only related to the rainfall in whole basin, but also to the previous water level. The critical rainfall of flood inducement decreased with the increase of previous water level, and vice versa. The critical rainfall showed a nonlinear responsive characteristics.

Abstract:[Objective] The characteristics of rainstorm flood disaster risk in main flood season were studied in Sichuan-Yunnan region to provide theoretical reference for defense of regional rainstorm and flood disasters. [Methods] Methods of inverse distance weighted interpolation(IDW) and natural disaster risk index were used. [Results] The highest risk area of rainstorm flood disasters was mainly concentrated in the eastern Sichuan Basin and the followed area was the southern part of Yunnan Province. Moderate-risk areas were mainly distributed in the southwest mountainous region of Sichuan Province and the most areas of Yunnan Province. Lower-risk area were sporadically distributed in East Yunnan Plateau, Northwest Yunnan Province and the northeastern part of Western Sichuan Plateau. The lowest-risk area was mainly located in Western Sichuan Plateau. [Conclusion] The main influence factors of rainstorm flood disasters were atmospheric circulation, precipitation, topography and river network; the change of land use due to human activities was the trigger of rainstorm flood disasters.

Abstract:[Objective] In order to reduce the damages of conventional grilled dam caused by debris flow, a novel debris dam with friction damper is proposed. [Methods] Simulating of massive stone in debris flow by steel ball, the finite element software ABAQUS was used to simulate the dynamic responses of the impact of large stones. [Results] As compared with the ordinary grilled dam, the stress response of beam-column joints was obviously reduced when an impacting force was applied against the dam. [Conclusion] The damped dam had well impact-resistance performance either in displacement withstanding or in energy reduction.

Abstract:[Objective] The water quality of the river basin was evaluated through the establishment of related models in order to provide practical tool for ecosystem restoration. [Methods] Using analytic hierarchy process(AHP), fuzzy membership function and comprehensive index method, taking Sushui river basin as a study area, factors that influences water quality indexes were evaluated comprehensively. Evaluation system of water environment quality and was established and the models of the environmental health in arid and semi arid river basin was illustrated. [Results] In Sushui river basin from 2008 to 2011, the water quality environment was categorized as grade Ⅲ, at a status of ordinary health. The evaluation results were commonly the real status. [Conclusion] The health evaluation system of water environment quality in that arid and semi arid river basin proved reasonable, can meet the needs of health assessment of water environment quality in river basin.

Abstract:[Objective] Designing a series of measures to bring the floodwater back to the floodplain on the premise of guaranteeing flood control, no destroy to current land use and hydraulic facilities in order to accelerate storing floodwater on the floodplain and make the water resource allocation more reasonable. [Methods] According to the ecological theories, the ecological floodwater storage design was carried out on the base of current river improvement work by image analysis and field investigation. The design core was floodplain water diversion net for a floodplain of Huihe river in Ningwu County of Shanxi Province. [Results] It contains measures such as pool & riffle sequences, chain of ponds and passageways of flood diversion. It can bring the floodwater into the floodplain and store the water under the ground to recover the water storage function on floodplain as far as possible, and to adjust the river discharge and weaken the flood. [Conclusion] Floodplain water diversion net design conforms to the natural law of the river ecosystem. It can give furthest play to ecological benefits on the premise of economic and social development, to protect the ecological water storage function for small rivers, and to recover healthy rivers and watersheds.

Abstract:[Objective] Through the investigation of the "7·25" massive mountain torrents geological hazards in Tianshui City of Gansu Province occured in 2013, we expected to reveal the landslide mechanism and provide a scientific basis for early identification, prevention, and reduction of rainfall-induced geo-hazards in the loess ridge-hill areas of China. [Methods] The characteristics, distribution law of geological hazards and its causes were studied. Three dimensional continuum dynamic numerical models were established to calculate the dynamic character of landslide in Tianshui City. [Results] The results showed "7·25" massive mountain torrents geological hazards had characteristics of occurrence universally, outbreak massively, locally and unnoticeably, and had strong hazard potentiality. The hazards were exacerbated by the effects of earthquake and rainfall. The slope geometry shapes of landslide in the torrent's geological hazard are linear concaved. Most slopes are in the range of 35°~45°, and among which, 40° slopes were found more frequently. Loess slope landslide is usually in a narrow strip and with small volume. The average velocity, maximum velocity, total kinetic energy and potential energy of typical landslide increased dramatically in slope motion process. These indices dropped sharply after entering a horizontal plane. Erosion plays an important role in landslide movement, which make slope sliding in a high speed and lead to more destructive hazards. [Conclusion] The risk degree of group geo-hazards remains severe in Tianshui City. Precipitation is the main factor that cause and aggravate the geological disasters.

Abstract:[Objective] The research studied the characteristics of soil and water loss on slopping land of abandoned dreg field of hydropower production and construction projects, which was expected to help us to harness comprehensively the loss of soil and water in loess hilly region. [Methods] The experiment was conducted in 2013 and the corresponding precipitation data were collected in the same year in Linzhao County, Dingxi City of Gansu Province. The loss characteristics of soil and water were demonstrated in runoff plots at Xiaojiahe Hydropower Station Ⅱ project with different treatments. [Results] (1) In 2013, Lintao County had a normal precipitation of 580.2 mm. (2) The product of precipitation and mean rainfall density can be well fitted with the amount of soil erosion with a coefficient greater than 0.85. (3) Different vegetation pattern could affect soil and water loss of abandoned dreg field. The mixed pattern of Pinus tabuliformis and alfalfa effectively reduced the soil erosion and runoff. (4) The initial soil moisture of topsoil had a significant impact on soil and water loss, and the initial subsoil moisture had no significant influence on them. [Conclusion] Soil loss of abandoned dreg field of hydropower production and construction projects were influenced by the product of precipitation and rainfall times, vegetation pattern and initial soil moisture status of topsoil.

Abstract:[Objective] Correlations among precipitation, soil water and river water were analyzed in Dayekou Basin of Qilian Mountains in order to explore the ecological and hydrological processes of basin and river runoff formation. [Methods] More than 380 thousand data observed artificially for 18 years and obtained automatically for 2 years were processed using methods of characteristic-parameters algorithm, correlation analysis and multiple regression. [Results] (1) The annual precipitation, air humidity and river runoff depth averaged over the 18 years' artificial observations were 374.06 mm, 60.91% and 166.73 mm, respectively. The river runoff accounted annually for 44.57% of the precipitation. The precipitation, air humidity and river runoff all showed rising trends with average rates of 18 mm/10 a, 1.12%/10 a and 18 mm/10 a, respectively. (2) The precipitation, air humidity, soil moisture and river runoff varied intra-annually in step. (3) With the height increase from forest ground, the influence of precipitation on air humidity decreased; In 0-80 cm soil profile, with the increase of soil depth, the influence of precipitation on soil moisture also decreased . (4) The relationship between rainfall, air humidity, soil water, river water more closely, the regression model among precipitation, air humidity, soil moisture and river runoff can interpreted the 95.2% and 88.8% and 97.6% variances of precipitation, soil moisture and river runoff, respectively, and with averaged prediction accuracies of 93.4%, 84.6% and 96.7%. [Conclusion] The proportional allocation among precipitation, soil water, river water could be quantified and regulated. The data acquiring methods of manual observation and automatic monitoring could well solve the ecological and hydrological processes research in river basin.

Abstract:[Objective] Vegetation coverage in Bayanbulak grassland of Xinjiang Autonomous Region was graded and the regional vegetation coverage was determined in order to provide theoretical reference for the prevention pasture degradation. [Methods] With the help of American SOC_710 portable visible/the near infrared spectrum imaging spectrometer, the normalized difference vegetation index(SOC_NDVI) was adopted to establish the MODIS spectral estimation model between NDVI(MODIS_NDVI) and actual vegetation coverage(VC) using linear regression analysis method. The grading and determining of regional vegetation coverage were completed on the inversion coverage result of the model. [Results] The prediction accuracy of MODIS spectral estimation model was high with a standard error of 11.55%, the overall accuracy reached 88.92%. The 5 vegetation coverage levels had extreme high coverage, high, moderate, low and extreme low coverage, and these coverage proportion were: 18.87%, 25.61%, 31.28%, 13.86% and 10.38%. [Conclusion] The vegetation coverage on the whole study area was high in the north and west, and low in the east. The research area was covered mainly by middle and high coverage grades; proportions of other coverage grades as low, extreme low and extreme high, were small.

