Abstract:[Objective] The formation age, process and soil nutrients of wetland in Muli-Jiangcang coal mine area in Northeastern Qinghai-Tibet Plateau were studied in order to provide scientific basis for vegetation restoration of open-pit coal mine spoil heaps.[Methods] The strata analysis, optically stimulated luminescence(OSL) dating method and soil nutriology were applied to study the forming progresses of humus layers in alpine wetlands.[Results] ① The Jiangcang coal mine area was composed of alluvial gravels, loess, peat sediment, and humus layers, which had an OSL age of 1.7±0.1 ka. The Muli coal mine area was composed of weathered crust and humus layers which had the ages of 2.0±0.2 ka. ② There were high contents of organic matter, total nitrogen, available nitrogen, and total phosphorus in the humus layers.[Conclusion] The forming age of the humus layers of the wetlands underwent two thousand years at least, indicating a long evolution history. The plants of the wetlands depended on the abundant nutrients of humus layers. It is suggested to adjust measures to local conditions, and increase soil thickness and soil fertility as soon in order to recover the vegetation on coal mine spoil heaps.

Abstract:[Objective] Runoff and sediment yield characteristics of different grass-planting slope protection in typical dikes of Poyang Lake were studied in order to provide a scientific basis for the selection of grass species and the guiding of dike slope protection.[Methods] Responses of soil and water loss characteristics to different rainfall intensities were studied using rainfall simulation under 5 dike slope types, which are bare land(BL), natural restoration slope(NRS), Cynodon dactylon sowing in drill slope(CDS), Zoysia sinca sowing in drill slope(ZSS), Eremochloa ophiuroides and-stem planting slope(EOS), in Jiuhe Dike of Yongxiu County, a typical dike of Poyang Lake.[Results] As compared with BL, other four slope protection models played positive effect in prolonging initial runoff times and reducing flow velocities, and there was the lowest flow velocity under EOS treatment. There were no significant difference of runoff coefficient between BL and other four slopes under 20 mm/h rainfall intensity, but with the increase of the rainfall intensity, the inhibition of vegetation protection to surface runoff were becoming more and more obvious. Sediment yields increased with the increase of rainfall intensity under 5 treatments.[Conclusion] Compared with BL, vegetation protection slopes could effectively reduce dike sediment loss, especially under high rainfall intensity.

Abstract:[Objective] The experimental studied runoff yield, sediment yield and runoff hydrodynamic parameters during erosion process of red soil slope in order to provide the basis for revealing the mechanism of slope erosion and sediment yield on red soil slope.[Methods] Red soil was used, a total of 18 rainfall simulation experiments were conducted in a 8.0 m long drainable flume, with treatments including three levels of typical slope gradients (6°, 10°,15°) and three rainfall intensities (120, 180, 240 mm/h). The processes of runoff generation, sediment yielding, and runoff hydrodynamic characteristics variation were analyzed.[Results] The accumulative runoff and sediment load significantly increased with the increasing of rainfall intensity under the same slope gradient. The runoff rate variation showed a steady state after an initial increased fluctuation. The sediment yield rate increased with the increases of both rainfall intensity and slope gradient. The sediment generation process showed a variation that increased rapidly at the beginning and decreased quickly with the experiment time passed. There was a good exponent relationship between Froude numbers and Reynolds numbers, while flow Darcy-Weisbach friction coefficients and Reynolds numbers had no obvious correlation.[Conclusion] There is a significant correlation between runoff hydrodynamic parameters and erosion sediment yield. By comparison, Reynolds number of runoff is the most closely related to slope erosion sediment yield.

Abstract:[Obejective] The variation of runoff in the Tuotuo River in the headwaters of the Yangtze River in the past 51 years under different time scales of precipitation, such as interannual, interdecadal and season, and also the lagging effect of runoff on precipitation were analyzed in order to provide a theoretical basis for the management and utilization of water resources in the basin.[Methods] This paper used the runoff and precipitation data of hydrological station and the meteorological station in Tuotuo River of the Yangtze River source region from 1961 to 2011, and combined the statistical methods such as cumulative anomaly, variation coefficient, concentration frequency and concentration period, to investigate the variations of runoff and precipitation at decadal, annual and seasonal time scales. The hysteresis effect of runoff to precipitation was also discussed.[Results] The annual and seasonal runoff of the Tuotuo River Basin in the past 51 years showed an increasing trend. The annual, spring and summer runoff increased significantly. The climatic tendency rates were 1.00×10⁸ m³/10 a, 6.00×10⁶ m³/10 a, 6.30×10⁷ m³/10 a, respectively. The runoff of the river was mainly concentrated in the period from May to October, especially from late July to mid-August. There was a significant correlation between runoff and precipitation. The runoff had a lagging effect on precipitation in most years, and the average lag time was about 10 d. The hysteresis period was observed being increased over the past time.[Conclusion] In the past 51 years, the trend of runoff and precipitation in the study area had increased, and the lag effect of runoff on precipitation was about 10 days.

Abstract:[Objective] In order to provide theoretical support for the sustainable development of ecosystems in the Mu Us sandy land, the research on the vegetation growth status in this region from 2001 to 2016 was carried out.[Methods] Based on MODIS EVI vegetation index, we analyzed the vegetation growth status of the growth season and non-growth season in Mu Us sandy land during 2001-2016. The relationship between vegetation and climate change, human activities was discussed.[Results] ① Vegetation coverage in Mu Us sandy land was relatively low. The vegetation coverage in the southern area was significantly higher than that in the northern region. ② The vegetation coverage in Mu Us sandy land showed an obvious improvement during 2001-2016. ③ In the growing season, the rate of vegetation coverage change in the southern and eastern regions was higher than that in the central and northern regions. Vegetation coverage in the southern and eastern region displayed a significant increase, and some showed a significant decrease. In the non-growth season, vegetation coverage in the southern region was mainly increased. ④ The annual maximum value of EVI in Mu Us sandy land was positively correlated with precipitation and weakly negatively correlated with temperature. The annual minimum value of EVI was strongly positively correlated with precipitation, and weakly positively correlated with temperature. ⑤ Human activities such as the increase of crop acreage, large-scale afforestation projects, and the control of large livestock numbers all contribute to the improvement of vegetation coverage.[Conclusion] Due to climatic factors and human activities, the vegetation growth of Mu Us sandy land had improved since the 21st century.

Abstract:[Objective] To study the effects of different dosages of water-retaining agents on seed germination of four typical desert plants, the suitable dosage of seed-coated water-retaining agents was screened to provide scientific basis for vegetation restoration and desertification control in desert areas.[Methods] Four typical desert plants, Reaumuria soongarica, Caragana korshinskii, Nitraria sphaerocarpa and Hedysarum scoparium, were studied. Their seeds were treated with 1%, 4%, 7%, 10%, and 13% water-retaining agents, and indices of germination rate, germination potential, average germination rate of these seeds were measured.[Results] With the increase of water-retaining agent dosage, the germination rate of Caragana korshinskii showed a downward trend. Hedysarum scoparium, Nitraria sphaerocarpa and Reaumuria soongarica showed a trend of increasing firstly and decreasing afterwards, and the highest germination rate showed when the amount of water retaining agent was 4%. The different amounts of water retaining agent had a significant effect(p < 0.05) on the seeds of germination potential. The germination potential increased first and then decreased with the increase of the amount of water-retaining agent. When the amount of water-retaining agent was 1%, Caragana korshinskii had the highest germination potential, and when it was 4%, Hedysarum scoparium, Nitraria sphaerocarpa and Reaumuria soongarica had the highest germination potential. Different amounts of water-retaining agent treat had significant effects on seed average germination rate and germination index(p < 0.05). The two indices of the seeds of Nitraria sphaerocarpa and Reaumuria soongarica increased first and then decreased with the increase of water-retaining agent dosage. The average germination rate and germination index were the highest at 4%. When the amount of water-retaining agent was 1%, Caragana korshinskii had the highest germination index.[Conclusion] The effect of water-retaining agent dosage on seed germination varied from species to species, and a suitable amount of water-retaining agent can promote the seed germination of typical desert plants.

