Abstract:Based on space for time methods, the characteristic of soil anti-erodibility in four provinces(Jiangxi, Hunan, Sichuan, Hubei) planted with ramie for different years in slope land of Southern China were studied. The results showed that:(1) With principal component analysis, the content of >0.25 mm, >0.5 mm water stable aggregate composition and rate of structure deterioration could be used to indicate the soil anti-erodibility of different slope land planted with ramie;(2) Planting ramie could increase the content of >2 mm and >0.25 mm water stable aggregate composition, while decrease its structure deterioration rate, and the effects increased with planting time. For content and rate of structure deterioration of >2 mm aggregate, the effects are striking;(3) In the four study areas, planting ramie improved soil anti-erodibility most in Dazhou, Sichuan Province, followed by Xianning, Hubei Province.

Abstract:In order to understand soil reinforcement by root, to explore the role of soil-reinforcement by roots in soil conservation under different conditions, Pinus tabulaeformis roots anti-tensile strength and anchoring force, and the root-soil composite triaxial compression apparatus tests were carried out. Results showed that tensile resistance of Pinus tabulaeformis roots increased with increasing diameter according to a power function, but tensile strength had no obvious change rule with the increasing diameter. The root stress-strain parameters were different in different curves, and the quadratic polynomial model was very reasonable to describe its stress-strain response. All of them showed the single-peak curves with elastic-plastic material characteristics. Ultimate stress and ultimate elongation had no significant correlation with their diameters. There was an approximate linear relationship between root soil friction and root diameter. The larger diameter and deeper depth of root were, the bigger root-soil interface friction and the stronger anchoring role were. With the same diameter, it was found that root-soil complex shear strength increased with the increase of confining pressure. With the same confining pressure, shear strength of root-soil complex increased with the increasing diameter, and with the same diameter and confining pressure, the increasing influence with vertical root was better than that with horizontal root.

Abstract:Semi-buried checkerboard sand-barriers were easy to be buried by sand and had short windproff duration. A novel sand prevention measure-upright checkerboard sand-barrier which was 1 m in height, 8 m in length and width was introduced, and its windproof efficiency was investigated. The results were as follows:(1) The barrier significantly reduced the incoming wind velocity, and the effect became more intensive approaching land surface. The averaged wind speed from five monitoring sites within the barrier showed a 33.0% reduction at 2 m high and 81.5% at 0.2 m high.(2) Wind velocity profiles within the barrier deviated from logarithmic curve below the height of the upright checkerboard sand-barrier(1 m). Above the barrier height, wind velocity profiles still followed the logarithm law, and wind velocity gradient was higher.(3) The average land surface roughness within the barrier region increased 44 times compared to the control point.

Abstract:Using the loess hillslope model and the artificial simulated rainfall experiment, morphological development of rill and the quantitative characteristics of morphological parameters were analyzed quantitatively under the rainfall intensities of 45, 87, and 127mm/h. The results showed that the quantitative morphological parameters of rill was not a single increase or decrease with the rainfall intensity increase, it presented the volatility changes with soil erosion development. Bare ground 1 and bare ground 2 showed different trends of change because of their different soil volume weight. A good relationship between the rill length and density and the fractal dimension of rill showed that the non-linear quantization parameter was not independent with the traditional one-factor quantization parameters. The fractal dimension as a quantitative parameter, can better reflect the change of rill length and density.

Abstract:Taking coal gangue mountain of Panyi coal mine in Huainan mining area as the study object, through the analysis of physicochemical properties, scanning electron microscope(SEM), energy dispersive spectrometry(EDS), total organic carbon(TOC) contents of weathered coal gangue, the authors preliminarily studied the distribution and release of organic carbon from weathered coal gangue, and the content of dissolved organic carbon(DOC) in soil, which was affected by accumulation and eluviation of coal gangue mountain. The results showed that the contents of TOC in weathered coal gangue decreased from the top of mountain to the mountainside, and to the foot, and with the increasing depth of sampling, the contents became higher. The contents of TOC in weathered coal gangue was positively related with the particle size, and negatively related with the weathering degree of weathered coal gangue. With the increase of time of leaching time, the soluble amounts of DOC leached from weathered coal gangue of different particle size reduced. In the 96 hours leachate, the soluble amounts of DOC tended to be stable, and the values were comparatively similar. Within the distance of 2~100 m to the foot of coal gangue mountain, the increasing distance of sampling, the contents of DOC in soil tended to decrease, and within the distance of 80~100 m to coal gangue mountain, the contents of DOC in soil were similar to that in normal farmland.

Abstract:Engineering geological characteristics of Xigeda strata in Sichuan Province was analyzed. Xigeda strata has multiple chemical composition that contains a certain amount of soluble salt, and tends to bring about chemical reaction and forms secondary minerals when submerged in ground water or surface water. This may reduce the strength of Xigeda strata and cause slope instability. Headward erosion is a kind of river erosion, and if the flow of the lateral erosion and gravity act on the slope at the same time, it would accelerate the instability velocity of slope. The main factors affecting headward erosion were analyzed using mechanical methods of soil mechanics, hydraulics etc. A generalized physical model of Xigeda strata slope was established on the basis of the unsaturated soil calculation. In order to make the model more accurate and reliable, the model took river lateral scouring and hydrodynamic pressure into consideration. Since the present unsaturated soil shear strength calculation was not unified, the stability calculation formulas of unsaturated soil slope was deduced and optimized. The stability of Xigeda strata slope was analyzed based on the headward erosion model, and the calculated stability coefficient of slope was 1.061, but slope stability coefficient under the same conditions was 1.212 using classical Bishop method. Because the coefficient calculated by the optimization calculation formula was lower.

Abstract:Using root exclusion method, and based on the field observation data of root respiration in a period of two years from an abandoned land soil in Tianlong mountain area of Shanxi province, we analyzed the relationships between root respiration and environmental factors. The results showed that the root respiration in the abandoned land exhibited a seasonal variation following the variation in soil temperature, with high values in summer and low values in winter. In terms of carbon content, the root respirations in 2007 and 2008 was 329.5 and 392.5 g/m² from March to December, respectively. Soil temperature was a main factor influencing root respiration, and it could explain a variation of respiration from 79% to 88%. Soil moisture had little impact on root respiration. The model including soil temperature and soil water content variables could explain the seasonal variation of root respiration from 81% to 89%. The percentage of root respiration in total soil respiration changed over the season between 24% and 54%. Percentage of the mean root respiration from March to December in the total soil respiration in 2007 and 2008 was 24.9% and 30.9%, respectively.

Abstract:A comparative analysis of soil physical properties and their influencing factors was carried out between soils developed from either acidic and calcareous rocks in Xiaoshengtang small watershed in the Yimeng mountainous region. The results showed that:(1) The soils developed from acidic rocks contained more gravel and sand than those from calcareous rocks. Soil textures ranged from sandy loam to loamy sand, and the gravel content increased with soil depth. The silt and clay contents of the soils were slightly higher in soils developed from calcareous rocks than from acidic rocks. However, the particle size compositions of the upper and lower soil layers were similar for soils from the calcareous rocks. Both soil types had relatively low fractal dimensions, which were influenced by the parent rock, but those of the soils developed from acidic rock were lower. Furthermore, they were both poorly developed soils with gravel contents higher than 10%.(2) Soils developed from acidic rock had higher bulk densities than that from calcareous rocks, which had higher total and capillary porosities. The bulk densities and capillary porosities of the two soils increased with increasing soil depth and, conversely, the total porosities and non-capillary porosities decreased. Furthermore, the capillary porosities were mainly influenced by soil fractal dimensions.(3) The saturated hydraulic conductivities of the soils developed from acidic rock were higher than those from calcareous rock, and they were higher in the 10-20 cm soil layer than in the 0-10 cm layer. However, the saturated hydraulic conductivities of the soils developed from calcareous rock did not exhibit consistent changes in different soil layers. Soil texture, especially the sand and silt contents, was the main influencing factor of soil saturated hydraulic conductivity in the Yimeng mountainous region.

