PSR-BASED EVALUATION OF THE CULTIVATED LAND QUALITY IN HAILUN CITY OF HEILONGJIANG PROVINCE

To scientifically evaluate the quality level of existing cultivated land in Hailun City, Heilongjiang Province, the environmental satellite image, Landsat8 remote sensing image and geochemical survey data are used to extract the information of soil fertility, water content, heavy metal pollution and other indexes. The temperature vegetation dryness index(TVDI) which has a stronger correlation with soil water content, replacing the traditional difference vegetation index(DVI), is applied to establish a soil quality evaluation method based on pressure-state-response (PSR) model. The analytic hierarchy process(AHP) is used to assign weights to each evaluation index, combined with expert scoring and linear interpolation, to realize the quantitative evaluation of evaluation factors and obtain the minimum evaluation units by spatial weight superposition of all evaluation factors. The results show that the first-grade cultivated land accounts for 28.75%, with 71.17% of second-grade, 0.08% of third-grade and below, and the quality of cultivated land is generally high in Hailun City. Finally, some suggestions for improving cultivated land are put forward by analyzing the spatial distribution of cultivated land of different grades.