Abstract:[Objective] The pollution characteristics and potential ecological risk of heavy matals in reclaimed industrial sites were investigated in order to provide scientific basis for the management and remediation of similar reclaimed industrial sites.[Methods] Eight heavy metals(As, Cd, Cr, Cu, Ni, Pb, Zn and Hg) were quantitatively analyzed in the surface, subsurface and deep soil of thirty-three typical reclaimed industrial sites in Shanghai City. The potential ecological risk and pollution degree of heavy metals in the sites were evaluated by using Nemerow index and potential ecological risk index.[Results] ① The risk of 8 heavy metals was acceptable overall. The contents of heavy metals in 17 points were higher than the screening value, while the pollution of Cu and Zn in surface soil was the most prominent. The average contents of 8 heavy metals in subsurface and deep soils were lower than the background value of Shanghai City, with certain accumulation of heavy metals in some points; ② The Nemerow index of heavy metals in vertical soil profile was 1.21, 0.78 and 0.73 respectively, was in a light pollution or still clean level. Among which, Cd and Zn in surface soil were the most prominent; ③ The heavy metals in the reclaimed industrial sites were all at a slightly latent ecological risk level, except of Hg(medium) and Cd(medium) in surface soil. The potential ecological risk of surface soil was 107.22, which was close to a medium level, while the risks of subsurface and deep soil were mild.[Conclusion] The soil heavy metals in the sites were in an accumulative pollution to certain extent and the pollution of Cu, Cd, Hg and Zn were the most prominent. If the toxic response factors were concerned, Hg and Cd should be paid more attention.

Abstract:[Objective] The dynamic response of soil microbial characteristics and environmental factors to the change of paddy fields into orchards was discussed in order to provide a scientific basis for further study of the impact of land use change on soil ecological environment and prediction of the long-term change trend of soil quality after the change of paddy fields to orchards.[Methods] One representative soil series of land-use change from paddy to orchard were chosen in Zhejiang Province, furthermore, the law of dynamic response of soil physicochemical properties, enzyme activity and soil microbial biomass to land-use change was analyzed using the post-cut time series method.[Results] Soil moisture, > 0.25 mm water stable aggregate, pH value, organic matter, base saturation, total nitrogen and alkali-hydrolyzable nitrogen fell down significantly(p < 0.01), however, total phosphorus, available phosphorus and available potassium increased by 21.9%,54.7%,42.0% and 6.65 times, respectively, and these indexes were correlated with years of planting trees significantly(p < 0.01). After the land-use change, the average of soil microbial biomass carbon and nitrogen decreased by 74.4% and 73.3%, respectively. The average of soil urease and acid phosphatase activity increased by 40.0% and 41.8%, respectively. However, the mean value of soil catalase activity decreased by 69.3%, and they were significantly(p < 0.01) correlated with the time of planting trees.[Conclusion] After the land-use conversion from the paddy field to orchard farm, soil environmental factors changed periodically, and the influence of land-use pattern was greater than that of land-use history. Moreover, soil comprehensive fertility decreased, and the ecological environment and sustainability of land use were adversely affected.

Abstract:[Objective] This paper studied the effects of straw returning on soil nitrogen and microbial biomass carbon and nitrogen contents in different soil depths to provide scientific basis for improving the efficiency of returning straw.[Methods] Five different treatments were labeled as control CK(no straw), T₀(surface coverage), T₁₀(10 cm returning field), T₂₀(20 cm returning field), T₃₀(30 cm returning to the field).[Results] ① Compared with the control, the contents of soil organic matter, total nitrogen and nitrate nitrogen in straw returning treatments increased 3.98%~29.36%, 2.72%~45.52%, 10.48%~56.64%, respectively. The contents of ammonium nitrogen decreased about 7.75%~39.20%. ② The straw returning treatment had a significant effect on soil microbial biomass. Compared with the control, the soil microbial biomass carbon and nitrogen increased 5.01%~35.78%, 9.69%~52.56%, respectively. ③ Principal component analysis method was used to evaluate the soil quality with different straw returning treatments. The comprehensive score order was CK < T₃₀ < T₀ < T₂₀ < T₁₀. When the straw returned to the field at 10 cm and 20 cm depth, labeled T₁₀ and T₂₀ treatments, had more significant effects on soil nitrogen levels and microbial biomass carbon and nitrogen contents than other treatments had, and the treatment effect of 10 cm straw returning was most obvious.[Conclusion] Straw returning could increase soil nitrogen and microbial biomass carbon and nitrogen content, improve soil traits. Better effects for 10 cm and 20 cm depths of straw returning were found, especially for 10 cm depth straw returning, and its effect were the most significant in soil nitrogen and microbial biomass carbon and nitrogen.

Abstract:[Objective] The effects of enclosure on specie diversity of Xilamoren grassland in Inner Mongolia were studied in order to provide the scientific basis for the study of the grassland species diversity under the enclosure.[Medthods] This study analyzed the species diversity of enclosed grazing grassland based on the 11 years data of local annual precipitation in Inner Mongolia Autonomous Region.[Results] After enclosure, the interannual fluctuations of Artemisia frigida, Potentilla verticillaris, Cymbaria dahurica, Potentilla bifurca and Potentilla acaulis were larger. The diversity of the plants was reduced by the enclosure treatment. But Simpson ecological dominance index, Shannon-Wiener species diversity index and Pielous evenness index of the grassland plant in arid years were just the opposite in less precipitation years (2014 with annual precipitation less than 200 mm). Enclosure reduced the correlation coefficient between species richness and annual precipitation.[Conclusion] Enclosure treatment was not conducive to the plant diversity of Xilamuren grassland, but enclosure could alleviate the effects of climate change on species diversity under arid climate.

Abstract:[Objective] The lagging infiltration recharge in south margin of Mu Us sandy land and parameter sensitivity of numerical model were studied in order to provide scientific basis for rational exploitation and utilization of groundwater resources and protection of ecological environment in this area.[Methods] Lagging infiltration recharge was analyzed based on field monitoring data, and sensitivity analysis of numerical model parameters was conducted using ratio of variation(ROV).[Results] The response depth of water content to the precipitation was 3~10 cm in small rain scenario, and 30~60 cm, 60~90 cm, more than 90 cm in middle, heavy and storm rain scenarios. The groundwater recharge was approximately 4~11 h lagged. Sensitivity analysis showed that saturated water content (θ_s) was the most sensitive parameter to the bottom flux.[Conclusion] The response depth of water content are linearly correlated with the precipitation and the groundwater recharge lag time has a positive correlation with θ_s.

Abstract:[Objective] The soil particle size characteristics of different vegetation types on the southern slope of Qilian Mountain were analyzed in order to provide a scientific basis for the sustainable use of regional soil resources and ecological environment protection.[Methods] 75 samples were collected and measured from different vegetation types on the southern slope of Qilian Mountain by Mastersizer 2 000 laser particle size analyzer. Then the parameters of particle size were calculated by using Fokker and Ward formula and performed one-way ANOVA.[Results] ① Picea crassifolia, Juniperus przewalskii and alpine meadows were of silt-clay(< 63 μm) grade, mixed shrubs and alpine grassland were of sand grade(> 63 μm). The size of the forestland soil was finest and the alpine meadow was followed in composition of size. Mixed shrubs and alpine grassland showed degradation trend, and had coarser grain composition than those of forestland and alpine meadow. ② The mean grain size of different vegetation types was Picea crassifolia(6.15Ф) > Juniperus przewalskii(5.81Ф) > alpine meadow(5.22Ф) > mixed shrub(5.07Ф) > alpine grassland(5.04Ф). The sorting coefficient of different vegetation types was alpine grassland(2.65) > alpine meadow (2.45) > mixed shrub (2.33) > Picea crassifolia(2.17) > Juniperus przewalskii(2.11). The skewness of different vegetation types was alpine meadow(0.19) > alpine meadow(0.12) > mixed shrub(0.035) > Picea crassifolia(0.032) > Juniperus przewalskii(-0.05). The kurdishness of different vegetation types was Picea crassifolia(0.968) > mixed shrub(0.966) > Juniperus przewalskii(0.929) > alpine meadow(0.887) > alpine grassland(0.867). ③ There were some similarities and differences in frequency curves of different vegetation types. The peak shape of forestland and shrubs was nearly symmetrical and unimodal. The peak shape of alpine meadow and alpine grassland was multi-peaked and the fact indicates that grassland was greatly disturbed by external factors and sources were mixed.[Conclusion] In the case of natural environmental impact and high human activity intensity, the grain size of alpine meadows and alpine grasslands would be further coarsened, and the risk of desertification is the greatest, which is the type of vegetation that is relatively urgently needed for conservation in this area.

