Abstract:Cultivated slopes are the major soil loss area and the major river sediment source in the Three Gorges Reservoir region. However, reliable studies of soil erosion and sedimentation in the region are limited and the fundamental research on soil erosion is inefficient. A study was carried out to investigate soil erosion on a cultivated slope in the region using ¹³⁷Cs technique. Preliminary results showed that the ¹³⁷ Cs reference inventory of the study catchment was estimated to be 1 420.9 Bq/ m². The ¹³⁷ Cs inventories of gentle cultivated slope with a mean degree of 11.4°ranged between 398.5 and 1649.6 Bq/ m² and the average value of slopelengt weighted was 816.0 Bq/ m². Soil erosion rate on the cultivated slope was estimated by revised simplified mass balance model. Soil erosion rate on he study slope ranged between - 3358.8 and 4937.4 t/(km²·a) and the average value of slope length weighted was 1 294. 6 t/ (km²·a) . Influenced by the tillage, soil erosion rates in two slope segments decreased downslope and deposition occurred at the bottom of slope. The lower soil erosion rate is because the cultivated slope has a gentle gradient. On the other hand, a series of tillage method are adopted by the local farmers for preventing soil and water loss efficiently, which greatly reduces soil erosion.

Abstract:Waste grassland is the main native ground type in the project of Banduo hydropower station of the Yellow River. Description of runoff processes in the area can reveal and estimate soil erosion processes and its degree. Based on field scouring exper iments, runoff processes on waste grassland were studied and following results were obtained: (1) For different water supply discharges and the same slope, runoff yield varied with runoff process could be described by a logarithmic equation. ( 2) Runoff processes on waste grassland varied with flow rate on different slopes and at the same water supply discharge were similar to those at dif ferent flowrates. They both increased with souring time and then reached a stable state. ( 3) A log arithmic equation can be used to describe runoff depth varied with runoff process under different flow rates. Runoff depth increased with increased flow rate.(4) On different slopes, runoff depth on waste grassland increased when slope increased and the relationship can be described by a pow er equation. ( 5) Runoff depth on waste grassland changed with slope and flow rate and it can be described by a duallinear equat ion. Flow rate had a great effect on runoff depth than slope.

Abstract:The research was carried out in the severely eroded granite area located in Changting County, Fujian Province. There were two kinds of management measures: whole hill side coverage with Bahiagrass(WHCB) and the mixed forests of multitree species(MFMTS). The research also set two check measures: severely eroded region without restoration measures (CK₁) and geomantic forest (CK₂). The effects of ecological restoration were discussed in the aspects of biomass and productivity. Results showed that the averaged biomasses of WHCB and MFMTS were 23.03 and 23.13 kg, respectively, which were significantly higher than those of CK1(6.02kg) and significantly lower than those of CK2 (582.87kg). The productivity 〔5.30 t/(hm²·a)〕and restoration degree (RD) of productivity (0.40) of WHCB were low, so its biomass was also low (28.26 t/hm²) and RD of biomass was 0.11. The productivity 〔9.19 t/(hm²·a)〕and RD of productivity (0.78) of MFMTS were higher. Its biomass was (39.88 t/hm²) and RD of biomass was 0.17. The difference in RD showed the different effects of WHCB and MFMTS.

Abstract:By taking the Kuqa oasis as a study area, the response of satellite SAR images to the ions of saline soils was analyzed. Two Radarsat images collected in March and October, 2001, were selected, and field sampling to soil profiles of 0 -10 and 0-50 cm was made. The values of eight microcosmicions(Na⁺, K⁺, Mg2+,Ca²⁺, Cl^-,SO₄^2-, HCO₃^--, CO₃^2-), pH value, conductivity, hardness degree, and salt content of saline soils in the typical region were measured according to the measurement point coor dinates in field. The values of each point in the remote sensing images were calculated. The gray associate analytic method was used to carry on the relevant arrangement of eight large ions and the values of the remote sensing images. Results indicated that Radar images in March intensely responded to pH value. The response was unstable to salt content and common to conductivity and hardness degree. For positiveion, the response was most remarkable to Ca²⁺; and for negativeion, the HCO₃^- response was most remarkable. Radar images in October intensely responded to pH value and conductivity, were unstable to the salt content, and were middle to the hardness degree. For positive ion, there was no evident rule; and for negative ion, the Cl^- response was most remarkable and there was no evident rule in SO₄2^- and HCO₃^-.

Abstract:Anti-tension and tensilest rength of single root ( the diameter range of roots is between 0.3 and 3 mm) under momentary gale were determined. Plants studied were Caragana microp hylla Lam, Salix psammophila C. Wang et Ch. Y. Yang, Sabina vulgar is Ant., and Artemisia sphaerocephala Krasch., which were 3~ 4 years old. The function of momentary gale was simulated by instantaneous tension. Results show that in the early growth period ( early May) and the vigorous growth period ( mid-August), anti-tension of four kinds of single root shows a positive exponential relation to diameter. The plants, interms of anti-tension and average tensile streng th, are ranged in the order of Caraganami crop hylla Lam> Salixpsammop hila C. Wang et Ch. Y. Yang> Sabina vulgaris Ant.> Ar t emi sia sp haer ocep hala Krasch. Anti-tension and average tensile strength of single root in the early growth period is greater than that in the vigorous growth period except Caragana microphylay Lam.

