Abstract:Comprehensive controlling soil and water loss on the loss plateau has made great achievements since 1949, but there are some problems which should not be neglected: ( 1) The harnessing effect mainly focused on the important regionsand typical watershed, the overall degree of controlling is not good, the total controlling level is quite low, the speed of harnessing is not quick|( 2) The density of population on the loess plateau is far exceed the reasonable capacity there, the contradiction among population, farmland forestry and grain is marked,the controlling on loess plateau made the solving food problem ( dressing warmly and eating fully, etc. ) as its effect|( 3) The purely government conduct and freeinvestment pattern are not beneficial for improving the comprehensive controlling, beside that, the harness policy on loess plateau and enforcement principle have not been thought with the native social, economic and cultural background as a whole, in other word, we have not converted the controlling into the conscious action of native masses themselves, so the results are not good, eco-environment is getting from bad to worsen, so serious soil and water loss and poverty are still the main obstacles for developing society and economy there. In order to put an end to the backwardness of loess plateau, we must change our controlling thought reconstruct the new controlling pattern, the most important measurement is reconstructingeco-system.

Abstract:Based on the results of investigation in Gaoqiao demonstration region, the principle and direction of structure adjustment of plant farming are analyzed and discussed. It is considered that plant farming should not only concentrate on higher yield of grain. On one hand, plant farming should concentrate on its benefit raising, changing from the type of dress warmly and ear one's fill to the economy type, and from the economy type to the higher benefit type|On the other hand, plant farming should sustain grassland animal husbandry that is dominant commercial industry, changing from the plant type to the combination type of planting and breeding. The structure adjustment of plant farming should be based on the distribution and utilization of water resources, and bringing regional dominant commercial industry into full play, improving agricultural environment, constructing regional commercial and efficient ecological agriculture.

Abstract:Estuary locates the intersecting zone between ocean and river, it is the wetland ecosystem type with great resources potent and environmental values. Besides it can provide a lot of foods, materials and water resources, it can keep regional eco-balance, maintain biodiversity and rare species, regulate water resources, control flood and fight natural adversities, degrade pollutions and provide trip etc.. However, owing to the unreasonable exploitation and utilization for a long time, the living environment has degenerated, biodiversity has decreased seriously, the environmental pollution, erosion of coast and estuary deposition have been aggravated. It is imperative to conserve and utilize reasonably estuary resources. The menaces faced with of estuaries and the main problems during the management, conservation and utilization of Chinese estuaries are analyzed, and the sustainable management countermeasures are put forward.

Abstract:Main research achievements in soil erosion prediction models in the world are summarized. Besides well-known erosion models, such as USLE/RUSLE, WEPP, LISEM and EUROSEM, ephemeral gully erosion model, gully erosion prediction model are also introduced. Steep hill slope erosion prediction model including shallow gully erosion supported by GIS, the process based hillslope erosion prediction model, and watershed erosion prediction model in China are outlined. Based on summary and assessment on soil erosion prediction model in the world and China, the tentative plan on soil erosion prediction model in China is proposed.

Abstract:Based on the geographic information system and remote sensing, the spatial distribution of karst rock-desertification is studied, and the 1∶100000 map of rock-desertification is made. The methods of bivariate correlation and principal component are used to pick up the information included in driving factors. The relations between rock-desertification and each factor are discussed, and then the system of influential factors indexes are built. As a result, the percentage of forest cover, area of karst regions, drainage networks density, arable land, area of cultivated land, average altitude, cultivation index, grassland and ≥25° surface slope are proved to be the key factors to the rock-desertification. The rock-desertification dynamic index (I R) is also established and the significant value of each factor is calculated. The most important factor of karst rock-desertification is irrational human activity. Its comparison with the GIS-RS derived data shows that I R can reflect the potential capacity of the rock-desertification and also the dynamic process is studied to reveal the dominant factors in karst regions. All these studies may be of great help for the mitigation of the rock-desertification.

