Abstract:Yangou watershed in the Loess Plateau was selected as the study site to determine the characteristics of soil erosion intensity on cultivated hillslopes of different cultivation ages. The radionuclide tracer technique was employed as a new method and a method was developed to calculate average area concentrations of radionuclide and soil erosion intensity of whole hillslopes by using the average gradients of hillslopes and average area concentrations of radionuclide on hillslopes, with a weighting for slope length. The results of partial correlation analyses among soil erosion modulus, cultivation age, slope gradient and slope length show that the correlation coefficient between erosion modulus and cultivation age is high, higher than that between erosion modulus and slope gradient. The relationship between erosion modulus and slope length was not significant. The conclusion is that soil erosion intensity on hillslopes becomes more severe with increasing cultivation age, mainly due to the gradually effect of the destruction of forestland and grassland.

Abstract:运用遥感(RS)和地理信息系统(GIS)技术来进行中国陕西省北部地区的土壤水蚀风险评估。综合运用RS和GIS技术以及修订的通用土壤流失方程式(简称RUSLE)来定量化地评估土壤侵蚀。建立了一个关于土壤侵蚀、斜坡长度/坡度、降雨侵蚀和人类活动的评估系统。评估值输入修订的世界土壤亏损方程式中,用来计算土壤退化进程的风险,土壤退化又叫土壤侵蚀。利用榆林和靖边两地区的1987年和1999年的陆地卫星TM传感图像来制作研究区土地使用/覆盖情况的地图,然后用这些地图产生RUSLE方程中的人类活动因子。使用ERmapper/Info两个软件来管理和处理主要数据,及处理卫星图像和表格数据源。根据统计分析,3985.9km²(33.12%)的土地面积有轻微到中度的土壤侵蚀,2941.4km²(24.44%)的土地面积有高的土壤侵蚀,总土地面积中3522.1km²(29.27%)正面临着很高的土壤侵蚀风险,总体上来说,研究区处于高的土壤水蚀风险中。

Abstract:The main hydrology factors in one river includes precipitation, runoff and sediment discharge. These three hydrology factors are impacted largely by regional land use/ land cover change. The Yanhe River Basin with the area of 7725km² and in middle of the Loess Plateau, is one of the hot-spots for regional afforestation and soil water conservation in China. So studying on the temporal change of the main hydrology factors in the Yanhe River Basin is very essential for providing the basic information and supporting the decision of local government. We collected the precipitation data and worked out the regional tendency from the 6 wide-spreaded rain gauge stations from the middle of 20^th century to 21^st century. We also got the runoff and sedimentation discharge data from 2 hydrology stations in the same period. It's founded: (1) The monthly distribution of each of those three main hydrology factors tended to be uniform, and the annual change was prone to be tempered. (2) Compared to the average in 1960s, the annual precipitation in the 1970s, 1980s and 1990s in the basin, has respectively reduced by 10.5%, 11.7% and 14.0%. (3) The annual water yield in the basin has separately reduced by sediment discharge, reduced by 14.1%, 13.1% and 21.4%. (4) The annual sediment discharge reduced by 21.1%, 46.2% and 41.7%.

Abstract:Populus simonii Carr. is a species widely planted on the Loess Plateau. The results of the study show that the growth of P. simonii Carr. is constrained by spatial site conditions. Its growth reached the highest in gullies where soil water conditions was better than in other sites. On the same slope, the P. simonii Carr. grows better in lower part than in middle and upper parts. The height growth reached 12.67m in lower part while reached 5.70m and 5.21m respectively in middle and upper parts. The diameter at the base and chest height, the height of the lowest branch and the canopy growth showed the same trend. With the gully bottom as the reference site, the growth of P. simonii Carr. was evaluated. The height growth reached 77.53%, 34.88% and 31.88% of the potential growth in lower, middle and upper parts respectively while the growth of the diameter at chest height reached 75.59%, 39.51% and 33.36% of potential growth respectively. When mixed with Hippophae rhamnoides L.subsp., the P. simonii Carr. showed better growth than planted in single species. The analysis of biodiversity showed that the mixed forest of P. simonii Carr. and Hippophae rhamnoides L.subsp.had the higher biodiversity values and more evenly distributed species, and had a higher ecological benefit. These results showed that P. simonii Carr. can be planted only in gullies where soil water conditions were better, and can not be planted in large scale, especially in middle and upper parts of the slopes.