Abstract:[Objective] The soil water content in Horqin sandy land was measured by ECH₂O EC-5 sensor to validate the reliability of the sensor. [Methods] Values obtained by weighting method was compared with the ones of ECH₂O EC-5 sensor measurement, and calibrated with regression analysis. [Results] The equation of water correction between the values of weighting method and the ones of sensor measurement for the sandy land was a linear function(R²=0.96, p<0.01). The validation results showed that the root mean square error(RMSE) and relative root mean square error(RRMSE) between the soil water contents predicted by regression equation and the contrast standard values were 0.38%, 6.29%, respectively. [Conclusion] Soil water contents measured by ECH₂O EC-5 sensor for sandy land were accurate and reliable.

Abstract:[Objective] The influences of different resampling methods on the quality of DEMs were analyzed to explain the accuracy of those methods which were widely used in digital terrain analysis. [Methods] Based on data error analysis, the RMSEs of elevation of those DEMs were calculated from different resampling methods, and from the original DEMs generated by digital photogrammetric method in Yaojiawan valley, Suide County of Shaanxi Province Were compared. [Results] No improvement of the quality of resampled DEMs was observed for all the resampling methods. The spatial distribution of elevation error of resampled DEMs depended on the resampling methods. The larger errors emerged in the positions with the vigorous changing of surface. Meanwhile, the values of RMSE were decided by original grid size and the methods of resampling. [Conclusion] The DEMs resampled by nearest method had the highest RMSE, while the Cubic method obtained the lowest RMSE and Bilinear method got slightly higher RMSE than that of Cubic method.

Abstract:[Objects] Carbon emission and carbon footprint of He'nan Province were predicted in order to understand the potential of carbon emission reduction in the future and to find low-carbon development strategies. [Methods] Based on the provincial level, taking He'nan Province as an example, this paper analyzed the carbon budget and carbon footprint of He'nan Province, and predicted the carbon emission peak value by STIRPAT model and scenario analysis approach. [Results] (1) The total amount of carbon emissions in He'nan Province increased from 6.83×10⁷ t in 2000 to 1.77×10⁸ t in 2012 with the increasing rate of 159.2%. The carbon emissions were quite different among different industries, in which, the manufacturing industries contributed the most of total carbon emission. The increasing rate of different types of carbon emissions were obviously different from each other. The carbon sink capacity of terrestrial ecosystems of He'nan Province decreased since 2000. (2) The carbon footprint of energy consumption of He'nan Province increased from 1.71×10⁷ hm² in 2000 to 4.42×10⁷ hm² in 2012. The expansion of carbon footprint caused the ecological deficit of 1.68×10⁸ hm². (3) Carbon emissions will reach to its peak value in 2040 or 2035 under benchmark or low-carbon scenario, respectively. If the regional carbon compensation was considered, peak values of carbon emissions under benchmark and low-carbon scenario will arrive in advance, in 2035 and 2025, respectively. [Conclusions] The carbon sinks of He'nan Province do not match carbon emissions. If carbon compensation is applied, there is huge room for carbon emission reduction in the future.

Abstract:[Objective] The fractal dimension of particle size distribution in a basin with coupled wind-water erosion processes was studied to provide theoretical and experimental basis for the research and control of coupled wind-water erosion and hyper-concentrated flow sediment. [Methods] Xiliugou catchment, which is located in the upper stream of the Yellow River in Inner Mongolia Autonomous Region, was selected as the study area. Total 43 Surface sediment samples at different locations were collected in the catchment. The sediment grain size composition was measured by a laser particle size analyzer. Based on the fractal theory and using the ANVOA and K-means cluster methods, the fractal dimensions of particle size distribution in the Xiliugou catchment were obtained and its influencing factors were analyzed. [Results] (1) The fractal dimension of particle size distribution varied under different depositional environment. The highest fractal dimension(2.48) was found in the hilly-gullies region where water erosion prevail, and the lowest(1.87) in the desert region, where wind erosion is much active. (2) The fractal dimension increased with the increase of particles content lower than 0.05 mm, but decreased with the increase of particles content within 0.05~1 mm. The relation between the fractal dimension and the content of particles larger than 1 mm was not significant. The influence of silt content on the fractal dimension was greater than that of clay content. [Conclusion] The sediments on river bed in different geomorphic units had significant discrepant particle size composition and the particle size composition of sediments on berms changed evidently both in different geomorphic units along the river and in different depositional environment within the floodplains. The particle size composition of sediment sources, the regolith or loess, did not show obviously variations between different geomorphic units.

Abstract:[Objective] This paper aimed to analyze the regional difference of national rural ecological civilization construction level in order to provide some references for policy making. [Methods] On the basis of defining the meaning of rural ecological civilization, the evaluation index system for rural ecological civilization construction level was constructed based on the PSR(pressure-state-response) model, then an empirical analysis was conducted in China by the improved grey target model and obstacle degree model. [Results] The rural ecological civilization construction has regional differences in China, the construction level of the eastern region being higher than that of the central region, the construction level of the central region being higher than that of the western region. For rural ecosystem pressure, the central region is bigger than the eastern region but smaller than the western region; while for rural ecosystem healthy status and rural ecosystem management level, the central region is lower than the eastern region but higher than the western region. [Conclusion] According to the diagnosis results of the obstacle factors, this paper suggests that: the eastern region should make great efforts to achieve rural ecosystem healthy and reduce rural ecosystem pressure. The central region should promote the rural ecosystem management level through the development of rural ecological economy, the input reinforcement of rural ecological civilization construction, and so on. The western region should improve rural ecosystem healthy status and promote the rural ecosystem management level.

Abstract:[Objective] The environmental situation of Guiyang City of Guizhou Province was comprehensively assessed to provide guidance for optimizing land use. [Methods] Ecological footprint and energy theory were used respectively to quantify environmental carrying capacity(ECC) and environmental load, both of which were stimulated by Grey model for the changing tendency in near future. [Results] ECC fluctuated noticeably since 2005 which was predominantly driven by the variation of arable land and construction land. In contrast, environmental load increased stably and quickly, which was mainly caused by the significant expansion of consumptions of petroleum, electric power, building materials and phosphate, and by the ever growing emission of exhaust gas. [Conclusion] Environmental load has been below ECC so for, but environmental deficit would come according to the prediction. Measurements that tailored to the main influence factors of ECC and environmental load should be taken to avoid environmental deficit and to facilitating local sustainable development.

Abstract:[Objective] Through studying three-dimensional(3D) modeling processe and method, we expected to provide solid basis for subsequent building of digital park. [Methods] Based on GPS mapping and ground survey of the park, visualization modeling was applied to the soil and water conservation project. [Results] Jiangxi Soil and Water Conservative Ecological Science and Technology Park was taken as an example, constrained triangulation and spatial interpolation were employed to solve some key issues. For example, seamless tiling of surface features and topography, soil body modeling, rapid generation of plant model, and so on. Finally a 3D model with aboveground and underground integration system including such elements as project measures, vegetation, and soil, etc., was constructed. [Conclusion] The developed 3D visualization system can make the water and soil conservative ecological demonstration park playing a better role in scientific support, social promotion, typical drive and demonstrative radiation.

