论文部分内容阅读
数字地形分析的很多方法已经在极为广泛的领域中应用,作为最主要的环境参数,数字地形分析的结果往往被各种各样的环境、资源、工程和地理模型所采用,数字地形分析的主要应用范畴有水文学、地貌土壤学、生态学等,同时数字地形分析的理论与技术也大量地应用于人类的生产、生活和政治活动中。因此,对一个地区作数字地形分析是有科学价值的。坡度坡向等地形因子是影响水文过程、生物分布、地貌特征、环境变迁等的重要因子,地形属性的空间分布特征通常是人们用来描述这些空间变化过程的重要指标。利用地理信息系统软件(AcrGIS10.2)为工具,利用中生代某地区的基础数据构建不规则三角网TIN和GRID,并对该地区的TIN和GRID进行坡度坡向分析,将实验中提取的坡度坡向图和研究区域的土地利用现状图等进行叠加分析,最后综合坡度坡向的分级以及土壤气候等因子的情况,最后获得的数字地形分析的结果可用于政府的科学决策工作上。1.在AcrMap中进行数字地面模型分析1.1定义坐标系:File—Add Date—Add XY Date(添加相应的.xlsx文件)1.2.利用高程点数据,生成GRID和TIN1.2.1Arc Toolbox—3D Analyst Tools—Raster Interpolation—Kriging(输出为:Kri)1.2.2Arc Toolbox—3D Analyst Tools—TIN Management—create TIN1.3生成栅格数据:Arc Toolbox—3D Analyst Tools—Conversion—From TIN—TIN to Raster1.4利用生成的GRID数据提取地形参数1.4.1提取坡向参数:Arc Toolbox—3D Analyst Tools—Raster Surface—Aspect1.4.2提取等高线参数:Arc Toolbox—3D Analyst Tools—Raster Surface—contour(等高线圆滑Arc Toolbox—Cartography Tools—Generalization—Smooth Line)1.4.3提取坡度参数:Arc Toolbox—3D Analyst Tools—Raster Surface—slope1.4.4提取山体阴影:Arc Toolbox—3D Analyst Tools—Raster Surface—Hill shade1.5利用生成的TIN数据提取地形参数1.5.1坡度:Arc Toolbox—3D Analyst Tools—Terrain and TIN Surface—Surface Slope1.5.2坡向:Arc Toolbox—3D Analyst Tools—Terrain and TIN Surface—Surface Aspect1.5.3等高线:Arc Toolbox—3D Analyst Tools—Terrain and TIN Surface—Surface contour2.在AcrMap中进行水文分析—以鞍部点的提取为例2.1流域分割:洼地填充—计算水流方向—计算累积量—重分类—河流连接—流域分割2.1.1Arc Toolbox—Spatial analyst tools—hydrology—fill(输出为fill)2.1.2Arc Toolbox—Spatial analyst tools—hydrology—flow direction(输入fill,输出为flow-dir)2.1.3Arc Toolbox—Spatial analyst tools—hydrology—flow accumulation(输入flow-dir,输出为flowacc)2.1.4Arc Toolbox—Spatial analyst tools—reclass—reclassify—flow-acc(分两类,中介值为1000)2.1.5Arc Toolbox—Spatial analyst tools—hydrology—stream link(依次输入重分类后的数据,flow-dir,输出为stream L)2.1.6Arc Toolbox—Spatial analyst tools—hydrology—watershed(依次输入flow-dir,stream L,输出为watershed)2.2流域转换为栅格山脊线:栅格—面—线—栅格—值改为12.2.1Arc Toolbox—Conversion tools—from raster—to polygon(输出raster T)2.2.2Arc Toolbox—Data management tools—features—feature to line(输入raster T,输出为raster TF)2.2.3Arc Toolbox—Conversion tools—to raster—feature to raster【输入raster TF,输出为dem(设置分辨率)】2.2.4Arc Toolbox—Spatial analyst tools—map algebra—raster—输入公式:dem*0+1输出为raster12.3提取山脊线高程值,并进行邻域分析最低处(候选鞍部点),依次进行山脊线高程值计算—邻域分析—提取候选鞍部点2.3.1Arc Toolbox—Spatial analyst tools—map algebra—raster—输入公式:raster1*dem(输出为raster2)2.3.2Arc Toolbox—Spatial analyst tools—neighborhood—focal statistics(不能选block statistics)输入raster2,输出为focal2.3.3Arc Toolbox—Spatial analyst tools—map algebra—raster—输入公式:(raster2-focal)==0输出为raster32.3.4Arc Toolbox—Spatial analyst tools—extraction—by attributes(输入raster3,输出为extract)2.4计算正地形:邻域分析求均值2.4.1Arc Toolbox—Spatial analyst tools—neighborhood—focal statistics(输入dem,输出为focal dem)2.4.2Arc Toolbox—Spatial analyst tools—map algebra—raster—输入公式:(dem-focal dem)>0.输出为raster42.5鞍部点的计算:【候选鞍部点】*【正地形】==12.5.1Arc Toolbox—Spatial analyst tools—map algebra—raster—输入公式:extract*raster4(输出为raster5)2.5.2Arc Toolbox—Spatial analyst tools—extraction—by attributes—get unique values(输出为extract R)2.5.3Arc Toolbox—Conversion tools—from raster—to polygon(输入extract R,输出为raster TE)2.5.4Arc Toolbox—Data management tools—features—feature to point(输入raster TE,输出为raster WF)