Analysis of Soil retention service function in the North Area of Guangdong based on the InVEST model

Abstract

Based on the InVEST model, the spatial and temporal evolution trends of water and soil conservation service functions in northern Guangdong in the three periods from 2000 to 2018 were evaluated, and the factors affecting the changes and spatial distribution of soil conservation time were further analyzed. The results indicate: (1) The average soil erosion per unit area in the study area in different years is 5.9∼7.6 t/ha•a, 81∼87% of the study area is mild erosion. (2) The amount of soil retention per unit area in the study area increased firstly and then decreased, reaching a maximum of 68.87 t/ha•a in 2010. This change was mainly caused by the difference in rainfall erosivity caused by precipitation. (3) The low-value areas of soil retention in the study area are mainly distributed in the central urban areas of Shaoguan, Qingyuan, Nanxiong Basin and Wengjiang Basin. The high-value areas are mainly distributed in the mountainous areas, such as Dadong Mountain, Qiweishan Mountain, Luoke Mountain, Huashui and Huangsi-nao Mountain. (4) The main factors affecting the spatial difference of soil retention in the study area are land use type, altitude, and slope. Under different land use types, the amount of soil retention per unit area from large to small is woodland> grassland> water area> cultivated land> construction land.