Research and Harnessing Plan Abount Soil and Water Loss in Shanyang County in Hunan Province

摘要

The ShaoYang county of Hunan Province is an old revolutionary district and a district of poverty. Owing to all sorts of natural and human factor, the soil was suffered with severe water loss and soil erosion. The lost areas account for 37.7%, thereinto, light_lost areas is 41.2%, mid_lost areas is 37.7%; strongjost areas is 0.5%; terribly_lost areas is 4.3%, extremelyjost areas is 0.5%. In order to concern this severe crisis the author composes this paper. Fisrt, the basic condition in Shaoyang County is introduced. Next, it deeply studies the occurence and development rule of the soil erosion from the original society till now, points out all kinds of reason and harm of soil and water loss. Then, the types of soil_erosion and its correspond harness measurement is classified according to the present situation,,and planning of defension and prevention is put forward. The planning period is 30 years.i.e. from 2001 to 2030. In the planning , forecasts are first made from 6 aspects:population forecast,soil usage forecast for food and produce_extend balance, soil usage forecast for vegetable and its produce and sale, usage forecast for forest for firewood, fruit forest forecast and its produce and sale, meadow and other non_produce soil forecast. Base on above forecasts, author raises in_system soil using plan and detailed adapting plan.changes the cultivate regime. Also,integrate harness method and quantization index for the present situation are described.Also,author detail arrangement of "according our own abilities.carry into execution by stages",and make the investment budget and benefit analysis:from the social benefit perspective.author discusses the water_accumulation and soil_reservation and erosion_decreasing benefit by creature measure and by project measure.and the improvement of the forest covering percentage.the increasing of the humidity and precipitation,the improvement of the ability of drought_fighting,etc.From the economic benefit perspective.author specifies the benefit of production increasing of all kinds of measures,and also calculate the total run_expense,yearly net benefit,time limit in year of sensitivity investment recycle and output_input ration etc.At last,three necessary guaranty measures for the implement of the project is presented.