Abstract:The growth process of Pinus massoniana under three improving and control patterns of grass-planting(pattern Ⅰ), arbor mixed with shrub(pattern Ⅱ) and arbors-mixed(pattern Ⅲ) in severely eroded red soil at Hetian town, Changting county, Fujian province are studied. The results showed that compared with control plot, the growth of Pinus massoniana developed in plots where having taken some measures for soil and water conservation. On initial stage, three patterns promoted tree growth, and the effect of pattern Ⅲ was the best, while that of patternⅠwas the poorest. With time going on and fertility exhausted, the growth of Pinus massoniana declined again, and the duration of the effect was the longest for pattern Ⅱ, whereas the shortest for pattern Ⅰ. It is clear that combination of mechanical and fertility measures are necessary for the control of degraded eroded soil, and how to regulate them on late stage to accelerate the restoration of ecosystem remains a critical question for future research.

Abstract:The total numbers of 69 root nodules which were collected dispersed over 21 genera, 45 species of legumes according to our investigation of rhizobium resources of leguminous plant in Bailong river basin, Gansu province, 63 strains of root nodule bacteria from 69 samples were isolated. Experiments on 44 stains among 31 were inoculated back to 13 species hosts. The shapes of nodules of these plants were circular, ellipse or cudgel with pick in color. The results of acetylene reduction detection showed that 88.5% were effective for nitrogen fixation. Activities of nitrogen fixation in nodules varied littlely and were higher than that in other areas of Gansu province.

Abstract:The debris flow with the characters, such as rush occurrence, short duration, high viscousity and density, strong impact, was triggered by a storm in both of the west gully and the east gully in the Litoujian hill, Lulin district, the Mt.Lushan on 15th August, 1995. It was resulted from avalanche in the sources of the gullies. It affected the road and hotels below the hill and destroyed landscape on the hill. Potential hazards are still existing in the gullies. The comprehensive planning for controlling the debris flow, which consists of check dams, a drain system, retain walls and planting, was made. Up to now, 24 check dams, retain walls with 335.0 m length, a drain system and planting have been finished. In 1998, serious flood hazards occurred in Jiangxi province and many debris flows occurred in the Mt.Lushan. The project is successful because the controlling works passed the test by the storm. The constructions of its own, as well as the road and the hotels are under the protection of works, were not damaged at all.

Abstract:Debris flow and landslide are two types of common disasters in the mountain area of Beijing city, and among which debris flow is especially serious. There are 700 debris flow gullies distributed over 61 villages and towns of districts and counties of Fangshan, Mentougou, Changping, Huairou, Yanqing, Miyun and Pinggu. The heavy incidents of personal injuries and deaths, and properties losses from debris flow and landslide have occurred many times there. The action is of great significance for improving environment and protecting the source of water supply of Beijing city.

Abstract:The climate changes taking after the project of transferring water from south to north are studied. After the project is executed, the river's water level will be lowered, the water velocity will be slowed, the water surface will be narrowed in the middle-and-down reaches of Hanjiang river. The middle-and-down reaches of Hanjiang river are distributed into 11 zones by cities, the changes in water surface evaporation caused by the narrowness of water width are studied and the model of relationship between temperature, humidity and evaporation are established. The average temperature and humidity in every zone in 2000 are used as the initial temperature and humidity, which is taken into model to calculate, so as to achieve the change of temperature and humidity in every zone under different water transferring scale.

Abstract:The moisture status and its meaning of latosol under Eucalyptus in Leizhou peninsula was characterized by lower in stored water content, only being 150 mm in 0-100 cm soil layer|Controlled by rainfall distribution, the stored water presented clear annual and seasonable changes, being longer in dry season|Even in rain season, very wide range in change of the stored water content within a short time could bring out, which means that the latosol under Eucalyptus is quite easy to suffer from drought. More attention should be paid to relieving the effect of water stress on Eucalyptus growth.

Abstract:The ecological and environmental protection during the construction of an important large-scale project in Shenzhen city are expounded, and the water source network project of eastern Shenzhen city are presented. The protection of ecological and environmental is divided in four phases, we dealt with the each phase in particular, expounded the importance and hardship of the ecological and environmental radically. It could be a good reference of how to protect environment during large-scale underground engineering projects.

Abstract:The UML wasintroduced to modeling the real software for evaluating the balance between supply and demand in water resource system in its analysis and design by using Rational Rose, drawing out some C++ Class of instance from the real system. Its software was finally come true by using Visual C++ 5. 0 on Win32 technique in Windows95.