Abstract:The properties of SMBC(soil microbial biomass carbon), q_SMBC(biological information entropy) during revegetation on hillslope land with purple soils in Hengyang City of Hunan Province were studied using the space for time method. The results showed that:(1) SMBC and q_SMBC significantly increased from bare land(Ⅰ), herbaceous community(Ⅱ), shrubby community(Ⅲ) to arboreal community stage(Ⅳ);(2) SMBC significantly decreased but q_SMBC significantly increased from soil layer of 0-20 cm, 20-40 cm to 40-60 cm;(3) From stage Ⅱ,Ⅲ to Ⅳ, SMBC in R(rhizosphere) and S(non-rhizosphere) were significantly increased, and expressed the properties SMBC_R>SMBC_S, SMBC_R/SMBC_S in stage Ⅱ was obviously higher than that in Ⅲ and Ⅳ. q_SMBCR and q_SMBCS significantly increased from stage Ⅱ to Ⅳ, and q_SMBCR<q_SMBCS, but q_SMBCR/q_SMBCS had no significant difference;(4) Correlation analysis showed:SMBC and q_SMBC highly or significantly positively correlated with soil organic carbon and cation exchange capacity(CEC), and significantly negatively correlated with bulk density.

Abstract:Soil amendment was applied by one-time in aeolian sandy soil to study its long-term effects on physical properties and the yield of maize planted in the following years. The results showed that the sandy soil amendment treatments significantly improved soil aggregate content which particle size were greater than 0.25 mm in 0-40 cm soil layer, promoted the small particle size between 0.1~0.25 mm and enhanced the transformation of particles of 0.1~0.25 mm into 0.25~0.5 mmand particles greater than 2 mm, especially in 0-10 cm soil layer at the fourth year. Compared with CK, the soil particle size between 0.1~0.25 mm in 0-10 cm soil layer of the fourth annual treatment decreased by 34.55%, and the soil particle size in 0.25~0.5 and greater than 2 mm were increased by 1.63 times and 12.31 times than CK. The soil water content, increased by 42.21%~48.48%, 32.48%~38.11%, 28.35%~34.3% and 19.15%~29.47% compared to CK in the third, fourth and first year treatment. There was a significant differences among the treatments in maize yield, the yield of treatments increased by 15.1%~59.62% compared to CK. After the first three years, sandy soil amendment treatments applied could significantly improve soil aggregate structure, water storage capacity and maize yield, which showed that sandy soil amendment has remarkable effects on soil improving and yield-increasing.

Abstract:Taking the rhizosphere soil of artificial seabuckthorn forest in loess hill and gully region of Eastern Gansu Province as experiment objects, the soil humus composition and combined form and optical properties of humic acid in different recovery stages of artificial seabuckthorn forest were investigated. The results showed that the organic carbon content in humin(HM) >humic acid(HA) >fulvic acid(FA) in different years, meanwhile, PQ(proportion of HA) of CK >the soil of artificial seabuckthorn forest of 7 years old >in 2001 soil of artificial seabuckthorn forest of 10 years >the soil of artificial seabuckthorn forest in 1995, and all the PQ were more than 52% at each layer of the artificial seabuckthorn forest soil of 15 years old. The value of E₄/E₆ and hue coefficient(ΔlgK) demonstrated that:15 years >10 years >CK >7 years; the humification degree of soil of 15 years was significantly higher than that of 10 years, CK and 7 years, which demonstrated that, along with recovery time, humification degree of soil trend to simple, and the oxidation stability of soil humic acid decreased. Meanwhile, it was adversed to the advancement of soil fertility. Therefore, artificial seabuckthorn forests should be regenerated when it was planted more than 15 years to prevent soil erosion and improve soil fertility.

Abstract:In order to explore the water-thermal conditions of different mulching treatments, and their effects on potato yield and water use efficiency in arid and semi-arid area, the field experiment was conducted, which included common plastic film(CPF), straw(S), green manuring(GM), liquid film(LF) and bare land(CK). Soil water content, topsoil temperature, yield and water use efficiency of different mulching treatments were investigated. The results showed that, compared with the conventional tillage technique treatments, CPF, S, GM, LF increased soil daily mean temperature in 0-25 cm layer by 3.62℃, 2.01℃, 1.50℃ and 2.38℃, respectively. The different mulching treatments increased the soil moisture. CPF, S, GM and LF could increased soil water content in 0-25 cm layer by 3.25%, 2.24%, 2.40% and 2.50%, respectively. Compared with CK, the tuber yield with the treatments of CPF, S, GM and LF increased by 10.33%, 23.03%, 20.27% and 27.17%. The descending order of water use efficiency of different mulching treatments was liquid film, green manuring, straw, common plastic film and CK. Therefore, liquid film had significant effect on soil water conservation and potato yield.

Abstract:Taking Larix principis-rupprechtii forest in Xiaowutai Mountain in Hebei Province as the case study, the relationships between forest growth, topography, and herb diversity were studied through field investigation and laboratory analysis. The results showed that:(1) Slope was significant negative correlation with tree height, diameter at breast height, under crown height and canopy size, but tree growth were not significantly correlated with elevation, slope position and slope shape;(2) In terms of correlation coefficients and correlation strength, the effect size of whole forest growth on herb diversity had an order as following:canopy density >under crown height >DBH >height >canopy size;(3) the Shannon-Wiener diversity index and Pielou evenness index showed a relatively stable trend with the increase of altitude from 1400 to 2000 m, and Simpson diversity index and the Menhinick richness index showed a fluctuating trend;(4) The effect of elevation, slope shape and slope gradient on herb diversity was smaller, but slope position showed a significant negative correlation with Menhinick richness index and Simpson diversity index of herbs, indicating that the impact of slope position change on herb diversity was greater.

Abstract:Taking the natural desert steppe as CK, soil stoichiometry characteristics of artificial Caragana korshinskii shrubs with different density(HD, MD, LD) of the same forest age were investigated to reveal soil C, N, P balance and internal circulation in artificial shrub-grass ecological system. The results showed that with the increase of the density, soil organic carbon(SOC), total nitrogen(TN), total phosphorus(TP) and ratio of nitrogen to phosphorus(N/P) in 0-100 cm presented an increase trend, while the ratio of carbon to nitrogen(C/N) and carbon to phoshorus(C/P) presented a decrease trend, and the variation coefficient of TP was higher than other soil stoichiometry; Vertical direction SOC, C/N and C/P showed unimodal curve with the increase of soil depth, while TN, TP and N/P showed a sharply decrease trend in 0-40 cm soil layer with the increase of soil depth, but in 40-100 cm soil layer showed a slow decrease and tended to be stable. In 0-40 cm soil, TN and TP accounted for 61.82% and 55.56% of total content, and the content of TN and TP soil could be used as artificial C. microphylla shrubs sensitive index of soil nutrients; Correlation analysis showed that N content was positively linearly correlated with P content(p<0.01), and both was significantly negative correlated with C/N(p<0.01), and indicates consistent demand of N and P content in soil for C. microphylla shrubs.

Abstract:In order to explore the differences in physiological responses of oat(Avena nuda L.) seedlings to NaCl and KCl stress, the changes in seedling growth, reactive oxygen species metabolism and osmotic adjustment in leaves of oat seedlings under NaCl and KCl stress of different concentration were investigated by hydroponics method. The results showed that:(1) At the concentration of 75 mmol/L and 150 mmol/L, NaCl stress had greater inhibition effect on the seedling growth and greater damage to the membrane lipid peroxidation than that of KCl stress, the activities of superoxide dismutase(SOD) and catalase(CAT) and the contents of soluble protein, soluble sugar and proline in the seedling leaves of NaCl stress were lower than that under KCl stress; The contents of O₂^-., H₂O₂, malondialdehyde(MDA), soluble protein and soluble sugar under KCl stress were much higher than that under NaCl stress when the concentration increase to 225 mmol/L, but the activities of SOD and ascorbate peroxidase(APX) and the glutathione(GSH) content of KCl stress were lower than NaCl stress.(2) After treated with 225 mmol/L of KCl and NaCl, the leaf water potential was-0.867 MPa and-1.034 MPa. Besides, the osmotic potential was-1.409 MPa and-1.252 MPa, respectively, indicating that the increased damage caused by 225 mmol/L of KCl was not due to the osmotic stress. Under the stress of 225 mmol/L KCl, the leaf Na⁺ content decreased by 36.5% and K⁺ content increased by 1.49 times, compared with the control, while the supplement of 20 mmol/L NaCl could increase the Na⁺ content and the activities of SOD and APX, decrease the contents of K⁺, H₂O₂, O₂^-.and MDA in leaves of oat seedlings under 225 mmol/L KCl stress significantly. The active oxygen accumulation induced by ion toxicity in oat seedling leaves could be responsible for the enhanced damage caused by 225 mmol/L of KCl than that by NaCl.