Abstract:Based on the experiment on plots, impacts of grass coverage change on runoff and sediment yield in the Tianchi Lake Natural Reserve Area in Xinjiang were investigated. Grass coverage had much more influence on sediment yield than that on runoff. Total runoff depth for 35% grass coverage was 1.4 , 1.5 , and 2.2 times that for 50 % , 55 %, and 75 % grass cover degrees, and total sediment yield for 35 % grass coverage was 4, 6, and 10 times that for 50 %, 55 %, and 75 % grass cover degrees, respectively. The relations of grass coverage to total runoff and sediment yield can be described by exponential function. Rainfall intensity had much more influence on sediment yield than runoff. In the same condition of grass coverage, runoff and sediment yield were increased with increased rainfall intensity. The relation of rainfall intensity to total runoff and sediment yield can be described by binomial function. The relation between grass coverage and total runoff depth can be described by exponential function.

Abstract:The soil physical characteristics of five main vegetation types in Daqing Mountains were studied. Results indicated that in 0-100 cm soil layer, gravel content (particle fraction ≥1 mm) and soil bulk density increased with the increase in soil depth; and soil total porosity, field capacity, and maximum moisture capacity decreased with the increase in soil depth. Besides the mixed forest of Quercus liaotungensis and Ostryopsis davidiana, gravel content and soil bulk density in arbor forest were less than those in shrub land. Soil total porosity, field capacity, and maximum moisture capacity in arbor forest were higher than those in the shrub land. The order of vegetation types, in terms of the average sat urated soil hydraulic conductivity, was: Ost ryopsis davi diana shrubs> Populus davidiana natural forest > Beula platyphylla natural forest> Pinus tabulaeformis plantation > mixed forest of Quercus liaotungensis and Ostry opsis davidiana. The maximum water storage in 0-60 cm soil layer in Popul us davidiana natural forest was the highest among the five vegetation types and its value reached 3550.36t hm². The mixed forest of Quercus l iaot ungensisand Ostryopsis davidiana and Ostryopsis davidiana shrubs had the lower values of 2319.85 and 2271.87 t/hm² , respectively.

Abstract:By the experiments of water retention capability for the red-brown purple soils, grey-brown purple soils, and brown purple soils that were disturbed or undisturbed, the effects of gravel on water retent ion capabilities of purple gravelly soils in a hilly area were studied. Results showed that by considering gravel of undisturbed soils, the saturated water contents were reduced by 0.70%~ 10.70% and the field capacities, by 2.07%~ 4.33%. When the gravel content was less than 10%, it did not have an obvious relationship with the saturated water content sand field capacities of undisturbed soils. When the gravel content was more than 10%, the saturated water content sand field capacities increased with the decreased gravel content. At 0~ 30kPa, the water-holding capacities and the avalues of power functions for undisturbed and disturbed soils, the clay contents of undisturbed soils, and the specific water capacities of disturbed soils were all increased with the decreased gravel content. The specific water capacities of undistur bed soils decreased with the decreased gravel content.

Abstract:Structure characteristics of plant community with two restoration measures, namely natural vegetation enclosure and artificial cultivation + enclosure, were investigated in southern margin of Tengger Desert. Moving sandyland without enclosure was taken as the control. Results showed that the invade species richness of artificial cultivation + enclosure increased to 12 species after 15 year enclosure, in which density of A rtemisia scoparia was 7.6 plants/m²; Corispermum patelliforme, 3.2 plants/m²; Bassia dasyphylla 3.0 plants/m²; A griophyllum squarrosum, 1.6 plant s/m²; and Set ari aviridis, 1.1 plants/m²2. The species composition and life forms were closed to natural vegetation enclosure, but the differences still existed. In families and genera compositions, the differences of the two measures were dominant family and the species numbers of each family. In species diversity, Shannon index and richness index of natural vegetation enclosure was significantly different compared with artificial cultivation + enclosure, except the other indexes. In shrub layer, ecological dominance index of natural vegetation enclosure was higher than artificial cultivation+ enclosure. The similarity index indicates that ecological distance between artificial cultivation + enclosure and natural vegetation enclosure was still far and ecological distances between the two restoration measures and moving sandyland + nonenclosure of vegetation sprinkling distribution were significantly far. In conclusion, enclosure can significantly promote the diver sity restoration of sandy land vegetation and the effects of cultivation on restoration of species diversity on sandy land is relatively slow and gradual.

Abstract:In view of the geological condition of soft metamorphic rock slope in Jinpen Reservoir, the influence of clay minerals on soft metamorphic rock slope is systemat ically studied through a careful analysis of the main properties and formation mechanisms of clay minerals, from micro to macro levels. Results show that soft metamorphic rock can easily produce clay minerals because of such characteristics as complex origin, various mineral composition, and weak water stability. However, clay minerals in rock may bring about marked changes in some properties of parent minerals, mineral aggregation or rock and promote rock to evolve toward loose medium. Moreover, the illuviation of clay minerals in macro discontinuities and the formation of mudded intercalation will cause the strength of discont inuities and rock mass to decrease. To sum up, clay minerals may accelerate deformation of slopes and their contribution to slope evolution and failure is notable.

Abstract:The research area is a typical karst catchment subject to rocky desert ification in Huajiang Gorge, Guizhou Province. One representative soil sample was collected in each plot of strong, medium, light, or latent desertification grade. The research focused on soil organic carbon (SOC) and total nitrogen (TN) of physical fraction in the processes of rocky desertification. Results elucidated that the par ticulate organic carbon and nitrogen ( POC and PON) and light fraction organic carbon and nitrogen( LFOC and LFON) were higher than the mineral fraction in the process of rocky desertification. The C/ N values of part iculate fr action and light fraction were higher than those of total soil. The content sof POC, PON, LFOC, and LFON decreased with the increase of rocky desertification grade. The content of part iculate fraction and distribution ratio acted in accord with rocky desert if ication grade, while the above index of light fraction did not act in accord with rocky desert if ication grade. The enrichment and distribution ratios of POC and PON, as well as LFOC and LFON, were not the same. The decrease of POC and LFOC was faster than that of PON and LFON in the process of rocky desert if ication. Most POC in wood chopping sequence integrated with silt-clay particle to form organic-inorganic complex, with the integration way POC was protected and was diff icult to decompo se by microbe, while most POC in reclamation sequence integ rated with sand particle, with this kind of integr ation way SOC tended to be in a low humic degree and to be decomposed by microbe easily.