Abstract:Daily and event data from 8 weather stations was used to analyze the relationship between daily and event rainfall. The result showed that the difference was not marked, and it was feasible and reasonable to estimate erosivity using daily rainfall data instead of event data. The regression function of rainfall erosivity estimated from daily rainfall and the one from event data was 1∶1 line, and the average R-square of 8 stations was 0.950. Because the coefficient of the line was not different greatly in different climatic regions, an estimated rainfall erosivity model using daily rainfall amount and its maximum 10-min intensity was set up, and its R-square was 0.966 . This analysis will simplify the calculation of rainfall erosivity and stimulate the meteorological data application for soil erosion model.

Abstract:In order to effectively manage the data from the project of west China eco-environment investigation, a Shaanxi Provincial Eco-environment Database System was designed and set up. This GIS based database system tones up the interface operation efficiency not only intuitively and flexibly, but also optimize the method of spatial data browsing and processing integrally. By means of a specially designed information searches program, this system can provide people with more valuable and comprehensive environment spatial distribution information. This research is of great significance both in theory and in practical applications.

Abstract:Plant coverage is a very important ecological index and it is essential for predicting soil loss quantitatively. The plant coverage of two fields located in Beijing city was measured periodically in order to analyze the errors of overhead photograph and visual estimation for plant coverage. The results showed that the overhead photo graph combined image processing was an accurate and fast method, and the maximal absolute error was less than 5 % . The plant coverage estimated by different persons have significant difference. The individual maximal absolute error was up to 40 % and average maximal absolute error for 7 persons was up to 10. 2 % .

Abstract:Based on summaries of soil and water loss control measures in some typical controlled watershed in wind-sandy area of loess plateau, several typical watersheds with abounded basic information in control methods, geography, social system, etc. are selected. Through examples analysis on the relationship and interaction of factors such as soil erosion intensity, designed management goal and key control methods, and those factors' combination, and also analysis on benefit estimation, the key measures and its combinations on soil and water comprehensive control are discussed. At present, the western region is on priority agenda to be invested to rebuild its environment. Therefore, wind-sandy areas should be considered in precedence and also planed as a whole in practice. Otherwise, the western region could not be developed smoothly which will affect the eastern region's economy to be sustainable and steady developing. Researches on comprehensive control of soil and water loss could benefit on reducing soil and water loss and resuming vegetations in the region.

Abstract:The soil and water loss and its control during urbanization is still a new subject. Based on detail investigation of soil erosion and analysis on the characteristic of soil and water loss in the area of weathered granite soil, the erosive intensity control and erosive modules adapted to urban developing platform are put forth and the basic scientific data for it is provided. Based on this study, the priority harness of triple sides was performed with control practice of double viewpoint on soil and water loss and urban landscape. Furthermore, the control mode of regulating water system, surrounding control and control method are also put forth.

Abstract:Gully-slop lands are superior lands for apple trees cultivation. Techniques of erosion controlling on gully-slop road should be established, and apple trees should be planted in autumn, fertilized, irrigated and pruned should be according to the soil and trees needing. Ecological prevention and control of apple disease and pests, and the excellent fruits and post harvest handling should be strengthen etc.. All above are apple cultivation technical measures for top quality and high yield on gully-slop lands in the gully region of loess plateau.

Abstract:With a case study at Guangzhou city, the present situation and characteristics of the urban soil and water loss in Zhujiang delta area are illustrated. Then the measures of control on the urban soil and water loss are put forward aiming at the severe soil and water loss which is due to quarrying, traffic construction, development area building and slope tillage. The benefits of soil and water conservation by use of the measures are evaluated. The results will contribute to the ecological environment construction of soil and water conservation.

Abstract:The significant effects on stabilizing or raising grain output were obtained by extending the techniques of keeping crop seedling against drought, adjusting planting frame, using excellent varieties, applying fertilizer, and using the ridge-furrow planting method. Although the rainfall decreased by 36.1 percent compared with the general annual rainfall in the extremely dry year of 2000 in Yangou watershed, which made the grain output approached to 525.1 kg per capita. These alternatives can play the significant roles in insuring the grain security after shifting the slope land to terrace, and accelerating the process of conversion of certain cropland to forestry land and grassland in the hill and gully region in the middle of loess plateau.