Abstract:A large number of the collapse, landslides and debris flows at different scales triggered by Wenchuan Earthquake are great sources of sediment for the river in earthquake area. To study effects of earthquake erosion on sediment transportation after Wenchuan Earthquake, field investigation and measurements were performed for the landslides and avalanches on the Mianyuan River. Based on the data for the past 5 years, 1.15×10⁸ m³ deposits were produced during this earthquake equivalent to about 100 times of the amount of soil erosion for a normal year, most of which were deposited and accumulated in the tributary ditches or channels. It indicated that only a few part of fine sediments were transported to the downstream as suspended load, as the dominant coarse particles were over the transportation capacity of the rivers without distinct change of hydrological conditions during the last five years. Although earthquake erosion resulted in a huge amount of sediment in the upstream Mianyuan River, the annual sediment discharge had no obvious difference from that before the earthquake, which showed that the effects of sediment from earthquake erosion on sediment transportation in the lower Mianyuan and Tuojiang Rivers are limited in the short term.

Abstract:Taking the typical urban soil of Tongchuan City of Shaanxi Province as the research object, the morphological distribution characteristics, environmental migration and potential ecological risk of anthropic elements Pb, Cu, Cr, Zn were investigated by the modified BCR(the European Community Bureau of Reference) sequential extraction method and Hakanson potential ecological index method, respectively. The desorption characteristics and leaching kinetics of Pb, Cu, Cr, Zn by EDTA, DTPA and Vc were conducted with batch experiments for 24 h at 25℃. The results showed that the pollution from heavy metals Pb, Cu, Cr, Zn in soil of Tongchuan City industrial park was serious, and potential ecological risk was strong. The trend of heavy metal Zn and Cu mobility was high. The leaching kinetics experiment indicated that there were the similar processes in leaching and desorption of Pb, Cu, Cr, Zn by organic acid EDTA, DTPA and Vc, however, the leaching speed and desorption quantity were different with different acid. The sum of Pb, Cu, Cr, Zn in soil had a exponential function with their corresponding leaching and desorption concentrations by APCAs EDTA and DTPA, but had the linear function with those of Vc. The results would further infer that the mechanisms of leaching kinetic were different between EDTA, DTPA and Vc.

Abstract:The effects of grass residue of sophora alopecuroides, seeds residue of sophora alopecuroides and licorice residue on soil physical-chemical properties, microbial quantities and enzyme activities in abandoned salkaline land in arid area of Ningxia Hui Autonomous Region were studied. The results showed that the soil bulk density, pH value and total salt content after applied with residue were lower than not applied with residue(CK), especially the total salt content and pH value decreased significantly. Soil organic matter, total phosphorus, available nitrogen, available phosphorus and available potassium increased significantly, and there existed significant difference in available nitrogen, available phosphorus and available potassium between different treatments, and also, the ability to provide available potassium and available nitrogen of seeds residue of sophora alopecuroides is significantly higher than that of grass residue of sophora alopecuroides and licorice residue, the ability to provide available phosphorus of licorice residue is significantly higher than that of grass residue of sophora alopecuroides and seed residue of sophora alopecuroides. After the application of waste residue, the number of soil bacteria, fungi and actinomycetes were significantly higher than that of CK. The activity of alkaline phosphatase increased significantly by application of seed residue of sophora alopecuroides and licorice residue, and the activity of soil catalase increased significantly by application of seeds residue of sophora alopecuroides. Soil organic matter, available nitrogen, available phosphorus and available potassium showed a significant correlation with microbial quantities and enzyme activities, which were promoted each other.

Abstract:Taking the field experiment, the change of gravel-mulched field soil moisture of different planting years within three days after the precipitation pulses of 7.1 and 1.9 mm was analyzed quantitatively. The results showed that soil moisture content of gravel-mulched field had a positive exponential relationship with time, and the correlation coefficient ranges from 0.9381 to 0.9873, the increase of soil moisture content showed an order as following:new gravel-mulched field >middle gravel-mulched field >old gravel-mulched field. When precipitation pulses was 7.1 mm, soil moisture content of new gravel-mulched field, middle gravel-mulched field and old gravel-mulched field increased by 42.3%, 27.4% and 23.2% respectively on the third day after rainfall, and the average moisture content increased by 52.7%, 52.7% and 45.5% respectively than that of bare land. When precipitation pulses was 1.9 mm, the soil moisture content increased by 22.6%, 27.1% and 7.6% respectively, and the average moisture content increased by 171.8%, 156.4%, and 110.3% respectively than that of bare land. When precipitation pulses was 7.1 mm and 1.9 mm, the moisture content in gravel-mulched field started to decrease in 7 days and 5 days after precipitation respectively. Both of two rainfall showed that the average soil moisture content was that new gravel-mulched field >middle gravel-mulched field >old gravel-mulched field >bare field. Compared with the bare land, gravel-mulched field can improve the utilization efficiency of the rainwater.

Abstract:In order to find the effect of soil macropore distribution on overland flow and solute transport, artificial rainfall experients were carried out. The results showed that compared to original macropore soil tank, in the increased density macropore soil tank with the surface porosity of 57% and the volume porosity of 0.285%, the increasing extents of the soil water content of every layer were less, the velocity of overland flow was smaller and the runoff amount of surface was less, the runoff amount of underflow appears earlier and was more in increasing-density macropore soil tank. The results also indicated that in increased density macropore soil tank, the concentration of Br^-, NH₄⁺ and NO₃^- in surface runoff were lower, the concentrations of Br^- and NO₃^- in the underflow runoff were higher in earlier stage of the groundwater outflow, but the concentration of NH₄⁺ was lower and the increasing extend was smaller.

Abstract:Freezing-thawing cycles have important effects on physical and chemical properties of soil, which affect adsorption and desorption characteristics of phosphorus in soil. A laboratory experiment was conducted to determine the effects of freezing-thawing on phosphorus adsorption and desorption characteristic of black soil. The results showed that, the trend of phosphorus adsorption in freezing-thawing treatment was that all the phosphorus adsorption capacity increased with the increasing of phosphorus concentration, and there was obvious turning point when the exogenous phosphorus concentration was 120 mg/L. Compared to the no freezing-thawing treatment samples, black soil adsorbed more phosphorus and had higher adsorption rate after freezing-thawing cycles. At low exogenous phosphorus concentration, freezing-thawing cycles have relatively large influence on phosphorus adsorption quantity, on the contrary, at high exogenous phosphorus concentration, the influence reduced. In the condition of freezing-thawing, phosphorus adsorption curves could be well fitted by Langmuir equation. Under the condition of successive freezing-thawing cycles, maximum adsorption capacity P_max, combining ability between soil and phosphorus and phosphorus adsorption maximum buffer capacity has the same trend of gradual increase.

Abstract:The adsorption-desorption behavior of Hg(Ⅱ) in brown soil was studied to find the difference of the behavior with and without organic matter(OM). The results showed that OM has a great influence on the adsorption-desorption of mercury in brown soil. Without OM, brown soil adsorption rate for Hg(Ⅱ) dropped from 95.62%~93.18% to 62.8%~56.70%, desorption rate rose from 2.39%~7.47% to 2.65%~11.23%. Freundlich equation, Langmuir equation, Henry model and Temkin equation can well describe the isothermal adsorption on mercury process in brown soil with and without OM. The matching result of dynamics equation showed, brown soil adsorption-desorption rate for Hg(Ⅱ) was reduced after OM was removed, elovich equation and double constant equation were optimum, it reached highly significant positive correlation(R>0.708).

Abstract:A pot experiment was conducted to study the effects of soil water stress in whole growth period on fine root morphology and function of Reaumuria soongorica. The results were as followings:(1) The diameter and volume decreased with the increasing of soil water stress, on the contrary, with the increasing of soil water stress, root length, specific root length(SRL), surface area and specific root surface area(SRA) increased, which indicated that under soil water stress conditions, fine root of R. soongorica seedling could adapt stress by the increasing root length, SRL, surface area and SRA and reducing the diameter and volume. The diameter increased with the rise of root order, root length and SRL increased, while SRA firstly increased and then reduced.(2) Total C content decreased with the increasing of soil water stress, while with soil water stress increasing total N content first decreased significantly and then showed the increasing tendency, which indicated that respiration of fine roots of R. soongorica seedling was restrained under medium soil water condition. Total C content increased with the rise of root order, total N content decreased, which indicated that the low roots have stronger respiration and metabolic activity.(3) The root length had a highly significant positive correlation with C content. The diameter had a significant positive correlation with C content. The SRL was negatively correlated with C content.