Abstract:Taking Harbin region for an example, the spatiotemporal pattern and dynamic changes of soil erosion in Songhuajiang watershed from 1995 to 2005 are studied by using the ArcGIS and DEM. The topographic characteristics of spatial distribution of soil erosion is analyzed based on the DEM. Results show that water erosion is the main form of soil erosion in the watershed. Weak erosion mainly occurs at the altitude between 0 and 400 m where the transformation of weak slight erosion, slighter osion weaker osion, slight ° moderate erosion, and moderate intensive erosion in the area are intensive. Erosion changes mainly occur in the area less than 25° where erosion changes decrease firstly and then increase with the increase in slope degree. In the 0°~ 6°area, soil erosion mainly occurs on the 0.5°~ 5°cropland. In the 6°~ 15°area, the transformation of weak slight erosion and slight weak erosion is relat ively strong. Slope aspectin erosion change is characterized by a double- peak structure, while strong water erosion change occurs in northeast and southwest aspects. The proportion of weak erosion change in the flat area is greater.

Abstract:By taking the typical walnut-peanut intercropping system in the loess region of West Shanxi Province as the study object, the effects of soil moisture in different layers of soil profile (0-100cm) were studied using the traditional weighing method in 2008. Results showed that (1) the seasonal variation of soil moisture was very significant in the intercropping system. (2) Soil moist ure content increased with the increased depth of soil in vertical direction and the variance of soil moisture in 0-40 cm soil layer was strong. Soil moisture content increased with the increase of the distance from treerow and then became stable in horizontal direction. The curve of soil moisture could be described by a parabola equation. (3) Soil moisture had positive effects in the intercropping system, comparing to peanutsole cropping. The analysis indicated that there was an ecological niche overlapping between trees and peanut, which may negatively impact the production of peanut , but the competition between fruit trees and crops was not strong.

Abstract:Soil physical and chemical properties of different landuse patterns in semi-arid degraded mountainous areas were investigated. Results showed that soil mechanical composition for different landuse measures had a certain difference. The amount of coarse sand particles and middle sand particles in 0-40 cm soil layer for the landuse with measure was higher than that for the landuse without measure. In 0-100 cm soil layer, the order of landuse, in terms of the largest field water capacity under different landuses, was plantation >artificial grassland > natural grassland; in terms of capillary water holding capacity, the order was artificial grassland > plantation > natural grassland; in terms of soil total porosity, the order was plantation > artificial grassland > natural grassland; in terms of capillary porosity, the order was artificial grassland > plantation > natural grassland; and in terms of soil permeability, the order was plantation > artificial grassland > natural grassland. In 0-100 cm soil layer, the order of landuse, in terms of organic matter content, was plantation > natural grassland > artificial grassland ; in terms of soil nit rogen content, the order was plantation > artificial grassland > nat ural grassland; and in terms of soil available phosp horus content, the order was plantation> artificial grassland > natural grassland. The order sindicate that reasonable landuse can improve soil structure and soil fertility, increase soil permeability, and improve soil conditions. Artificial plantation is bet ter than other landuse patterns. It improves soil properties such as micro aggregates, soil bulk density, water holding capacity, and soil nutrients and is conducive to rapid vegetation recovery.

Abstract:The using depth of soil water and water consumption by littleleaf Caragana korshinskii is the base of studying the relationship between soil water and the plant growth. The dynamic of soil water were continuously measured with a neutron probe in wasteland and young peashrub forest land during the period from 2002 to 2006. Results showed that in 2002, the depth to which plant use soil water was increased from about 2 cm sowing on 24th June to 90 cm on 1st Sep, 110cm on 15th Oct, 170 cm on 1st Nov, and 220 cm on 15th Nov. The using depth of soil water and water consumption by littleleaf peashrub were increased and the amount of soil water storage was reduced with increasing age apart from the wet year (2003) in which the amount of soil water storage was increased by 122.8 mm in the 2-year-old peashrub forest land. It was also discovered that soil desiccation at which water content was smaller than and equal to the upper limit of wilting coefficient occurred at the soil depth of 100 cm in the 3-year-old peashrub land and soil desiccation occurred in the soil layer from 60 to 300 cm in 5-year-old peashrub land. Some effective measures should be taken to control plant density and growth in order to reduce soil water consumption and realize sustainable use of soil water.

Abstract:The paper dealt with soil nutrients of a Chinese firstand after clear cutting in Yunyong Forest Farm based on the determination of soil pH value, soil organic matter, hydr olyzable nitrogen, available phosphorus, and available potassium in 0) 100 cm layer in October, 2004 and April, 2005. The study may provide a scientific basis for Chinese firstand reforestation and site productivity maintenance. Compared with all the soil layers in 2004, the pH values of all the soil layers in 2005 decreased; the contents of soil organic matter and available potassium and the contents of soil available phosphorus except for 0) 5 cm increased; and the contents of hydrolyzable nitrogen increased in some soil layers and decreased in other soil layers.

Abstract:The analysis of particle size of street dusts in Xianyang City collected in April, 2008 indicates a bimodal dist ribution spect rum with the first mode being 35～75μm and the second, 280～500μm. The averaged particle size is found to be 80μm. The dist ribution is characterized by wide kurtosis, better symmetry, and better sorting, which is similar to the particle size distribution of loess and modern duststorms. This indicates that street dusts are a mixture of coarse particles derived from local area and fine particles transported over a long distance by aeolian agent. Under the proper aerodynamic conditions, 56.7 % of street dust particles can be picked up and transported by suspension.