Abstract:[Objective] The canopy hydrological effects of four economic forests in Taihang Mountains, Hebei Province were studied in order to reveal their water conservation functions.[Methods] Four main economic forests including walnut, apple, apricot, and cherry in the southwest mountainous area of Shijiazhuang City were selected. The throughfall was measured by rain tube, and the stemflow was measured by trunk winding method. The hydrological effects of canopy in these forests were then analyzed.[Results] The trunk runoff and throughfall of the four economic forests increased with the rainfall. The canopy interception increases with the rainfall until which reached 45.1 mm, and later the increasing trend slowed down. When the rainfall ranged from 14.3 to 29.5 mm at one precipitation event, the canopy interception of the four economic forests was the largest with 20% of interception percentage at least. When the rainfall was constant, the canopy interceptions of four economic forests were different, with following order, cherry > Apple > walnut > apricot, which was consistent with the order of crown density. The order of trunk runoff respected the following order, cherry > apricot > walnut > apple, which was basically consistent with the order of averaged base diameter.[Conclusion] The redistribution effect of canopy on the rainfall was obvious in the four economic forests, mainly related to the rainfall, and also influenced by the forest type, canopy density, and base diameter.

Abstract:[Objective] The effects of the adoption of nitrogen and phosphorus fertilizer on the passivation effectiveness of super absorbent polymer(SAP) on heavy metal Pb and Cd in soil are studied in order to reveal the coordination mechanism of moisture and fertilizer conservation and heavy metal pollution control, and provide reference for SAP application rules.[Methods] We adopted the soil column leaching method, testing the impact of nitrogen and phosphorus fertilizer on SAP's passivation effectiveness on Pb and Cd in the contaminated soil.[Results] When SAP dosage was 1.0 g/kg in lead and cadmium contaminated soil, the effect of nitrogen conservation and phosphorus activation synergism was better. Pb accumulative leaching loss amount was reduced by 5.1% compared with comparison group without SAP, and Cd was 13.6% higher than the contrasting group. In the comparison experiment of adding nitrogen and phosphorus fertilizer in the soil, it showed that the accumulative leaching loss of Pb was increased by 76.7% when soil with SAP treatment was added with nitrogen fertilizer, the cumulative leaching loss of Cd increased by 47.6%, and the cumulative leaching loss of Pb was reduced by 26% when adding with phosphate fertilizer, and the cumulative leaching loss of Cd decreased by 20.5%; Besides, the cumulative leaching loss amount of Pb decreased by 2.3% when adding nitrogen and phosphate fertilizer compound in the soil treated with SAP, and that of Cd increased by 8.3%.[Conclusion] SAP has the effect of conserving nitrogen and activating phosphorus, and has passivation effect on Pb and Cd in soil; nitrogen fertilizer inhibites SAP's passivation effect on Pb and Cd, and phosphate fertilizer promotes the work. Nitrogen and phosphate fertilizer compound on SAP's passivation impacts on Pb was not significant, and it inhibited the SAP's work on Cd.

Abstract:[Objective] The characteristics of litter decomposition in karst forest ecosystems were studied in order to provide scientific basis for prevention and control of rocky desertification and soil and water conservation in karst forest natrue reserve.[Methods] By using 1 mm mesh pore decomposition bag, the decomposition dynamics of different tree species of leaf litters(deciduous and evergreen leaf) in different slope position for 18 months were analyzed, including the dynamic change of litter loss rate and dry weight residue rate, decomposition rate and nutrient release characteristics of Maolan Karst Forest Natrue Reserve.[Results] The decomposition process of litter showed a "fast-slow-fast" cycle, and the decomposition rate in spring and summer was faster than that in autumn and winter. The decomposition rate of deciduous tree litter was faster than that of evergreen tree litters, and the decomposition rate of litters on different slopes was characterized by downhill > mid slope > uphill. This study used the Olson model to estimate the time of decomposition of 50% and 95% leaf litters. The time required for decomposing 50% and 95% of deciduous tree litter is 0.95~1.66 a and 4.13~7.19 a, respectively. The time required for decomposing 50% and 95% of evergreen tree litter is 1.14~1.69 a and 4.92~7.30 a, respectively. The difference between them is not significant. The decomposition rate of leaf litter in the Maolan karst forest was lower than that of the evergreen broad-leaved forest and evergreen-deciduous broad-leaved mixed forest in the eastern subtropical zone, but higher than that of the karst secondary forest and plantation in the same region. The release pattern of N element in deciduous and evergreen leaves is enrichment-release mode, and the C content varies significantly with the decomposition time. The overall trend of C content is reduced, so the C/N ratio is decreasing.[Conclusion] Due to the difference of initial nutrient content and leaf physical and chemical structure of different tree species, deciduous leaf had faster decomposition rate and nutrient release rate than evergreen leaf, which played an active role in promoting material circulation of karst forest ecosystem.

Abstract:[Objective] To provide scientific basis for the formulation of relevant environmental control measures, this study investigated the ecological environment changes in mining area.[Methods] Based on Landsat images from 1989 to 2016, remote sensing ecological index(RSEI) was used to dynamically monitor the spatiotemporal variation characteristics in the Shendong mining area and its main mines.[Results] ① In mining area scale, the ecological environment quality improve gradually; the area with the middle and above level quality in 2015 accounted for 59.2% of the study area, and increased by 23.7% compared with the area in 1989. ② In mine scale, ecological environment qualities had differences among the different mines. The ecological environment quality in the Yujialiang mine was the best, while that in the Ulan Mulun mine and JinJie mine without mining were the worst. Compared with the ecological environment in the mining area, that in the area without mining was better.[Conclusion] The mean RSEI presented an overall increasing trend in each mine, which indicated that the ecological environmental quality became better gradually.

Abstract:[Objective] A suitable quality evaluation system for ecological slope protection was established to evaluate the quality grade of ecological slope protection project, and to provide a theoretical basis for selecting the slope ecological restoration method.[Methods] In combination with the system engineering theory, the ecological slope protection engineering is regarded as a complex system of "slope-matrix-plant community". A new evaluation model of unascertainty measure and set pair analysis were established to be used in the process of ecological slope protection project quality evaluation. Using unascertained measure theory, the multi-index comprehensive measure evaluation vector of each ecological slope protection scheme was calculated, and the uncertainty information in the ecological slope protection system was transformed into relatively unascertained information. The pair analysis reflects the degree of similarity, difference and inverse relation between the certainty and uncertainty of ecological slope protection system, and further improve the accuracy of evaluation. Finally, the model was applied to evaluate three alternative schemes of railway slope ecological restoration project.[Results] The quality standard of the three kinds of schemes are all level Ⅱ. The correlation numbers index were:0.384, 0.386 and 0.539, respectively. The results showed the third option (TBS Ⅱ slope protection) was the best.[Conclusion] The result of optimization was almost consistent with the calculation result of grey evaluation model and reflected the result of engineering practice well. We concluded that the method adopted in this paper is an effective new method to study the effect of ecological slope protection.

Abstract:[Objective] In order to provide scientific support for the prevention and control of water pollution in Yanhe River, the change trend of Yanhe water quality and the main influencing factors were studied.[Methods] An optimal index system was established by Pearson correlation principle to evaluate the water quality of Yanhe River. Based on the system, 283 data series of water quality(2013-2017) were analyzed.[Results] The Nemero index of Yanhe water quality increased and the water quality deteriorated year by year from 2013 to 2017. In the change of Yanhe water quality, the contribution rate of ammonia nitrogen in the evaluation index system increased year by year. It has reached 38.7% in 2017, far exceeding other pollutants. To improve the water quality of the Yanhe River, the total amount of ammonia nitrogen should be mainly controlled.[Conclusion] ① Using an index system including the four factors of ammonia nitrogen, total phosphorus, petroleum and chemical oxygen demand can make the evaluation work more simple and exercisable. ② Controlling the total amount of ammonia nitrogen into the river and improving fresh water supply would reverse the deteriorative trend of Yanhe River.