Abstract:The formula of bioactive fertilizer and its effects on the physical and chemical properties of soil and economic benefits of maize was studied using field test in the Hexi Corridor light irrigation desert soil of Gansu Province. The results showed that the optimum proportion of biological active fertilizer was as follows:functional improving soil agent was 0.12 tons, bacterial manure was 0.09 tons, and biological active fertilizer was 1.20 tons. There was a positive correlation between fertilization quantity and soil porosity, aggregate structure, water contents, saturated water content, botanical traits, the economic characters and yields of maize. In addition, There was a negative correlatation between fertilization quantity and bulk density, pH value. According to regression analysis, the optimal economical application rate was 1.8 t/hm², and the theoretical yield was 6597.24 kg/hm².

Abstract:Soil and water conservation benefits of different manage measures in different years were analyzed by applying the method of comparative analysis and monitoring the surface runoff of the different management stations of the Huangyuan quarry runoff plots with two consecutive years. The results sowed soil and water conservation benefits of different types of slopes, different control measures and different vegetation coverage varied considerably in the early treatment in quarry. The runoff plot with slope of 25°using the ecological bags reduced soil and water loss significantly. The main reason of soil and water loss was soil porosity of the loose media slopes when the vegetation coverage was less than 15%. Rainfall and rainfall intensity became the most important reason when the rate of vegetation coverage was more than 60%.

Abstract:Based on the long time monitoring data, taking the two typical land-use types(vegetable land and forest) in the plain of Taihu Lake basin as an example, the correlation between soil moisture and precipitation was analyzed with the time series method. The results showed that:(1) Precipitation time series was temporally uncorrelated, soil moisture contents in different depths, however, were self-correlation series.(2) There was a relationship existed between soil moisture and precipitation, the related time was in the range of 1~8 days due to the influence of seasons, soil depths and land-use types.(3) The seasonal change of the related time in forest can be described as:summer and autumn >spring >winter. With the increase of soil depth, the relationship between soil moisture and precipitation showed a trend of decrease in summer and autumn. The correlation in winter and spring, however, were the opposite. In conclusion, the effective time of precipitation on soil moisture was longer in forest than in vegetable land, and the regularity of the relationship between soil moisture and precipitation in forest was much better than that in the vegetable land.

Abstract:Concentration and chemical speciation of heavy metals(Zn, Cu, Pb, Ni) in soil and tea collected from tea garden in South Anhui Province were analyzed by Tessier's sequential extraction method. Bioavailability of heavy metals were assessed by the ratio of active state to total amount. Results showed that concentrations of Zn, Cu, Pb and Ni in the tea garden soils were lower than that of the national secondary standard. Cu, Pb, Ni concentrations exceed soil background value of South Anhui Province, which indicated there were obvious enrichment phenomenon. Zn, Cu, Ni mainly existed as residual speciation, accounted for 72.55%, 90.00%, 81.79% of the total respectively; Pb existed in iron and manganese oxides, accounted for 70.09%; The active speciation(bioavailability) ratio of Zn, Cu, Pb, Ni were 5.04%, 1.51%, 0.97%, 0.23%, respectively. Active speciation of heavy metal in soil showed significantly positive correlation with the concentration of heavy metal in tea. Concentration of heavy metals is in the range of limited value and is safe in tea of South Anhui Province.

Abstract:Based on the Morlet wavelet transform and R/S method, the evolution features of the 55 years annual withered runoff in Guilin hydrometric station of Lijing River was analyzed. The results showed that the lowest runoff have primary period of 12 years and 30 years and subperiod of 4 years and 6 years, which represented the period change. The annual lowest runoff showed the tendency of dropping off and the 6, 12, 30 years shared the same tendency. 4 years showed the tendency of increasing. Meanwhile, P-Ⅲ was used to calculate the minimum frequency of every period. The frequency of the lowest runoff(8.09 m³/s) for 4 years was 35%~40%, the frequency of lowest runoff(5.3 m³/s) for 6 years was 10%~15%, the frequency of lowest runoff 10.2 m³/s for 12 years was 55%~60%, and the frequency of lowest runoff(3.8 m³/s) for 3 years was 1%~5%.

Abstract:Cultivation experiments were conducted to evaluate the efficiency of four phosphate fertilizers including DAP(diammonium phosphate), MPP(mono potassium phosphate), SSP(calcium superphosphate) and TCP(tricalcium phosphate) as stabilizing agents of Cd in contaminated soils. Five molar ratios of P/Cd were tested:0, 2:3, 3:2, 2:1, 4:1. The toxicity characteristic leaching procedure(TCLP) and sequential extraction methods were used to evaluate the efficiency. The results showed that four phosphate fertilizers all could effectively reduce soil TCLP extractable Cd concentrations with the stabilization efficiency as MPP >DAP >SSP >TCP. The most effective dose with greatest Cd reduction was 4:1 of P:Cd ratio, the most reduction was 49%; Additions of all tested phosphate fertilizers can greatly improve the soil available phosphorus concentration with the concentration as MPP >DAP >SSP >TCP at the same level of P, TCLP extractable Cd concentration were significantly negatively correlated with soil available phosphorus concentration(R=-0.903^**); The decline of exchangeable Cd concentrations in DAP, MPP, SSP, and TCP treated soils was respectively 23.75%, 39.06%, 16.60% and 18.36%, but increased the Cd in WSA, OX, Fe-Mn-OM and RES. It indicates that Cd in soil can be adsorbed by phosphate fertilizers, reducing the bioavailability of Cd.

Abstract:Based on the 12 months observation of the sap flow rate and environmental factors by using sap flow meter and mini weather station in Dongshanqiao Forest of Nanjing City from September 2012 to August 2013, the impact factors of the sap flow of Chinese fir sapling and its contribution to transpiration of Chinese fir forest was analyzed. Results indicated that:(1) The sap flow rate of Chinese fir sapling showed seasonal differences and the change of the sap flow rate took on a single-peak curve in different seasons. Sap flow rates in daytime were higher than those during the night.(2) The crest values of the sap flow rate in spring, summer, autumn and winter was 79.97, 105.22, 70.30, 33.19 g/h, respectively.(3) The domenant environmental factor of sap flow rate was solar radiation, the next was vapor pressure deficiency. The correlation between daily sap flow and solar radiation, air temperature, vapor pressure deficiency, soil temperature at all layers showed a significant positive correlation.(4) The models to relate the sap flow rate, daily sap flow with environmental factors were established. These models could better explain the change of the sap flow rate and daily sap flow.(5) The ratio of contribution of Chinese fir saplings sap flow throughout the year to the total transpiration of Chinese fir forest was 6.12%, and the ratio of contribution in summer was the largest.

Abstract:The branch water potential, average tree height and basal diameter of P.×Xiaozhuanica young forest were determinated based on the water controlling experiment. The results showed that there was no significant change for the branch water potential of P.×Xiaozhuanica when the soil water content was higher than 15.6%, but the branch water potential decreased rapidly when the soil water content was less than 11.03%. The young forest grew normally and the growth amount increased significantly when the soil water content was higher than(17.71±2.75)%. However, the young forest showed up severe recession characteristics, nearly stop growing, and some of the tree even dying when the soil water content was below(7.12±2.75)%. Therefore, the perfect soil water content should be(17.72±2.75)% for the rapid growth and maintaining the stability of P.×Xiaozhuanica young forest.