Abstract:A pot experiment including five treatments of CK(neither urea nor chicken manure was applied), N₁₀₀(100% of nitrogen was provided by urea), M₁₀N₉₀(10% and 90% of nitrogen was provided by chicken manure and urea, respectively), M₃₀N₇₀(30% and 70% of nitrogen was provided by chicken manure and urea, respectively), and M₅₀N₅₀(50% and 50% of nitrogen was provided by chicken manure and urea, respectively) was conducted to evaluate the effects of chicken manure co-applied with inorganic fertilizer on root morphological characteristics and ecological environment of 1-year PopulusבLulin-1’seedlings rhizosphere soil. The results indicated that in comparison to N₁₀₀ treatment, M₃₀N₇₀ treatment significantly increased the root surface area, specific root surface area, total root length and root volume, and obviously increased the content of total amino acids, total organic acids and total sugars in root exudates. In the meantime, M₃₀N₇₀ treatment apparently increased available nitrogen, available phosphorus, available potassium and trace element contents, but decreased the pH value in the rhizosphere soil. Besides, different fertilizer treatments had great effects on humus composition of rhizosphere soil. M₃₀N₇₀ treatment decreased the ratio of humin to humic acid, while significantly increased the humic acid contents and the ratio of humic acid to fulvic acid. However, in M₁₀N₉₀ and M₅₀N₅₀ treatments, less effects on poplar seedlings was observed than that in M₃₀N₇₀ treatment. In conclusion, chicken manure co-applied with inorganic fertilizer, especially M₃₀N₇₀ treatment, is beneficial to the root morphological characteristics and ecological environment at rhizosphere soil, which is importance to increase the transplanting survival rate of poplar seedlings.

Abstract:Different forms of water soluble nitrogen contents in surface sediment and contents of NO₃-N and NH₃-N in surface water from Longquan Lake, Sichuan Province were studied. Average contents of water soluble total nitrogen, water soluble NH₃-N and water soluble NO₃-N were 6.64 mg/kg, 1.22 mg/kg and 2.83 mg/kg in surface sediment, respectively. Average contents of NO₃-N and NH₃-N were 5.09 mg/L and 0.05 mg/L in surface water, respectively. The correlation of NO₃-N content between surface water and surface sediment was not significant, but NH₃-N content between surface water and surface sediment was significantly positively correlated, indicating that NH₃-N of surface water may be caused by NH₃-N released from surface sediment.

Abstract:Fifteen sites were selected for water sampling from the Xiaohe River watershed to study the distribution of ammonia, nitrate and nitrite and their relationship with dissolved oxygen. It was found that the contents of HNO₂-N at all the sampling sites are relatively high. Except water conservation area with a gradeⅠ of surface water quality according to the national standard(GB3838-2002), the rest sites belonged to Grade Ⅳ, which was associated with the discharges of both industrial and domestic effluents along the river system of Xiaohe River in Jinzhong section and Baima River in Shouyang section. The contents of water nitrogen have a reamarkable change in river interchange and channel slope mutation place. Three nitrogen were affected by the contents of water dissolved oxygen in different degree:the contents of NH₃-N and HNO₂-N at all the sampling sites reduced with the increase of dissolved oxygen. Influenced by NH₃-N, the contents of HNO₃-N at S₃, S₄, S₇, S₉ and S₁₂ Sites were reduced with the increase of dissolved oxygen, the contents of HNO₃-N at all the rest sites increased with the increase of dissolved oxygen. The linear regression analysis showed that only the contents of HNO₂-N had a significant correlation with dissolved oxygen.

Abstract:Using dilute plate counting method and most probable number method, the dynamic of rhizosphere soil microbial quantity was studied during cherry annual growth period under four kinds of cherry rootstocks(Cerasus pseudocerasus, Cerasus sachalinensis Colt, Cerasu smahaleb). The results showed that soil microbial quantity was positively related to the cherry annual growth stages-soil microbial quantity began to rise at germination period and quickly reached its peak at flowering, fruiting or maturation period, but decreased slightly at leaf fall period. The numbers of microbial physiological groups were significantly differences cherry rootstocks, and bacteria was dominant, followed by actinomycetes, and fungi was the least. Soil microbial quantity presented rhizosphere effects. The change trends of total amounts of soil rhizosphere microorganisms and biodiversity indices were different among cherry rootstocks. Therefore, choosing suitable cherry rootstock varieties can be beneficial to increasing the number of soil microorganisms, and create a good micro-ecological environment for the growth of cherry trees.

Abstract:In order to explore the light and heat use characteristics of crops in continuous drop frost period of later autumn and increase resource utilization thresholds of the season, LI-6400 portable photosynthesis system was used to monitor photosynthetic characteristics during rootstock growing stage of beets, kohlrabi and mustard in cold and arid North China. The limiting factors affecting the daily change of P_n(photosynthetic rate) of three crops were analyzed combined with the changes of T_r(transpiration rate) and WUE(water use efficiency). The results showed that the daily changes of P_n of three crops in continuous drop frost period were bimodal curves. Beets possessed the ability of wide region use of light radiation in quantity and quality, and its daily accumulative dry mass were 1.13 and 1.54 times than that of kohlrabi and mustard, respectively; The daily accumulative transpiration amount of beets were 1.06 and 1.25 times than that of kohlrabi and mustard, respectively, indicating that beets had the highest average daily WUE. The diurnal variation of net photosynthetic rate of three crops exist a midday "P_n inefficient" period, and the reasons may be stomata partial closure caused by leaf water loss and low photosynthetic activity of mesophyll cell. Compared with kohlrabi and mustard, T_r daily variation of beets showed a character of postponed rapidly rising stage, higher at bottom keeping stage and delayed descending stage, which make it to be the dominating crop with higher light, heat and water use efficiency, and had higher productive potential in continuous drop frost period.

Abstract:By observing meteorological elements of lakes and sand dunes in Badan Jaran Desert hinterland over the same period, authores made comparative analysis on radiation characteristics, energy balance, albedo, divergence and sand environment differences between the lake and desert surface. The results showed that the air pressure of lake surface was higher than that of the desert area, with an average of about 2.43 kPa. The drag velocity was 0.31 m/s on dune surface, while it was 0.24 m/s on lakes. The divergence field(D) had a good correlation with the vertical velocity at lake center. In the evening, when D was greater than zero, the center of the lake airflow was sinking, and the vertical velocity was negative; while in the daytime, when D was less than 0, the center of the lake flow was rising, and vertical wind speed was positive, indicating that there was a certain amount of local circulation.

Abstract:Using MSS data in 1975, TM data in 2000 and 2007 as the source of information, the current situation and change of desertification of Shaanxi Province were studied from 1975 to 2007 through a scientific desertification classification system and interpretion symbol, and suppotted with the geographic information system. The results showed that the total area of desertification was 82300 km², accounted for 40.15% of Shaanxi Province by the end of 2007. The desertification types include sandy desertification, water erosion desertification and salinization desertification. The main type was the water erosion desertification. The three types of desertification accounted for 7.48%, 32.37%, 0.3% of Shaanxi Province area, respectively. The desertification area keept reversing during the past 32 years, and the reversed amplitude of 2000-2007 was more than that of 1975-2000 years. The sandy desertification land along the Great Wall in Northern Shaanxi Province and the water erosion desertification land in Loess Plateau reversed obviously, the water erosion desertification land in Qinba Mountains of Southern Shaanxi Province reversed on the whole, at the same time, some areas was developed.