Abstract:[Objective] Soil fertilities of seven substrate slopes in Xiangjiaba hydropower project area were measured in the years from 2005 to 2014. The changing trend of soil fertility was predicted to provide theoretical and technical support for slope vegetation restoration in large water conservancy and hydropower project. [Methods] Grey theory and logistic equation were integrated to establish a structurally sound and high-precision logistic model for forecasting the future trend of main soil fertility. The main soil fertility was decided by Grey correlation degree among various soil fertility factors in different slopes. [Results] Grey correlation degrees between microbial biomass and other fertility factors were all larger than the ones among other fertility factors, and thereby the soil microbial biomass can be regarded as the main soil fertility factor and denote the soil fertility level. Soil fertilities indicated by microbial biomass were predicted having an overall order in 2005-2040 that is natural forest(NF) >natural secondary forest(NSF) >vegetation-growing concrete gunning(VGCG) >thick layer substrate(TLS) >framed beams and soil covered(FBSC) >external-soil spray seeding(ESS) >discarded residue(DR). [Conclusion] Soil microbial biomass on different substrate slopes will eventually get stable with the time pass by. The VGCG slope's fertility level is the best.

Abstract:[Objective] Land ecological sensitive zoning was comprehensively analyzed under different land use type to provide reference for regional land use planning. [Methods] Yixing City, a typical city in Southern Jiangsu Province was taken as an example, its land use ecological sensitive zones were divided according to the zones of soil and water loss sensitivity and biodiversity preservation priority using USLE model and landscape security pattern. [Results] The ecological sensitivity in Yixing City was thought relatively low. The zones with extremely high sensitivity accounted only for 7.87% of the total area, the zones with high sensitivity, moderate sensitivity and low sensitivity covered 23.96%, 35.71% and 32.46%, respectively. The zones with extremely high sensitivity were clustered together in space. Sensitivity declined gradually from the southern hill district to the northern plain district. [Conclusion] The application of USLE model combined with landscape security pattern can comprehensively recognize the factors that influence ecological sensitivity, and quantitatively grade the land use ecological sensitive zones.

Abstract:[Objective] Revealing the slope erosion of Yunnan laterite as dependent variable caused by independent variables of rainfall intensity, slope gradient, slope length in order to provide bases for the prevention and control of soil erosion in Yunnan laterite area. [Methods] Artificial rainfall erosion was simulated indoor and analyzed theoretically. [Results] (1) The slope erosion of Yunnan laterite could be regressed significantly with rainfall intensity, slope gradient, slope length(R²>0.95). (2) Under certain slope gradient and length, the slope erosion modulus of laterite had power function relationship with rainfall intensity as independent variable. (3) Under certain rainfall intensity and slope length, the slope erosion modulus of laterite had a quadratic polynomial relationship with slope gradient. (4) Under certain rainfall intensity and slope gradient, the slope erosion modulus of laterite had a quadratic polynomial relationship with slope length. [Conclusion] The slope erosion modulus of Yunnan laterite increased with the increase of rainfall intensity. When the slope was less than the critical slope 21.4°, slope erosion modulus increased with the increase of slope. When the slope is greater than the critical slope 21.4°, slope erosion modulus decreased with the increase of slope. The slope erosion modulus increased with the increase of the slope length.

Abstract:[Objective] The effects of soil and water conservation measures on soil respiration were studied to scientifically evaluate the role of soil and water conservation to climate change. [Methods] Four soil and water conservation measures, including cross-slope tillage and contour sod strip, cross-slope tillage, down-slop tillage and weed clearing, were designed to assess the effects on soil respiration. And the response of soil respiration rate to soil moisture and soil temperature was illustrated. [Results] Soil respiration rates of four Citrus reticulata plantation treatments had the same seasonal change trend, they all changed in an unimodal curve with their peaks in July. Soil respiration rate increased to some extent as soil and water conservation measures taken. Soil respiration rate had a significantly positive correlation with soil temperature. The temperature sensitivity index Q₁₀ values in the cross-slope tillage and contour sod strip treatment and cross-slope tillage treatment were higher than that in the treatments of weed clearing and down-slop tillage. [Conclusion] Soil respiration increased after soil and water conservation measures was implemented, which could influence of soil temperature to some extent.

Abstract:[Objective] The influences of Shenfu coal mining subsidence on the movement of aeolian sand were studies to provide scientific basis and guidance for the controlling of wind erosion and recovery of vegetation. [Methods] Based on local field observation in a typical sand dune, this paper studied the impacts of sand dune position and the surface damage ratio on the thickness of aeolian deposit. [Results] The results showed that the thinkness of aeolian deposits on the ground that had undergone one year of subsidence and two year of subsidence were -28.2 cm and -45.6 cm, respectively; while the reference sand dune was -2.8 cm. The overall probabilities of wind erosion of the above three dunes were >60%, >90%, and<10%, respectively. Surface accumulation occurred more intensely on the surface with a higher damage ratio. The movement of wind-blown sand gradually shifted from accumulation or filling to wind erosion as the surface damage ratio decreased. The relation between the thickness of aeolian deposit(Q) and the surface damage ratio(V) can be described by a polynomial function. [Conclusion] It was concluded that the coal mining-induced subsidence significantly promoted the movement of aeolian sand and changed the thickness of aeolian deposit locally, and it may reactivate fixed or semi-fixed dunes.

Abstract:[Objective] The qualitative and quantitative relations between the expansive force of weathered-sand-improved expansive soil and the effects of weathered sand content, the number of freezing-thawing cycles on the expansive force were studied. [Methods] Weathered sand was put into the expansive soil with the proportions of 0,10%,20%,30%,40%,50% and the expansive force was tested on the consolidation test apparatus in condition of freezing-thawing cycles with the times of 0,1,3,6,9,12. [Results] The expansive force of weathered-sand-improved expansive soil reduced obviously. Both the expansive force of weathered-sand-improved expansive soil and the extent of the expansive force reduces as the proportion of weathered sand increased in the same time of freezing-thawing cycles. In contrast, the two items reduced as the times of freezing-thawing cycles increased in the same proportion of mixed weathered sand. The expansive force of the weathered-sand-improved expansive soil and the natural logarithm of the number of freezing-thawing cycles showed negative linear correlation relationship in the same content of weathered sand. [Conclusion] Both of the freeze-thaw cycles and the proportion of mixed sands all affect the expansive force of expansive soil.

Abstract:[Objective] By analyzing the changes of soil water content beneath the canopy of rain-fed Haloxylon ammodendron forest in which sand barriers were established, this paper aimed to provide theoretical basis for evaluating the ecological functions of sand barriers as well as forecasting the growth and development situation of the Haloxylon ammodendron forest. [Methods] Two sites of 5 and 25 years old Haloxylon ammodendron forests were selected to establish wheat straw and plastic net sand barriers. Wherein, soil water contents of 0-50 cm depth, crust thickness, near-surface wind speed beneath the canopy were measured and analyzed. [Results] Under the influence of sand barriers, soil water contents of 0-50 cm increased, air flow velocity in near-surface decreased and the formation of crust was speeded up. The sand barriers had no significant influence on the spatial distributional pattern of soil water contents beneath the 5 years old Haloxylon ammodendron canopy. Whereas, "dry island effect" was observed for the 25 years old Haloxylon ammodendron canopy, i.e., soil water contents decreased monotonically with the distance decreasing from the tree trunk. Soil water content in the vertical profile between plastic net sand barriers area and contrast area had a significant correlation(p<0.05), while had no evident correlation between wheat straw sand barriers area and contrast area. The depth with biggest soil water content in wheat straw sand barriers area descended to 30-40 cm. [Conclusion] Establishment of sand barriers had somewhat acceleration effects on the recovery of degenerated Haloxylon ammodendron forest, it was more obvious for the middle age forest than the young forest with regard to the effect on soil water.

