Based On GIS Analyzing Impacts Of Soil And Water Conservation On Economy And Society

Ansai county is located in the hinterland of the loess plateau, in which the terrain is fragmentary and the gullies are in a crisscross fashion and soil and water loss is severe. As same as another soil and water loss regions, the local people have accumulated much experiences and created great achievements during the practices of struggling against soil erosion. In the loess plateau, one of the most spectacular measures is terraced field which has the best effects in conserving water and soil and increasing production. Terraced field can conserve water, soil and maintenance nutrient, and improve local ecological environment. At the same time, its impacts on local social economy and shaking off poverty are important. It has an important realistic meaning and theory value on harness of soil and water loss, changing local production conditions, speeding up ecological rehabilitation, developing local economy and prosperity by researching the relationship between local social economy development and soil and water conservational measures represented by terraced field. On the basis of studied results, the relationship between terrace and local social economy of Ansai county was analyzed through building the Comprehensive resource-environment database of Ansai county using the space technology of RS and GIS and integrating the data files of soil and water conservation as well as analysing under guiding the basic theory of soil and water conservation. The main results are as following:1. The resource-environment database of Ansai county was established using the space technology of RS and GIS and integrating the data files of soil and water conservation. It provides foundation for the soil and water conservation program, the evaluation of soil and water conservation achievements and the guidance of ecological rehabilitation and soil and water conservation building. The database contains the data of natural resources and social economy. The natural resources data contain environmental, resources, land use, vegetation, and so on. Social economy data contain GDP, total agricultural output, total industrial output, net income per person, education, soil and water conservation projects, and so on. The data format includes attribute tables and space paragraphs, by which we can do some spatial analysis.2. From the analyzing the historical development of soil and water conservation in Ansai county, it shows the area of basic farmland increased from 76.88km2 in 1985 to 95.48km2 in 1999, and per person has 0.06ha (the terraced fields increased from 0.25% in 1985 to 0.88% in 1999). According to the development trend, before 1996 the annual average growth of terraced fields was 10.38khm2, but it tended to stabilization after 1996. It shows that the terrace of per person has basically met the demands.3. Terraced fields played an important role for local growth of agriculture economy, grain yields and residents'income which had rose up to 1126 yuan from 187.65 yuan. Because of oil production, after 1996 the economy developed very quickly. In 2003 the total industrial production rose 975.4% comparing with the one in 1995 while the oil production raised 27.65 ten-thousand-tons which had a very important role for local economy.4. The impacts of terraced fields on society of Ansai county were mainly reflected in the period between 1991-1997. At that time, with the development of terraced fields, the production and income of agriculture increased year by year, and peasant's existence became ensuring, and the proportion of the one who were studying in secondary school increased year after year while the rate of this proportion was the basic same with the one of terrace building. In 1997 the proportion of the students in secondary school occupied 38.4‰in total population.