Abstract:The spatio-temporal heterogeneity of soil moisture in Kelan County, Northwestern Shanxi Province was studied in wasteland, Caragana korshinskii forest land and Populus simonii forest land. The soil moisture was determined for the 0-600 cm profile in April, May, June and July. Results showed that:(1) Soil moisture changed between 3.34%~17.19% with irregular variation in the layer of 0-200 cm; However, as the soil depth increased from 200 to 600 cm, the soil moisture of wasteland was increasing, the soil moisture of Caragana korshinskii forest land was decreasing gently and the soil moisture of Populus simonii. forest land decreased at first and then increased gently, respectively.(2) The profile distribution of soil moisture had a significant difference(p<0.01) within different months and different land use types.(3) The variation coefficient of soil moisture was usually in the range of 0~30%, but some individual values are over 50%, suggesting that the structure of soil moisture presented overall stability except special points.

Abstract:Using different amount of water retaining agent to pelletize Astragalus adsurgens seeds, the effects of water retaining agent on pelleted seeds germination and seedlings were studied. By pelletizing, Astragalus adsurgens seed with water retaining agent in different content level, the seedling growing trial and drought-resistant tests were studied. In the germination and seedling growth trial, compared with the control treatment, using water retaining agent at the level of 7%, 9% could significantly increase germination rate by 70% and 63.19%, and root length, root surf area increased by 19.36% and 45.26% respectively; In the drought-resistant tests, the bottom leaves of Astragalus adsurgens wilted first, the top leaves showed same symptoms when the soil was much drier. Compared with the control treatment, water retaining agent at the level of 5% and 7%, the quantity of the yellow leaves decreased by 15.58% and 22.07% respectively at 13th day after thinning seedlings; the content of soluble sugar decreased by 13.1% and 13.6% respectively with increase of water retaining agent concentration when water retaining agent was at the level of 7% and 9%; proline was decreased by 20.33%, 22.85% and 19.08% respectively at the level of 5%, 7% and 9%. The results showed that the appropriate content of water retaining agent was 7%~9% in pelletizing Astragalus adsurgens seed.

Abstract:A typical farmland-desert transitional zone in the Heihe River Basin was selected to explore soil water and heat dynamics in soil freezing-thawing processes under different landscapes. The main results were as follows:(1) Soil temperature was in response to air temperature quickly, but its amplitudes decreased with the increasing soil depth. The variation of soil temperature were ordered as:desert >farmland >shelterbelt, whereas the soil frost depth was ordered as:farmland(100 cm) >shelterbelt(80 cm) >desert(60 cm);(2) Due to the soil properties and surface cover, the soil moisture content of farmland and shelterbelt changed greatly, and the maximum occurred in early April, while soil moisture content of desert was almost invariant;(3) Changes of soil moisture laged behind that of soil temperature, soil water and temperature changes of shelter forest is slower than that of farmland;(4) Shallow groundwater level dropped during the freezing period, and rose during the thawing period, and the rise rate was greater than the drop rate. The soil freezing and thawing process could effectively reduce soil moisture evaporation and seepage by lifting subsoil moisture upward, and therefore help to conserve water in the deep soil, which has great significance to plants of the following year.

Abstract:Co-existence probability of antibiotics and heavy metals in soil environment increased with the large-scale development of feed and livestock industry. In order to analyze the effects of antibiotics and heavy metals on soil microorganism ecosystem, we studied the single or combined pollution of oxytetracycline(OTC) and cadmium(Cd) on soil respiration and enzyme activities by laboratory cultivation. The results showed that the soil respiration was inhibited firstly, and then stimulated by sole treatment of 10 mg/kg Cd, while activities of invertase, urease and phosphatase in soil were significantly inhibited during the whole process. The order of inhibiting rate for enzyme activity was invertase >phosphatase >urease. Soil respiration was significantly activated by sole treatment of OTC at concentration of 1 mg/kg, while inhibited first, then activated by OTC at concentration of 50 or 200 mg/kg. Activities of invertase and urease were inhibited but the activities of phosphatase fluctuated when oxytetracycline was solely used. The combined pollution treatments of OTC+Cd(1+10 mg/kg) as well as OTC+Cd(200+10 mg/kg) showed antagonistic action, while the treatment of OTC+Cd(50+10 mg/kg) presented synergistic action on soil respiration and the 3 kinds of enzyme activities. Soil respiration responded more sensitively than soil enzyme activity by combined pollution of OTC and Cd, with the maximum inhibition and activation rates of 98.98% and 300.82%, respectively. Effects of OTC and Cd on enzyme activities were less than that on soil respiration.

Abstract:The spatial distribution and dynamic change of main trace elements in soil were studied in the loess hilly region of Qinghai Province. The result showed that the effective trace elements Fe, Cu, Zn, B had higher variability, Mn had higher or moderate variability. In view of soil series, the effective state of trace elements in the Dark Cinnamon and the Chernozem reached the rich level(high level), while that in the irrigated soil was far below the threshold. From the view of the soil stratification, the coefficient of variation changed little. In the shrubbery forest lands, soil trace elements were lacking relatively expect available B which just reached to the rich level. However all the trace elements reached the high levels in the mix forest lands.

Abstract:In order to improve the durability and prolong the service life of the stabilized soil, the methods of curing stabilized soil in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide and in the saturated limewater were proposed based on the idea of improving the curing environment of stabilized soil. The unconfined compression strength test, dry-wet cycle test, freezing-thawing cycle test and scanning electron microscope(SEM) test were conducted to compare the two kinds of saline solution curing methods. The results showed that curing stabilized soil in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide or in the saturated limewater could improve the strength, the resistance of dry-wet circulation and freezing-thawing circulation; Considering the effect on improvement of strength and durability, curing in the mixture solution of sodium silicate, sodium sulfate and sodium hydroxide was better than curing in the saturated limewater; Microscopic structures showed that the two kinds of curing methods generated more dense gel material, increased the cohesion, reduced the porosity, and decreased the macropore of the stabilized soil.

Abstract:Based on field investigation carried on three loess high-cutting slopes in Xi'an City and combining indoor moisture content test, the influence of the slope position, slope gradient, slope direction, vegetation type and vegetation protection mode of the loess cutting slope on spatial characteristics of soil moisture was studied. The result showed that soil moisture content was greater in middle slope site than that in downhill, in downhill was greater than that in uphill; in high slope level was greater than that in low slope level; in low gradient slope was greater than that in the high gradient slope; in cloudy slope was greater than that in sunny slope; in ground vegetation was greater than that in the vertical vegetation; in the slope with grass and shrub combination mode was smaller than that in the single shrubs mode, but the growth of the former was better than the latter.

Abstract:Hydrogeological conceptual and mathematical models were established by Visual Modflow, then taking Daheng coal mining as an example to explore the impacts on groundwater level and quantity in Shuozhou City of Shanxi Province. We conducted an investigation of water level in wells within the scope of 50 km² around the mining boundary. According to the mining time of each mining district, and combining with the regional groundwater buried depth and regional stratigraphic trend, as well as the monitoring results of the well water level during various periods within the scope of investigation, a model on Daheng coal mining and verification of the accuracy of the model was constructed. The result showed that the coal mining of Daheng mine will cause the cone of depression 28.8 years after mining, which has an area of 9.5 km² and depth of 55 m. It indicated that coal mining will make the overlying aquifer drawdown and the formation of the cone of depression.

Abstract:Based on the soil erosion data from field observation and survey monitoring in 191 ministerial and provincial level projects, the main characteristics of soil erosion in point engineering and line engineering were analyzed. The results showed that two type projects soil erosion in the construction period accounted for about 90% of the total soil erosion. Line engineering soil erosion intensity(200.00 t/hm²) was greater than that of point engineering(151.37 t/hm²). Line engineering and point engineering were both in intensity and above grade of soil erosion. The quantity of soil erosion and the area in construction period of two type projects had a positive linear correlation(R_point²=0.9318, R_line²=0.9439), soil erosion modulus had a positive correlation with per unit area cut-fill volumes in both type projects(R_point²=0.9595, R_line²=0.9324) after the disturbance.