Abstract:To study the effects of different vegetation types on runoff generation on slope land in the Three Gorges reservoir area of the Yangtze River, 4 standard runoff plots with different vegetation types were laid out in the J inyun Mountains, Chongqing City. The different vegetation types included mixed broadleaf-conifer forest, broadleaved forest, Phy l lostachys pubescens forest, and shrub. Rainfall and surface runoff from the plots were measured. Results show that vegetation types, in terms of the averaged value of surface runoff depth, were ranged in the order of Phy l lost achys pubescens forest > broadleaved forest > mixed broadleaf -conifer forest > shrub. Surface runoff depths for the vegetation types are found to be 3.094, 1.972, 1.751, and 1.170 mm. The amount of surface runoff in selected arbor forestlands is smaller than that in Phy l lost achys pubescens forest and significant difference in the amount of surface runoff does not exist in mixed broadleaf-conifer forest, broad2leaved forest, and shrub. The correlation between rainfall amount and surface runoff in forestlands is significant and the correlation between rainfall intensity and surface runoff in forestlands are not notable. Under the same rainfall condition, the variation tendencies of surface runoff in these types of forestlands are different and the amount of surface runoff in Phyllostachys pubescens forest is always the largest.

Abstract:Research on the soil moisture characteristics in Alnus cremastog yne and A lnus formosana forestland with the red soil developed from quaternary red earth in Northern Hu'nan is conducted. Results show that maximum moisture content for the Alnus cremastogy ne litter is 24.76t/hm, which is 1.22 times of that of the A lnus formosana. By both the total capillary porosity and non-capillary po rosity, landuses can be ranged in the order of A lnus formosana plantations > A lunus cremastogy neplantations > wasteland. The maximum soil moisture content for the Alnus formosana is 24.55 mm. By the infiltration parameter in 0 -45 cm soil layer, landuses can be ranged in the order of Alnus formosana plantations > Alnus cremastogy neplantations > wasteland. This indicates that the Alnus plantations could improve soil structure and make the soil to keep very good soil moisture characteristics.

Abstract:This study was conducted in a sugarcane field in order to promote vinasse application as an effective fertilizer resource and develop a mode of water and nutrient management in sugarcane fields. Three treatments were designed as follows: CK₁ (no fertilizer treatment ), CK₂(chemical fertilization treatment ), vinasse (75 t/hm² vinasse treatment). The effect softhree treatments on soil moisture, Cu, and Cl uptakes by sugarcane and runoff losses were investigated and food safety or environmental contamination in surface runoff water was assessed. Results showed that the application of vinasse increased soil moisture utilization rate and decreased Cu content in sugarcane and surface runoff, as compared with treatment CK₂. However, the application of vinasse increased Cl content in sugarcane and Cl contents or concentrations in sugarcane juice or runoff for all treatments were far less than GB value. It is concluded that in this experimental condition vinasse (containing much orgnic matter) application to sugarcane field decreases water and copper loss, but no serious consequence is found on quality of sucrose and surface water environment. Vinasse is suitable for sugarcane field application.

Abstract:Through analyzing soil type on the Loess Plateau of Nort hern Shaanxi Province, the fractal dimension, fragmentation, and dominance are selected as the indexes of soil type. The indexes of soil type are analyzed using Fragstats and the value of the sensitivity of soil erosion for the soil type is calculated using ArcGIS. The relationship between sensitivity of soil erosion and pattern of soil type is then analyzed. Results show that the value of the sensitivity of soil erosion increases with the increase in the fractal dimension of fragmentation, but decreases with the increased soil dominance.

Abstract:Nitrogen loss on the slope with purple soil is studied by simulated rainfall of 5 rainfall intensities. The following conclusions can be drawn: (1) Proportion of surface runoff is increased wi h rainfall intensity increasing. (2) Nitrogen loss is reduced gradually with the rainfall intensity increasing. Ammonium nitrogen and nitric nitrogen are the soluble nitrogen. Their density is high in the initial time, tends to be stable or decrease with rainfall continuing, and increases in the later period. (3) Surface runoff plays a key role in nitric nitrogen loss and nitric nitrogen density plays a leading role in interflow loss. Soil nitric nit rogen loss is dominated at small rainfall intensity, but surface nitric nitrogen loss is increased with increased rainfall intensity.

Abstract:Sewage sludge can be used as soil amendment and fertilizer. Through potexperiment growing Xanthoceras sorbifolia Bunge in greenhouse, effects of applying sewage sludge in reclaimed soil on biomass of plant, soil moisture content, and wilting point are studied. Results show that sewage sludge not only increases the biomass of Xanthoceras sorbifolia Bunge, but also increases the water retention ability of plant subst rate. However, the more sewage sludge added does not mean the higher water retention ability of plant subst rate. The ability of plant subst rate may decreases when continuously adding sewage sludge if the ratio of added sewage sludge is over 60%. So utilization of sewage sludge as planting subst rate in the reclaimed land of a mining area is a feasible way to reuse and dispose of sewage sludge.

Abstract:The water holding characteristics of litter layer on the land from the converting cropland into forest land project in Datong County in the upper reaches of the Yellow River are studied experimentally. As time lasts, the thickness of litter layer incr eases and the litter layer storage capacity increases from 4.19 to 59.91t/hm². The maximum water holding capacities in the undecomposed and half-decomposed litter layers for Picea crassifolia and Picea crassifolia + Betula platyphylla natural communities are 27.22 and 60.48 t/hm², respectively. T he minimum capacities for Picea crassifolia + Hippop haerhamnoides and B etula platyphylla + Populuscathay ana+ Hippop haerhamnoides communities are 6.85 and 4.75t/hm², respectively. The corr elation coefficient of the storage capacity is more than 0.96. The average thickness and water-holding ratio of litter layer for the art if icialplant communities are 44.20% and 33.28% of those of natural plant communities. The relations of the water holding capacity to age of forest, biomass, thickness, and storage capacity reaches extremely significant level ( a= 0.01).