Abstract:[Objective] Exploring the variation process of seepage field and transient saturated zone of fractured rock slope under the influence of rainfall to provide support for the study of the law of rainfall infiltration, engineering technology and water conservation. [Methods] Based on discontinuous fracture network model, a Matlab program was designed to calculate the permeability tensor. Based on equivalent continuous medium model, a program using FISH language was designed for unsaturated seepage analysis. [Results] Permeability tensor of fractured rock mass was obtained through the engineering case. With the increase of rainfall intensity and rainfall duration, the surface of zero pore water pressure will extend to the inside of the slope and the scope of transient saturated zone will expand. Moreover, the appearance of transient saturated zone will occur in the case when rainfall intensity is greater than the the infiltration rate of the slope. [Conclusion] The characteristics of anisotropic and unsaturated seepage in fractured rock mass can be better elucidated by using discontinuous fracture network model and equivalent continuous medium model and the models can be used to analyze the rainfall infiltration of fractured rock slope.

Abstract:[Objective] The slope flow velocity in abandoned dreg site and the effects of gravel content, slope gradient, water flows discharge, and sediment concentration on it were demonstrated to provide scientific reference for revealing the erosion mechanism on dreg site. [Methods] Field scouring experiment was carried out to study the velocity of residue slop in Shenfu Coalfield. [Results] Results showed that flow velocity experienced fluctuated processes within a certain range on all flow discharge conditions. The velocity along discharge time was multi-valley multimodal, and its fluctuation range observed in flow sections increased with the increase of discharge amount. Power function could be used to describe the relationships between flow velocity and the influence factors, including gravel content, flow discharge and sediment concentration. Quadratic power function could express the relationship between velocity and slope gradient. Stepwise regression analysis showed both flow discharge and gravel content significantly influenced flow velocity. [Conclusion] Variation of flow velocity on abandoned dreg slope was complicated. Gravel amount and upstream catchment area were two key factors influencing flow velocity.

Abstract:[Objective] Soil property is one of the important factors that influence the tillage erosion intensity. Revealing soil erosion susceptibility by tillage operations under different soil conditions was expected to provide basis for the adoption of appropriate tillage measures on steep land. [Methods] Magnetic tracer was used to measure the soil translocation and soil flux under up and down slope tillage and contour tillage by rotary cultivator. The effect of variations in soil properties on net soil displacement and the associated tillage erosion was investigated for the two tillage practices in purple soil under two different soil conditions is consolidated soil(conventional tillage about half a year ago) and loosened soil(consecutive tillage for 20 times tillage operations). Seven soil physical, chemical and mechanical properties were selected as indices, including soil bulk density, soil water content, soil organic matter, total nitrogen, available phosphorus, soil shear strength and soil compactness. [Results] The results showed that net soil displacement distance and soil flux were not only influenced by slope gradient but also by soil properties irrespective of tillage practices. Soil mechanical and physical properties had significant impacts on tillage erosion. For the up and down slope tillage, net soil translocation rate was significantly positively correlated with the indices of soil shear strength, soil compactness, and soil bulk density. For the contour tillage, net soil translocation rate was significantly positively correlated with the indices of soil shear strength, soil compactness, soil bulk density and soil water content. No significant correlations were found between net soil translocation rate and soil chemical properties index for the two practices. [Conclusion] It is suggested that soil shear strength, soil compactness and soil bulk density could be taken as indicators in evaluating soil erodibility for tillage erosion.

Abstract:[Objective] The effects of revegetation on soil carbon(SOC), light-fraction organic carbon(LFOC) was analyzed to provide background data for rocky desertification restoration. [Methods] Sites with severe rocky desertification land was taken as contrast and using space as a substitute for time, SOC and LFOC in sites with 5, 10, 15, 20-year restoration in Guohua karst rocky desertification area of Pingguo County, Guangxi Zhuang Autonomous Region were measured and their changes along revegetation were illustrated. [Results] SOC and LFOC contents increased obviously after revegetation, especially in 0-10 cm soil layer. The increment of surface soil LFOC storage was much higher than that of SOC storage, suggesting that vegetation restoration on rocky desertification land had a large effect on LFOC. [Conclusion] Vegetation restoration can prevent land rocky desertification and increase carbon circulation.

Abstract:[Objective] The effects of rainfall intensity and slope gradient on runoff process were studied to provide scientific basis for soil and water conservation control on purple soil areas. [Methods] Researches were studied based on indoor artificial rainfall simulation experiments. [Results] Runoff courses could be generally divided into concave and convex type, and can be described by exponential function and log function, respectively. With the increases of rainfall intensity and slope, the runoff initiation time decreased, the runoff amount increased, and the runoff course became similar. At low rainfall intensity, the effect of slope gradient was obvious in runoff generation, while at high intensity, the effect decreased. In this case, slope gradient was the main factor at low rainfall intensities(33,54 mm/h), while rainfall intensity became the main factor at high rainfall intensity(94,125 mm/h). [Conclusion] Both rainfall intensity and slope gradients were the main factors of hillslope erosion. With the increase in rainfall intensity, the hillslope erosion became more sharply. And the main erosion factor transferred from slope to rainfall intensity.

Abstract:[Objective] Studying the nonlinear variations of runoff in Yihe River and the climate factors in different time scales, which was expected to provide theoretical basis for analizing the impact of climate change on runoff. [Methods] The methods of ensemble empirical mode decomposition(EEMD), Mann-Kendall test, Pearson correlation analysis and Linear regression were adopted. [Results] The runoff appeared a significant linear downward trend(p<0.01) during 1951-2013, with a rate of 3.33×10⁸ m³/10 a butan aberrant trend existed around 1976. Meanwhile, runoff was decomposed into four IMFs. The contribution of variance of inter-annual scale(quasi-3 and quasi-6-year) to the overall one was the largest, reaching 58%. The contributions of inter-decadal scale(quasi-13-year) and multi-decadal scale(quasi-31-year) were 11% and 6%, respectively. Subsequently, the contribution of nonlinear variation to the overall runoff was 25%. [Conclusion] The effects of climate factors(PDO, ENSO, temperature and precipitation) in different time-scales on runoff and its mechanism were proved different. The climate factors in inter-decadal scale and multi-decadal scale are more closely related to runoff change.

Abstract:[Objective] To provide references and scientific bases for environmental management of the Three Gorges Reservoir areas, the effect of three simple organic acids(oxalic acid, citric acid, tartaric acid) on the properties of leachate and soil(purple soil and grey-brown purple soil) were investigated. [Methods] leaching experiments were conducted using intermittent soil column in lab. [Results] Low-molecular-weight organic acids at high concentration(≥50 mmol/L) can upset the acid-alkaline buffer system of grey-brown purple soil. Either oxalic acid, citric acid or tartaric acid, when the concentration was higher than 50 mmol/L, pH value of grey-brown purple soil was observed declined from around 8 to lower than 4.11. Whereas, the buffer effect of purple soil behaved strong. soil pH value of it varied between 6.84 and 8.71 after leaching, no significant differences were observed with the contrast value of blank treatment. Electrical conductivity of grey-brown purple changed more obviously than the one of purple soil. In the treatments of high concentrations of low-molecular-weight organic acids, the highest electrical conductivity of grey-brown purple soil even reached 34.400 mS. The leached amount of ions by the three acids had a rank of citric acid>tartaric acid>oxalic acid. [Conclusion] The main reasons affecting pH value, electrical conductivity of leachate and soil pH value were acid splitting and complexing action of the low-molecular-weight organic acid. Meanwhile, the acid-participated chemical and biochemical processes of the purple soil and grey-brown purple soil were also important. The presence of low-molecular-weight organic acids has certain risk to water environment in the Three Gorge Reservior areas.

