Evalution On Forestry Suitability Of Resource In The Basin Of Northwest Hebei Mountains On GIS

Since 1990s, the crisis of population-resource-environment which human being are encounting has deteriorated furtherly. It has become study foucus to resove this problem in order to abtain sustainable use of recources. In the system of population-resource-environment, the land recources is in the most essential position. So for survival and development, we must make precise evaluatation for the land suitability. The forest suitability evaluatation belongs to the category of land evaluatation, and its aim is to study the reasonable development and utilization of the forestry.In this paper, the Basin of Northwest Hebei Mountains as the study area, the combination of the remote sensing and GIS technologies will be applied, Firstly the objects of evaluation include forest land,. meadow , a part of orchard, uncultured grass land, sandlot, bare land and the margin suitable and unsuitable farming land, the unit of evaluation is 30m*30m grid. Secondly, on the base of probling and building the spatial and attributive database of suitability evaluation through models such as digital elevation and inverse distance weighed interpolation, it establishs the factor system of suitability evaluation of forest land.According to the principle of selecting the evaluated factors, the 7 evaluated factors used in the forest resource suitability evaluated have been defined. And the classification indexes of evaluation factors have been classified through simulating the relation between growth conditions of forest land and evaluation factors. The growth conditions of forest land have been described by NPP(Net Primary Productivity) and the NPP of forest land in the study area got from the relation model . of NPP and NDVI(normalized difference vegetation index). The weigh of each factor has been confirmed by Delphi method. And we got the result of forest suitability evaluatation according to method of weighted aggregative index number, analyzed thequantity and space distribution , at last found out mostly confined factors of each grade.The forest suitability evaluatation result shows that the area of the highly suitable, the medium suitable, the margin suitable and unsuitable forest land in the study area are 1579.86km2 > 4455.23 km2^ 2534.83 km^ 1153.11km2, and take 16.2°/^ 45.8%^ 26.1%^ 11.9% of evaluatation land gross area. According to single factor evaluatation of different level, we find out mostly confined factors of each grade. And According to the actual conditions of the studying area, the relation of forestation and spatial layout in the area is analyzed. The result provides the basis for the forest land use inthe future.