Abstract:Through analyzing the nitrogen concentration and the flow at hydrologic station of Huaxian County during 1996-2009, the characteristics of nitrogen pollution in Weihe River were discussed. The results showed that:(1) The annual mean concentration of ammonia, nitrite and nitrate decreased in the study years from 7.31 mg/L, 0.74 mg/L and 2.25 mg/L during 1996-2000 to 6.88 mg/L, 0.71 mg/L and 1.99 mg/L during 2001-2006, the average concentration of total nitrogen was also decreased.(2) The magnitude of the nitrogen average concentration in Weihe River was:ammonia >nitrite >nitrate.(3) The concentration of ammonia in the dry season was higher than that in wet and normal seasons, which was due to the decrease of flow and the increase of waste water in the Weihe River basin.(4) The point source pollution load proportion of the nitrogen pollution decreased and the non-point source pollution load proportion increased, and the general trend was that the non-point source pollution load proportion increased strikingly from 1996 to 2006.

Abstract:On the basis of preliminary judging the tide situation by tidal level, the streamline was interpreted, the flow direction was extracted and the flow velocity was represented from the Landsat TM images by the texture characteristic analysis method, such as the Gabor filtering and texture entropy calculation, then the semi-quantitative interpretation of the flow pattern was realized. The results were validated by the numerical model Mike21_FM and the average root-mean-square error(RMSE) of the flow direction of flood and ebb was 9.33°, the average fitness of flow velocity classification was 73.1%. It indicates that the remote sensing interpretation of the estuarine flow pattern by the texture characteristic analysis method to semi-quantitative flow pattern information is feasible and innovative.

Abstract:It is subjective to calculate the runoff from rainfall by soil conservation service(SCS) model due to the large differences of CN parameter among regions. In attempt to get the particularly suitable CN parameter for the red soil region, the CN parameter was calculated based on runoff and rainfall data from the observation plots of Yanjiagou watershed in De'an County of Jiangxi Province during 2001-2003. The regression analysis between rainfall and CN parameter produced the CN simulation functions for different runoff plots. The result indicated that the reliability of CN simulation functions of different runoff plots were very well. Meanwhile, it also showed the feasibility of the application of SCS model in estimating runoff volume in slope field of red soil.

Abstract:The study on vulnerability plays an important role in planning of prevention and mitigation, and risk management of regional disasters. He'nan province, suffered from frequent natural disasters, was taken as the study area, and the prefecture-level cities as basic assessment unit. Eleven independent impact factors were selected using rank correlation analysis and PCA(principal component analysis) method, and the assessment model of social vulnerability was constructed. The relative weights of each index were determined using the AHP(ainalytical hierarchy process) method, and the social vulnerability to natural disasters of each unit was assessed using the comprehensive index method. The assessment results were mapped and studied using ArcGIS software. The results showed that:(1) The social vulnerability to natural disasters presented a certain regional distribution pattern.(2) Zhoukou City, Shangqiu City and Zhumadian City were in higher social vulnerable area, belongs to level Ⅲ, Zhengzhou City, Jiyuan City and Sanmenxia City were in lower social vulnerable area, the levelⅠ, and others were in moderate social vulnerable area, the level Ⅱ.(3) The area ratio of He'nan Province in higher, moderate and lower social vulnerable area was 22.68%, 65.35% and 11.97%, respectively.

Abstract:Using different farming and coverage methods, an experiment in farmland was conducted to determine soil moisture dynamic change regulation with TRIME-IPH and miniature micro-lysimeter soil moisture tester during fallow period. The advantage of different farming and coverage methods were compared with weather and other auxiliary data. The measured data were analyzed to learn the effect of different farming and coverage measures on soil water and precipitation utilization. It indicated that traditional farming model combined with cover measures could reduce surface soil evaporation and improve the utilization and conversion rate of natural rainfall. The soil moisture of suitable treatment for farmland surface(commune+ridging+covering film, commune+ridging+covering grass and commune+flat+covering film) increased by 40.8%, 31.3% and 29.7% in 20 cm before freezing compared with conventional treatment(commune), the daily average evaporation decreased 0.36 mm/d, 0.20 mm/d and 0.27 mm/d respectively in leisure period, and the cumulative evaporation capacity decreaseed by 23.3%, 15.0% and 24.1%. Among them the inhibition of evaporation processing effect for commune+flat+covering film is most significant. Considering the factors such as cover material collection, procurement cost, leisure farm uses the commune+ridging+covering film and commune+flat+covering film are the suitable water control measures for in Minqin oasis.

Abstract:Collecting the statistical data of remote sensing and socio-economy in Three Gorges Reservoir area in 2007 and 2010, the full cover 20 km×20 km grid were adopted to generat the space plots. Based on the geo-statistical method, the spatial distribution of population carrying capacity of cropland in Chongqing section of the Three Gorges Reservoir area were simulated and analyzed. The results indicated that, the carrying capacity of cropland's profit and loss value in Three Gorges Reservoir area changed from 2007 to 2010. The carrying capacity of cropland overloaded 4.6376 million people in 2007. And in 2010, the carrying capacity of cropland had a potential space for 565700 people. The carrying capacity of cropland in Three Gorges Reservoir area had an obvious trend effect. In east-west direction, the trend effect was 1-order, and was multi-order in the north-south direction; The carrying capacity of cropland had strong spatial correlation. The spatial distribution of carrying capacity of cropland was in banding shape in the Three Gorges Reservoir area, and it reduced gradually from southwest to northeast. From 2007 to 2010, the spatial distribution of carrying capacity of cropland changed, and the capacity increased in the southwest part of nine districts, while reduced obviously in Jiangjin and Changshou Districts.

Abstract:Health evaluation of land use system is a significant foundation for improving the health of land use system and the sustainable land use of land. In view of the health on land use system's uncertainty, the authors constructed an evaluation index system based on the PSR(pressure-state-response) model, and established the health evaluation model on land use system based on the set pair analysis and the improved entropy method, and utilizing set pair analysis theory and the malleability of the original relation degree to extend the comprehensive evaluation ranking from 3 levels to 5 levels, and then conducted an evaluation of the health on land use system of China. The results showed:(1) The health of land use system in China was gradually improved from unhealthy to critical state from 1999 to 2008, but the level of "critical state" was not high in 2008;(2) Crucial constraint factors for improving land use system health include the growth rate of fixed asset investment, per capita arable land, land reclamation rate, extent of soil erosion and per capita GDP. The evaluation index system based on the PSR model can accurately reflect the relationship between various elements of the land use system health, while the set pair analysis can discover specific problems in land use system. Therefore, the evaluation index system and the set pair analysis are suitable to assess the health of land use system.

Abstract:北京市水资源短缺的问题已成为制约社会经济发展和影响社会稳定的重要因素之一,因此,如何协调北京市城市绿化与水资源的合理有效利用问题亟需得到解决。基于北京市城市绿化现状及水资源利用现状,采用尺度扩展法,计算了2012年北京市城市绿化的生态需水量,并结合北京市有效降雨利用量和实地调查数据,求得2012年北京市城市绿化的理论供水量和实际供水量。在此基础上,利用灰色马尔科夫链模型与熵值法对北京市城市绿化供水的3种来源(地表水、地下水、再生水)做出评估,得出2014年实际供水量预测值区间。2012年北京市理论供水量为5.07×10⁸ m³,实际供水量为6.86×10⁸ m³。2014年预测实际供水量区间为7.29×10⁸~7.93×10⁸ m³。评估结果表明,北京市仍存在城市绿化用水供需风险问题,并据此提出相关节水措施和建议,为保障北京城市供水安全与水资源可持续利用相关研究提供参考和借鉴。

Abstract:Based on observating the concentration data of heavy metals including Pb, Cu, Zn, Cd and Cr in the surficial sediments from the Hanjiang upstream, and the data of the content of each heavy metal distribution characteristics, the potential ecological risk of heavy metals in research area were analyzed and assessed by the method of potential ecological risk indices presented by Hakanson. The results indicated that the accumulating order for these heavy metals were Cd >Zn >Pb >Cr >Cu. The single pollution mean coefficient of Pb, Cu, Zn, Cd, Cr were 1.06, 0.83, 1.25, 1.33, 1.02, respectively. Among which, only Cu was less than 1, indicating slight pollution. The other elements were greater than or equal to 1, indicating moderate pollution. Combining with the heavy metal pollution coefficient(C_d), heavy metal potential ecological risk coefficient E_rⁱ and the potential ecological risk index(I_R) of surficial sediments from Hanjiang River, the contamination level of surficial sediments in Hanjiang upstream was slight ecological risk.