Abstract:In order to quantitatively assess ecological benefits of China grain for green project, an ecological benefits monitoring network was constructed by integrated data of China forestry zone, grain for green zone, forest ecology station and DEM data interconnecting with spatial analysis of GIS firstly. The network included 130 grain for green ecological monitoring zones and 157 ecological stations, in which 79 were established and the remaining 78 stations were in planning. Secondly, accuracy assessment of this network was done based on county-level data of grain for green project, and the total accuracy was 96.2%. Furthermore, the main focuses of different ecological benefits monitoring of grain for green project were pointed out. The network can implement forest ecological inventory in the area of China grain for green project, and provide data and decision support for the ecological benefit assess of the project.

Abstract:Jianghuai watershed area was selected as the research object. The vegetation index, dryness index, humidity component and surface temperature were selected to express green degrees, dryness, humidity and heat indexes. Comprehensive ecological quality evaluation index(CEQEI) was built in combination with principal component analysis to evaluate ecological environment condition comprehensively in the study area. The results showed that the average of CEQEI growth from 0.357 in 2000 to 0.529 in 2005, and it continued to grow to 0.615 in 2010. It indicated that the whole situation of ecological environment improved continually, and CEQEI could be used to evaluate the environmental conditions systematically in the study area.

Abstract:Eighteen typical wind power generation projects and photovoltaic power generation projects in Hexi Corridor were taken as the object. We comparatively studied the influence range and degree of different partitions under prevented and controlled, and systemly analyzed the characteristics of soil and water loss in process under construction. The conclusions are as follows:the proportion of disturbed surface area in all partitions under prevented and controlled was in the order of:road area(63.33%) >fan zone(21.85%, photoelectic cell board area) >integrated circuit area(10.47%) >construction camp area(2.93%) >monitoring center area(1.42%), photoelectic cell board area(68.72%) >road area(27.17%) >othet area(1.77%) >management area(1.18%) >construction camp area(1.15%); the proportion of excavated amount in all partitions under prevented and controlled was in the order of:fan zone(77.38%) >road area(13.76%) >integrated circuit area(6.39%) >monitoring center area(2.16%) >construction camp area(0.32%), photoelectic cell board area(65.09%) >road area(30.45%) >anagement area(1.82%) >construction camp area(1.48%) >other area(1.15%); so the road area and the fan zone were the most serious zone of disturbed engineering construction and those zones were also the key link of soil and water loss in the building projects of footing excavation, transport, and filling. The value of water and soil loss impact index in wind power generation projects and photovoltaic power generation projects construction of the Gobi desert were 0.314 and 0.419, with unit capacity calculation, the value of soil and water loss impact index of photovoltaic power generation projects was significantly higher than that of wind power generation projects.

Abstract:The agricultural resources of Xiannangou watershed were not used efficiently, the system of agricultural practices grow inconsistently with agricultural resources, and the chain network structure of ecological agricultural system with commodity(EASC) was incomplete. In order to solve these problems, Three phases and five scenarios of the possible development path of ecological agriculture with commodity(EAC) was set on the principle of clean development mechanism(CDM), and further efforts were made to optimize the EASC. The results showed that the economic benefits of each phase had been improved and the land use structure had also been significantly changed after the optimized of EASC. The economic benefits of phase Ⅰ to Ⅲ had been improved by 34.4%, 53.0~55.2%, and 72.8~73.7%, respectively comparing with the actual state. On the principle of CDM, the coupling of agricultural economic system and agricultural ecosystem, a better land use structure(agriculture:forestry:animal husbandry=1:12.6:4.4) was produced, implying that the proportion of forestry increased compared to phase Ⅰ and phase Ⅱ.The development progress of EASC with the development trend of the actual state→the modified chain network construction of EASC→the optimization of agricultural economic system and agricultural ecosystem coupling has its historical inevitability.

Abstract:Based on the relatively low density sampling data from China's second national soil survey in northeast China, we compared the erformance of four spatial interpolation methods, inverse distance weighting(IDW), radial basis function(RBF), ordinary Kriging(OK) and regression Kriging(RK), under seven sample sizes in generating digital map of soil total nitrogen content at large scale based on the software ArcGIS and GS⁺. Results showed that soil total nitrogen content was in the range of 0.08~21.48 g/kg with great variability. The Nugget effect showed a medium strong spatial autocorrelation of soil total nitrogen content in the region, and the range of spatial autocorrelation was greater than research on smaller scale in the same region; Spatial variability of soil total nitrogen content changed when sample size was less than 171, in this case, spatial structure and accuracy test of interpolation were unbelievable. All of the four compared methods predicted the spatial pattern of soil total nitrogen content well with decreasing from northeast to southwest. The accuracy of interpolation changed in the order of RK >OK >RBF >IDW. With incorporated auxiliary variables of soil cation exchange capacity, soil depth, soil pH value and annual mean air temperature, the RK improved accuracy by 19.40%, 18.50% and 16.15% than IDW, RBF and OK, respectively. It also exhibited more details on soil total nitrogen content variation at the areas with sparse sample points. It suggested that the RK is a potential spatial interpolation method to improve the soil mapping accuracy at large area with low density sample sites.

Abstract:Relief amplitude is used as one of the terrain factors to describe the macroscopic topographic change, which can be used as one of the topographic indexes for evaluation of regional soil and water loss. The Loess Plateau, Sichuan basin, Hengduan mountainous region, Southeast hills, Shandong hills and northeast regions 6 typical samples were selected based on dynamic effect model(DEM) of 1000 resolution of China, relief amplitude was extracted with the 6 methods of local elevation range, local standard deviation, the ratio of surface area and the projected area, RUGN, the vector method and relief degree of land surface(RDLS). The results of extraction were analyzed, and then the amounts of information were calculated. The results showed that local standard deviation and local elevation range were the two better methods, and different regions have different suitability.

Abstract:The purpose of this paper was to evaluate the salt field reclamation feasibility and analyze the limiting factors in coastal area in Jiangsu Province, and to provides support for spatial selection and technology design for salt field reclamation, and to increase the sources and the ways of arable land supplement and ensure the effective implementation of the coastal development strategy. On the basis of field survey, taking coastal waste salt field remediation for arable land as evaluation objective, the construction of the evaluation index system was based on natural conditions suitability, feasibility of economic support, implementation of the project operability addition of overall efficiency and ecological sensitivity. Meanwhile, the study area of salt field reclamation was divided into four suitablity types, and the limiting factors of salt field reclamation were determined. The results showed that, in the next few years, the areas of suitable remediation salt fields are mainly distributed in the southeastern of Lianyun district, Guanxi saltern of Guanyun County, the south of the Guanhe River, Sheyang saltern in the South Bank of Sheyang River, the eastern part of Dongtai City and the southeastern part of Rudong County. The main limiting factors of salt field reclamation feasibility in Jiangsu Province are government receipt, the distance from coastline and relative altitude.

Abstract:Based on the technologies of 3S(RS, GPS and GIS) and universal soil loss equation(RUSLE), soil erosion and its spatial distribution in Yulin City in 2001 and 2010 was calculated and analyzed. The results showed that mean soil erosion rate was 4411 t/(km²·a) and annual average sediment yield was 1.93×10⁸ t in Yulin City in 2001, mean soil erosion rate was 6237 t/(km²·a) and annual average sediment yield was 2.72×10⁸t in 2010. During the period from 2001 to 2010, there was an obvious spatial difference between various regions in the soil erosion change, the soil erosion intensity changed from medium to high in Fugu, Shenmu, Yuyang, Hengshan, Jingbian, Jiaxian and Zizhou County(District), which indicated that soil condition deteriorated continuously. While, the soil erosion intensity changed from high to low in Dingbian, Mizhi, Wubu, Suide and Qingjian Counties, showing soil and water loss was effectively controlled.