Abstract:[Objective] The influencing factors of measuring the accuracy of soil physical properties by ring knife were discussed in order to provide reference for accurate determination of physical properties of bulk soils.[Methods] Taking different types of soil as the research object, the characteristics of soil water holding capacity were determined by ring knife method, and the influence of soaking water level, soaking time, sand blasting time and filter paper on the determination results were analyzed.[Results] When the water level was above or below the edge of the ring knife, the soil water holding capacity was difficult to reach the maximum. When the water level was along the edge of the ring knife and the ring knife was soaked for 12~14 h, the soil water holding capacity tended to be the maximum. The ring knife was placed for 2~2.5 h to avoid the interference of gravity water, and the capillary holding capacity was accurate and stable. The ring knife continued to be placed for 72~76 h, and the minimun water holding capacity was representative. Ignoring the water holding weight of the filter paper in the ring knife would cause a certain deviation in the determination of the maximum water holding capacity and the capillary holding capacity, and removing its weight was beneficial to improve the accuracy of the measurement.[Conclusion] This experiment optimized and improved the existing test conditions for determining soil physical properties by ring knife method, and the test results were representative and comparable by reducing errors. It was suitable for the detection and analysis of batch soil samples.

Abstract:[Objective] Quantitative assessment of soil erosion in West Baiyanggou watershed on the north slopes of Tianshan Mountains and its distribution characteristics were studied in order to provide the scientific basis for ecological management and soil erosion control.[Methods] Taking the West Baiyanggou watershed in Urumqi County of Xijiang Wei Autonomous Region as the research area, using the methods of sampling plot survey, geographic information system(GIS), remote sensing system(RS) and CSLE model, soil erosion was assessed and the spatial distribution of erosion intensity was analyzed.[Results] The average soil erosion modulus was 748.91 t/(km²·a) in the West Baiyanggou watershed on the north slope of the Tianshan Mountains. In most areas of this watershed, the intensity of soil erosion was at weak or slight level. Strong, extreme or severe erosions were mainly distributed in the middle and lower reaches of the basin. Soil erosion was significantly impacted by the topographic factors. In the regions with slope of 20°~40°, the highest soil erosion modulus varied between 1 127.22~1 229.62 t/(km²·a). In the regions with slope < 20°, the slope factor has a positive effect on the soil erosion modulus. While in the regions with slope of 40°~70°, the slope factor has a negative effect on the soil erosion modulus. Soil erosion mainly occurred on the south slope, southeast slope and east slope, and influenced by land use types with the following rank:shrub land[1 709.80 t/(km²·a)] > woodland[1 389.40 t/(km²·a)] > natural grassland[605.20 t/(km²·a)] > artificial pasture[334.71 t/(km²·a)] > irrigated land[113.69 t/(km²·a)].[Conclusion] The intensity of soil erosion is generally at slightness and lightness level. Strong erosion, extremely strong erosion, and severe erosion are mainly distributed in the middle and lower reaches of the basin. Soil properties, slope and land use types were closely related to the soil erosion distribution in the study area.

Abstract:[Objective] The main objective of this paper is to quantitatively study soil erosion status of waste residue (such as spoil and slag) from production and construction project under natural rainfall conditions, and provide reference for soil erosion prediction in Jiangxi Province.[Methods] Based on K-means method, the local rainfall was classified into four types:A(maximum rainfall, long rainfall duration, moderate rain intensity, low frequency), B(medium rainfall, medium rainfall duration, light rain intensity, high frequency), C(large rainfall, long rainfall duration, heavy rain intensity, low frequency), and D(medium rainfall, short rainfall duration, extremely heavy rain intensity, high frequency medium rainfall). In addition, the 8 kinds of spoil ground runoff test plots were chosen to carry out quantitative research on soil erosion of spoil in the National Soil and Water Conservation Ecological Science and Technology Park of De'an County, Jiangxi Province.[Results] Through the observation of 43 erosive rainfall in 1 year, the results show that:① The rainfall pattern of A and D are the main types, B has the least influence, and C falls in between A and D. ② There is significant correlation between runoff and sediment for red sandstone(HSY),stencil red clay(SJHT), purple soil (ZSYY), coal gangue(MGS), slag soil(FZT). ③ The rain pattern above large rainfall will lead to the highest sediment yield from the single abandoned waste residue.[Conclusion] When the bare abandoned soil and slag are predicted or monitored in production practice, different types of rainfall should be selected to carry out according to the actual demand, and the largest amount of large-scale rainfall over 50 mm is predicted or observed so as to improve the prediction accuracy and reduce the monitoring cost and improve the monitoring efficiency.

Abstract:[Objective] The effects of different rooting agents on the rooting performance in sowing of stem segments of Eremochloa ophiuroides were studied in order to provide reasonably and effectively technological guidance for Eremochloa ophiuroides' function for soil protection and fast growth plantation.[Methods] Focused on some key experimental aspects in sowing of stem segments, the ratio of rooted stem to sowed stem, rooting time, and survival rate of Eremochloa ophiuroides were measured under different rooting agents treatments to select the best rooting agent and methods.[Results] In terms of rootage efficiency, the reduction of rooting time and survival rate, the indolebutyric acid(IBA, 100 mg/L) was the most efficient rooting agent for sowing of stem segments of Eremochloa ophiuroides. Fabric covering also played a vital part in promoting the rooting efficiency and rootage time reduction after sowing, while there was little effect on the ratio of survival.[Conclusion] Different rooting agents have significant effects on the sowing of stem segments of Eremochloa ophiuroides, indolebutyric acid is the best among them.

Abstract:[Objective] This paper studied the distribution rule and influencing factors of the governing valleys project in the Baota District of Yan'an City in order to provide scientific methods and management ideas for the later governing valleys project.[Methods] Based on the high-precision remote sensing image and the aerial interpretation of the aerial image of the drone, the mathematical statistics method and the quantitative analysis method were used to study the distribution rule and influencing factors of the governing valleys project through different indicators.[Results] ① In the 31 basins counted in the study area, the gully rate of 17 river basins was 30% or more, and the gully rate of each single basin increased linearly with the increase of the average elevation of the basin; ② The elevation rate of 244 elevation points in the governance project in a single watershed was counted, and 186 elevation ratios were greater than 0.38; ③ The elevation rate of 32 settlements was counted, and the 23 elevation rates were below 0.4.[Conclusion] The trench governing valleys project is distributed more upstream in the basin of the study area, and the downstream distribution is less; the governance projects in a single basin are mostly located in the middle and upper reaches of each basin; the slope has an impact on the governing valleys project, and the governance projects are mostly distributed in the branch ditch where the slope itself is moderated. The elevation rate of the residential area in the study area is relatively low, and it is mostly distributed in the downstream of the river basin. The governing valleys project has no large-scale impact on the living area of the residents.

Abstract:[Objectives] The effect of the fourth-type urease inhibitors on soil microorganisms was investigated to provide a theoretical basis for the safety evaluation of slow-release urea containing Schiff base complexes urease inhibitors in agricultural production.[Methods] Using indoor constant temperature and humidity incubation, the soil urease activity and bacteria, fungi and actinomycetes were determined at different concentrations(0.1%, 0.5%, 1% of urea application) under the condition of new Schiff copper base urease inhibitors.[Results] ① When the inhibitor concentration was 0.5% and 0.1%, the effect on soil urease activity was not significant. When the concentration was 1%, the inhibitory effect on soil urease activity was the best, and the maximum inhibition rate was 40.8%, which played the role of moderate regulation. ② Soil bacteria, fungi and actinomycetes showed different sensitivity to urea hydrolysis, among which actinomycetes and fungi were more sensitive. The maximum inhibitory rate of urea hydrolysis on soil actinomycetes and fungi was 46.4% and 89.7%, respectively. In contrast, the hydrolysis of urea can promote the growth of bacteria, and the maximum promotion rate is 83.6%. ③ The fourth-type urea inhibition could promote the growth of soil bacteria, actinomyces and fungi. The maximum promotion rate of bacteria, actinomyces and fungi is 86.2%, 31.9% and 83.6%, respectively. Therefore, it can be concluded that the fourth-type urease inhibitors have little effect on actinomycetes, while have greater effect on bacteria and fungi.[Conclusion] The fourth-type urease inhibitor has a good inhibitory effect on soil urease activity and can promote the growth of soil bacteria, fungi and actinomycetes. The optimal application concentration of the fourth-type urease inhibitor is 1%.