Abstract:Taking the Sheila Muren grassland as the research object, based on the comparision of soil mechanical composition, moisture content, density, porosity, organic matter content, alkaline hydrolysis nitrogen, available phosphorus, available potassium and other indicators in degraded grassland with different terms of enclosure, the effects of enclosure on degraded grassland soil properties was explored. The results showed that with the increase of enclosed years, 0-20 cm layer soil clay content and porosity increased, but the bulk density and moisture content gradually reduced year by year in grassland. As the enclosed time going on, the soil available potassium content reduced, but soil organic matter, available phosphorus and alkaline hydrolysis nitrogen content increased gradually. Regression analysis results indicated that the change in soil organic matter, alkali-hydro nitrogen, available phosphorus and available potassium content had significant correlation with enclosed years. Thus, it can be seen that enclosure is an effective measure to promote soil improvement and vegetation restore in degrded grassland.

Abstract:Selecting the subsidence area of Shenfu-Dongsheng Mining area as the experimental samples, using the orthogonal test, the authors analyzed the effect of water content and survival rate of covering materials, water-retaining agent application amount and fertilizer ratio were analyzed. The results showed that:the influences of covering materials, water-retaining agent application amount and fertilizer ratio on survival rate and soil moisture content of Amygdalus pedunculata Pall. were significant different, and the order of influence degree was:covering material >water-retaining agent application amount >fertilizer ratio. Under water retention measures which including plastic film mulching, water-retaining agent(60 g), ration of local soil and fertilizer(4:1), soil moisture content was up to 17.11%, and A. Pedunculata Pall. reached the highest survival rate of 80.5%. Soil moisture content of no water measures was 8.59%, and survival rate was just only 30.13%. The best water retention technique measures combination for A. Pedunculata Pall. was:plastic film mulching with water-retaining agent(60 g) and fertilizer ratio(4:1).

Abstract:Three types surface soil from Datong coal mine subsidence in Huainan City of Anhui Province were collected for remediation evaluation. Sample A was from the control area with a mixture plantation, sample B was taken from an area with chemical waste filling, and sample C was taken from an area with coal gangue fillin. The physical and chemical properties, and the occurrence characteristics of Cr, Cd, Cu, Pb, and Hg of the samples were analyzed, and the environmental effects of the soil restoration were assessed. The results showed as follows:First, in the three samples, available P content in area A >area B >area C, but available N in area C >area A >area B, and content of heavy metals and exchangeable Na⁺ of area B was higher than in other areas, and in particular, the ESP(exchange sodium percentage) content was up to 22%; Second, high alkalinity of the filling soil was widespread, showing a serious lack of available N and P. The soil fertility in area A >area C >area B. Third, the levels of heavy metal pollution found in the soil showed that area A reached slight levels, area B reached moderate to high levels, and area C reached different types of heavy metal pollution. The total content of Cr, Cd, Cu and Pb in the soil was, to different degrees, greater than that found in typical Huainan City background values; Fourth, the effect of the soil restoration in subsidence sample C was superior to subsidence sample B, and the environmental problems of the soil in area B was severe, it should be improved promptly.

Abstract:Based on RS and GIS techniques, land use information of Xiamen City was extracted from four Landsat images in the years of 1994, 2000, 2006 and 2013. By the methods of transition matrix, dynamic degree model, transition probability matrix and Markov model, the dynamic change characteristics of land use in Xiamen City during the recent 20 years were analyzed, and the tendency of land use change in the next 10 years was also predicted. The result showed that land use changed with higher speed and then decreased, and there were about 46.75% areas changed in recent 20 years. The overall characteristics of land-use change fit well with the city development strategy to become the economic leader in West Coast Economic Zone, and strengthen the marine economy. The change of construction land will still be the leading type of land use change in Xiamen City from 2014 to 2023, and it is necessary to protect farmland and forest land to promote sustainable development of land use.

Abstract:Based on analyzing of debris flows in Dianhuying village of Yuanshi County, Hebei Province, by using of extenics analytic hierarchy process(EAHP) method, 12 indicators were seleted as the assessment factors to evaluate debris flow risk degree. The debris flow risk assessment model was established for Dianhuying village. Then the model was applied to assess the risk degree of local debris gullies. The result has good consistency with the actual situation. It is practical and effective to evaluate the debris flow risk in Dianhuying village of Yuanshi County, Hebei Province, by using EAHP method.

Abstract:Using the independently made undisturbed soil column, the authors analyzed the migration rule of carbendazim as added in vegetable land with acidified black soil, and studied the inhibiting measures by regulating soil pH value and organic matter contents. The results showed that:(1) Soil pH value increased from 5.1 to 6.2, carbendazim leaching amount peak was delayed, and the total amount of leaching decreased by 31.3% compared to the control after application the hydrate lime.(2) When soil organic matter content was increased from 21.2 g/kg to 30.7 g/kg, the total amount of carbendazim adsorbed by soils decreased by 23.7%.(3) When addition of the hydrated lime and straw in soil at the same time, carbendazim leaching peaks were delayed too, and the total amount of leaching was 46.0% lower than that of the control. The effect of mixed application of the hydrated lime and straw on leaching delay was better than that of single application of hydrated lime or straw, but it was slightly lower than the sum of the hydrated lime and straw.

Abstract:Based on the GIS, the geographic database was constructed through metrological data analysis, field survey, filed sampling and laboratory analysis, digital elevation model(DEM) calculation, remote sensing interpretation. The soil erosion amount in the Danjiangkou reservoir region was evaluated with the universal soil loss equation(USLE). The economic loss of annual soil erosion was evaluated(with constant price in 1990) by applying market value approach, opportunity cost method and shadow engineering price method. The results showed that the average annual soil erosion modulus was 2394 t/(km²·a). After converting the annual soil nutrient loss to standard chemical fertilizer(i.e. Diammonium phosphate and Potassium chloride) and fuel wood with some conversion coefficients, the corresponding economic loss of total N, total P, total K and soil organic matter were 1.64×10⁸,7.25×10⁷, 1.17×10⁷ and 2.97×10⁷ yuan, respectively. The annual average soil erosion loss was almost euqual to 61.94 km² land abandoned, and the economic loss was 3.71×10⁷ yuan. The economic losses of water conservation decreased, silt retention and sediment deposition, which were caused by soil erosion. were 3.22×10⁵, 1.88×10⁷ and 1.95×10⁶ yuan respectively. Total annual economic loss of soil erosion in the area reached up to 1.50×10⁹ yuan, in which the nutrient loss was accounting for 96.11%.

Abstract:Environmental economic principles were utilized to analyze and evaluate the environmental achievements and benefits of measures to construct ecological and clean-type small watersheds in Beijing City. The value calculation model of efficiency of land renovation, forest ecological, wetlands, grass planting, sewage and litter management and engineering measures were developed to compute the benefits of each practice. The ecology and assets values of construction measures for 3 typical small watersheds in Changping District were analyzed. The results indicated that ecological value were concentrated in the ecological restoration area in Guozhuang and Dashipo small watersheds, which covered 99.99% and 99.42% of its total ecological value, respectively, but it was centralized in ecological management area for 96.99% in Yangtaizi. Nevertheless, the assets values of all the 3 small watersheds were centralized in ecological management area, and the percentage of the total assets were 99.67%, 96.16% and 91.89%, respectively.

