Finding the most effectiveness spatial natural factors in watershed by spatial multi criteria evaluation (SMCE) in GIS

摘要

Some spatial natural factors such as slope degree, slope aspect, slope convexity, stream net, land use, and vegetation cover, are effectiveness and more important for natural resources and watershed management. Combination of these factors, can give ideas about land and water planning in watersheds. Objective is finding the most effectiveness spatial natural and economic-natural factors in watershed by pixels value evaluation in GIS environment. The Miankouh watershed in Yazd was selected. Natural factors, and social-economic factors, with constraints, for spatial soil conservation priority were selected. In spatial multi criteria evaluation (SMCE) method, factors and constraints were standardized and factors weighing was done. Then tree model was designed in GIS. Result, was composite map with pixels value 0 to 1. These pixels values were imported to spreadsheet program. The effects of changes (decrease and increase) in weight of each spatial natural factor on the pixel values in GIS were recorded. After analyzing and coparison pixel values in spreadsheet, more effectiveness factors were known. It was inferred the most effectiveness factors are covering the watershed vastly, such as, stream net. With these results, land and environment programmers can weigh the spatial natural and economic-natural factors with more recognition in the watershed.