一种统计坡面上土地表面积的方法研究

本文主要介绍和研究一种统计坡面上土地表面积的方法。建立在G IS的基础上,利用江浦县1∶25万、1∶5万地形图、六合县1∶5万地形图的数字化等高线生成的DEM数据,自动提取坡度信息、计算坡度的正割值信息,并分别与江浦县和六和县的同空间分辨率的土地利用栅格数据进行叠合分析,得出两县不同土地利用类型在不同坡度级上的表面积和投影面积数值。并经不同比例尺、不同空间分辨率、不同区域内各类土地的表面积与投影面积之比作比较。研究结果表明,利用此方法提取的表面积在一定研究范围内,对于那些坡度较大而且面积亦大的土地利用类型面积的准确统计有重要意义。

Research on a method of computing slope land''''s surface area

A method of computing slope land's surface area is discussed in this paper.This method,using GIS technology and DEM produced by digitizing contour from 1:50000 and 1:250000 topographic maps of Jiangpu and Liuhe county,can automatically extract slope information and calculate secant value.By overlay analysis of this extracted information and raster data with the same resolution of the same places,the authors calculate the surface area and vertical projection area of different land use types at different slope grades.After comparison of surface area with vertical projection area of different regions,different scales and different spatial resolutions,a conclusion shows that if slope lands locate on quite steeper place and in large size,it has an important meaning to use this kind of method to calculate their surface area accurately.