Abstract:[Objective] The long-term effects of ecological rehabilitation patterns on soil enzyme activity on different standing conditions was studied to provide theory for soil cultivation and remediation. [Methods] A secondary forest and an artificial forest in disturbed area of Xiangjiaba hydropower station were selected as studying sites to measure soil enzyme activities in different slope position and slope exposure and to analyze the relationships between enzymatic activity and other fertility factors. [Results] Except of soil pH value, nutrition level in the lower slope was relatively high in comparison with that at upper and middle slope positions, it was 1.1 times or higher of the levels of the latter two positions. The changes of enzymatic activity was coincided with the indices of soil fertility along different slope positions. Excepting for the slight change of peroxide enzyme activity, other enzymes were all obvious. Among which, phosphatase activity at lower slop position increased 91.67%~116.67% in contrast with the one at upper position urease activity increased 5.3%~5.3%, and invertase activity increased 1.38~1.56 times. In terms of the enzymatic changes of slope exposure, except of peroxide enzyme, other enzymatic activates in shady slope behaved better than the ones in sunny slope. Correlation analysis showed that the correlations between alkaline phosphatase, urease and invertase were significant with each other. The correlations of catalase were not significant with the above three enzymes. [Conclusion] For soil fertility factors, an overall increasing trend from up slope to down slope, and a comparative high in northern slope exposure were both tested. Implying that standing condition can affect the process of soil internal environment. Therefore, for the remediation of upper slope and sunny slope, appropriate fertilization might make the cultivation of soil fertility and the ecological habitation better.

Abstract:[Objective] The relationship between soil structure and soil saturated hydraulic conductivity was explored in Hongshi Park of Laiwu City to provide a theoretical basis to forecast the process of soil moisture migration. [Methods] Stratified sampling was carried out using ring knives in six sites of Redstone Park of Laiwu City. Soil saturated hydraulic conductivity and physical structural traits of the soil samples were measured to analyze the relationship between them. [Results] Soil bulk density and stone content of different land use types ranked as: herb soil >shrub-herb soil >trees-shrub soil. Indices of R_0.25(>0.25 mm water stable aggregate), soil moisture, soil porosity and soil saturated hydraulic conductivity had a same rank of trees-shrub soil >shrub-herb soil >herb soil. Soil structure and saturated hydraulic conductivity behaved better in surface soil layers than that in deep soil layers. Soil saturated hydraulic conductivity was found significantly and negatively correlated with soil bulk density and rock fragment. [Conclusion] Soil saturated hydraulic conductivity had significantly positive correlations with porosity and R_0.25. Soil porosity was the key factor affecting saturated hydraulic conductivity.

Abstract:[Objective] Spatial distribution of aboveground biomass and its relationship with environmental factors were studied in desert grassland in the middle part of Hexi Corridor to provide a reliable data for the assessment of grassland ecosystem carbon stock, and to illustrate its change at regional scale. [Methods] The present study, based on a total of 52 sampling sites in desert grasslands in the middle region of Hexi Corridors, illustrated the regional distribution pattern of aboveground biomass and its response to environmental factors were investigated. [Results] The results showed that aboveground biomass of desert grasslands ranged from 11.17~523.76 g/m², with an average of 149.67 g/m², and increased from the southeast to the northwest in the survey area. There were 15 communities with dominant species appeared in these 52 sampling. Average aboveground biomasses of Lycium ruthenicum and Scorzonera divaricate community were 49.88±7.42 g/m² and 201.69±98.48 g/m², respectively, which were also the minimum and maximum of aboveground biomass among the 15 communities. Aboveground biomass was significantly and negatively correlated with longitude, and was significantly and positively correlated with elevation. 39.8% of the spatial variation of aboveground biomass can be interpreted by soil factors. Among which, soil type, soil bulk density and soil organic matter were significantly affected aboveground biomass distribution of desert grassland, while the effects of soil moisture on aboveground biomass was weak. [Conclusion] Aboveground biomass in desert grassland of Hexi Corridor increased from the southeast to the northwest. Altitude and soil environmental factors are the key factors affecting the distribution pattern.

Abstract:[Objective] The evolution of drought frequency and intensity was demonstrated yearly and quarterly in Chongqing City to provide scientific basis and reference for drought mitigation. [Methods] Standardized precipitation index(SPI) drought index method was used, and the monthly precipitation data collected from 34 meteorological stations in 1964-2011 were dealt. [Results] Frequency of drought had obvious regional and seasonal traits. The seasonal frequency of droughts varied differently. In spring, summer and winter, it had a range of 25.9%~35.1%; In fall, it had a big range from 16.7% to 40.0%. Either for yearly drought intensity or seasonal intensity, they both had an overall increasing trend, among which, annual drought intensity and the autumn one were more obvious. In the past 50 years, the study area was prevailed by intensity grades of mild drought and drought, either counted by years or by seasons. Drought occurred in summer and autumn were more severe than that in other seasons and in a whole year. [Conclusion] Standardized precipitation index(SPI) can be used as indicators for monitoring the climate change of Chongqing City. The frequency of drought in Chongqing City has obvious regional and seasonal traits.

Abstract:[Objective] Soil moisture under different land use patterns were measured and its links with the characteristics of plant communities were studied to provide guidance for the vegetation restoration and rehabilitation. [Methods] Based on field investigation, mathematical analysis was used. [Results] The aboveground dry biomass of main vegetation in Zhifanggou watershed ranged from 310.0 to 10036.2 g/m² among ten land use types, and the mean aboveground dry biomass ranked as: forest land >shrub land >farmland >artificial grassland>natural grassland. There was a significant positive correlation between aboveground fresh biomass and vegetation height(R²=0.967 4, p<0.01). Soil moisture in 0-100 cm of different land use types had high content and varied greatly. Comparatively, the soil moisture content in 100-500 cm was nearly constant. The amount of most easily available soil moisture in check-dam and terrace with Z. mays planted were 221.73 mm and 221.99 mm, respectively. The soil moistures in C. korshinskii and R. pseudoacacia were extremely low, with hardly-available soil moisture contents of 311.44 mm and 333.09 mm, respectively. Soil moistures in the other six land use types were classified as easily-moderately available soil moisture. [Conclusion] In the loess hilly region, all vegetation types, to a certain extent, can improve local ecological environment, but some artificial forest and shrub can lead to the excessive consumption of deep soil moisture, and are not propitious to the sustainable development of vegetation.

Abstract:[Objective] Through evaluating the impact factors of soil erosion sensitivity for the Cixi City of Zhejiang City, references for conducting the environmental functional zoning and the layout of water conservation measure were expected to be provided. [Methods] According to the USLE model, rainfall erosion force, soil texture, vegetation cover and terrain fluctuation were selected to construct sensitivity evaluation system of soil erosion. Moreover, GIS was employed to analyze soil erosion sensitivity. [Results] Results showed a semicircle structure in the spatial distribution pattern of soil erosion sensitivity in Cixi City. The area of slight sensitivity was 733.05 km², accounting for a high percentage of 75.7%, which was widely distributed in the villages and towns of plain area. The insensitive part located in the offshore area of tidal flat. The areas of extreme sensitive, high sensitive and moderate sensitive were mainly distributed in the hill and mountain regions of the southern part of Cixi City. [Conclusion] The results of sensitivity evaluation were in accord with the spatial distribution of soil water loss, indicating that more attentions should be paid to the conservation of soil and water.

Abstract:[Objective] The process and mechanism of erosion and sediment yield of rubbish-dump in dry upland of Northern Weihe river were illustrated to provide scientific bases for the prevention and control of rainfall erosion on rubbish-dump. [Methods] Experiments of erosion and sediment yield were conducted on rubbish dumps with two slope gradients(steep slope and tiled dump) and rainfall simulation intensities(1,2 and 2.0 mm/m). [Results] When rainfall intensity I was at 1.2 mm/min, the sediment yield on the steep slope dump was 117.94 kg, an increment of 107.08 kg was observed in comparison with the one on tiled dump of 10.86 kg. When rainfall intensity was at 2.0 mm/m, the sediment yield on steep slope dump got an increment of 225.72 kg in contrast to the one on tiled dump. The energy of erosion(E), including the consume energy(E_{startup sediment},E_{move sediment}), and the dragging resistance at bottom plate(F) were elucidated: The existed space and soft layer between rubbish-dump and the original landform below it can reduce the E start up sediment, the energy of erosion(E) was mainly consumed by moving sediment. [Conclusion] The current with the sediment yield will keep a high speed and a strong dragging force from bottom plate(F). As a result, rill erosion was strengthened.