Abstract:This study was conducted to compare the cost of for estation using super absorbent polymers (SAP) and the cost of conventional for estation in the converting cropland to forest program. Chong li County and Kangbao County were taken as two examples to estimate sylvicultural cost of SAP. Results showed that the sylvicultural cost of SAP was higher than that of conventional planting.However, the survival rate of forestation using SAP was increased and the cost of replanting was reduced. Thus, the sylvicultural cost can be reduced relatively. SAP function was affected by moisture condition because SAP can not product water. When SAP was used in forestation, soiltype, SAP type, dosage, method, and forestation season should be considered.

Abstract:The soil aggregates stability is one of the important factors to analyze soil structure. Soil aggregates were investigated in view of the f ractal fraction, the amount of > 0.25 mm aggregates and the aggregate weight dimension (MWD). Results showed that there was a negative correlation between the fractal fraction and the amount of > 0.25 mm aggregates. On the contrary there was a positive correlation between the MWD and the amount of < 0.25 mm aggregates. This indicates that the fractal fraction and the MWD can be used to appraise soil structure and the fractal fraction is better than the MWD because the fractal fraction is able to reflect soil water and other properties.

Abstract:The study method used is the one investigating the effluent from activated sludge treatment and artificial wastewater in two experiments. The first experiment examined the nitrogen and phosphorus removal efficiency of effluent from activated sludge treatment by several plants. The second experiment explored the removed efficiency of different forms of nitrogen with different concent rations of phosphorus in the artificial wastewater. The aim of the study was to filter out the proper plant varieties for eutrop hication treatment. Results showed that the three plants of I pomiea aquatica Forsk, Rumex acetosa L, and Cy perus glomerat us L had perfect purification capacity and growth in good condition. The concent ration of nit rogen and phosphorus in the effluent decreased during experiment, especially TN removal reached more than 90% by Cyperus glomerat us L and R umex acetosa L Cy perus glomerat us L had the best removal efficiency of 93.4 %, the removal rate of TP exceeded 70%, and I pomiea aquatica For skhad the best removal efficiency of 76.9 %. In the pretreatment, NH₄⁺-N had significant changes and Cy perus glomerat us L treatment showed the best purification of 94.4 %. The content of NO₃^--N gradually decreased in preexperiment period and then showed an increased tendency. The best removal efficiency by Rume xacetosa L reached 65.4 %. Nitrogen and phosphorus removals in control treatment were lower than in treatments of plant system. The experiment for different forms of nitrogen removal with different concent rations of phosp horus in the artificial wastewater by three plants showed that both N H₄⁺-N and NO₃^--N were absorbed by the three plants, with the priority absorption of N H₄⁺-N. The order of plant purification effect for NH₄⁺-N and NO₃^--N was Cy perus glomerat us D L > Rumex acetosa L > I pomiea aquatica Forsk.

Abstract:Changes in landuse, especially construction land of Xianyang City during the years from 1999 to 2006 are analyzed. Urban land, rur al residential land, and highway land in Xianyang City have undergone relatively significant change in various types of construction land. Based on national economic development data of Xianyang City during the research period, some indicators are selected, such as gross domestic product, output values of secondary and tertiary industries, total investment in fixed assets, fiscal revenue, fiscal spending, retail sales of consumer goods, and total population. SPSS software is used for these indicators by the method of principal component analysis and the driving forces of construction land changes of the city are determined. T hrough the analysis of construction land, driving forces of construction land changes of the city are found to be policy factor, economic factor, the level of urbanization, and arable land factor. Finally detail analysis is made on the impacts of various factors and comments and suggestions are given for the construction land development of Xianyang City.

Abstract:The main-function regionalization is a course of judging the properties of nature and economy and then classifying them. Fuzzy clustering method is the optimization technology that may be used to create fuzzy matrix and ensure clustering relation by subjection according to the properties. The idea of fuzzy clustering is introduced in the land classification based on the regional landuse and nature economic society indexes. By taking Jiangsu Province for an example, the main functions of the region are divided into priority development zone, key development zone, and rest ricted development. Result from the study shows that the method is practical and effective.

Abstract:Soil erosion protecting plan is not only the precondition before the production and construction projects approved, but also the technological document when implementing soil and water conservation projects. The profundity of soil erosion protecting plan at the feasibility stage may have a direct influence on“the three simultaneous works”institution in soil and water conservation. According to the technical specifications of soil erosion protecting plan in production and construction projects and the demands on compiling the feasibility study report profundity of the general investment to the fixed asset projects, this paper investigates the profundity of feasibility study for soil erosion protecting plan in production and construction projects.

Abstract:As an important part of ecological compensation, the soil and water conservation ecological compensation is receiving increasing at tention by the state and society. Based on the analysis of the stat us of the oretical research and practice on soil and water conservation ecological compensation and problems, some suggestions on speeding up experimental site establishment, strengt hening legislation and basic research are proposed in order to promote the ecological compensation work.

Abstract:Firstly, tendency factors of groundwater dynamic are evaluated and analyzed with measured data of the Luohuiqu irrigation district in Shanxi Province based on the Markov chain model of multiple element time-space sequence. The improved grey slope coefficient cor relation degree analysis method is applied to analyze the sensitive degree of various factors and groundwater depth. The concept of critical evaporation is put forward and the ARIMA model is established subsequently to predictev aporation. Results show that the tendency of groundwater dynamic in the irrigation district is worse. Evaporation is the main factor affecting groundwater dynamic and the interact ionamongst various factors forms coupling relationship under the complicated condition. When evaporation exceeds the 1800 mm critical value, groundwater level begins to rise and soil is subject to the threat of soil salinization. It is predicted that the evaporation in following several years almost exceeds the critical value and the precision of model is relatively high. It is feasible and practical to apply above method system to the investig ationon groundwater dynamic in irrigat ion district. The study provides a scientific basis for unified management and regulation of water resources.