Abstract:The feasibility of information extraction for the degradation of salinized soil by means of RS in the Yellow River delta region was obtained through analyzing the spectral characteristics of TM & ETM data from the Landsat series satellites and constructing the saline information model. The results showed a deteriorating tendency of severe soil salinization in the past 10 years, and the trend in 2007 compared to 2003 was more severe than that in 2011 compared to 2007. However, the increasing trend slowed down in 2011, but it was still heavier than that in 2003. The degradation of salinized soil was obvious, that meant soil salinization becoming more serious. All the land degradation was closely related to human activities, including ignoring the constant protection and rational utilization of land in Gudong oilfield construction, the construction of coastal areas baysalt brine and aquaculture ponds, mild salinization area increased and the excavation of artificial irrigation area, the introduction of the Yellow River runoff and water conservancy engineering measures. The influence of human activities on soil salinization has side effects of both positive and negative.

Abstract:The operation mode of reservoir is one of the factors that can be controlled by human, and it will cause hydrology and heat changes in the river. The water temperature characteristics of different operation methods were analyzed based on the measured data and simulation results by taking two different types of regulation reservoirs as an example. The result indicated that when multi-year regulating reservoir running on a high-water level in the flood season of the dry year, there would be a stable three-layer of vertical water temperature phenomenon and small changes on the bottom cryosphere, also an obviously flat phenomenon of the discharged water temperature thoroughly changed the sine distribution rule of natural water varying with the season. The vertical temperature of reservoir was mixed distribution in the dry season and dual stratification distribution in the flood season without cryosphere in bottom when the reservoir running on a lower water level in the average year. Meanwhile, the discharged water had little impact on the down-stream river water temperature. Moreover, the effects on water temperature are between the former two while the reservoir running on a middle-water level of the flood year. As to the multi-year regulating reservoir, there were little differences on water temperature distribution in the flood year or the average year, but an obviously delay of the discharged water temperature in the warming up time of the dry year. Therefore, different operation modes should be taken into consideration and the negative effect of cold water can be avoided by setting the reservoir on an appropriate operation mode.

Abstract:Water flow characteristics and distribution of polluted belt of chemical oxygen demand(COD) at estuary of Fenhe River into the Yellow River were simulated to discuss its migration and transformation law. According to the measured elevation values of section 59-60, interpolation method was used to supplement the terrain data and unstructured grid was used to divide the terrain. A two-dimensional hydrodynamic and water quality model was established, and alternating direction implicit method(ADI) was adopted to give an integral of the flow's continuity and momentum conservation equation. The result showed a high match between the simulation and the actual measurement. In addition, the velocity distribution and contaminant concentration distribution were given by simulation of COD in 50%, 75%, 90% hydrologic year types in the estuary of Fenhe River into the Yellow River. Moreover, as the increase of hydrologic frequency years, the area of river mouth beach formed was reduced, and the COD value reached the standard over the distance of 2.35, 3.00, 4.20 km.

Abstract:On the basis of defining the meaning of rural land consolidation project achivements, the evaluation index system was constructed from decision-making achivements, implementation achivements and operation achivements, and the entropy-weighted extension matter-element model for evaluation on rural land consolidation project achivements was established, then an empirical analysis was conducted on the projects of Suzhou City. Results showed that:(1) The achivements levels of rural land consolidation project in Suzhou City are quite different. Two projects' achivements levels are "good", that of three projects are close to "good", and one project is close to "poor".(2) The major obstacle factors of rural land consolidation project achivements include the raising rate of vegetation coverage, the raising amount of grain productive capacity, the increasing amount of annual income for farmland, the raising rate of land use, the increasing rate of the irrigated area, the density of shelter forest network, the increasing rate of mechanized farming area, and so on.(3) The rural land consolidation project achivements could be continuously improved by strengthening the rural land consolidation project management, establishing rural land consolidation mode based on the landscape ecology, sounding final-period management and maintenance mechanism in the rural land consolidation project, reasonable implementation farmland management in larger scale, readjustment of agricultural structures, and so forth.

Abstract:Based on daily rainfall data of nearly 40 years over 32 meteorological stations in Heilongjiang Province, half-month rainfall erosivity was calculated, and basic database was built for GIS. The Kriging interpolation algorithm was used to analyze the spatial distribution variation of half-month rainfall erosivity and the trend analysis method was used to analyze their temporal dynamics.The results showed that:(1) The average half-month rainfall erosivity of each meteorological station from the second half of April to the first half of October presented a single-peak curve which increased gradually at first, and reached the maximum value in July and August, then descended gradually.(2) The half-month rainfall erosivity exhibited great spatial differences especially in July and August, and half-month rainfall erosivity of the second half of July got to the annual maximum value.(3) Over the entire province, the minimum value of average ten-year rainfall erosivity occurred in 1972-1981, and the maximum value was in 1982-1991, compared with that in 1982-1991, the average ten-year rainfall erosivity kept decrease in 1992-2001 and 2002-2011.(4) The average rainfall erosivity nearly 40 years had a strong spatial correlation. Average annual rainfall erosivity showed a parabolic distribution trends which direction was from west to east and from north to south within the scope of the province. It presented an obvious decreasing trend northward from Yilihuli Mountains, from east to west in Song-Nen Plain, from west to east in Sanjiang Plain, from south to north in Xiaoxing'an Mountains, and from north to south in Zhangguangcai Mountains and Laoye Mountains.

Abstract:Land use balance degree in Chongqing balancing urban and rural comprehensive development pilot area in 2012 was estimated. The driving mechanism of balanced development of regional land use was analyzed, and the regional land use potential were estimated quantitatively. The results showed that:(1) Highly balanced development and more balanced development class counties were mainly located in economic circle within one hour driving distance from the urban center. In the five imbalanced development cities, Xiushan and Youyang County are located in southeastern part, Chengkou, Wushan, and Wuxi County in northeast region.(2) The twelve highly balanced counties showed the trend of relatively harmonious and balanced development in three systems. The three kinds of efficiency drive were in all the seventeen more balanced counties, the four basic balance and the five disorders develop counties all belong to eco-efficiency-driven.(3) Following the land use potential model:The land use potential of Wushan and other two counties are defined as greatest, and Xiushan and Chengkou County are defined as greater, Shizhu and other three counties are defined as great; The results showed that the counties have potential to develop; Relatively the land use potential of Shapingba and other sixteen counties were defined as poor, which means it is hard to develop under the current technical level unless investing huge economic cost; However the land use potential of Jiangbei and other eleven counties demonstrated that there was almost no potential to develop in this counties.

Abstract:Based on gray relational analysis, the driving forces of urban expansion in Wuhan City was studied using statistical data during 2003-2012. Result showed that the improvement of traffic conditions, the growth of people's income and population were the main driving forces of construction land expansion in Wuhan City during the past decade. The driving forces showed certain time scale dependence:the two factors, traffic and population, showed more significant effect on promoting rapid expansion in short-term, while the effect of income was mainly reflected in long-term. The increase of macro economy and the adjustment of industrial structure improved the efficiency and intensive level of land use.

Abstract:The indicators system of water resources pressure were was developed according to water resources quantity pressure, water resources economic pressure and water environmental pressure. Then, this indicator system was used for calculating water resources pressure index in Heihe River from 2000 to 2010. Results showed that the water resource pressure index in Heihe River was high, but overall, it showed a decreasing tendency. The index of water pressure had fallen from 0.58 in 2000 to 0.28 in 2010. This was attributed to the integrated river basin management including the water-saving society construction. However, It is still necessary to reduce water use in agriculture and increase ecological water use, to reduce the pressure and promote sustainable utilization of Heihe River basin water resources.

Abstract:The externalities of arable land utilization brings both economic and socio-ecological benefits to state and farmers. The estimation methods of social stability value, social security value and ecological benefits value of arable land resources were discussed based on the construction of appropriate value system. The results showed that:(1) The social stability benefit of arable land resources in Wuhan City was increasing year by year, from 1.50×10⁸ yuan in 1996 to 4.24×10⁸ yuan in 2009;(2) The social security benefit of arable land resources was decreasing year by year, from 7886.65 yuan/(hm²·a) in 1996 to 6618.74 yuan/(hm²·a) in 2009, which indicated that the social security system in rural needed to be established urgently.(3) The ecological benefit value of arable land resources showed a trend of rising after falling, and the change of arable land quantity was an important influence factor. The general socio-ecological value fluctuant trend of arable land resources in Wuhan City was rising. It is necessary to fully take into account the value of arable land resources due to the coexistence of extension growth, and extensive, inefficient utilization of city land in our country.

