INTEGRATED LAND COVER AND TERRAIN ANALYSIS FOR SUSTAINABLE LAND USE PLANNING AT WATERSHED SCALE: A CASE STUDY OF BAN DAN NA KHAM WATERSHED OF NORTHERN THAILAND

Abstract

Soil is a fundamental natural resource that is vital to the sustainable development of human societies. However, in many developing countries, increased intensity of use and inadequate land use planning has put a lot of pressure on marginal soil, leading to various forms of land degradation. The purpose of this study is to generate an integrated the land cover and terrain classification of the Ban Dan Na Kham watershed of Northern Thailand as a tool for sustainable land use planning. The watershed boundary and slope classes were delineated using the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model (DEM). The slope was subsequently classified into gentle (<8o), moderate (8-30o) and steep (>30o). The land cover map was generated through the supervised classification of Sentinel2 satellite imagery. Both map products were then integrated to provide the basis for land allocation and land use planning. The results show that 58 % of land currently under arable farming is either marginally suitable or practically unsuitable for that purpose. This ultimately leads to increased land degradation and soil loss. The land should consequently be reforested. Nevertheless, up to 10 km2 of the watershed that is dedicated to other land use types – almost twice the current arable land area – is suitable for arable cropping. As such, given the proposed reforestation of the marginal and unsuitable arable lands, a large proportion of suitable land is still available to make up for the deficit. This will ultimately lead to increased productivity and reduced land degradation.