Impacts of Climate Change in China: Northward Migration of Isohyets and Reduction in Cropland

Changes in the environment and in land use interconnect and interact. To ascertain the impact of meteorological factors, namely temperature, precipitation, and sunshine, on land use changes, an analysis was conducted using meteorological data and the China land use dataset spanning from 1990 to 2020. Pearson correlation analysis, grey correlation degree, and vector regression model were employed to assess the influence of meteorological factors on land use alterations and to pinpoint the primary driving forces. The findings reveal the following: (1) The spatial distribution of isohyets and isotherms is shifting towards the north, with the most significant northward movement observed in the 1600 mm isohyets and 15 °C isotherm contours. (2) Overall, the areas of croplands, shrubs, grasslands, and wetlands are decreasing, notably, with a reduction of approximately 100,000 km2 in cropland, while forests, water, and impervious surfaces are expanding annually. (3) Temperature and precipitation exhibit notable impacts on various land use types, with temperature exerting the most substantial influence on changes in cropland area, contributing to 8% of the observed variations. This study can provide a scientific basis for the rational optimization and allocation of land resources under changing environmental conditions.