Abstract:In order to promote the development of grass industry in the drought-hit area, the construction of the animal husbandry base, and the development ecological agriculture, to select the species of artificial herb with high regeneration, high output and high WUE, the yield, the speed and the water use efficiency of re-growing hay of twelve alfalfa cultivars from domestic and aboard are studied in 2001 and 2002. The results showed that re-growing speed of all introductions in the 2nd harvest was higher than the local cultivar Hui'ning , most of introductions were higher than local cultivar in 3rd harvest. The yield of all introductions were higher than local cultivar Huining. Algoquin, Emperor, Cimmaron, Siriver, WL-323Ml have high re-growing hay yield, high WUE and strong regeneration.

Abstract:Spring is the most suitable season for Platycladus orientalis growth on arid southern mountain slopes. The ideal temperature range is from 10℃ to 17℃. If the species is planted earlier or later than the optimal season, the afforestation survival rate is lowered. Annual growth of juvenile trees exhibits one slow stage and two fast stages. Stage boundaries are the first 10-day period and the mid-summer, in this case mid-July, with growth greater in the earlier stage than in the latter stages. Rainfall may simulate growth but high temperatures restrain growth. That is, although the Platycladus orientalis can endure aridity, growth is promoted more by moisture than optimal temperature. The species responds sensitively to rainfall, usually over 10 days.

Abstract:The elements of soil erosion from a systems perspective and current methods of preventing soil erosion are analyzed. Based on the results, the authors discussed the drawbacks of preventing soil erosion, the ideal model for preventing natural soil erosion and the basic methods for preventing induced soil erosion. The discussion is centred around village sustainability.

Abstract:Based on 1986TM and 2000ETM data, land use and landscape pattern changes in the source region of the Yellow River were studied using geographical information(GIS) technology. The results show that the area with a high coverage of grassland, wetland and glacier decreased in the time period, while the area of barren land increased. The comprehensive land use index decreased remarkably, indicating that desertification worsened. The degree of land scape fragmentation of the study area increased, although, the diversity index and fractal degree decreased.

Abstract:The soil and water conditions of natural tropical forests in China, at the regional level and the forest management unit level are reported with direct reference to ITTO Criteria and Indicators for Sustainable Management of Natural Tropical Forests. An assessment of the application of these criteria and indicators is conducted. In line with standards for soil, water and forest management in natural tropical forests in China, indicators for soil and water, and the application of the ITTO Criteria and indicators in China are developed. Problems with the application are pointed.

Abstract:Vegetation landscape is an important and highly valued component of famous mountain scenic areas. This paper provides an analysis of the status of the vegetation landscape on Huashan Mountain and an current conditions evaluation. Measures of exploitation of the vegetation landscape are advanced on the basis of these conditions. Finally, some properties of famous mountain scenic areas are discussed, such as topography, vegetation communities and disturbance. An argument is made that the status and use of famous mountain scenic areas depends on the vegetation landscape form. The process of analysis and evaluation of present conditions and measures for utilization may be useful to assessment in famous mountain scenic areas similar to Huashan Mountain.

Abstract:Continuous drought in Northern Shaanxi Province was examined on the basis of its effects on plant growth and soil moisture. It was found that soil moisture in the study region has decreased, with very low soil moisture measured at depth in the soil profile. High plant mortality and reduced cropland productivity was also observed. The study also identified some plant species, such as oriental arborvitae, Chinese jujube, Caragana, Calabazilla, mung bean and broomcorn, with high drought tolerance.

Abstract:Effective moisture of base material mixture is one of the important indices evaluating thick layer base material spraying bio-slope engineering. Based on spraying experiments on simulated rock slope, different organic matter and absorbent agent contents' effect on base material mixture's moisture constants are studied. This has some significance for the selection of base material mixture composition and proportion.

Abstract:The border of chernozem area in the Northeastern China has been discussed for a long time, but the view differed, and it would directly affect the zoning and the measure selecting in conducting "Soil erosion prevention and control project of chernozem area in Northeastern China". We try to expound the scale of the chernozem area in Northeastern China in a broad sense from the regional soil, geomorphology and economic structure. Some constructive suggestions on ecological construction of chernozem area are put forward in view of soil and water conservation.