Abstract:Based on the analysis of long-term experimental data from Luohui and Baojixia irrigation regions in Shaanxi Province, some important irrigated indicators such as the depth of wetted soil, suitable soil moisture and the method of irrigation were determined, which may provide helpful guild for getting the goal of saving water and high crop yield of wheat and corn for Guangzhong irrigation region of Shanxi Province.

Abstract:As an important area of resource carrying capacity researches, land carrying capacity is an important reference basis to evaluate sustainable development ability of a special region. Selecting Jiangsu Province as a study case where has fast socio-economic development speed and prominent man-land contradiction, the paper established the evaluation indicator system of comprehensive land carrying capacity from the four supporting systems including water and land resources, economy and technology, society, and eco-environment. Then, comprehensive land carrying capacity is evaluated by applying the weighted multi-factors synt hetic appraisement method at county level. According to the evaluated results, land carrying capacity of Jiangsu Province is divided into three types , i.e., high, moderate, and low carrying capacities. On the whole, it decreased from south east, midwest to north and seaboard of Jiangsu Province.

Abstract:By taking He'nan Province for an example, factor analysis method is used for the quantitative eva-luation and rank division about intensive utilization levels of arable land in 2000 and 2005. Results show that (1) input level, output level, agricultural protection level, and intensive utilization level are the main factors that influent intensive utilization levels of arable land in He'nan Province, but the coordination of the four is poor. (2) Only measuring the gap between the levels of intensive utilization of arable land by input level or output level has certain limitations. (3) The intensive utilization levels of arable land in the northern part of He'nan Province are higher than other parts. (4) There is a difference in the inconsistency between the comprehensive levels of intensive utilization of arable land and the main factors, that is, input level, output level, agricultural protection level, and intensive utilization level. (5) The intensive utilization levels of arable land show a downward trend in the whole province and the range of composite index and the four factors increases.

Abstract:This study is based on the year-by-year investigation of nature, society, and economy in Zhangye City from 1998 to 2007. Driving forces of the changes of cultivated land and construction land were analyzed synthetically and quantitatively using mathematical statistics methods in order to discover the similarities and differences of driving forces. Results indicated that driving factors display a certain difference. At the same time, the direction and size of principal component factors are different. The level of economic development and economic structure factors make a negative driving to cultivated landuse change, but a positive driving to construction landuse change. The research result contributes to the quantitative and comparative under standing of driving forces on cultivated land and construction land and points out a way to the research on landuse change mechanisms.

Abstract:According to landuse statistic data from 1999 to 2007, the dynamic evolution of land use structure of Liangping County of Chongqing Municipality is exemplified based on information entropy principle and Markov transfer matrix model. Results show that information entropy H of Liang ping County' s landuse structure has undergo ne three stages, that is, 1999-2002 continual rising stage, 2002-2003 sharply decreasing stage, and 2003-2007 fluctuating stage.nChange in the degree of balance and dominance is similar to information entropy. Land types have been mainly transferred from cultivated land to woodland and lands for traffic, residential set tlements, and industry mining.The theoretical trend values of LUCC in the study area are analyzed by RBF neural network model. The trend that cultivated land is shifted into lands for traffic, residential settlements, and industry mining is the most dominant .From this tendency, cultivated land may be continuously reduced in the future and the contradiction between cultivated land conservation and the enlargement of urban building land becomes more serious. It is suggested to give energetic supports to land exploitation and reorganization, especially rural residential areas' combination and reorganization. Simultaneously, the works on excavating reserved constructional land positively and making landuse effective and intensive should be strengthened.

Abstract:Qapqal County, Xinjiang Wei Autonous Region was selected as the study object. The authors proposed four indexes, i. e., land utilization intensification coefficient, land consumption returns coefficient, land production coefficient, and land contamination coefficient. The coefficients were then used to evaluate the quality and sustainable utilization of land in Qapqal County, Xinjiang Wei Autonous Region. Results show that the land utilization intensification coefficient is lower. Although the land consumption redound coefficient is higher, the productivity of land is not raised as much as possible. In addition, the phenomenon of soil pollution and degradation in Qapqal Conty is serious, which rest ricts the sustainable development of agricult ural economy. From now on, we should strengthen intensification utilization of land resources and scientifically use fertilizer and chemicals to reduce soil pollution. In this way, we can promote the sustainable utilization of soil resources in Qapqal County.

Abstract:Based on the analysis of land resources and current population status and the characteristics in the Qinghai Lake region, the ultimate and maximal population carrying capacity of land and the pop ulation carrying capacity of cultivated land and grassland and its proportion in each county are estimated. Results show that the ultimate population carrying capacity of land in the region is 695973, in which cultivated land is 483720, grassland is 212703, and the corresponding capacity ratios are 69.44 % and 30.56 %, respectively. The total maximal population carrying capacity of land is 324620, in which cultivated land is 181219, grassland is 143410, and the capacity ratios are 55.82 % and 44.18 %, respectively. The maximal population carrying capacity is diffident in each county. Population carrying capacities of Gonghe County, Haiyan County, Gangcha County, and Tianjun County are 7.01756, 6. 00874, 5.96404, and 0.03318, respectively. The capacity of cultivated land and grassland in each county is also different.

