Migration characteristics of cultivated land gravity center and climate suitability evaluation in China

To understand the spatial patterns of change in arable land and climate suitability, data on cultivated land, precipitation and temperature in China were applied to gravity center migration model and ecological niche model, to analyze change characteristics． From 2010 to 2020, the center of gravity of cultivated land migrated 112 km to the north, the center of gravity of paddy field migrated 260 km to the northeast, the center of gravity of irrigated land migrated 116 km to the northwest, and the center of gravity of dry land migrated 90 km to the northeast． The cultivated land precipitation suitability gradually decreased from southeast to northwest, accumulated temperature suitability gradually decreased from south to north (Qinghai-Xizang Plateau the lowest), the climate suitability gradually decreased from southeast to northwest． The precipitation, accumulated temperature, and climate suitability for paddy fields are large in area for the relatively suitable． The precipitation and climate suitability of irrigated land are large in area for the generally suitable. But the suitability for accumulated temperature is large in area for the relatively suitable． The precipitation, accumulated temperature, and climate suitability for dry land are large in area for the generally suitable． The climate suitability of cultivated land was on a downward trend． For precipitation, the area of relatively suitable and unsuitable farmland has increased, while the area of extremely suitable and generally suitable farmland has decreased． The area of cultivated land with extremely suitable and unsuitable accumulated temperature has increased, but the area of cultivated land with relatively suitable and generally suitable accumulated temperature has decreased．The unsuitable climate leads to an increase in arable land area, but the extremely suitable, relatively suitable, and generally suitable climate leads to a decrease in arable land area． We advise to strictly protect cultivated land, especially high-quality cultivated land such as paddy fields, and cultivate or return cultivated land according to climatic conditions, to comprehensively protect the quantity and quality of cultivated land．