Abstract:[Objective] The problems of frequent flood and waterlogging disasters, poor drainage and inadequate utilization of rainwater resources in small and medium-sized riverside towns in Piedmont alluvial-alluvial plain were studied in order to provide reference for rational planning and application of rainwater storage facilities in small and medium-sized towns.[Methods] By choosing Yingqiu Town of Weifang City, Shandong Province as the research object, and according to the current drainage and land use situation of the study area, the planning steps of "sub-catchment division, land use mapping, water storage calculation, establishment of technical system and determination of construction sequence" were put forward based on GIS.[Results] The comprehensive rainwater storage and utilization system of "pervious pavement + concave green land + grass waterway, simple biological retention pond + wet pond, rainwater wetland" were adopted and its layout was planned. By introducing the hydrological sensitivity index, the order of sponge city construction in the catchment area of the township was specified.[Conclusion] This paper combines the technology of rain and flood utilization with the landscape planning of the town. The actual storage capacity of the comprehensive facilities with low impact is larger than the designed storage capacity of rainwater, which realizes the storage and utilization of rainwater resources in the town.

Abstract:[Objective] As a kind of slope disaster, the threat degree of sand-sliding slope has been increasing in recent years due to the influence of human activities. The stability of the sand-sliding slope around Lhasa City was studied in order to provide bases for the early warning and treatment of the sand-sliding slope.[Methods] By selecting the relatively typical sand-sliding disaster around Lhasa City, the paper analyzed the influence of ten factors, such as slope height, rock mass structure and annual average rainfall, on the stability of the sand-sliding slope by using analytic hierarchy process and fuzzy comprehensive evaluation.[Results] The sand-sliding slope formed by weathering-dominated rock mass was relatively high in risk level, and the whole was scattered and sandy, which was easy to spread. The sand-sliding slope formed by landslides along the road was generally low in risk level, with large debris particles and steep slope potential.[Conclusion] At present, the development trend of the unstable sand-sliding slope disaster in the area around Lhasa City is not optimistic, which should be paid more attention for relevant administrative agencies. The evaluation method in this paper is reliable, which can accurately and rapidly evaluate the stability of sand-sliding slope.

Abstract:[Objective] The water consumption and yield in the drip regulated deficit irrigation were studied by field experiment in order to provide a theoretical basis for the high yield planting of Isatis tinctoria in arid and semi-arid areas.[Methods] Water consumption and yield changes were analyzed by field trials.[Results] The water consumption in the vegetative growth period was gradually reduced with the increase of water deficit. Compared with the one of CK, water consumptions of regulated deficit irrigation reduced significantly by 4.11%~15.71%(p < 0.05). In an overall, the water consumption intensity basically showed its minimum in the seedling stage(about 0.90 mm/d). In the fleshy root maturity stage, it was larger(about 1.60 mm/d); and in the vegetative growth and fleshy root growth period, it got the largest(about 3.00 mm/d). There was no significant difference between the ones of WD₄(mild water deficit during growth and fleshy root growth) treatment and CK(p > 0.05). The yield of Isatis tinctoria reached 8 235.32 kg/hm². Treatment of WD₁(mild water deficit during vegetative growth) had the highest water use efficiency 23.62 kg/(hm²·mm), the one of WD₄ was 6.74% and its was higher than the one of CK. Comparatively, WD₄ was the best treatment.[Conclusion] Moderate water deficit had no significant yield difference with the one of CK, hence it can effectively reduce the water consumption of each growth period and correspondingly improve the water use efficiency. However, severe water deficit leads to a significant decrease in soil moisture, which is not conducive to the growth of Isatis tinctoria.

Abstract:[Objective] To solve the problem of excessive pollutants in Jiaogang Lake in Huainan City, four native aquatic plants were tested for water purification. The experiment was expected to provide a reliable basis for the use of aquatic plants to repair water quality in Jiaogang Lake.[Methods] Based on the water quality test data of Jiaogang Lake in Huainan City, Alisma plantago-aquatica, Lythrum salicaria, Acorus tatarinowii and Ceratophyllum demersum grown locally in Jiaogang Lake were selected as research objects, the removal effects of aquatic plants on TN, TP, NH₃-N and COD in water body of Jiaogang Lake were studied under simulated natural-alike conditions.[Results] The removal rate of TN was better in Lythrum salicaria, Alisma plantago-aquatica and Acorus tatarinowii. The removal rate of NH₃-N was better for Acorus tatarinowii and Ceratophyllum demersum. Lythrum salicaria had the best effect on removing TP, while for COD, the four aquatic plants had better removal effect.[Conclusion] The four selected aquatic plants have certain removal effects on pollutants. The optimum arrangement of planting area, quantity and time of aquatic plants can be used for water quality improvement of Jiaogang Lake.

Abstract:[Objective] In order to provide data support for sampling method and sampling density selection in regional dynamic monitoring of soil erosion, the influence of sampling densities on estimation precision of soil erosion factors was studied.[Methods] The paper took Mengyin County, in the Yimeng and Tai Mountains national key control areas, as the research object to calculate the precision loss of soil erosion factors estimation under 1% and 4% sampling densities. The precision loss of soil erosion factors estimation under 1% and 4% sampling densities, compared to the soil erosion factors of the county was evaluated by human-computer interaction interpretation, field investigation and statistical analysis, based on the SPOT5 remote sensing images in 2013 and 1:10 000 topographic maps.[Results] ① Under the 1% sampling density, the relative errors of S, E and K factors were 33.48%, 23.46% and 20.64% respectively, which are mainly influenced by slope, land use and soil types, while the relative errors of L, B and T factors were less than 11%. The average relative error of soil erosion factors was 14.44% in the field investigation units. ② Under the 4% sampling density, the relative errors of E, K and B factors were 15.07%, 13.94% and 10.69% respectively, which were mainly affected by land use and soil types, while the relative errors of L, S and T factors were less than 10%. The average relative error of soil erosion factors in the field survey units was 7.89%. ③ The results calculated by the element interpolation extrapolation method under the two sampling densities were higher than that of the grid calculation method. The area of soil erosion under the 1% sampling density was 19.73% higher than that of the grid calculation method, and under the 4% sampling density, it was 11.77% higher.[Conclusion] The 1% and 4% density factors of Mengyin County had different degree of precision loss, which had a certain influence on the results of soil erosion estimation. In the process of dynamic monitoring of regional soil erosion, the appropriate sampling density can be selected according to the demand.

Abstract:[Objective] This study investigated the response of three global DEM data's accuracy to different terrain factors in the Qinghai-Tibet Plateau region in order to provide support for application and research of global DEM in various fields.[Methods] This study takes GLAH14 DEM data of ICESat/GLAS as referential data to explore the responses of accuracies of SRTM DEM, ASTER GDEM and HydroSHEDS DEM to terrain factors, e.g., slope, aspect, and terrain roughness.[Results] In general, the accuracy of STRM DEM was the highest, while that of HydroSHEDS DEM was the lowest. Different terrain factors had different effects on three DEM accuracy. Three DEM errors present several trends because of aspect distribution. Specifically, positive and negative measurement deviation values in the SRTM DEM located in southern and northwestern aspects, ASTER GDEM in northwestern and southeastern aspects, and HydroSHEDS DEM in eastern and southwestern aspects. There was obvious quadratic polynomial relationship between DEM accuracy and terrain roughness expressed as fractal dimension D.[Conclusion] In the Qinghai-Tibet Plateau region, there have different levels of correlation between DEM accuracy and terrain factors, where SRTM DEM accuracy is the highest with slight influence from terrain factors, on the contrary HydroSHEDS DEM accuracy is the lowest with intense influence from terrain factors.