Abstract:Soil total salt, salt ions composition and correlations of different salt ions in habitat of Halogeton glomeratus in Minqin Oasis were studied. Results showed that H. glomeratus can accumulate salts and formed a certain salt island around its habitat. In the horizontal direction 0-60 cm away from H. glomeratus, the soil salinization degree aggravated with soil depth increases in 0-60 cm on the soil profile, among which anions were mainly Cl^-, and SO₄^2- and cations were Na⁺ and Ca²⁺. The main soil salinity were sodium chloride, calcium chloride, sodium sulfate and calcium sulfate, followed by magnesium chloride and magnesium sulfate. In 0-40 cm distance away from plant, the total salinity contents of the 0-20 cm soil layer on the soil profile were 0.98~1.52 g/kg and belonged to non-salinization soil, while that of the 20-40 cm and 40-60 cm soil layers were 2.25~2.30 g/kg and 3.10~3.16 g/kg, which belonged to light salinization soil and medium salinization soil, respectively. Furthermore, in the horizontal direction 60 cm distance away from the H. glomeratus, the total salinity content of 0-40 cm and 40-60 cm soil layers on the soil profile were 0.83~1.86 g/kg and 2.43 g/kg, which belonged to non-salinization and light salinization. There were extremely significantly positive correlations between soil salt content and ions contents except the content of HCO₃^-.

Abstract:The root system characteristics, such as root length, root surface area and root biomass in different soil depths were studied to assessed the correlation between root system characteristics and aboveground biomass, root-shoot ratio. This research was conducted on gentle slope, steep slope, middle bar and artificial bank slope of four typical site types on the aquatic-terrestrial ecotone of Lijiang watershed. The result showed that:(1) Within the same site type, the root biomass, aboveground biomass and root-shoot ratio of different main herbaceous plants were different significantly; Root length and root surface had some differences in different site type. On steep slope and artificial bank slope, there were significant differences between root length and surface area(p<0.05). On middle bar, the difference of root surface area was significant(p<0.05).(2) Polygonum hydropiper and Conyza canadensis grow best on the gentle slope. Steep slope was the most suitable site for Sida rhombifolia L. and Achyranthes bidentata Bl. The middle bar was the most appropriate area for Tatarian aster and Artemisia argyi. Artificial bank can provide the optimum environment for the growth of Humulus scandens Merr.

Abstract:Water management is one of the key problems to the soci-economic development and eco-environment construction of endorheic drainage in the northwestern of China. Therefore, one of the important mission we are facing is how to make effective water management, particular in the northwestern inland river. By analysing the conditions of Heihe river basin in China and the Murray-Darling river basin in Australia, we explored the water management of these two rivers through comparative analysis, and theoretically provided the methods and plans for the water management system of Heihe river basin. Meanwhile, a set of measures were suggested:optimizing the structure of water use to improve economic returns, attaching great importance to the unified management to realize the optimal allocation of water resources, strengthening the organizational management to formulate the river basin law, and encouraging the public to participate in the water management of the river basin, further deepening the reform of water right system.

Abstract:Zhenhai District of Ningbo City was taken as the research objective and the method of ecological footprint was employed to calculate its ecological footprint(EF) and ecological capacity(EC) from 1997 to 2011. The results showed that the ecological footprint per capita in Zhenhai District increased from 6.4178 hm² to 7.7374 hm² during 1997-2011. Meanwhile the ecological capacity per capita, the ecological deficit per capita and the ecological tension index increased from 0.3370 hm², 6.0808 hm², 19.04 to 0.3624 hm², 7.7130 hm², 20.79 respectively. The ecological footprint per capita exceeded the ecological carrying capacity per capita, which showing a huge ecological deficit and indicated that the land ecological system of port areas was in a very unsafe state. The rapid development of urbanization, the layout of heavy chemical industry and the adjustment of residents' consumption structure were important factors which influenced the land ecological safety of Zhenhai District, and the risk of land ecological system was much higher than the original system due to the international trade. Finally, it was concluded that the measures of coordinating the relationship between port and city, reducing the proportion of fossil energy and improving the ecological land ratio should be taken to adjust the status of land ecological security in port areas.

Abstract:Based on the integrated technology of RS and GIS, combining the means of statistics and analysis, taking three TM remote sensing images in three periods(1993, 2000 and 2010 year) as the main data source, we analyzed LUCC, and selected thirsty chief driving factors of land use and cover change. Then quantitatively analyzed the correlation between different land types and different driving factors by grey correlation model in Guiyang City. The results showed as follows:(1) The area of paddy, dry land, brush and unused land reduced by 135.2, 55.4, 80.8, 98.6 km² respectively; but the area of water area, woodland and construction land increased by 49.1, 128.3, 183.4 km² respectively;(2) The comprehensive land use index was increased 301.2, 307.7, 319.0 in 1993, 2000 and 2010 respectively.(3) The orderliness and stability of land use structure system showed a trend of increase first then decrease, and the information entropy of land use structure raised from 0.76 in 1993 to 0.78 in 2001, then fell to 0.77 in 2010 in Guiyang City.(4) The main driving forces of LUCC in Guiyang City was population growth, economic development and per capita resource status.

Abstract:According to the data from the second soil survey of Yunnan Province, the soil organic carbon(SOC) density and storage were estimated with soil type method; Meanwhile the spatial distribution of SOC density in Yunnan Province and the main factors on SOC density were analyzed. The results showed that the SOC density estimated in the 0-20 cm layer was 59.77 t/hm² and stock was about 2.30×10⁹ t; and the SOC density estimated in the 0-100 cm layer was 159.95 t/hm², its storage was about 6.15×10⁹ t accounting for 7.28% of the total in China and 0.41% of the global terrestrial ecosystems; the top four soil types in SOC storage were red soil, yellow-brown soil, lateritic red soil and brown soil totally taking up about 60% of that in Yunnan Province. The spatial distribution pattern of SOC density was the highest in Yunnan Province was in the northwest and northeast of Yunnan Province, followed by east of Hengduan Mountains and the western Yunnan plateau, and that of the purple soils in the north central area was the lowest. Otherwise, due to the impact of rainfall, temperature, elevation and land use types, the distribution of SOC density in the region was uneven. Furthermore the natural factors such as rainfall, temperature and elevation were the main factors affecting SOC density.

Abstract:Using the data separation technology, based on the data extracted from the 1:250000 available and regional geochemical data of the content of natural radionuclide(²³⁸U, ²³²Th, ⁴⁰K) in different type soil in Chengdu Economic Area, field sampling and analysis were carried out. Then, the distrbution characteristics of natural radionuclide content in different type soil were studied in this area. The results showed that:(1) The contents of natural radionuclides in the area soil were at the same level with the world, the whole nation and Sichuan Province.(2) The contents of ²³⁸U in yellow soil, brown soil, purple soil, paddy soil, gray soil and grass mat soil were 3.18, 2.40, 2.12, 2.45, 2.48, 2.73, respectively, the average was 30.41(the unit was 10^-6 g/g); the contents of ²³²Th were 14.27, 14.64, 11.67, 13.98, 13.41, 14.09, the average was 54.35(10^-6 g/g); the contents of ⁴⁰K were 2.06, 2.38, 1.94, 1.74, 1.83, 2.22, the average was 1.98(10^-2 g/g);(3) The contents of natural radionuclides in different type soil showed up the rules as following:the content of ²³⁸U in yellow soil >grass mat soil >gray damp soil >paddy soil >brown soil >purple soil; the content of ²³²Th in brown soil >yellow soil >grass mat soil >paddy soil >gray damp soil >purple soil; the content of ⁴⁰K in brown soil >grass mat soil >yellow soil >purple soil >gray damp soil >paddy soil;(4) In the same type soil, the natural radionuclide content of plain soil was lower than that of mountain.