Abstract:[Objective] The grain production status in Shandong Province during 1994-2014 and the food security during 2015-2025 were studied to provide scientific basis for making reasonable production planning and agricultural economic policy. [Methods] Models of the cultivated land pressure index based on minimum per capita arable land area, logistic population prediction model and grey model〔GM(1,1)〕 were used to carry out the research. [Results] (1) The cultivated land pressure index was greater than 1 in many years during 1994-2014 in Shandong Province, implying that a state of food insecurity existed. (2) Cultivated land pressure index in 1994-2014 showed a slow periodical upward trend with a 4~5 a cycle. (3) In the next 10 years, grain output and total population will present a growth trend; while indices of arable land, arable land per capita, the minimum per capita cultivated land area and cultivated land pressure index are predicted having a downward trend. And the cultivated land pressure index value will be less than 1 in most years. [Conclusion] Through expanding food economy, grain production and food supply will be in a safe state in the next 10 a in Shandong Province.

Abstract:[Objective] The effects of rainfall intensity on the happening of overflowing and breaking on basin tillage and the relevant variations of basin tillage's soil and water conservation efficiency were explored to provide references of suitable requirements for the application of basin tillage and for the evaluation of its soil and water conservation efficiency. [Methods] Simulated rainfall was applied on two tillage patterns of basin tillage and compared conventional tillage, and to analyze their processes of soil and water production and the variations of soil and water conservation efficiency. [Results] When rainfall intensity was under 60 mm/h, there was ridge overflowing occurrence but no damage or breaking for basin tillage, and the efficiency decreased slightly. When rainfall intensity was over 60 mm/h, damage and breaking occurred as soon as overflowing happened, whereafter the efficiency decreased remarkably. Average runoff conservation efficiency was 87.5% and the soil conservation efficiency was 88.2%. When basin tillage was damaged, the above two items decreased to 34.1% and 21.0%, respectively. [Conclusions] Basin tillage would remain good efforts on soil and water conservation when rainfall intensity under 60 mm/h. When it is over 60 mm/h, because dams of basin tillage might be broken down easily after overtopping, it would lost its ability of blocking water and soil, and hence relevant conservation efficiency decreased remarkably as well.

Abstract:[Objective] The quantitative study of soil hydraulic erosion in Liangshan area of Sichuan Province was conducted to provide data support for the investigation of soil erosion in this area. [Methods] Data of geographic conditions in Sichuan Province were obtained from previous provincial investigation and then processed based on the localization research of USLE model. [Results] Annual average amount of soil erosion in Liangshan Region is 1207.67 t/(km²·a). Soil erosion area is 15221 km², accounting for 25.19% of this area. Area around Jinsha River is the most serious soil erosion areas, followed by Anning River basin and Heishui River basin. [Conclusion] Soil erosion area is still large, and the situation of soil erosion is still grim in this place.

Abstract:[Objective] Through a case study in quantitative evaluation of benefits from comprehensive watershed harness of Yao'an small watershed of Qingyuan City in Guangdong Province, we expected that some references for the watershed harness and benefit evaluation. [Methods] According to the disaster characteristics of small watershed in the province, the harness destination and actual situation of Yao'an small watershed, 4 benefit types(flood protection and disaster reduction, soil and water conservation and ecological, economic and social benefit ) and 21 indices were chosen to evaluate the benefits from comprehensive harness of watershed. Methods of data standardization, fuzzy comprehensive evaluation model and analytic hierarchy process were used. [Results] (1) The indices system and evaluation model presented well the comprehensive benefit of soil and water conservation of small watershed, and were suitable in the region of Guangdong Province. (2) The comprehensive benefit and the above four benefit items were all improved with different percentages from 2007 to 2013 in Yao'an small watershed, among them, the disaster reduction benefits from flood protection and economic benefit were remarkable. [Conclusion] The indices and method used in quantitative benefit evaluation for comprehensive control were practical and suitable in the watershed of Guangdong Province. After comprehensive harness been conducted, the withstanding ability to disaster was signally enhanced and the situation of soil loss was moderated.

Abstract:[Objective] The benefits with regard to soil and water conservation, economy and ecological environment in the Yangtze River basin in Gansu Province were evaluated to provide a basis for the realization of sustainable development of social economy in the area of soil and water loss. [Methods] A comprehensive management evaluation system of soil and water conservation in the Yangtze River basin in Gansu Province and calculation method of soil and water conservation benefit(GB/T15774-2008) were used to analyze the benefits of soil and water conservation in the Yangtze River basin of Gansu Province.[Results] The results showed that the cumulative water diversion of various measures was 20.059 billion m³, of which measures on slopes was 20.056 billion m³, accounting for 99.99% of the total diversion water. The cumulative soil conservation by various measures was 0. 359 billion tons, of which measures on slopes was 2.96×10⁸ m³, accounting for 82.45% of the total conserved soil. The economic benefits of terraces, soil and water conservation forest, economic forests and artificial grass were 5.808, 18.002, 2.969, 1.52 billion yuan, respectively, totally 27.999 billion yuan. [Conclusion] Through holding the rainfall runoff, conservation measures effectively reduced the occurrences and damages of droughts and floods in the Yangtze River basin, and also in the sub-regions in it. Consequently, the measures effectively reduced sediment deposition in the downstream channel. Meanwhile, soil fertility was improved and the capacity of soil resistance to erosion was enhanced. Vegetation coverage increased from 1.47% in 1980 to 29.83% in 2011 with an increment of 28.36%.

Abstract:[Objective] The objective of this study was to analyze the driving forces of land desertification in Maqu plateau in order to provide basis and reference for ecological restoration of land degradation in the upper reaches of the Yellow River. [Methods] Land desertification information was elicited from multi-phase remote sensing data, and the driving forces data were collected from Maqu meteorological stations during 1964-2014 and social-economic statistical yearbook of Maqu County Gansu Province. Principal component analysis(PCA) was used. [Results] During 1964-2014, both natural and human factors contributed to the variation of land desertification area, their joint contribution was 57.18%. Driving factors of land desertification in Maqu Plateau varied in different stage during 1964-2014. The expansion of desertification land area in 1964-1980 was induced both by human and natural factors, but human factors played a dominant role with a contribution rate of 47.66%. The expansion of land desertification area in 1981-1997 was caused by the interaction of natural and human factors. The contribution rate of human factor and natural factor was 42.75%. During 1998-2014, the area of desertification land decreased by human factors. The contribution rate was 44.97%. [Conclusion] The development of land desertification in Maqu plateau was the result of mutual interaction between fragile alpine ecosystem and the intervention of human activities. For human activities, population and livestock are important driving factors. And eventually, human factors are more important and might determine whether progress or retrogress evolution will happen in a short term.

Abstract:[Objective] The comprehensive benefits from land reclamation in Qingyang City of Gansu Province were evaluated to promote the implementation of land reclamation and to improve land management. [Method] A evaluation system was established by the projection-pursuit classification model of real coding accelerating genetic algorithm(RAGA-PPC), in which twelve evaluation indices, including the aspects of social, economic and ecological, was used to evaluate the comprehensive benefits from 15 projects of land remediation in Qingyang City from 2012 to 2013. [Results] In 15 land reclamation projects, projects of Ningxian County project and Zhengning County project were assessed having the best comprehensive benefits, Xifeng District having good benefits, Heshui County and other 10 projects having intermediate benefits, the lowest was Chenshao Township of Huachi County project. [Conclusion] The overall benefits from land renovation project were thought better, but the construction entries of land renovation project and the management need to be conducted more reasonably and jointly.