Abstract:The root system of five-year-old Populus×euramericana cv.‘Neva’were manually pruned with a sharp spade at distances of six, eight and ten times DBH(diameter at breast height) from both two sides or four sides prior to buds break, to analyze the effects of different root pruning treatments on biological characteristics of the rhizosphere soil. The results indicated that:(1) The root pruning treatment of eight times DBH from two sides significantly increased the concentrations of the available P and organic matter in the rhizosphere soil, and increased total amino acids and total organic acids in the root exudates in contrast to the control. At the same time, the microbial populations and enzymes activities in the rhizosphere soil were also enhanced, showing 20.61%, 18.87%, 36.92% and 22.97% increases in the activities of urease, alkaline phosphatase, polyphenol oxidase and invertase enzymes compared to the control, respectively. However, the root pruning treatment of eight times DBH from two sides obviously decreased the available N concentration and pH value in the rhizosphere soil.(2) In comparison with the root pruning treatment of eight times DBH from two sides, the root pruning treatments of eight times DBH from four sides, ten times DBH from two sides, as well as ten times DBH from four sides had less effect on inproving physio-chemical and biological characteristics of poplar rhizosphere soil, which were still better than the control. In addition, the root pruning treatments of six times DBH from two sides as well as from four sides had the least effect on the physio-chemical and biological characteristics in the rhizosphere soil among all the treatments. In conclusion, the root pruning was beneficial to the ecological environment of rhizosphere soil at the eight times DBH distance along both inter-row sides.

Abstract:Taking upstream watershed of Qingshui river as an example, the typical watershed in western mountainous area of Beijing City, Geographic Information System(GIS) and SCS(Soil Conservation Service) were used to estimate the collectable rainwater resource of different land-use types from June to August in different hydrological frequency years, which are dry year, normal year, and wet year.In addition, the SCS-CN computed runoff data and the observed data which were selected from 10 times rainfall during June to August in 2008-2009, were used to analyze the errors and to test the accuracy of SCS-CN. The results showed that:(1) The collectable rainwater resource calculated from June to August in different hydrological frequency years were 7.16×10⁷ m³,10.36×10⁷ m³ and 5.71×10⁷ m³, respectively, accounted for the average percentage of 82.43%;(2) The percentage which rainwater resource of different land-use type collected from June to August in normal year were as following:lawn and woodland accounted for 86.13%, farmland and garden plot accounted for 4.87%, industrial and mining warehouse land, residential and other land use types accounted for 9%, respectively;(3) Comparing the computed runoff data with observed data, the acceptability was 90%.

Abstract:Ecosystem service function is the core of ecosystem evaluation and research hotspot of ecology/environmental economics. Qinling-Bashan Mountains which lies to the upstream of the Hanjiang River is one of the important water supplying and conserving area for China. In recent years, the degradation of forest ecosystem and the capacity of water supplying and conserving in the area have been restricted by both of the natural and human being factors. The dynamic changes of water conservation founction in the Upper Hanjiang River were analyzed by making use of In-VEST model. The results showed that the amount of water conservation of forest ecosystem in the upstream of Hanjiang River was 120.79×10¹⁴ m³ meters, The maximum depth of water conservation was 362.51 millimetres, the average depth of water conservation was 80.69 millimetre. The water conservation evergreen broad-leaved forest was the largest compared with other forest landscape, and the tree garden was the least. From the perspective of space, the amount of water conservation in north and south of Qinlig-Bashan Mountains area was larger, and water conservation function was obvious.

Abstract:Based on the AVHRR NDVI data and climate data from 1982 to 2006 in the Mongolian Plateau, the temporal and spatial variability of vegetation and its affecting factors were analyzed. The results showed that:(1) The vegetation of Mongolian Plateau had improved as a whole during the recent 25 years with the 0.0006 per year increase rate of annual NDVI. Mongolia had the largest annual increase rate(0.0008 per year), followed by Inner Mongolia(0.0004 per year), Ningxia(0.0003 per year) and Gansu(0.0001 per year) Province of China.(2) The trend of vegetation had obvious differences in spatial and seasonal characteristics. The vegetation in Northwest Mongolia and the Xilinguole of Inter Mongolia had significantly improved in recent 25 years, while the Hulunbeir of Inner Mongolia showed degrading trend. The vegetation had significantly improved in spring and autumn, while degraded in summer.(3) The change trend of vegetation was affected by temperature and precipitation to some extent. Rising temperature extended the length of growing season, which promoted the vegetation growth in spring and autumn. Rising temperature together with reducing precipitation resulted in vegetation degradation in summer.(4) The increased area and yields of grassland and cropland, directly or indirectly, led to NDVI increased, and the other human activities, for example, increased population, changed land cover/land use, returning farmland to forest, overgrazing, exploitation of mineral resources, may also have impacts on the vegetation changes.

Abstract:Applying the data of industrial energy consumption from 1997 to 2011, the data of energy consumption per unit of GDP in districts or counties of Xi'an City in 2010 were estimated, and the model to analyze the carbon emissions driving factors was built by using STIRPAT model. The results show that all kinds of carbon emissions presented generally, an increasing trend during 1997-2011. Carbon emissions, carbon emissions output and per capita carbon emissions and carbon emissions per unit area of land presented significant regional differences in each district or county. Moran index showed that the spatial correlation of carbon emissions in each district or county was positive correlation, and the spatial distribution feature of carbon emissions was that:the district or county with higher carbon emissions tended to aggregate to the one's of the higher, the district or county of lower carbon emissions tended to aggregate to the one's of the lower. The STIRPAT model showed that:the influence degree of economic development, population scale, industrial structure and technical level on carbon emissions was different. Moreover, economic development played the decisive role on increasing carbon emissions, but the industrial structure optimization had inhibitory effect on the increasing of carbon emissions.

Abstract:Based on Spot Vegetation data, using the methods of vegetation phenology analysis, Hurst index and partial correlation coefficient, the spatial and temporal variation characteristics of vegetation phenology, developing trends and driving factors on Loess Plateau in Shaanxi-Gansu-Ningxia region during 1999-2010 were analyzed. The results showed that:(1) The average phenology in the region from 1999 to 2000 showed the characteristics of the latitudinal zonality. At the higher latitude area, the start of growth(SOG) was delayed, the long of growth season(LOG)was shorten, and the end of growth season(EOG) was advanced. On the contrary, the SOG was advanced, and the LOG was extended, and EOG was delayed.(2) The Hurst index of the phenology in the region during 12 years was showed that the synthetic sustainability area was greater than the anti-continuity area, with the weaker sustainability changing, and the area was general distributed in east-west orientation.(3) The phenology in the region was affected by rainfall, and related to the latitude and river network. The temperature in the lower latitude was higher, it could promote the vegetation to absorb more moisture, thus, the vegetation turning-green was advanced and the growth cycle was extended in the area of lower latitude or rich in water resource; On the contrary, the temperature in drought and higher latitudes was lower, the stagnation of vegetation growth was advanced, and the growth cycle was shorten.

Abstract:In the Loess Plateau, restoring vegetation(grass, shrub, or tree), as the core of the ecological construction, directly caused the changes of the land use patterns. Based on the land use data of 1985, 1995, 2000 and 2008, using GIS and statistical methods, the authors analyzed the spatial-temporal changes of land use of Wuding River basin located in the middle reach of the Yellow River. The results showed that grassland had always been the dominant landscape, and recovering forest and grassland were the main form of ecological restoration through combating desertification and restoring vegetation. With the implementation of the grain for green project, forest and grassland expanded significantly, while the farmland area had been declining. Around 1995, the mutual transformation between land use types was more obvious, and the land-use comprehensive dynamic change rate was reached maximum level. Droven by the vegetation restoring, the gravity center of land use types moved significantly. The main features of the migration was that the core of farmland moved towards east of the downstream area, while the core of forest and grassland moved northwest on the whole.

