The Application Of 3S Technology In Returning Farmland To Forest (Grassland) The County Area

Returning Farmland to Forest (Grassland) is one of the six major forestry projects in China, and it is also an important part of the west development.the project aims at changing the irrational land use,reducing soil erosion,improving ecological environment and achieving regional sustainable development.Returning Farmland to Forest(Grassland) is a state-level major ecological construction project in the central and western China.Though years of practice Returning Farmland to Forest (Grassland) has made significant ecological benefits such as accelerating greening projects,controlling soil erosion,watering conservation and land desertification prevention and so on.So this project has become a sustainable and developmental issue in China.First of all,this paper introduces some cases of the nation-wide implementation of Returning Farmland to Forest (Grassland), as well as what is 3S technology. On the main part, the importance of 3S technology application in Returning Farmland to Forest (Grassland) in county area is discussed. A typical area of returning farmland to forest (grassland)-----Aohanqi Banner in Chifeng City is selected as the study area. We used soil type distribution map (1:100,000),soil erosion map, topographic map(1: 50,000),weather statistic data and other relevant materials as basic data to set up a spatial and attribute database respectively. After data processing and overlaying,we can get land suitability evaluation and establish a database.Through evaluating and analyzing based on the principles of the land suitability evaluation, we get the number and spatial distribution of farmland,forest,and grassland. According to statistic data, proportion of farmland,forest and grassland areas of Aohanqi Banner are separately 18.38,46.33,29.76 percent. We know that farmland area is less, forest and grassland areas are comparatively more. We divide farmland,forest and grassland into three grades and get the statistics. The results showed that the quality of farmland is lower, quality of forest is middling and quality of grassland is better;At the same time,we get the land use condition of Aohanqi Banner through the visual interpretation of TM images used image processing software of remote sensing, GIS and database systems.Then we overlay land-use map and the results of land suitability evaluation of Aohanqi Banner to get the amount and spatial distribution of farmland which should be returned to forest and grassland. Returning Farmland of whole banner is 259493.61hm2 , occupies the 63.17 percent of the farmland area in 2000, restoring forest or grassland areas are separately 206716.36hm2,51206.39hm2 . The spatial distribution obtaining from studies through applying 3S technique is anastomosis basically to the distribution of open country measured points, and the precision reaches the request of returning farmland and Returning Farmland to Forest (Grassland) project.Finally,we analyzed the major obstacles in applying 3S technology in Returning Farmland to Forest(Grassland),and put forward some reasonable suggestions on the following program of the project,and these can provide basis for decision-making and the policy-making.This research method can become a promoted model, and it will make great significance in the development of the western region and the successful Returning Farmland to Forest(Grassland).