Abstract:According to the statistical and survey data of land use change in Zhejiang Province from 2002 to 2011 and the date of the cities in Zhejiang Province in 2012, aiming at the cultivated land intensive use, the evaluation index system of cultivated land intensive use was established, which included 4 aspects and 12 specific indicators from the aspects of input intensity, output level, utilization degree and sustainable conditions of land. We evaluated the time serial change law of cultivated land use in Zhejiang Province and appraised the spatial variation characteristics of cultivated land use of the cities of Zhejiang Province through the efficacy coefficient method. The results showed that:the temporal variability of intensive use level of cultivated land was very obvious and the level of cultivated land increased with volatility in recent 10 a. The spatial variance of the intensive use was remarkable, showing a trend of higher in north area and lower in south area. The socio-economic development, agricultural development and policy factors were the three main factors that affected the situation of cultivated land intensive use.

Abstract:In this paper, we made a scientific research on impact of the value change of land ecosystem services on economic development in mountainous area of Southern Ningxia Hui Autonomous Region from 1996 to 2011, by taking Longde County of Hui Autonomous Region as an example and based on the least square method. The results showed that:(1) The aquatic ecosystem should be strongly protected, as the value change of aquatic ecosystem services had the greatest influence on economic development in Longde County.(2) On the basis of steady forestry construction, the subsequent industry should be emphasized, as the value change of forest ecosystem services had the smallest influence on economic development in Longde County.(3) The value change of farmland ecosystem services had the positive correlation with the economic development in Longde County, in contrast, the others were negative correlation. In the future, the value of farmland ecosystem services should be increased, while the area of forestland, grassland, aquatorium and the land difficult to use should be decreased properly.(4) The influence, which value change of ecosystem services of the land difficult to use had on economic development in Longde County, was relatively weak. This illustrated that the economic development of Longde County relied on natural resources and showed low degree of modernization. So the industrial structure should be further optimized in order to improve the level of economic development.

Abstract:Based on the indicators of economic value and environmental impact established by emergy and material flow method, the relationship between economic development and environmental quality was analyzed with the aspects of the features of environment Kuznets curve(EKC), eco-efficiency and the "decoupling". The results showed that:the characteristics of "inverted U" type was appearent between economic development and environmental quality, the turning point of EKC will occur before 2015, then the economic value and environmental impact will increase 8.83 and 4.38 times over 2009, respectively; Eco-efficiency increased 4.55 times in the last 11 years and is based on increasing ecological pressure; The decoupling phenomenon was characterized with alternative weak decoupling and expansion re-link and economic development was characterized with obvious weak sustainability, compared to waste discharge, resources input has a more significant role in promoting ecological pressure. Thus, it is the only ways for Yulin City to change traditional way of economic growth and develope circular economy to promote Yulin City to meet the whole social material needs, and at the same time, to achieve the coordinated development of economic development and population, resources, environment.

Abstract:The surface soil at the 500, 1000 and 3000 m in the east, west, south and north of coking plants were sampled and three methods(single factor index, geo-accumulation index and Hakanson potential ecological risk index) were adopted to assess the potential ecological risk of heavy metals(Pb, Cd, Zn, Cu, Cr and Mn) near coking plant in Taiyuan City. Results showed that the concentration of Cd in all soil samples was 2.1~2.7 times of the standard value(Ⅱ) of environmental quality standard(GB15618-1995) for soil, the concentration of the other heavy metals did not exceed the standard values(Ⅱ) and the concentration of six heavy metals was maximum at 1000 m; The relative degree of pollution was in the order of Cd >Cr >Cu≈Zn>Pb≈Mn; Likewise, the potential ecological risk was characterized by the order of Cd >>Pb >Cu >Cr >Zn >Mn and north >west >east >south, and the soil in the research area possessed serious potential ecological risk, specially the potential ecological risk of heavy metals in the north of the coking plant was very serious, in which, Cd was dominant contributors for ecological risk, for it accumulated markedly in soil around the coking plant.

Abstract:Taking the TM images in 2000 and 2010 as data resource, combined with land use change quantity analytical method and GIS and RS technology, the authors analyzed land use changes and its ecological response in Shenmu County of Shaanxi Province from 2000 to 2010 by adopting the comprehensive land using dynamic degree, land use degree and ecosystem services value(ESV). The result showed that the land use patterns transformed quickly and land use degree reduced in Shenmu County from 2000 to 2010, in which the intensity of land use change of cultivated land, grassland, woodland, water area, industrial land, urban construction and unutilized land reached-1.687%, 0.782%, 0.469%,-0.033%, 0.067%, 0.086%, and 0.316%, respectively. Total value of ecosystem services increased 94 million yuan in Shenmu County from 2000 to 2010. Meanwhile, the ESV of woodland and grassland increased by 347 million yuan and 192 million yuan respectively. On the contrary, the ESV of cultivated land decreased by 395 million yuan, and water area and unutilized land had the smallest change. Spatially, total value of ecosystem services in the northern township mainly declined, at the same time, in southern township, it mainly rose.

Abstract:According to moisture content in sand layers of the drilling sections in Haizetan Town of Jingbian County of Shaanxi Province, Mu Us sandy grassland, we studied the characteristics of moisture distribution in sandy lands, existing forms, water balance, supply of atmospheric precipitation to groundwater and appropriate vegetation. The result showed that variation of moisture within the depth of 500 cm was that the upper part contained less water and the lower contained more. The moisture content were found also high both below the depth of 200 cm in grassland and below the depth of 300 cm in shrub land. Sand moisture in grassland was significantly higher than that in shrub land. The moisture content of grassland ranged from 1.0% to 6.0%, with an average of 3.4%, and that of shrub land was 0.7% to 2.8% with an average of 1.5%. There were film water exceeding 3% and gravity water exceeding 5% below 200 cm on the sand section in grassland, which indicated the obvious supply of precipitation to groundwater. While the sand layers in shrub land was usually lacking of gravity water and high content of film water, it suggested that supply of atmospheric precipitation to groundwater was actually weak in the area. The important reasons why this area has positive water balance were high infiltration rate and small evaporation effect of sand layers, in addition to more precipitation. Owing to much rainfall in sandy lands of Jingbian County, active layer of sand moisture distributed at the depth of 200-300 cm, which was 100 cm to 200 cm deeper than that of desert area. Variation of moisture in the sand layers showed that sand moisture in the area could meet the needs for the growth of drought-resistant shrub, which was suitable for the development of shrub with good sand-fixing effect.

Abstract:An evaluation index system was established for Shaanxi Province which consisted of low-carbon system and development system about low-carbon economy, and the level and coordination of Shaanxi Province from 2003 to 2011 were evaluated using the model of entropy, catastrophe progression and coordinate. The results showed that the relatively level of the year from 2003 to 2006 was "unacceptable", that of the year 2007 was "average", and that of the year from 2008 to 2011 was "well". The level of ecological protection was obvious progress and the effect of technology to low-carbon economy was gradually highlighted, while industrial and energy structure was unstable in the development process of low-carbon economy in Shaanxi Province. Low-carbon system and development system in Shaanxi Province was antagonistic during the study period. During the 12th Five-Year Plan, it may enter the basic coordination phase and promote the development of low-carbon economy.

Abstract:Groundwater resources carrying capacity evaluation is extremely important in preserving harmonious and sustainable development of water resources, ecosystem, society and economy. In this study, fuzzy comprehensive evaluation of the groundwater resources carrying capacity in North China Plain(NCP) was conducted and grey relational theory was used in analyzing the influencing factors of groundwater resources carrying capacity. The results showed that the mean value of groundwater carrying capacity in cities of NCP was 0.38, among which cities that of much developed in groundwater but still with a little exploitation potential accounted for 19.0% of the total, while that close to potential and over-exploitation accounted for 38.1% and 42.9%, respectively. So groundwater resources had been over-exploited with extremely weak carrying capacity in NCP. The grey correlation degrees of groundwater exploitation with population, the first industry output, the third industry output, GDP and industry output were 0.71, 0.63, 0.59, 0.58, and 0.56, respectively. Generally, the most important influencing factors of the groundwater resources carrying capacity in NCP were the growth of population, the increased agriculture irrigation and the rapid economic and social development.