Abstract:[Objective] The construction of a urban integrated ecological security pattern was studied in order to provide scientific references for special studies such as urban master planning and urban ecological planning.[Methods] Taking Yanping District of Nanping City, Fujian Province as the research object, the ecological source land was selected on the basis of the ecological protection red line. The terrain gradient, land cover and vegetation cover were used as the resistance factors, and the minimum cumulative resistance model was applied to the mutation point of the ecological resistance surface histogram distribution. 2 983 and 9 268 are the boundaries, and the bottom line type, buffer type and ideal ecological security pattern of Yanping District are constructed respectively.[Results] The ecological source area of Yanping District, namely the bottom line ecological pattern, covered an area of 534.51 km², accounting for 20.10% of the Yanping District. The buffered and ideal ecological security pattern covered an area of 771.17 km² and 1 592.79 km² respectively, and accounting for 29.00% and 59.89% of Yanping District. Combining three different levels of safety and ecological security, the 13 ecological corridors and 5 key ecological nodes between the ecological sources were further clarified, and the comprehensive ecological security pattern of Yanping District was formed.[Conclusion] On the basis of the ecological protection red line, combined with the characteristics of Yanping District which is a landscape-type city, the ecological land distribution patterns of different safety levels, ecological corridors and key ecological nodes are determined, and the comprehensive ecological security pattern of Yanping District is formed.

Abstract:[Objective] The spatial distribution characteristics were studied in order for rational utilization of water resources utilization and ecological protection in the middle and upper Nujiang River Basin.[Methods] Making use of observations from meteorological stations, the performance of TRMM(tropical rainfall measuring mission) 3B43 product in the middle and upper Nujiang River Basin was verified, and then the applicability of MOD16(moderate-resolution imagine spectroradiometer) products were further examined. The spatial distribution characteristics of evapotranspiration and water yield were analyzed.[Results] ① At monthly scale, the correlation coefficient between TRMM 3B43 estimates and rain gauge observations was 0.86, indicating TRMM 3B43 data had good accuracy in the middle and upper Nujiang River Basin. The evapotranspiration obtained from MOD16 data was higher, but still had applicability. ② The mean annual evapotranspiration in the study area mainly ranged from 300 to 800 mm, and the regional mean value was 489.4 mm. ③ The spatial distribution of (P-E) was similar to that of P, while (P-E)/P(0.33) in barren areas and smaller in vegetation-covered areas.[Conclusion] The spatial distribution of evapotranspiration was heterogeneous, showing a low-high-low-high variation along the river. With widespread coverage and continuous observation, MOD16 products could provide reliable support for evapotranspiration research in lack-data watershed.

Abstract:[Objective] We carried out an assessment and regionalization of torrential flood disaster in Chongqing City to provide the corresponding reference for disaster prevention and mitigation of torrential flood.[Methods] According to the related theory of natural disaster, we established a risk assessment model of torrential flood disaster in Chongqing City with four assessment index subsystems, containing the dangerousness of disaster risk, the vulnerability of the disaster environment, the exposure of the disaster bearing body, and the ability of disaster prevention and reduction. Based on the meteorological, ecological and social economic data of Chongqing City, the assessment and regionalization of torrential flood disaster risk in Chongqing City were carried out by using the GIS spatial data analysis.[Results] The highly risk regions of the torrential flood disaster-causing factors is located in most areas of Hechuan and Jiangjin area. The highly vulnerable areas of disaster-prone environment are mainly located in the river valley along the Yangtze River and Jialing River. The exposure of torrential flood disaster bearing body is higher in Nanchuan, Wulong, Fuling and Chengkou City. The low disaster prevention and mitigation capacity areas lie in northeastern and southeastern part of Chongqing City.[Conclusion] The highest risk area of torrential flood disasters are largely located in Wuxi, Youyang, Pengshui, Jiangjin and Hechuan area.

Abstract:[Objective] In order to provide scientific basis for optimization of plant community in rural homegardens(HG), we took Langxi County of Anhui Province as a study case on species composition and diversity.[Methods] Cultivated plants of 369 HG were surveyed in ten villages in Langxi County of Anhui Province.[Results] There were 171 species belonging to 66 families and 139 genera in this area. Among them, Rosaceae, Cruciferae and Oleaceae contained more species than the others. Based on the abundance, frequency and importance value, Cinnamomum camphora and Osmanthus fragrans were the most important species in arbor layer and shrub layer, respectively. Generally, the level of species diversity was lower in each HG; however, the index of species diversity of No.1 village and No.7 village were better than that of the others in arbor layer and shrub layer, respectively. Species of ornamental plants and food plants accounted for 58.48% and 33.33%.[Conclusion] There were some problems in the rural HG of Langxi County, such as unhealthy structure of plant community, lower species diversity in each HG, overuse of some species, low utilization of native species etc. To improve the present vegetation of HG, it is key to develop the consciousness of farmers about optimization of ecological environment.

Abstract:[Objective] The development trend and main influencing factors of grain output in Hebei Province was studied in order to provide scientific basis for guaranteeing the grain security of China.[Methods] The trend of grain yield in Hebei Province from 1978 to 2015 was extracted by EMD method. The influencing factors of grain yield in Hebei Province were quantitatively studied by C-D production function and total factor productivity(TFP).[Results] The grain total output of Hebei Province displayed obvious gradualness. In details, it contained rapid increase stage, slow development stage and stagnation or even decline stage, respectively. For the grain yield influencing factors, their rank of contribution was:the planting area(51.99%) > the effective irrigated area(38.68%) > the scientific and technological progress(12.73%) > the agriculture forestry animal husbandry and fishery labor force(-2.86%) > the government expenditure on agricultural production and undertakings(-0.55%).[Conclusion] The main influencing factors to promote the growth of grain output of Hebei Province are the planting area, the effective irrigated area and the scientific and technological progress.

Abstract:[Objective] This paper analyzed the ecological footprint of water resources and its spatial and temporal changes in cities of Guizhou Province, and also of province wide values in recent 10 years, and to recognize its main influencing factors in order to provide reference for social and economic development of the province and the sustainable utilization of water resources.[Methods] Taking Guizhou Province as an example, based on the ecological footprint model, the ecological footprint of water resources and the ecological carrying capacity of water resources in the province in 2007-2016 years were calculated, and its evolution process was analyzed.[Results] ① The ecological footprint of water resources in Guizhou Province increased from 1.62×10⁷ hm² in 2007 to 1.66×10⁷ hm² in 2016. The ecological carrying capacity of water resources was less than the water demand of ecological footprint, but the inter-annual variation of ecological carrying capacity was obvious, as a result, the ecological stress index was much less than 1. The water resources had an ecological surplus of 1.779~3.827 hm²/person, so the potential for sustainable development and utilization was relatively large. ② Seeing from the changes in the per capita ecological footprint of water used in industry, agriculture, life and various ecological parts, the per capita ecological footprint of industrial water drooped significantly by 18.9% from 2007 to 2016, mainly because of the continuous reduction of ten thousand yuan GDP ecological footprint; The per capita ecological footprint of agricultural water and domestic water changed a little, which maintained at 0.085 hm²/person and 0.024 hm²/person, respectively. ③ The spatial variations of per capita ecological footprint of water and per capita ecological carrying capacity of water resources, as well as the ecological surplus in different cities and town in the Guizhou Province from 2014 to 2016 were significantly different. In an overall, the performance was significantly and positively correlated with economic development, while the central and western regions that had developed well in economy had a large demand for water resources and a low ecological surplus, and the eastern region where economy developed comparatively not well had a small demand for water resources and large ecological surplus.[Conclusion] The consumption of water resources in Guizhou Province was decreasing, the utilization efficiency was gradually improved. The development and utilization of water resources is in a safe state, and there is much room for the development and utilization, but the ecological footprint and ecological carrying capacity of water resources in 9 cities and counties of Guizhou Province were unevenly distributed, which needs to be reasonably allocated and utilized.

Abstract:[Objective] This paper studid the optimization of protecting the ecological land in a rational way in order to provide a scientific solution to the conflict between urban expansion and natural environment.[Methods] Fuzhou City was selected as the study area, this paper extracted the core ecological land through ecological importance comprehensive evaluation, then ecological land conservation zone was identified by utilizing the methodology of ecological security patterns. The conservation zone scheme was collated with the ecological protection red line which is currently administrated by the department of environment.[Results] The land cover type of the core ecological land in Fuzhou City was predominantly consist of forest and water area, and its spatial distribution emerged as a coast-inland pattern. In comparision with the ecological protection red line, the ecological land conservation zone had the advantage in the degree of landscape fragmentation and aggregation, and also with a better overall landscape connectivity.[Conclusion] Ecosystem services and ecological process would be more abundant and effective under the scenario of ecological land conservation zone. The method and conclusion from this example could not only supplement the technological process of the ecological protection red line but also improve its practicality, which is an efficient way of optimizing the ecological land protection and achieving government's goal.

