Abstract:Eco-economical division is a new model for integrated development of social economy, enviroment protection and natural resources utilization within a certain region. According to the eco-economic theory, 53 specific indexes suitable for classification of eco-economic systems of the Miyun reservoir watershed in Beijing were selected. These specific indexes were taken for classifiying the eco-economic systems of 38 townships at Miyun reservoir watershed and 5 methods of non-overlapping intrinsic hierarchical agglomerate analysis were adopted. The results indicate that the Ward's hierarchical classification method is better than the others during this classification. The whole region was divided into 5 eco-economic regions and 8 sub-regions by using this method, and the results was good and objective. In addition, the special causes of eco-economic characteristics and development in every eco-economic region were analyzed. It provides scientific base for optimizing eco-economic system structure at the Miyun reservoir watershed.

Abstract:On the base of extensive field investigation of man-made debris flow in Shenfu-Dongsheng minesite, and according to its characteristics and processes, the system controlling model were respectively summarized up with theory of many levels controlling system, and the peculiarities of system controlling of man-made debris flow in Shenfu-Dongsheng minesite were generalized. The main aim of system harness of man-made debris flow is to make potential debris flow not broken out and present debris flow decreased.

Abstract:The influence of coal exploitation and construction of Shenfu-Dongsheng coal mining area on sediment transportation of the Yellow river has been paid more attentions. Using precipitation data since 1960's, spectrum analysis is conducted to forecast precipitation in the 15 coming years and its seasonal distribution. The result shows that annual rainfall in the 15 coming years will increase by about 6%, annual rainfall fluctuation will increase and rainfall concentration in a year tends to increase, which will make flood and sediment increased.

Abstract:The main causes of soil and water loss and the correlations between vegetation characteristics and soil and water loss on granitic hillslopes in Meijiang watershed of south China are discussed. As the result, vegetation destructiton is regarded as the primary cause of soil and water loss, and extending revegetation as the fundamental strategy to control soil and water loss on granitic hillslopes in south China. What's more, several strategies for controlling soil and water loss respectively on different erosion types based on the vegetation ecology are suggested, especially the first-chosen plants in completing these strategies are proposed.

Abstract:The microbial quantities of rhizosphere at Huoditang forest region of the Qinling mountains are analysied. The result showed that the rhizosphere quantities of Chinese pine-Armand pine mixed forest>larch forest>Pine-oak mixed forest, and the quantities of bacterium were dominant. The microbial quantities order of soil under alike forest types was rhizosphere>non-rhizosphere; soil on the bottom of tree stem (within a range of 0～5cm)>the soil-body beyond 30cm of tree stems and used as control, and there had significant differences in the different forest types. The quantities distribution of rhizosphere microorganisms were positively correlated with the soil enzymic activities, contents of organic matter and soil nutrients.

Abstract:Through the research of growth, water and photosynthesis characteristic of maize under different combination of air humidity with soil moisture, the results showed the harm of soil water deficit exceeded that of air drought, water status and physiological activities were mainly decided by soil moisture. Short-term drought made photosynthetic rate decrease. For soil dry treatments, the main reason was nonstomatal limitation, but for air-dry-soil-wet treatment, stomatal limitation at first but nonstomatal limitation later. Dry matter continued to increase during the period of short-term drought.

Abstract:The research results on hydroseeding, hydroseeder and nationalization of hydroseeding mulching materials have been introduced. The prospect of utilization of the technology in China has been analyzed.

Abstract:Occurrence and damages of mountain hazards, such as torrent, landslides and debris flow, have close relation to human activities in mountain area. Most of mountain hazards widely dispersed over China are of small scale scattering over 31 provinical administrative districts. The experience in Alps and southwest mountains of China shows that small scale hazards were controlled successfully by small scale civil engineerings, with their advantages of simple construction, a little budget and great effectiveness in controlling hazards. For these engineerings, local materials and cheap labour are usually available. In addition, they can be combined with bio-engineering easily. In 1995—1997, small scale civil engineerings were used to cotrol small landslides, debris flow gullies and torrent gullies successfully in the southwestern mountains. The problems concerned in the application to all mountains in China are related to the support of the government, a good design handbook, train for young engineers and combination between the hazards control and economy development in mountain area.

Abstract:In present, sediment model research is usually focused on cases of small basin with short time interval record of rainfall and high density network of rainfall gauging station. There are two problems come usually across in the application of such model to middle and large scale of basins, that are time and space scale problems. A middle scale basin with high density network of rainfall station and six small scale basins with short time interval record rainfall were chosen. The relations of simulating accuracy respectively to time interval scale and to space scale were then analysed in turn. And finally, some useful conclusions were obtained.

Abstract:The main aim of runoff harvesting in semi-arid area is to lighten soil and water loss, solve the problem of watering people and domestic animals, develop courtyard economy, prevent drought and keep a full stand of seedings, irrigate supplementarily(SI) fruit trees, vegetables in greenhouse and solar radiation greenhouse, irrigate supplementarily field crops. Different use measures of harvested runoff have much different benefit. According to output value of water pur ton(OVPt). The results of benefits of every water use measures show: If soil water capacity is lower than 11 percent, water providing sowing technology can keep a full stand of seedings used 15～45m³/ha water. Water providing dibble technology can keep a full stand of seedings of corn or other thinly scattered crops used 1～1.5kg water pur spot or 30～45m³/ha water. Through SI, OVPt of fruit trees can reach 40 Yuan,and that of vegetables cultivated in solar radiation greenhouse can reach 72 Yuan, vegetables cultivated in greenhouse 15 Yuan, the OVPt of field crops are all lower than 11 Yuan. But most of the area which is suitable for runoff harvesting is far from household, it is difficult to produce fruit and vegetables in this area, cereals can be produced only. Although benefit of fields crops cultivated with SI is not goods enough, if SI is used in a big area, the problem of sufficient goods and adequate clothing can be solved stablely.

Abstract:The energy input from human, animal and machines in soil preparation, planting cultivation and management and cutting, etc.to 5 kinds of shrubs and 4 of trees were calculated, then the comparison of energy input with output of standing trees and/or fuel wood was conducted. The production of Astragalus adsurgens Pall., Medicago sativa L., Onobrychis visiaefolis Scop was analysed, in energy input through human labour and seed and energy output through grass, fuel and seed. The energy input to animals through raise and management and their output of energy through animal power, young animal, eggs and excrement of animals were calculated. Having studied energy output with energy input structure of the animals, a systematic analysis to energy flow for the sub-system of animal husbandry was made. It is suggested to develop the number of sheep and cattlas but limit and decrease the number of rabbit and chikens.

Abstract:Taking the evolution of eco-environment in Datian county as a lead, some scientific and technical problems related to soil erosion control and ecological agriculture construction are discussed. the law of evolution of agricultural eco-environment is expounded. The satus and properties of agriculture eco-environment are fully analysed, and the key problems of agriculture environment construction are discussed. To attain the goal of system engineering construction of eco-environment, the feasible countermeasures according to the specific condition of Datian county are put forward.

Abstract:Macro-regulation and strategy of exploiting and using rain water have been discussed. The major measures as follows: Geting more rain from the sky, storing more rain in soil, transferring water from the south to the north of China, water saving irrigation, using water high efficiently. These measures are very useful to dryland agriculture and water-saving agricultur in China.

Abstract:Since the 20th century, a great progress has been made in research on infiltration and runoff yield. Some developments and results in influence factors of infiltration, computation and analysis of infiltration, hillslope runoff yield and watershed runoff yield in China and other countries are introducted, and some brief reviews on them are given.