Abstract:Research in desertification is well established, but methodologies for assessing desertified land are in their early stages. A major hurdle has been the lack of a comprehensive and unifying scientific framework that facilitates the integration of the characteristics of desertified land and their contribution to the condition of the desert landscape. Here, desertified land is assessed using a desertification index National desertification survey information is used to standardize identification of every desertified patch. Then, an assessment of every priority county affected by desertification in western China was undertaken. Results indicate that the distribution pattern of desertification indices matches the spatial trend of sandstorm frequency. It is proposed that the desertification index may express the grade of regional land desertification.

Abstract:According to climate condition, soil condition and afforesting tree species and water requirement rule of forest and grass, the paper analysed and calculated the slope length for collecting stream of three site preparation methods which were reverse-slope terrace, level trench and scale-hole, and the slope length for collecting stream of deferent gradients and planting bandwidths were acquired.

Abstract:The circular slices method is one of the normal method for analyzing stability of slope which assumed the stabilities of individual slice is equal and equaled to that of whole slope, and belongs to an imprecise limit equilibrium method of rigid body with some irrationality. With a simple slope as research model, the circular slices method is improved. Postulating the slices can transfer internal force each other and the stabilit ies of individual slice are not equal, the differentiating condition of slope stabilization states is put forward via studying the transmission principle of slices force interacted by each other, and the theory formula calculating interact ion forces of individual slices is deduced at a stable slope. Based on above, the theory formula calculating stability factor of whole slope from the stability factors of individual slice is also deduced according to the principle of disjoin- join and the principle of weight weighted average of sliding factors.

Abstract:Resources and environment databases for the middle and lower reaches of the Liaohe River basin have been built on the basis of results produced by the national ninth-year-planning technology project. Soil erosion in the basin is analysed using remotely sensed images and the spatial functions of a geographical information system (GIS).

Abstract:Regional soil erosion is limited by a number of factors, including precipitation, relief, soil quality, vegetation and human activity. With reference to domestic and international work on the assessment of sensitivity to soil erosion and to the natural environment characteristics of Fujian Province, the primary influences on and sensitivity grades of soil erosion are determined. GIS software is utilized to index resulting data and to extrapolate soil erosion sensitivity analysis.

Abstract:This article describes the use of a distance model, which is based on the 3S model theories of global positioning systems(GPS), geographical information systems (GIS) and remote sensing (RS). The distance model is used to analyse the amount of water consumed in real and simulated water conservation forestry. The quantitative analysis of water conservation forestry is useful to macro-decision making in relation to water consumption. Calculation of the amount of water consumed accounts for forestry plot conditions, forest type, slope direction, solar radiation incidence and temperature. The 3S based model utilises spatial information and a resulting digital elevation model to generate vector graphs for land use, water conservation, forest type and soil type. These are used with Penman-Monteith to calculate the water consumption of the research forest area.

Abstract:Soil and water conservation monitoring in Dingxi City was undertaken using the three kinds of data from a comprehensive monitoring on typical station, the interim monitoring points of the state key project and hydrological stations in Dingxi area. The comprehensive monitor station is located in Anjia catchment of Anding district, and is supported by information from a weather station network covering 21 surface flow districts, one bayonet check station and one meteorological station. The main hydrographic stations are at Donghe and Xihe River in Anding District. Other stations occur at Tongwei, Weiyuan, Lintao and Min County. The model has been observed and implemented by the Bureau of Hydrology and Water Resource of Dingxi Prefecture. The interim monitoring points are at the three dam systems of Anding District, Weiyuan and Longxi Countied, and the two major ecological rehabilitation project in Anding District and Tongwei County respectively.

Abstract:The flood control projects of the lower reaches of the Yellow River are important to the safety of the zone, but they also have some negative impacts on the environment. The flood control system is extensive and covers different sites, primarily characterized by soil and stone. Single projects have limited environmental impact, but as the impact of the system as a whole cannot be ignored. The system of projects disturbs natural processes within and out of the river. The flood control reservoirs reduce the flow to the estuary, which affects the estuary ecosystem. Construction of projects induces soil and water loss. This paper proposes eco-environmental friendly measures for flood-control projects based on the principles of sustainable development.