Abstract:The hazard assessment of debris flow was conducted by applying fault tree analysis(FTA) on characteristics of debris flow line engineering in subtropical area after analyzing influence factors of debris flow and the logical relationships between them. The new hazard assessment was applied to evaluate the hazard degree of 16 debris flow gullies in Lechang City of Guangdong Province. The results showed that it is more reasonable than the traditional grey correlation method because it solved some of the problems the traditional method always got such as the applying area was limited, the influence factors and weight were inflexible, and the non-linear relationship between them was not considered. Therefore, the fault tree analysis(FTA) was proved to be an effective and feasible method for the hazard assessment of debris flow.

Abstract:Two maize cultivars(Zhengdan-958 and Yuyu-22) and two soybean cultivars(Zhonghuang-24 and Zhonghuang-13) were selected under monoculture and intercropping modes(2:2 and 2:4 ratios) respectively, to explore the effect of maize-soybean intercropping modes on maize growth on the Loess Plateau. The result showed that, compared with monoculture, Zhengdan-958 intercropped with the two soybean cultivars can increase the chlorophyll relative content, leaf area per plant, stem diameter and dry matter accumulation of maize starting from the huge bellbottom period, and the plant height exceed that in monoculture in the late growth stage. When Yuyu-22 intercropped with the two soybean cultivars, the maize chlorophyll relative content and stem diameter were higher than that in monoculture starting from the huge bellbottom period, and the dry matter accumulation were higher than that in monoculture starting from the silking stage. The leaf area per plant was higher than that in monoculture significantly in the silking stage, but the plant height lower than that in monoculture in the late growth stage. The dry matter accumulation of Zhengdan-958 was higher than that of Yuyu-22 in the late growth stage under intercropping, so it was more beneficial to maize yield. In the selected maize-soybean intercropping patterns, Zhengdan-958 intercropped with Zhonghuang-24 with 2:4 ratio was more beneficial to maize yield on the Loess Plateau.

Abstract:By taking apple-soybean intercropping system on the loess region of West Shanxi Province as the research object, the soil moisture content, biomass and yield of soybean were tested at different key phenophases. The results indicated that:(1) The soil moisture of apple-soybean intercropping system changed significantly in different phenophases, and the maximum consumption period for soil moisture was the flowering period of soybean. In different phenophases, the main competitive area and the degree of competition for soil moisture between apple trees and soybean were significantly different;(2) In horizontal direction, the soil moisture content increased with increase of the distance from the tree base, and the lowest soil moisture content was the area adjacent to the tree base;(3) In vertical direction, the soil moisture increased with the increase of soil depth in both of the intercropping system and soybean monoculture plots at soybean seedling stage and bearing pod stage. In the flowering stage of soybean, with the increase of soil depth, soil moisture decreased at first and then increased with the increase of depth;(4) Compared with monoculture plots, an overall negative soil moisture effect appeared in apple-soybean intercropping system and resulted in the loss of soybean production. Due to the soil water distribution in different phenological periods of apple-soybean system, the authors recommended that the appropriate regulation and management measures should be taken to alleviate interspecific competition for moisture and to improve soybean yields.

Abstract:Water-rich city not only has the general characteristics of urban water resources carrying capacity, but also has its certain particularity. According to the characteristics of the formation and utilization of urban water resources, the changes of urban water resources carrying capacity from 2006 to 2010 were analyzed by taking a water-rich city, Nanjing City, as a case, with comprehensive evaluation method. The results showed that the urban water resources carrying capacity of Nanjing City was rising on the whole, roughly in suitable load range, but the carrying capacity was limited with obviously fluctuation. The sensitivity analysis is applied to find out which indicators are the key factors for the changes of Nanjing urban water resources carrying capacity. On this basis, GDP per capita, water consumption per ten thousand Yuan GDP, urban daily water consumption per capita and the rate of sewage treatment are selected as four indicators for urban water resources carrying capacity promotion scenario analysis. It is find out, to strictly control the water consumption per ten thousand Yuan GDP and urban daily water consumption per capita, and steadily enhance the rate of sewage treatment, are very important to promote Nanjing urban water resources carrying capacity, and the corresponding countermeasures are put forward.

Abstract:Based on the SWAT(soil and water assessment tool, SWAT) model and Mann-Kendall method, the spatio-temporal change of blue water and green water resources in different growing season over the source of the Yellow River from 1961-2010 were analyzed. The results showed that the amount of green water resources was generally 2 times of blue water resources in the source region of the Yellow River. Blue water resources in spring and autumn showed a declining trend, and significantly decreased by 0.355 mm/a in autumn, while a weak increasing trend in summer. Green water resources showed an increasing trend in summer and autumn, and significantly increased by 0.286 mm/a in autumn, while decreasing trend in spring. From southeast to northwest, blue water and green water showed progressively decreasing trend. In the southeast, blue water resources decreased by 1.98 mm/a in autumn while green water resources increased in summer and autumn with the largest slope 1.62 mm/a. Because of global climate changes, the spatiotemporal difference in blue water and green water resources will be further increase. Hence, it is urgent to strengthen the systematic management of water resources in the source region. And the amount of inefficient water consumption and the high water consumption crops should be reduced. Thus the supply of water in the lower and middle reaches of the Yellow River can be guaranteed.

Abstract:With the implementation of the ecological migration project in karst area of Guangxi Zhuang Autonomous Region, a large number of grasslands were reclaimed for cultivated fields in immigration area, and land reclamation inevitably affected the the soil fertility. By choosing corn land of 30 years and 15 years and grassland as the research objects, we studied the influence of grassland reclamation on soil fertility based on the theory of space for time. Soil fertility was evaluated on the basis of determining weight of factors by means of the correlation coefficient and normalization of factors through membership function. The results showed that after grassland replaced by corn field, the soil fertility declined in 0-100 cm soil layer; The degradation of 30 years corn was less serious than that of 15 years corn, so the soil fertility of 30 years corn was better; The degradation of soil fertility related to soil depth; The degradation was most serious at the beginning of reclamation because of the interference of human activities, but soil fertility was restored with the extension of cultivation.

Abstract:Dating the sediments age with ¹³⁷Cs, using rainfall data since 1953, the grain size cycle characteristics of hydatogen sediments in natural check dam of loess depression are analyzed. Results showed that the 4 m depth of sediments was formed in the recently one hundred years, and its material was mainly coming from flood erosion. Rainfall was the main factor affecting the particle size of sediments. Flood sediments was mainly composed of coarse silt, while the ratio of medium sand was low and the coarse sand was not found. The section of sediments had distinct sedimentary layers, which have recorded at least 42 flood events. The grain sizes of flood sediment layer in different periods changed significantly, which showed the rules of watershed erosion and precipitation variation in the recently one hundred years.

Abstract:Based on the two field studies in Qaidam Basin Desert, sediments of linear dune and barchans dune that are distributed along the prevailing wind in Chaerhan Salt Lake were collected as samples. Then, the grain size of the selected samples was analyzed. The results showed that fine and medium sand was dominant in the sand, sandy clay and fine silt was also detected in a large quantity. The grain size changed from coarse to fine along the prevailing wind. Moreover, the grain size parameters implied that the mean diameter of the samples was higher than those collected from the other deserts in China, which indicated a higher maturity values of linear dune over those of barchans dune. Finally, the cumulative frequency curve demonstrated that the sandy area under research was primarily deposited by saltation and suspension population.

Abstract:Using the Pearson correlation coefficient method, annual runoff and sediment were analyzed in order to find out the evolution characteristics and its impacting factors in the Lishui River during 1955-2009. The results showed that the annual runoff had no obvious change during this period, while the annual sediment transportation appeared significant decline trend, and had sudden change in the year of 1983. The relationship between precipitation, runoff and sediment transportation variation were analyzed, it turned out that human activities were the main reason causing the sediment transportation descent when the annual precipitation has no obvious change during 1955 to 2009. Thus, the sediment from the Lishui River to the Dongting Lake decreased by 4.59×10⁶ t every year accordingly.