Abstract:The snow melt runoff in different scale observation sites of slope, mini watershed and small watershed were monitored during past four years in the typical black soil area of Northeast China. The results showed that the beginning and duration of snow melt runoff was determined by the daily maximum temperature and the amount of snowfall in the winter. The runoff coefficient of snowfall was much larger than that of rainfall, and the annual amount of snow melt runoff was even more than that of rainfall in some years. The runoff coefficient in slope scale was larger than that in watersheds. The amount of snow melt runoff in small watershed could figure out the amount of snow melt into river. The runoff coefficient of snow had a large fluctuation, from 3 percent to 83.6 percent during the past four years, and annual mean runoff of snow melt was 59.3 percent of runoff of precipitation. Hence, the snow melt runoff can not be neglected in runoff monitoring.

Abstract:Based on RS and GIS, taking the ETM data in 1999, vector data in 2009 as the data source, the temperal-spatial change characteristics of land use/cover of Delhi City in Qinghai Province from 1999 to 2009 were analyzed, and the evolution trend of land use/cover in the next 20 years was predicted with the Markov model. The results showed that, grass land was the main type of land use, the area of grassland reduced largestly, and the reduced area degenerated to unused land. The area of unused land reduced was next only to grassland, and the reduced area mainly transformed to woodland. The area of arable land reduced next to unused land, and the reduced area also mainly transformed to woodland. The area of woodland increased at most, mainly from the conversion of arable land and unused land. The degree of spatial dynamics of arable land was the biggest, followed by woodland. In the next 20 years, the area of arable land and grassland in Delhi City will continue to decrease, and woodland and construction land continue to increase.

Abstract:For comprehensive understanding, effective managing and protecting the saline-alkali soil of Luyang Lake in Weinan City, Shannxi Province, the authors analyzed the physical properties and salinity characteristics in the region. The principal component analysis combined with norm values were employed to select the indexes and establish the minimum data set, in which, organic matter, alkali-hydrolysable N, available P, available K, ESP, CEC, conductivity, and soil bulk density were selected as indexes for evalulating soil quality. The results showed that the soil texture was relatively heavy with more clay. The values of membership functions of the indexes revealed that organic matter(0.31), alkali-hydrolysable N(0.39), available P(0.26), and available K(0.38) were the major limited soil nutrients factors in the region. The membership degrees of soil bulk density, CEC and ESP were 1, 0.64 and 0.61, respectively, it indicated that the soil was compacted, but the alkaline was very extremely high. In short, the comprehensive index was 0.277 calculated by using the weighted index summation method to evalulate the soil fertility, which illustrated that the soil fertility in this region was at a low level. Therefore, it need to take appropriate improvement measures to improve soil fertility in Luyang Lake region.

Abstract:Aiming at resolving the ecological restoration suitability division problems within ecological restoration engineering construction in large-scale area, the authors evaluated the suitability of ecological restoration and zoning in Tongbai-Dabie mountains area by adopting the grading combination of dominant factors and thematic map overlay analysis methods. The results showed that:(1) The three dominant factors including geomorphological type(altitude), land cover type and the ground slope were proposed as the indexes for suitability assessment and zoning of ecological restoration.(2) According to the suitability degree in implement of enclosure measures(to promoting ecological natural restoration), the three levels in ecological restoration suitability including the "appropriate", "temporarily unfit" and "unfit" in Tongbai-Dabie mountains area was got in order to evaluate and determine ecological restoration suitability in different areas.(3) The Tongbai-Dabie mountains area was divided into two ecological restoration districts, four subdistricts and sixteen facilities in accordance with their ecological restoration suitability. The research could provide effective scientific basis and technical support for the ecological restoration projects in Tongbai-Dabie mountains area in soil and water conservation.

Abstract:Based on river structure data in 1960s, 1980s and 2009, the change characteristics of river structure of urban central area in Hangzhou City of Zhejiang Province nearly 50 years were analyzed with river density, water surface ratio, development coefficient, river network stability, connection rate and practical combination degree from aspects of quantity, structure and connectivity features. Results showed that:(1) The length and area of the whole river network showed a decreasing trend except that in the secondary river in 1960s-1980s had a small increase. River density and water surface ratio showed decreasing trends since 1960s.(2) Compared with 1960s, development coefficient of river network increased in the secondary river and reduced in the tertiary river in 1980s, which decreased in 2009, the river stability also decreased.(3) River connection rate and practical combination degree decreased, which made the river connectivity decrease slightly in 1960s-1980s. While in 2009, the river connection rate and practical combination degree decrease dramatically, the river connectivity also decreased distinctly, which made the flood risk increased simultaneously.

Abstract:Based on catastrophe theory, an evaluation system of flood disaster-bearing bodies' vulnerability was constructed by indexes of the conditions of population, economy, lifeline engineering and environment. Then, the model was used to evaluate the vulnerability in Xiangqiao district in Chaozhou City of Guangdong Province during 2000 to 2010. The results showed that vulnerability in Xiangqiao district decreased in fluctuation, and it had two turning-points in 2004 and 2008, the main influencing factors of which were population growth and vegetation coverage rate. Several measures should be taken to reduce the vulnerability of flood disaster-bearing bodies in the study area, which include to control the increase of population, to increase the coverage of vegetation, and to increase the density of drainage pipe network.

Abstract:According to 52-year precipitation data from 20 meteorological stations in Ningxia Hui Autonomous Region from their establishments in 2012, the mathematical analysis methods such as the trend line method and 5-year moving average method were applied to analyze the precipitation variation characteristics in more than 50 years, and the precipitation Z index and the precipitation anomaly indicators of plus or minus 20% points were also used to analyze the characteristics of droughts and floods in the region, then a trend judgment of the droughts and floods was made based on the symmetry of information forecast theory and commensurable calculation method. The results showed:(1) The precipitation in more than 50 years of Ningxia region was reduced at a rate of 8.57 mm/10 a, and the arid trend was obvious since 1990s;(2) The drought and flood disasters occurred alternately, the frequency of drought and flood was 32.7% and 28.7%, respectively, and it was only 38.5% in a normal year;(3) The droughts and floods occured with obvious characteristics of symmetry cycle, the drought years may occur in 2014 and 2015, floods may occur in 2017.

Abstract:Based on the field vegetation investigation of Yihejigede Lake in the Badain Jaran Desert, biodiversity was studied, and the relationship between vegetation and mega-dune morphology was analyzed. The results showed that there were less vegetation types in the study area, mainly composed by xeromorphic species, the vertical distribution and differences of vegetation communities was obvious. Vegetation in the study area belongs to 9 species, 9 genera and 6 families, from the top to the bottom of mega-dunes vegetation communities changed from herbaceous community to shrub communities to herb or subshrub community. Agriophyllum squarrosum distributed in the leeward slope, but Corispermum patelliforme and Artemisia blepharolepis distribuled in windward slope; The overall community diversity showed that diversity index was higher in the middle of both mega-dune slopes, and evenness index was higher in the top of leeward slope and the middle of windward slope. The hierarchical community diversity showed that diversity index and evenness index had little difference for herb community because of the relatively single species, the shrub community in the middle of windward slope had the maximum diversity index. The feature of vegetation communities was affected by the whole morphology of mega-dunes, there existed a well corresponding relation between the vegetation characteristics including distribution and diversity in the windward slope and the physiognomy morphology with order 1 and order 2 of mega-dunes. In a broader development period of desert, the sparse vegetation may play an important role in maintaining the height of mega-dunes through influencing sand transport rate and then intercepting the sand.

