Remote Sensing and GIS Application for Agricultural Land Quality Assessment of Yulin Prefecture

摘要

For optimum utilization of available agricultural land resources on a sustainable basis, timely and reliable information regarding their nature, extent and spatial distribution along with their potential and limitations is very important. The efficiency and accuracy of data are improved when remote sensing data products and GIS are used. This study aims at overcoming the difficulty of contributing factors cannot be accurately quantified by using information objectively derivable from remote sensing images. This approach yield a comprehensive agricultural land quality (ALQ) assessment using indicators like slope gradient, proportion of sandy land, water availability, soil fertility, and land use types organized into three indices of pressure resistance, land state, and land use response. And this assessment takes account of topographic setting, land degradation risk, moisture, vegetation growing condition, and land use response of farmers. The assessment results demonstrate that the ALQ value is generally low for the whole Yulin prefecture. Two-thirds of the agricultural lands face a serious land degradation risk. As water availability is a decisive factor influencing land productivity, ALQ is significantly correlated with the spatial distribution of water resources. Such assessment outcomes are essential for the prevention of land degradation and adjustment of agricultural structure to promote sustainable use of agricultural land.