Abstract:[Objective] The spatiotemporal variation pattern of land ecological security of Qianjiang District of Chongqing City was studied to provide scientific basis for the sustainable utilization of land resources. [Methods] An evaluation system of land ecological security of Qianjiang District was configured from four aspects of ecological load, ecological protection, ecological function and ecological economy. Methods of subjective and objective combined weight assignment and comprehensive index were used. [Results] Though the land ecological security level of Qianjiang District was not high enough, it was on the rise trend, and there was a big space for it to be improved. The spatial difference of the land ecological security had an obvious pattern with low center and high surrounding areas. [Conclusion] The subjective and objective combined weight assignment overcame the deficiency of single subjective or single objective assignment. The evaluation index system included ecological load, ecological protection, ecological function and ecological economy, and combined with the press-state-response(PSR) model and nature-economy-society model, hence, it could effectively reflect the temporal dynamic change and spatial difference of Qianjiang's land ecological security.

Abstract:[Objective] The ecological condition in the Niulan River was investigated to provide bases for ecological management and restoration project. [Methods] Based on the investigation of water quality, riparian zone and pollution sources of the study reach, a comprehensive evaluation method was used to evaluate the survey data. [Results] The natural condition of Kraal River is good. Of which, reaches of 8-10 are in the state of nature, 3, 5-7 reaches are in near natural state, 1, 2, 3 reaches are in a degraded natural condition. The water quality of Kraal River is general poor. If river harnessing being continued, the water quality would improve from downstream to upstream gradually. [Conclusion] The main pollution sources of the study reach are manure, garbage pollution and sewage pollution. Therefore, in the future governance, these pollution should be focused.

Abstract:[Objective] Revealing the urban land intensive utilization in Beijing-Tianjin-Hebei area, to provide basis for the study of urban land intensive utilization under the perspective of ecological health and low-carbon development. [Methods] The relative entropy method of combination weighting, multi-factor comprehensive evaluation method, coordinate measuring method and obstacle factor diagnosis method were used in this study. [Results] (1) The urban land intensive utilization of Beijing-Tianjin-Hebei region showed a "cross" diffusion situation with Beijing City and Tianjin City as its core. (2) Correlation between coordination of the system and the intensive use of land was found significant and different regionally. (3) The main obstacle factors focused on the ecological health and low carbon-related indicators in Beijing and Tianjin cities, and focused on the land use structure-related indicators in Qinhuangdao and Tangshan cities. It is focused on the ecological health-related indicators in Shijiazhuang, Handan and Baoding cities, and in the low-carbon and ecological environment-related obstacle indicators in Cangzhou, Langfang and Xingtai cities. It is focused on the obstacle factors of economic development and investment in Chengde and Hengshui cities, and factors focused on the economic development and ecological protection in Zhangjiakou City. [Conclusion] Taking the concept of ecological health and low-carbon development into the study could provide us more scientific and comprehensive view to reflect the urban land intensive use, and provide support for the scientific land use in the future.

Abstract:[Objective] To evaluate the suitability of rural residential land from the perspective of ecological environment protection, this paper took the conservation of water, soil and biodiversity into consideration according to the present characteristics of well-developed economy and superior ecological environment in Yixing City of Jiangsu Province. [Methods] Based on data of ETM, DEM, and vegetation coverage in Yixing City in 2010, the method of minimum cumulative resistance model was used to calculate the minimum cumulative resistance surfaces of water-soil conservation and biodiversity conservation, then the methods of spatial overlay analysis and natural break were used to determine the suitability grades by ArcGIS 9.3. [Results] The suitability of the rural residential land in Yixing City can be divided into four grades: highly suitable, medium suitable, lowly suitable and unsuitable, which accounts for 57.67%, 12.82%, 22.83% and 6.68% of the total area, respectively. [Conclusion] Suggestions of key development, moderate construction, restricted expansion and prior remediation were proposed at the above mentioned grade of rural residential land. The research results can not only satisfy the requirements of rural residential land layout in Yixing City for the purpose of ecological environment protection, but also can provide some references for the rural residential land layout optimization in other similar area.

Abstract:[Objective] The effects of drought on wheat seedling growth and selecting excellent wheat germplasm materials with drought resistance were studied to provide a basis for the breeding of new drought-resistive varieties. [Methods] Seedlings derived from the cross between Weimai 8 and Luohan 2 were used as experimental materials, which had 291 lines from a recombination inbred line(RIL) population(F₉). The seedlings were treated with different water conditions during germination stage, and multiple agronomic trait indices were measured. A comprehensive evaluation of drought tolerance of the RIL population and its parents were conducted by methods of principal component analysis and K-means clustering. And also, correlation analysis between drought tolerance indices and yields of all the lines was conducted. [Results] Those germinated wheat seeds treated with 10% PEG-6000 were observed to be promoted for coleoptile length and root number, while obvious inhibitory effects were observed for other agronomic traits. 44 excellent lines with drought tolerance were selected from the RIL populations, which provided valuable germplasm materials for drought resistive wheat breeding. [Conclusion] The responses of root to drought stress performed the mostly sensitive, because a strong root system under drought tolerance is one of the important conditions that decide the drought tolerance of seedling. Drought tolerance of wheat seedlings and its yield were remarkably positively correlated.

Abstract:[Objective] Farmers' willingness and acceptable payment level for the agricultural and ecological compensation in Yongdeng County of Gansu Province were studied to provide basis for related agricultural ecological construction by the government in the future. [Methods] On the basis of questionnaire survey, the farmers' willingness and payment levels for the agricultural and ecological compensation in Yongdeng County were analyzed by the adoption of contingent valuation method(CVM). [Results] (1) The farmers' ecological cognition and compensation willingness were high in Yongdeng County. (2) The farmers who had the compensate willingness accounted for 87.76% of the total; the average acceptable agricultural ecological compensation payment level was up to 52.11 yuan per person every year. (3) Issues that influence the farmers' payment willingness for the agricultural ecological compensation ranked as followings: eduction >per capita annual net income >the importance of the ecological environment >the influence degree to oneself >the out-working days >environmental awareness >whether rehabilitate or not >age >location. [Conclusion] Farmers have strong payment willingness for the agricultural and ecological compensation in Yongdeng County, and their payment levels are associated with their actual situation and are influenced obviously by their personal cognition and per capita income.

Abstract:[Objective] The impact degree of water quality preservation of the middle line of South-to-North Water Transfer project on fishery was discussed to provide a scientific basis for the fishery restructuring of Ankang City, Shaanx Province. [Methods] After reviewing related literatures and investigating into the fishery status, the factors that might limit the development of fisheries in Ankang City were listed and analyzed. [Results] Water quality protection might eventually has positive impact on fisheries development, but at present and in a short term, water quality protection is the limiting factor in terms of annual output value, breeding technology choices, consumers choice and so on. Annual revenue of filter-feeding fish farming is only 10% of the feeding fish farming. Fish farming restructuring leads to the significant drop off of fishery revenue in Ankang City. [Conclusion] To promote the well-being sustainable development of the fisheries industry in the city, measures of government propaganda, scientific guidance and supportive policy should be taken.

Abstract:[Objective] By exploring the link between carbon emission of agricultural land utilization and economic development in Shandong Province from 2000 to 2012, theoretical reference to carbon emission reduction and low-carbon economy development was provided to facilitate the formulation of agricultural policy. [Methods] From the input perspective of agricultural land utilization, applying carbon emission calculation model and decoupling elasticity method, this article calculated the carbon emissions of agricultural land utilization in 17 prefecture-level cities of Shandong Province from 2000 to 2012, and demonstrated the decoupling relationship between economic development and the carbon emissions on agricultural land utilization. Decoupling were classified into different types, upon which, the association evolvement of carbon emission and economic development was elucidated. [Results] (1) Carbon emissions had grown significantly in Shandong Province during 2000 to 2012. It was 7.12 million tons in 2000, and it was 8.39 million tons 12 years later, with an average annual increase of 97,700 tons. Weifang City contributed the most, while Laiwu City was the least. (2) There was a significant spatial differences in carbon intensity of agricultural land utilization in Shandong Province, with a spatial pattern of high in the east and low in the west. (3) Decoupling was prevailed widely by strong decoupling, though both strong and weak decoupling existed. (4) Decoupling was obvious spatially distributed. Of which strong decoupling was common, and weak decoupling mainly was concentrated in the Southwest. [Conclusion] The decoupling elasticity between agricultural land utilization emissions and economic development was reasonable to some extent in Shandong Province, but government still needs to increase the investment in science and technology for agricultural land utilization, and to make a reasonable assignment of material inputs for agricultural use.

