山区土地利用与地形因子的关系研究——以甘肃武山县为例  

Study on the Relationship Between Land Use and Topographic Factors in Mountainous Areas: Wushan County, Gansu

作　　者：吕玉娜 吴静 马引弟[1,2] LV Yu-na;WU Jing;MA Ying-di(College of Management,Gansu Agricultural University,Lanzhou 730070,China;College of Resources and Environment,GansuAgricultural University,Lanzhou 730070,China)

机构地区：[1]甘肃农业大学管理学院,兰州730070 [2]甘肃农业大学资源与环境学院,兰州730070

出　　处：《广东土地科学》2019年第1期31-37,共7页Guangdong Land Science

基　　金：国家自然科学基金(31760693);甘肃农业大学学科建设基金项目(GAU-XKJS-2018-208)

摘　　要：论文以武山县为研究区,使用多时相OLI遥感影像及DEM数据,利用ENVI5.3和ArcGis10.2分别获取反射率数据(以下简称RB)、NDVI、NDWI和地形参数(以下简称TP),对4种不同波段组合的图像进行随机森林分类获得精度最优的研究区土地利用类型图,并通过分布指数指标进行了研究区不同土地利用类型与不同等级的海拔、坡度、坡向因子的关系研究。结果表明:(1)4种不同波段组合的分类总体精度及Kappa系数的关系如下:NDVI+NDWI+TP+RB﹥NDVI+NDWI+RB﹥NDVI+NDWI+TP﹥NDVI+NDWI,这表明随着波段数的增加,总体精度和Kappa系数会整体提高。同时,多期关键时期的光谱特征对分类的作用是不可忽视的,地形因子加入对分类的总体精度和Kappa系数也都有很大的提高。(2)分布指数可以准确地描述各种土地利用类型与海拔、坡度、坡向之间的关系。低海拔、平坦、无坡向地区是耕地、建设用地和河流水面的优势分布区;高海拔、大坡度、阴坡地区是有林地的优势分布区;高海拔、大坡度、阳坡地区是草地的优势分布;河流水面不受坡向的影响。Taking Wushan county as the research area and using ENVI5.3 and ArcGis 10.2, reflectivity data(RB), NDVI, NDWI and topographic parameters(TP, including altitude, slope-degree and slope-direction) are obtained respectively based on multi-temporal OLI remote sensing images and DEM data, this paper classified four images of different bands by random forest, and obtained the most accurate land use type map of the study area. The relationship between different land use types and elevation, slope and aspect factors of different grades in the study area is studied through the index of distribution. The results show that:(1) NDVI + NDWI + TP + RB > NDVI +NDWI + RB > NDVI + NDWI + TP > NDVI + NDWI + NDWI, which shows that with the increase of band number, the overall accuracy and Kappa coefficient will be improved as a whole. At the same time, the effect of spectral characteristics of multi-period critical period on classification can not be ignored. The overall accuracy and Kappa coefficient of classification are greatly improved by adding topographic factors.(2) Distribution index can accurately describe the relationship between land use types and elevation, slope and aspect. Low altitude,flat, no slope area is the dominant distribution area of cultivated land, construction land, and river water surface;high altitude, large slope,shady slope area is the dominant distribution area of woodland;high altitude, large slope, sunny slope area is the dominant distribution of grassland;the river surface is not affected by the slope direction. This study is helpful to realize the rational distribution of land use types on different terrain and optimize the land use structure in this area.

关 键 词：山区土地利用 随机森林 地形因子 武山县 

分 类 号：S157.1[农业科学—土壤学]