Abstract:With the rapid development of social economy and growth of population, the quantity of arable land has decreased continuously and the quality of cultivated land has been reduced increasingly in Hu.nan Province. Scientifically predicting the demand on ar able land of Hu.nan Province and defining practical preserve measures will play an important role in its socioeconomic development. From the aspects of foodsafety, economic development, and ecological protection, the study predicts that the demand of cultivated land in Hu.nan Province in 2015 and 2020 is 3940900 and 3440700 hm², respectively. The result will be an important reference to the landuse planning in Hunan Province.

Abstract:Using Fragstats 3.3 and interpreted results of remote sensing images in Banchengzi Reservoir watershed in 2000 and 2005, changes of forest landscape pattern is obtained. Results showed that forest land is the matrix of Banchengzi Reservoir watershed from 2000 to 2005. Dominant index of coniferous and broad-leaved and mixed forest is higher than other landscape elements. The area of the patches is distributed unevenly. In landscape heterogeneity aspect, the heterogeneity of coniferous forest is increased; patch complexity of forest is higher than other landscape types; patch quantity of landscape elements is enhanced; and landscape elements are distributed more evenly. In spatial inter-correlation aspect, landscape fragmentation is increased and whole spatial aggregation of landscape level is reduced.

Abstract:In order to constructe the eco-environment of Luan mine land system scitifically, the variances of natural and environmental factor sand artificial factors such as industry and mining production are analyzed and the mine land eco-environment pressure evaluation index system is established. Eco-env ironmental pressure of Luan mine land is divided into four types, e. g., natura-l resources pressure A₁, resource consumption pressure A₂, environmental pollution pressure A₃, and production scale pressure A₄. Results show that the total eco-environmental pressure of Luan mine land system belongs to the moderate pressure and sub-pressures followed a descending order of resource consumption pressure A₂, environmental pollution pressure A₃, production scale pressure A₄, and natura-l resources pressure A₁. Because of different units of land system under different eco-environmental pressures, this may show different land ecological functions. Ther efore, the land system can be divided into production land type, protection land type, consumption land type, and mixed land type, according to the eco-environmental characteristics. Luan mine land is divided into eleven types of ecological function zones and the four regions of earth and rock slope consumption area, subsidence and wet land protect ion area, mine-industry eco-economic area, and Hirakawa arable land production area. Its area ratios are 6.50%, 19.16%, 8.77%, and 65.57%, respectively. The production land and consumption land are oversized and the mixed land and the protect ion area are very small, which indicates that there is an unreasonable use in Luan mine land system. Based on above analysis and Luan mine actual situation, the corresponding countermeasures of mine land system were proposed for eco-environmental protection and mult-i dimensional ecology economical system.

Abstract:Dynamic evaluation of ecological frangibility is not only important to understand, preserve, and improve ecological environment, but also essential to promote the harmony between man and nature. The characteristics of ecological environment frangibility in Jiangxi Province are analyzed. It is necessary to combine potential frangibility, intimidate frangibility, and realism frangibility together for the dynamic evaluation of ecological frangibility. The method and step of dynamic evaluation of ecological frangibility in Jiangxi Province are then presented. The analysis indicates that the eco-environmental frangibility in the province tends to relaxation. By comparing 1985 with 2000, the dynamic change of ecological frangibility is from high frangibility to low f rangibility and the total area is 102820.49 km², which accounts to about 61.61% of the total area of Jiangxi Province. At the same time, the evolution process and developing trend of ecological frangibility are analyzed and the division of ecological frangibility and the management of the fragile ecological environment are discussed.

Abstract:Flood disaster has seriously influenced people's safety of lives and property in the lower reaches of Weihe River. The purpose of this article is to analyze the causes of the disaster and its prevention. The main causes are found through contrasting and analy zing flood amount and level in history, such as deforestation for farming in the upper reaches and building of embankments in the lower reaches which affects the stability of river conditions and impede the smooth passage of floodwater. Due to Sanmenx ia Reserv oirs operation, heavy silting raises the riverbed in the main channel and makes flood disaster easily happen. To handle this problem, firstly we should have the right thoughts and make the breakthrough and innovation on the way and prevention. We should mainly take dredging, combine dredging and blocking tog ether, and lower river bed to solve the problem. In addition, we should reinforce river bank, combine engineering with biological practices, make scientific water and sediment transportation, and return the field to river. All of these should be done to guarantee the safety of Weihe River.

Abstract:Five species diversity indices were chosen to carry out species diversity analysis of deserted quarry areas during the maintenance period after artificial vegetation restoration in Zhejiang Province. Results showed that the quantity of species in the areas was large, while the composition of families and genera was unintensive. To be exact, herbs acted as the dominant group in the community selecting leguminious plants and gramineae plants as the two biggest communities for the introduced species. Shrubs and trees were mainly planted rather than growing from seeds. The index of species richness and species diversity of herbs, shrubs, and trees showed a consistent trend, among which the index value of herb communities was significantly higher than the index values of the shrub and tree communities. In addition, the community evenness index values of herb, shrub, and tree communities all stayed in a high level. Local herbs in the areas played a dominant role and the majority was compositae plants.

Abstract:Based on a large number of data, economical development and urban constructive situation of small and medium-sized cities in eastern part of Northwest China are studied by using comparative regression analysis and other methods. It is found that the eco-environmental problems consist mostly of urban soil and water loss, water resources shortage contradictory, insufficient urban g reen space, and local environment pollution. According to the specific circumstances, following countermeasures for the eco-environmental problems are proposed: carrying on the urban planning scientifically, combining characteristic economy with green economy, increasing the proportion of the ecological land, protecting water sources, and distribut ing water resources rationally.