Abstract:[Objective] The purposes of this paper are to evaluate the characteristics of carbon and nitrogen in soils with different proportion of arsenic sandstone and sand under different cultivation years in Mu Us sand land, and to determine whether the newly-formed soil structure can develop continuously and steadily.[Methods] Based on the data of field plots from 2013 to 2016, the temporal and spatial variation characteristics of soil organic matter and total nitrogen and the relationship between the three proportions of sandstone and sand in different planting years were studied.[Results] ① The soil organic matter and total nitrogen content of different proportions showed a steady upward trend with the number of crop cultivation years; ② In the four years, the soil organic matter and total nitrogen content of the three compound soils showed 1:1 > 1:2 > 1:5, and the difference was significantly different from that in 2013(p < 0.01). ③ There were significant positive correlations between soil organic matter and total nitrogen in the three proportions under different planting years. The correlation coefficients were 0.86, 0.89 and 0.74.[Conclusion] Proportions and cultivation years are important factors affecting the contents of organic matter and total nitrogen in newly constructed soil.

Abstract:[Objective] Taking Jiangsu Province as the research object, the ecological carrying capacity during 2001-2005 was evaluated according to its resource endowment and the degree of obstacle was diagnosed in order to provide scientific basis for the promotion of ecological bearing capacity in the area.[Methods] The DPSIR was used to construct and establish index system and then the index weights were assigned by the entropy weight method, the TOPSIS analysis method and obstacle degree model were applied for empirical analysis.[Results] The ecological carrying capacity of Jiangsu Province indicated a "N" shaped trend evolution, and the comprehensive closeness was at the poor stage. From the perspective of classification indicators, the pressure, driving and response subsystem evaluation index experienced different levels of upward trend while the evaluation index of subsystem was a downward trend, station subsystem remains stable. From the diagnostic result of obstacle degree, the response subsystem is one of the main factors that affect the ecological carrying capacity of Jiangsu Province.[Conclusion] The coupling and coordination degree of society, economy and ecology is relatively low in Jiangsu Province. It should put forward increasing investment in environmental finance, improving infrastructure construction, strengthening the construction of ecological civilization system and expanding the space for ecological development, so as to promote the improvement of ecological carrying capacity in Jiangsu Province.

Abstract:[Objective] Water quality pollution of the karst heritage site in Shibing County, Guizhou Province was studied in order to understand the causes of water pollution and to protect the river and environment of the karst heritage site.[Methods] In October 2017 and April 2018, the Huangzhou River basin in the heritage site sampling 8 representative samples of TP, TN, NH₃-N, CODMn,DO, Chl-a and other indicators for the determination and analysis, and the use of single-factor evaluation method, The mean-value index comprehensive evaluation method and multivariate statistical analysis method were used.[Results] ① Heritage site buffer overall water quality meet the national surface water class Ⅲ of the water standard, the core part water quality does not meet the national class Ⅰ water standard, main pollutants for total nitrogen. ② The water quality of the Huangzhou River basin in spring and autumn has little difference, and the water quality is better in autumn as a whole, and the water body has a strong self-purification capacity. ③ The main pollution sources are domestic sewage, solid waste and agricultural surface source pollution.[Conclusion] The environmental protection and comprehensive management of watershed water quality in Shibing dolomite karst heritage site should be paid attention to, which are to reduce the long-term use of nitrogen and phosphorus fertilizers, to prevent the free discharge and discard of domestic sewage and domestic waste.

Abstract:[Objective] The purpose of this research is to explore the correlation between land use structure and water quality in Shanxi reservoir watershed, and to provide basis for land use development and water source protection in sourthern hilly areas.[Methods] The 23 monitoring sections were set up in the reservoir area and the inflow point of the river. Sampling and monitoring were carried out in July 2017 and January 2018. The land use types of the research area were classified by using the 2016 TM image data. The whole basin was divided into 8 sub-basins by the hydrology and spatial analysis functions of ArcGIS so as to analyze the land use structure of each sub-basin. Four water quality monitoring indexes such as permanganate index(COD_Mn), total nitrogen(TN), total phosphorus(TP) and dissolved oxygen(DO) were selected to analyze their spatial and temporal distribution characteristics and to explore the impact of land use structure on water quality in different slopes of the sub-basin.[Results] The land of Shanxi reservoir is mainly forest, grassland and arable land that accounts for the 80% of total basin area. The water quality of river banks in dry season is better than that in wet season. Each water quality index was negatively correlated with the proportion of forest and grassland, but positively correlated with cultivated land and construction land. The correlation between land use structure and water quality was more obvious in wet season than in dry season. The correlation between water quality and land use types on different slopes was different, COD_Mn in low slope zone(< 15°) was positively correlated with the proportion of cultivated land, TN and TP in middle slope zone(< 15°~25°) were negatively correlated with the proportion of forest and grassland, and TN was positively correlated with the proportion of cultivated land.[Conclusion] Most of the water quality in the reservoir area were good. The forest, grassland and cultivated land are the main land use types affecting the concentration of pollutants in water at watershed scale. Cultivated land is the main source of nitrogen and phosphorus output in wet season. Forest and grassland reduce the nitrogen and phosphorus into the rivers to a certain extent, which has a positive effect.

Abstract:[Objective] The effects of human disturbance on the community structure and species diversity of wild fruit forests in the Western Tianshan Mountains were studied in order to provided a theoretical basis for the restoration and protection of the wild fruit forests.[Methods] The present study investigated the effects of human disturbance on plant diversity of wild fruit forests in Western Tianshan Mountain based on the 32 representative plots with 20 m×20 m for each plot. The arbor diameter structure, the height structure, and the species composition and species diversity index of each forest layer were used as evaluation indexes. The effects of slight human disturbance(far from the core scenic area at 2~3 km), medium human disturbance(far from the core scenic area at 1~2 km) and severe human disturbance(far from the core scenic area at 0~1 km) on community structure and plant diversity of wild fruit forests were investigated.[Results] ① From the perspective of community structure, the individuals with arbor under mild and moderate disturbance were mostly distributed in the medium diameter class(20 cm < DBH ≤ 30 cm) and medium height class(5 m < tree height ≤ 8 m); individuals were mostly distributed in low diameter class(10 cm < DBH ≤ 15 cm), medium diameter class (20 cm < DBH ≤ 25 cm) and high height class(8 m < tree height ≤ 10 m), and their community structure and mildness. The community structure of the tree layer was significantly different from moderate disturbance. ② Among the 32 plots with a total area of 1.28 hm², 93 plant species were recorded, belonging to 40 families and 84 genera; the number of species showed a decreasing trend with the increase of human disturbance intensity. The numbers of species in the community under mild, moderate and severe disturbances were:93 species, 69 species, and 51 species. The Shannon-Wiener index and the uniformity index J decreased with the increase of human disturbance intensity, and the dominance index H' increased with the increase of human disturbance intensity.[Conclusion] A severe human disturbance could reduce the plant diversity of the wild fruit forest community and result in an unstable community structure, which is not conducive to vegetation restoration and species diversity protection.

Abstract:[Objective] The temporal and spatial variation of water resources and ecological environment in Hexi Corridor as well as their spatial and temporal correlation from 2003 to 2015 were analyzed in order to provide scientific basis for promoting reasonable development and utilization of water resources and realizing sustainable development of production, life, and ecology in the study area.[Methods] Based on the GRACE gravity satellite, TRMM precipitation, and MODIS vegetation index data, this study investigated the spatiotemporal variations of water resources and ecological environment as well as their interaction mechanisms in the pixel, watershed, and region levels, using the linear regression and correlation analysis.[Results] The annual water storage in the Hexi Corridor and its three watershed areas presented a downward trend with the highest decline rate in the Heihe and Shiyang basins. There had nonsignificant trend in the precipitation in the study area, and the vegetation presented an increasing trend. The monthly water storage was positively correlated with monthly precipitation and NDVI. The annual water storage was independent of annual precipitation, while it was highly negatively correlated with annual averaged NDVI, and this relationship presented apparent spatial heterogeneity and scale dependent.[Conclusion] The rapid and continuous increase in the artificial vegetation, especially in the cultivated land, accelerated the water resources consumption and caused the decrease in annual water reserves in study area.