Abstract:Xiaojia Gully is a typical debris flow gully in the earthquake zone near Yingxiu town which located in the left of Yuzi River, and has a drainage area of 7.19 km² and an average longitudinal slope of 485‰. Many debris flows occurred in this gully after Wenchuan earthquake. In August 14, 2010, a large scale debris flow(the volume is about 6.50×10⁵ m³) was triggered by heavy rainstorm, blocked the Yuzi River and caused dam-breaking disaster. Xiaojia Gully was risky because of its large amount of loose materials and abundant rainfall. The Yingxiu part of S₃₀₃ highway would be interrupted if the debris flow occurs. The Yuzi River would be blocked in the condition of large scale debris flow, and the dam-breaking flood could potentially cause damage to the newly constructed Yingxiu Town. At present, the gully still had 5.22×10⁶ m³ of solid materials, of which about 2.02×10⁶ m³ was prone to debris flow in the future when it encounters great rainstorms. Analyzing the activity characteristics of Xiaojia Gully debris flow after the earthquake based on formation conditions, the brief ideas for Xiaojia Gully debris flow control were discussed.

Abstract:The correct interpretation of stoichiometric characteristics can promote the understanding of C, N, P circulating law within the ecosystem. Through sample plot survey and sample collection, the C, N and P content of several arbor, shrub, grass and litter were determined, and the element stoichiometric characteristics of several plants were systematically analyzed in Lüliang mountainous region. The results showed there were differences between the same element content of different organs of the same species, and also between the same element content of same organ of the different species. It indicated that the plant genetic characteristics and different function of organs determines the difference of stoichiometry. The same element of shrub's organs were significantly correlated, indicating that organs of plant individual decided collectively the stoichiometry. The stoichiometry of grasses was similar to shrubs. C, N, P content and the C/N, C/P, N/P radio were significantly related to local environmental factors. Slope had a significantly negative relation on the content of C and N/P. Crown density was only significantly correlated to C/P ratio, and altitude factor was significantly correlated to all measurement indexes except of N/P, indicating that environment, energy and material flows of plant had an influence on stoichiometry.

Abstract:Taking Changting County of Fujian Province as a study area, based on the geomatics technology, the amount of soil and water loss was calculated by using USLE(universal soil loss equation). Then combined with the green biomass of every town, the model of quantitative description of the relationship between these two factors was established. The result showed that the green biomass of unit area was negative correlated to soil and water loss obviously, the R² of each model was more than 0.5. The research conclusion can provide support for decision-making of regional forest management and soil and water conservation.

Abstract:Mu Us sandland with dry climate, scarce water, and fragile ecological environment, is very sensitive to all kinds of anthropogenic disturbances. Coal Mining resources in this region is bound to increase the burden on local environment, and make the ecological environment worse. Taking Dabaodang coal mine as an example, the number of patches, shape index, diversity index and other indicators were analyzed through field investigation, to find out the type and distribution of natural vegetation, using geographic information system technology and surface subsidence prediction model, and vegetation landscape pattern change caused by coal mining was predicted. The results showed that after coal mining, the landscape fragmentation increased, patch shape was complexitied, the landscape heterogeneity decreased, and the vegetation biomass reduced. The vegetation types changed. Bushes originally had Sabina vulgaris, Salix psammophila, Astragalus adsurgens as the dominant species of succeed to shrubs which was dominated by species Artemisia ordosica. From the change of whole mining area, there are some disturbance of coal mining to the natural ecological system, but was not cause the radical change, the natural ecological system still had certain recovery and control ability. A series of biological and engineering measures should be taken to promote ecological environment of the mining area to the direction of sustainable development.

Abstract:Based on the annual air temperature and precipitation data of 46 meteorological stations from 1961 to 2012 in the farming-pastoral ecotone of Northern China, the climate variation of temperature and the spatial-temporal characteristics of the drought and flood in the entire region were analyzed using the methods of climate trend rate, Mann-Kendall test and Kring interpolation. The results showed that:(1) In the past 52 years, the climate showed a warming and drying trend in the farming-pastoral ecotone of Northern China, and the trend had been enhanced after 1986.(2) The variations of temperatures and precipitation showed different characteristics in different spatial and temporal scales.(3) The drought and flood level was rising in the entire region and the three sub-zones, and showed a remarkable difference in different regions.(4) The distribution of flood disaster was in patchy shape, and that of severe droughts was in speckled pattern. Overall, the region was relatively more prone to drought, there was relatively more susceptible to floods in the northeastern section, more susceptible to drought in Northern China.

Abstract:Soil and water conservation, as an integral part of the eco-civilization development, needs an innovation-driven national strategy to speed up the science and technology development and promote the progress of preventing and controlling soil and water loss. The authors summarized the roles of science and technology development in soil and water loss control in different industries of China, and analyzed the situations and potential of science and technology in soil and water conservation. Then we proposed key points for the development of science and technology in soil and water conservation at present, which include transforming governmental functions, increasing the investment in the science and technology, and enhancing the infrastructure management. We also need pay more attention to the development of disciplines and scientific and technological talents, and science and technology coordination.

Abstract:The effect of different agricultural land use types on soil properties and soil environment in Yanqing County of Beijing City were studied to provide the basis of agricultural soil utilization and sustainable development for Beijing City. The results showed that the soil pH value, organic matter content and alkaline hydrolysis nitrogen content in grain field, vegetable fields and orchard were significantly lower than those in woodland. The As, Cd, Cr content in surface soil of four different agricultural land use types had 0.93 mg/kg, 0.09 mg/kg and 15.3 mg/kg higher than the soil background values, respectively. The heavy metal content of grain field and vegetable field in plough layer were higher than that of woodland and orchard. Nemerow index and the single pollution index evaluation showed that there were non-pollution in the four different agricultural land use type. Although the soil environment quality was at safe level, the highest value of single pollution reached 74% of the alarm value, but the single pollution index showed the soil heavy metal accumulated rapidly in the area. For example, the content of As and Cd in grain field increased by 20.9% and 38.5% than the forest returned from farmland. The soil pollution will be further intensified if uncontvoued.

Abstract:To discover the characteristics of nitrogen pollution, the authors collected and studied water samples from the upstream of Hanjiang River for six times in 2011. A careful examination of the samples revealed that the average nitrogen concentration in the forms of ammonia nitrogen(NH₃-N), nitrate nitrogen(NO₃-N) and nitrite nitrogen(NO₂-N) was 1.037 mg/L, 1.751 mg/L, and 0.044 mg/L, respectively. The annual distribution curve of NH₃-N concentration fell into the double-peak pattern with the highest concentration in flood season, relatively low concentration in dry season, and the lowest in normal water period. The annual distribution of NO₃-N concentration fell into the single-peak pattern curve with the highest concentration in flood season, relatively low concentration in dry season, and the lowest in normal water period. The annual distribution of NO₂-N also fell into the single-peak pattern curve with the highest concentration in flood season, relatively low concentration in the dry season and common water period with little difference. The spatial distribution of nitrogen pollution demonstrated increasing in concentration of NH₃-N and NO₃-N at first, and then decreasing in these two types of pollutants all the way from the source to the downstream part of Hanjiang River. The source of the NH₃-N pollution mainly comes from rural domestic waste water, and livestock and poultry breeding. NO₃-N pollution is mainly due to soil erosion.

Abstract:Rural residential land is the mainly settlement form for rural people in China. Taking Xingyi Town in Fengdu County of Chongqing City in hilly and mountainous areas of Sourth-West China as a study area, an evaluation system for effects on rural residential land layout was set up based on ArcGIS spatial analysis, mathematical statistics, SPSS clustering analysis and other research methods. And then the rural residential land use of every zone in Xingyi Town was optimized. The results showed as follows:(1) Through the single factor quantitative analysis and comprehensive evaluation, it showed that rural residential land layout comprehensive suitability of Xingyi Town was 0~45.52, in which, the higher suitable area, moderately suitable area, lower suitable area and inappropriate area accounted for 25.16%, 29.49%, 29.09% and 16.26% of the total land area in Xingyi Town, respectively;(2) Using the method of cluster analysis, four types of districts were divided, they were moderate exploration district, key development district, expansion-limited district and priority management district, and the area of four districts was 113.30, 188.59, 104.01 and 41.72 hm², respectively. Moreover, the corresponding control methods were put forward to optimize the land use structure for different districts.