Abstract:A decision-making support system for integrated watershed management was developed using Visual Basic 6.0 language. The support system was developed on the basis of an investigation of current physical and socio-economic conditions in Baizhuang watershed. A treatment and development plan was developed as well. According to the treatment development plan, which were developed for the Taihang limestone mountain area, a engineering shield system was built, which comprises measures to capture hilltop runoff, prevent slope runoff, store runoff on the footslope and drain runoff when field capacity is exceeded. The goal was to establish optimal ecological agriculture for soil and water conservation conditions. Tests and research were carried out to determine optimal planting structures and to determine possible improvements in local ecology using fruit trees and grafting of new varieties. After analysis and evaluation of the current state of animal husbandry and feedback relationships with the local ecological system of Baizhuang Village in Taihang Mountain, the key problem for animal husbandry was identified- degradation and damage of pasture due to lack of overall planning, effective monitoring, as well as effective management. Two main factors determining the numbers of animals in the watershed were identified. These were the market demand for animal products within and outside the watershed and the primary productivity of fodder plants in the catchment. Based on the current state of ecological agriculture, a development model is proposed incorporating the various stages of animal husbandry development in the small watershed. The model is based on the principles that the intensity of animal husbandry should reflect fodder productivity and development should be market driven.

Abstract:In the semi-arid area of western Liaoning Province and the semi-humid area of eastern of Liaoning Province, field observations showed that the temperature in a mining area was higher than CK in summer by 2℃ and 7℃ respectively, but below CK in the spring and the autumn. In the spring and autumn, the moisture content of the mining residue pile was 6% and 11% respectively, while the moisture content of the mining residue pile in the arid period was at wilting point or lower. Evaporation from mining area increased by 1-5mm compared with CK, but the humidity of mining area was much lower than CK.

Abstract:The chernozem region of Liaoning Province covers the southern part of the chernozem region in northeast China. The Liaoning chernozem area covers 123200km². In this region, land affected by soil erosion covers 33300km², or about 27% of the total land area. Soil erosion in the region has caused severe problems, such as cultivated land area reduction, land productivity decline, river bed and reservoir aggradations, environment pollution and frequent drought and flood. Some strategies for ecological construction to prevent water and soil loss are put forward based on the physical conditions of the region.

Abstract:Over-grazing and tourist visitation are causing degeneration of the grassland in the Xilamuren area. To protect the natural resources and realize sustainable development, the health of the local eco-system must be maintained. There fore, it is imperative that prompt technological measures be taken to harness the degenerated grassland.

Abstract:Paying attention to and ensuring the security of terrestrial ecology in ecologically vulnerable areas are essential to realizing sustainable utilization of regional land resources. The concept and theoretical basis of securing regional terrestrial ecology in ecologically vulnerable areas are advanced on the basis of analyzing factors of the ecological management system. A new method, based on remote sensing (RS) and geographical information systems-environmental impact systems (GIS-EIS) and involving evaluation, precaution, simulation and optimization of the system, is advanced. The final result of the research is a comprehensive system for terrestrial ecology management in ecologically vulnerable areas, which contributes to progress in the field of securing regional ecological environments.

Abstract:The swamps in Hebei Province could be divided into five types, namely inner-river swamp, nature low-lying swamp, around reservoir swamp, the Luanhe River-tail swamp, and riverway swamp. The measures of prevention and harness on the swamps could be different with the differences of geography and water level. There are some important measures like filing water, depollution, plant control and chemistry control. Attentions should be paid to protect vegetations and animals in the swamp harness in order to construct the harmonious situation between human and environment.

Abstract:Owing to the various situation, the conversion of farmland(back to forest or grassland) in foreign countries has various objectives, such as alleviating social contradiction, eliminating grain overstock, conserving biodiversity, reconstructing landscape, mitigating greenhouse effect, etc. Proceeding from analysis of the farmland's conversion abroad, we can make a conclusion that economic strength is the basis of this kind of farmland's conversion, the surplus of grain is the pledge and the shift of labor to towns or cities is the precondition. Furthermore, the success of the farmland's conversion benefits from the changes of revenue policies to a great extend. To put the Farmland's Conversion Project into effect in China, taking the experience of other countries and considering of China's specific situation, this research proposes two advises: on the one hand, the economic construction and grain production must be strengthened; on the other hand, the living of the farmers who convert their own cultivated land back to forest or grassland should be well arranged. The government may carry out a series of preferential policies about revenue and credit etc. to make those farmers live better.