Abstract:The World Natural Heritages, Jiuzaigou and Huanglong, are located in the eco-fragile areas of West China. Since 2001, 12 repairing models of degraded landscape in the eco-fragile areas were implemented in Songpan County, i.e., Lycium chinense, Hippophae rhamnoi des, Amygdal us davidiana + Picea as perata, Armeniaca sibirica + P.asperata , P.asperata, Syringa komarowii + Malus kansuensis, P. asperata + Salix argentinensis, P.asperata + Populus cathayana, S .argentinensis, S .argentinensis + P.cathayana, P.cathayana, and A.sibirica + S.argent inensismodels. This paper analyzed both horizontal and vertical species diversity in the 12 models. Results showed there were generally poor species richness and diversity in woody layer. On the contrast, herb layer of most models possessed considerable diversity, along with about 20 species and Shannon-Weiner index over 2.0. Further, most models possessed sound species diversity, contributed by diversity in herb layers. Most models possessed sound species diversity indexes and diversity between models was also greater. With the developing of diversity, it is helpful to constructing a stable and healthy ecosystem and establishing a material foundation for developing to further stage

Abstract:Ecological restoration is one of the main tasks of soil and water conservation. The implementation of ecological restoration by fitting measures to local conditions has a significant meaning in the works on ecological restoration. Based on“The Study on National Ecological Restoration of Soil and Water Conservation”, the types of ecological restoration are further studied for improving the operability of local ecological restoration planning. The maps with four first grades ecological restoration dist ricts and thirteen second grade ecological restoration district sare then put forward at county scale. Natural, economic, and social conditions of each type are analyzed as well.

Abstract:This study is conducted in combination with the works on ecological restoration and the implementation of demonst ration projects in recent years. Different models and sub-zone control measures for ecological restoration in various zones of China are put forward according to the natural conditions, socio-economic conditions, soil characteristics, and direction of economic development . The models and measures can be used in soil and water conservation planning and the implementation of ecological restoration at all levels for reducing soil erosion, and speeding up the restoration of degraded ecosystems.

Abstract:Effects of soil and water conservation measures on soil properties in the low mountain and hill area of Jilin Province were studied and the benefits of soil and water conservation measures were analyzed. Results showed that the benefit of bedding ridge plot was the worst; the benefit of field bund floral zone and fell bush bund plot, in medium level; the benefit of ecology restoration and lagging ridge plot, very good; and the benefit of horizontal plat form field plot, the best. Study of soil and water conservation benefits from different measures can provide a foundation for local cultivation methods. There were differences in effects of different soil and water conservation measures on soil physical properties. The rehabilitation obviously improved soil pH, soil bulk density, and field water holding capacity and however, the effect of soil and water conservation measures on soil texture was unobvious. In short period, the rehabilitation of SOC by soil and water conservation measures could not get better effect. The differences of soil available nutrients resulted from different soil and water conservation measures were significant because of soil texture, vegetation, and other conditions. In view of current soil and water conservation measures, ecology restoration was the best choice to manage small water shed and restore soil quality.

Abstract:Taking two composite Landsat 5 TM (thematic mapper) images in 1986 and 2006 and land use map of Yinzhou town, Mizhi County in 1996 as data resources, land use/land cover changes (LUCC) of Yinzhou from 1986 to 2006 are studied using the Geograp hical Information System(ArcGIS 9.0) and ERDAS( remotesensing software). Results show that great changes have taken place in land use/ land cover in Yinzhou from 1986 to 2006. From 1986 to 1996, change of land use structure was characterized by increases in cropland and other land use types and on the contrary water area, by decreases in woodland and grassland. Cropland changed obviously and woodland and grassland were mainly converted into cropland. From 1996 to 2006, change of land use structure was characterized by increases in woodland and grassland increased. On the contrary, water area, cropland, and other land use types decreased. Cropland was mainly converted into woodland and grassland driven by the policy of returning farmland to forest and grassland. From 1986 to 2006, change of land use structure was characterized by increases in grassland and other land use types increase and on the contrary, by decreases in water area, cropland, and woodland. Water area, cropland, and woodland were mainly converted into grassland and other land use types. Land use change was mainly taken place in slope area and some croplands beside Wuding River were converted into other land use types. Although the ecological environment had been greatly improved in the area, it is still a long term task to protect and recover ecological environment by the policy of returning farmland to forest and grassland.

Abstract:The adso rbed phosphorus loss is one of the adverse effects of soil erosion, which results in not only the degradation of soil fert ility, but also the deterioration of water environment. The adsorbed phosphorus loss is recognized as an important part of non-po int source phosphorus pollution. Studying the adsor bed phosphorus loss by the investig ation of soil erosion is a commonly used method. This article summarizes the researches at home and abroad and analyzes the China. scurrent problems of adso rbed phosphorus loss together with soil erosion. Domestic study of soil erosion and adsorbed phosphorus loss doesnot match the requirements of practical applications. On one hand, there are the needs to increase number of experiments, enhance works on experiments, adhere to continuous monitoring, and deeply understand China's soil erosion and adsorbed phosphorus loss mechanisms. On the other hand, we should actively construct a model suitable to national circumstances, build the basis of information databases, and study the applicability and difference of foreign models.

Abstract:After giving the scientific connotations of ecosystem, tourism and tourism resources of soil and water conservation and the relations between soil and water conservation and tourism are discussed. Soland water conservation can provide some tourism resources for tourism production development, make sound ecological environment for some traveling places, sightseeing areas or sig htseeing spots, and add beauty sense for sightseeing highlights. Research on soil and water conservation tourism can promote social and econom-ical effects of soil and water conservation works. Based on the analysis of main types and their functions of soil and water conservation tourism, some suggestions are presented, such as enhancing cooperation between soil and water conservation department and tourism department of government, increasing development consciousness of soil and water conservation tourism, car rying out relevant research on soil and water conservation tourism, fostering typical examples, and summing up experiences continually.