The Decision Analysis On Returning Farmland To Forest Of Liuyang City Based On 3s Technology

Returning Farmland to Forest is the ecological project and one of the Six forest ecological projects. It's the important content of harmonious society, environmental protection under the guidance of Scientific Concept of Development in now times. The project aims at changing the irrational land use, reducing soil erosion, improving ecological environment and achieving regional sustainable development. Though the ten years of practice Returning Farmland to Forest has made significant ecological benefits such as accelerating greening projects, controlling soil erosion, watering conservation and land desertification prevention and so on.Returning farmland to forest land means step by step to stop cultivate of the farmland which easy work water and soil loss and ground translate to sand, and then plant tree and grass to get back vegetation. Take the 3S technology in the research of the Returning farmland to forest, the aims is to provide accurate, scientific data and the implementation plan for the Returning farmland to forest project, with the modem spatial information technology continues to develop, research methods and technology is continuously updated, the technology can be generalized to provide a scientific basis for the relevant departments.In the paper, the author uses the RS, GPS, GIS technology, set the city Liuyang as an example, take a decision-making analysis on the Returning farmland to forest project, we get the cultivated land area and spatial distribution which need Returning farmland to forest., and make a decision note about the times and trees and grass configuration. concrete measures:ldata processing, combining remote sensing and GPS location survey to interpretive remote sensing image processing,establish current land-utilization Database, and extract slope information from DEM.2.Analysing land-utilization situation, slope, soil erosion situation.3.Identify returning area, amount, distribution, sequence and design returning farmland chart by analyzing and determining.The research result of this thesis are as follow:(1) The manipulation and the interpretation of remote sensing have provide great base map to make land-utilization data; The establishment of current land utilization database through field mapping & software ofMAPGIS.(2) The design of soil erosion map of research area through visual interpretation, mathematical model, reference, the analyze of soil erosion.(3) The identification of dry land amount & distribution which need to convert,by analyzing GIS overlay, buffer area, land-utilization data, slop land data. It shows that there is 70.97ha sloping farmland need to turn because of incline over 25°; 98.27ha sloping farmland need to turn because of high soil erosion level; 199.57ha sloping farmland because of incline under 15°-25°. and high soil erosion.17.87ha sloping farmland need to turn because of distance within 1km nearby LIUYANGHE river.(4) To design the system for Returning Farmland to Forest upon different client, and function module.