Demonstration And Dissemination Of Effective Utilization Of Water Resources In A Representative Watershed On The Loess Plateau

In the hilly region of the Loess Plateau, a semi-arid area, the shortage of rain water has seriously limited the development of local agriculture development. On the other hand, most small springs and ground water in the valley are not used efficiently. It will be of great significance to collect and use tthese water resources by some pint-sized engineering works. And it could help develop the local high-facility agriculture, to reform the planning structure, to enhance personal income and to accelerate the restoration of eco-environment.By analysis of the structure, basic characteristic distribution, water use potential and present water resources situation in the hilly region of the Loess Plateau, this paper points out the main issues and solutions to water resource exploitation as a whole in this region. (1) Contradiction between various spatial and temporal water supply and plant need—planting in the rain season to enhance rain water use efficiency;(2) Improvement of soil water supply capability—management of runoff water resources;(3) Exploitation of runoff water resources—rainwater saving and runoff harvesting techniques;(4) Improvement of water use efficiency—applying and disseminating water saving irrigation techniques.By study of the relationship between spatial and temporal distribution of rainfall, runoff and soil water and the water need of plant in this watershed, we offer the comprehensive technique system of rainfall, soil water and runoff(all of which are small-sized water resources), to use them with harmony and high efficiency together. And that can be carried out as follows: reforming planting structure, i.e. to plant in the rainy season; keeping a sustaining supply capacity of soil water by the protection of biological and engineering works; exploiting pint-sized water resources; improving water use efficiency to a high level to insure environment, economy and society development in the managed watershed.On the analysis of its gradient spatial characteristic of water resources(rainfall, soil water, runoff) in the hilly region of the Loess Plateau, this paper tries to show that the exploitation and use of these kinds of water resources also have gradient characteristics, which is applied and disseminated in Yangou watershed, Yan'an, coping with the assignment of my supervisor's project. They form into a gradient water exploitation and high efficient use system, which is summarized as"saving rainfall, holding up runoff and using soil water".It is feasible to build pint-sized engineering works with low investment and high benefits, for the high stability of small-sized springs and underground water and the great potential in this region. And it is easy to be disseminated in other similar regions. It is suggested to take measures to save the limit water resources, to study the complementary irrigation methods and to choose better water saving techniques, and to spread them in other similar areas.