Abstract:[Objective] The temporal and spatial changes of ecological carrying capacity and its influence factors in Daqing City of Heilongjiang Province were analyzed comprehensively in order to provide a scientific basis for the ecological environment management of Daqing City and similar resource cities.[Methods] The ecological footprint model was used to analyze the temporal and spatial changes of ecological carrying capacity in Daqing City and other administrative regions in nearly 30 a. The PLS model was applied to screen the influencing factors of ecological carrying capacity in Daqing City quantitatively.[Results] In the past 1986-2016 years, the ecological status of the study area showed an ecological deficit. Except for the urban area, the level of ecological deficit in all regions presented an upward trend. Although the influences of externality of energy consumption were eliminated, the area of low ecological security grade in Daqing City still showed expanding trend; the ecological coordination coefficient of each region has declined to varying degrees. Except for Lindian County and Dulbert, other regions were in a state of poor coordination. During the study period, five factors, including the amount of investment in agricultural fixed assets, the growth rate of GDP, the proportion of the total industry, the total retail sales of social consumer goods and the total output value of agriculture, had significant impacts on the ecological carrying capacity of Daqing City.[Conclusion] At present, the ecological carrying capacity of Daqing City is characterized by high pressure, uneven spatial distribution and diverse factors. When making measures to increase ecological carrying capacity, we must pay attention to local conditions and conform to reality.

Abstract:[Objective] This study evaluated the potential of vacant village land consolidation under the background of rural revitalization in order to provide scientific basis for the smooth implementation of rural land consolidation work.[Methods] The analytic hierarchy process was used to select the nine factors affecting the implementation of land remediation in the vacant village, and the evaluation index system for the remediation potential of the vacant village was constructed. The entropy weight method was used to determine the weight of each indicator and establish a potential evaluation model. Based on the evaluation model of land remediation potential of Wulian County vacant village and the standardized numerical results of various township evaluation indicators, the evaluation scores and zoning of land remediation potential in the village were obtained.[Results] ① The priority remediation area includes Wanghu Town, Yuli Town, Zhongzhi Town and Hongning Street, with an average score of 0.56 and a total area of 4.40×10⁴ hm². ② The secondary remediation area includes Gaoze Town, Xumeng Town and Jietou Town, with an average score of 0.32 and a regional area of 4.31×10⁴ hm². ③ The general rectification areas include Songbai Town, Hubu Township, Shichang Township, Kouguan Town and Chaohe Town, with an average score of 0.11 and an area of 4.15×10⁴ hm².[Conclusion] Firstly, land consolidation should be carried out in priority consolidation areas, and reasonable consolidation plans and paths should be formulated. It is suggested to strengthen the propaganda of land consolidation in the secondary consolidation areas, guide properly the policies and guidelines, encourage the local government to actively lead and carry out land consolidation work, increase the economic investment in general renovation areas, and introduce rural industries suitable for the economic development of the region.

Abstract:[Objective] This paper studied the spatial characteristics of the influencing factors of cultivated land resource utilization at 35 prefecture-level cities in Hubei and He'nan Provinces from 2000 to 2015, in order toprovide reference for the protection and sustainable use of cultivated land resources.[Methods] Based on the statistical data of cultivated land resources at prefecture level in Hubei and He'nan Provinces, the relative changes of cultivated land resources were analyzed. Geographically weighted regression(GWR) model was adopted to analyze the spatial characteristics of socio-economic driving forces for the cultivated land resources changes, among which the analysis based on the residuals was emphasized.[Results] ① From the spatial pattern, the cultivated-land-reduction areas were mainly distributed in the eastern and southwestern regions. The cultivated-land-balance areas were concentrated in the central and northern regions. Most of the increased areas of cultivated land resources were distributed in the southeastern region. ② Cultivated land resources was positively correlated with local population, fixed assets investment and mechanization level of farming, and was negatively correlated with GDP. ③ The high residual values appeared in the cultivated-land-balanced area and the increased area. The low residual values were distributed in the cultivated-land-reduction area and the balanced area with smaller amplitude change.[Conclusion] Protecting cultivated land should adopt corresponding adaptive measures in different regions according to the spatial characteristics of the influencing factors.

Abstract:[Obejective] The risks of secondary disasters and its impact on nature reserves and natural heritages in Jiuzhaigou earthquake area were studied in order to provide references for post-disaster recovery and reconstruction planning, as well as for nature reserves and natural heritages protection.[Methods] Based on land use data, DEM data, vegetation cover and natural protected area and heritage data, the spatial characteristics of ecological environment in Jiuzhaigou earthquake area were analyzed and the risk level of secondary disasters was assessed. Then, the risks of secondary disasters in nature reserves and natural heritage in earthquake area was assessed.[Results] The high earthquake intensity area was mainly located in the areas over 3 000 m altitude, where the land use was dominated by forest and grassland, and the mean vegetation coverage was up to 58%. The total area of high-risk zone accounted for about 30% of the study area, which mainly near to the fault zone and steeper slope zone. Nature reserves located in the central and south of the area, and most natural heritages located in high-risk zone, while the west and north regions were low-risk zone. To some extent, the secondary disasters aggravated the ecological risk of Jiuzhaigou scenic area and natural heritage.[Conclusion] The natural heritage areas, forest and grass and animal habitats were damaged by the earthquake with varying degrees, which had a serious impact on tourism in Jiuzhaigou scenic area. Therefore, Jiuzhaigou scenic area and Jiuzhaigou natural heritage should be the priority areas of restoration and reconstruction, and strengthen ecological protection and risk prevention.

Abstract:[Objective] The change of ecosystem service value was estimated in order to provide references for major ecosystem service functions of decision-making in ecological protection, ecological regionalization, natural resources accounting and ecological compensation.[Methods] The method of unit area value equivalent factor was used to construct the secondary classification equivalent table of land use, and the ecosystem service value of each ecological environment support area in Hebei Province was calculated with land use data in 1980, 2000, and 2015.[Results] ① During 1980-2015, land use change happened mainly from cultivated land to construction land, and from other ecological land use types to cultivated land. ② The annual average value of total average ecosystem service value during 1980-2015 was 3.56×10¹¹ yuan based on the price in 2015. ③ The total ecosystem service value of of Hebei Province was reduced by 7.00×10⁹ yuan from 1980 to 2015. ④ The ecological environment support areas with the highest ecosystem service value per unit were Yanshan-Taihangshan, followed by Bashang, Hai'an-Haiyu, Beijing-Tianjin-Baoding and low plain. ⑤ Ecosystem service value of Beijing-Tianjin-Baoding decreased 15.0% from 1980 to 2015, which was the highest among different ecological area.[Conclusion] Ecological construction after 2000 played an important role in recovering and enhancing ecosystem service functions of Hebei Province.

Abstract:[Objective] To provide a theoretical reference for optimizing the comprehensive land consolidation model for the construction of beautiful countryside, the coupling relationship between the rural land consolidation project and the construction of beautiful countryside was studied.[Methods] Eleven project areas in Nanjing City were taken as an example to firstly establish the evaluation index system of land consolidation and the construction of beautiful countryside. Secondly, the entropy weight method was used to determine the weight of index, and the relative coefficient evaluation method was used to calculate the respective scores of the basic data. Then the 11 kinds of curves in SPSS were used to estimate the regression model so as to explore the coupling relationship between land consolidation project and the construction of beautiful countryside. Finally, the relationship between land consolidation project and construction of beautiful countryside was analyzed by referring to the correlation coefficient R² and the trend of the correlation curve.[Results] The relationship between the land consolidation project and the environment of countryside in Nanjing City is relatively insignificant and the correlation degree of democratic management needs to be improved.[Conclusion] For the rural land consolidation work in the future, the protection of environment should be valued, and the public participation in the project should be improved to get a better coupling relationship between land consolidation project and the construction of beautiful countryside, achieving a mutual benefit between two systems.