Abstract:[Objective] Based on the land use survey data and the associated socio-economic data from 1996 to 2011, the changes of cultivated land were analyzed in Hu'nan Province. [Methods] According to the regional characteristics in the study area, 14 indices, including total population, GDP, agricultural mechanization level, and so on, were selected to elucidate the driving forces of the cultivated land changes using the main reason method. The changing trend of these cultivated lands are predicted using the GM(1,1) model. [Results] From 1996 to 2011, the cultivated land area per person of Hu'nan Province decreased from 0.0669 hm² to 0.0580 hm². The cultivated land changed differently in different regions. The driving forces of farmland changes in Hu'nan Province had issues of the social development, the advancement of agricultural production capacity, people's living standards, and the increase of population. The prediction results showed that the cultivated land area in Hu'nan Province will decrease from 2014 to 2020. [Conclusion] Therefore, local government is required to pay extensive attention and take effective measures to protect the cultivated land, as well as to promote regional food security and to ensure the development sustainable.

Abstract:[Objective] The soil physical and chemical properties of Caragana Nebkhas were analyzed in different slope position and slope direction at the he Bashang area of Hebei Province in order to keep the slope eco-environment stabile . [Methods] Investigation data of 638 nebkhass and assay data of 86 soil samples were analyzed by geo-statistics. [Results] From the top to the foot of the investigated hills, contents of coarse sand, medium sand and fine sand and pH value gradually decreased, whereas, contents of clay, silt, organic matter, total N and total P showed an increased trend. Soil particle composition was different for slope wind exposure, the contents of coarse sand, medium sand and fine sand in the windward slope of nebkhas were greater than the corresponding values in the leeward slope; Comparatively, contents of very fine sand and silt were less than that in the leeward slope. Soil nutrients(organic matter, total N and total P content) in the foot of windward slope were greater than that in the foot of leeward slope; However, in the middle and top of the windward slope were less than the corresponding values of the leeward slope. pH value had a reverse trend. [Conclusion] Soil properties of nabkhas are different in different slope positions and directions resulted from wind-involved pedogenesis.

Abstract:[Objective] The distribution and charcteristics of freeze-thaw erosion in Heilongjiang Province were explored to provide basis for sustainable development of agriculture in black soil area. [Methods] On the basis of investigation and analysis of influence factors of the freezing and thawing erosion of Heilongjiang Province, the distribution of freeze-thaw erosion was determined by method of analytic hierarchy process(AHP) and by referring other relevant research. [Results] The scope of freeze-thaw erosion is in 131°-122°E, 53°-48°N in Heilongjiang Province. The erosion area is 3.29×10⁴ km², covering 11.98% of the total area of the province. Among them, areas of mild erosion, moderate erosion, strong erosion and extremely strong erosion accounted for 21.78%, 42.32%, 23.788% and 12.12%, respectively. Erosion intensity decrease from north to south. [Conclusion] Freeze-thaw erosion distribute widely and had regional erosive intensity in Heilongjiang Province. The intensities of erosion are mainly moderate and mild.

Abstract:[Objective] Degradation characteristics of urban wetland of Tianjin City and its driving factors were recognized and their correlation were analyzed to impulse the protection and recovery of wetlands. [Methods] Single factor correlation analysis, multiple stepwise linear regression and typical correlation analysis were used. [Results] The results showed that the increase of population and the rapid development of urban economy were the main artificial factors of wetland degradation, the reduction of water resources resulted from them directly caused wetland degradation. Agricultural population and per capita water resources were main impact factors of coastal wetland. Annual rainfall and sewage were the main influence factors of wetland water quality. Population density was the main impact factors of the wetland biodiversity. [Conclusion] Both natural factors and artificial factors affected the health of wetland. Water shortages, reclamation and construction projects were the main reasons of wetlands degradation in Tianjin City; Meanwhile, aquaculture, rice cultivation and artificial construction were the main factors of transformation of natural wetland to artificial wetland; Sewage and fertilizer use were the main factors for the degradation of wetland function.

Abstract:[Objective] The decoupling evolution of the construction of the land and economic development in Anhui Province was analyzed to provide theoretical basis for implement differentiation of land policy in Anhui Province. [Methods] First, time-series data were used to explore the evolution of decoupling between the cultivated land occupied by construction and economic development of Anhui Province in 2002 to 2013. Then, regionalization of 16 cities was conducted in Anhui Province according to their decoupling coefficients. Then a detailed analysis of the decoupling characteristics of different regions was made and the corresponding causes were given. [Results] Decoupled state of the cultivated land occupied by construction and the economic development in Anhui Province fluctuated over time. The decoupling between agricultural economic development and the cultivated land occupied by construction belonged stronger decoupling type. The situation of decoupling between non-farm economy and the cultivated land occupied by construction was not optimistic, it got slight improvement in 2005-2007, but rebounded from 2008 on. There was obvious regional differences in decoupling between the cultivated land occupied by construction and the economic development. And there was a strong correspondence between the distribution of decoupling type and regional industrial division. [Conclusion] The government should strengthen the supervision of the construction approval of the cultivated land occupation, and other measures as to increase the support for modern agriculture, to improve the efficiency and productivity of arable land, and to actively promote industrial restructuring and the construction of the main functional areas. All these measures are helpful to achieve the strong decoupling between economic development and the cultivated land occupation by construction.

Abstract:[Objective] The research progress of carbon cycling in domestic and abroad was reviewed to provide bases for the ecological restoration of degraded land and the environmental protection. [Methods] The paper summarized the main approaches of soil organic carbon cycling, including laboratory culture method, isotope tracer technique, modeling and computer simulation, etc., and their characteristics and existing problems were elucidated from several aspects. The mechanism of soil organic carbon cycle and the main factors affecting soil organic carbon cycle were analyzed. [Results] There are big differences between the estimation method, data base, results of soil organic carbon pool and model of soil organic carbon cycle, which often bring certain difficulties to study soil organic carbon cycle research. Changes in land use and land cover are the immediate anthropogenic factor, which affect terrestrial soil organic carbon changes and recycling. [Conclusion] In the future, we should pay attention to role of land use and land cover in soil carbon cycle and the status. And we need to set up model of soil carbon cycle for China's national conditions. The future soil carbon cycle research should explore the standard, high precision of organic carbon storage estimation method.

Abstract:[Objective] Through exploring the framework of collapsed gully erosion risk assessment, to provide a scientific basis for prevention planning and staging control of collapse gully erosion in the South China. [Methods] The concept and methods of risk assessment, in combination with the research progress on the developing process of collapsed gully erosion were reviewed. Methods of risk assessment process was put forward with reference to the assessments of risk-liable ecological environment and geological disaster. [Results] Results in this paper included defining the connotation of risk of collapsed gully erosion, proposing the risk assessment method of collapsed gully erosion, establishing the risk assessment index system of collapsed gully erosion, and putting forward the risk assessment procedures of collapsed gully erosion. [Conclusion] Risk assessment provided a new idea and method for the study on collapse gully erosion and soil erosion.

Abstract:[Objective] Nebkhas, a kind of dune that is commonly distributed in arid desert areas. In this article, its forming process, morphological characteristics, ecological effects and environmental evolution were reviewed and summarized to provide knowledges for the research of its ecological mechanism and the ecological stabilization. [Method] Literatures were reviewed and summarized with regard to the development process and the formation mechanism of the nabkhas in the arid desert region. [Results] The formation and development of nebkhas, the morphology, spatial distribution, sediment characteristics were reviewed. And various ecological effects of nebkhas and the related regional environmental evolution were described. The trend of nebkhas research was prospected. [Conclusion] Research of nebkhas evolution in arid land was expected to help us to understand more about the interior relationship between the process of regional eco-environmental change and global climate change in the future.