Spatiotemporal variation of soil moisture in Northern China based on climate change initiative data

Abstract

AbstractIn view of the sparse, uneven distribution and poor data continuity of measured soil moisture sites in China and the lack of large‐scale research, the soil moisture data set of the European Space Agency (ESA) Climate Change Initiative (CCI) was applied to carry out spatial‐temporal variation analysis of soil moisture in five agricultural ecological zones in Northern China. The Pearson correlation coefficient and multiple‐component metric Kling–Gupta efficiency were used to verify the validity of remote sensing data and to analyze the temporal and spatial variation of soil moisture with the concept of temporal and spatial persistence. The ESA CCI remote sensing soil moisture data had good spatial and temporal adaptability for the whole year in the Huang‐Huai‐Hai region, in summer in Northeast China, in spring in Northwest China, in summer and autumn in the Loess Plateau, and in summer and autumn in the Inner Mongolian Plateau. The annual mean soil volume water content in Northern China from 1991 to 2016 was 0.06–0.39 m3 m−3. Spatially, soil moisture in Northern China has been gradually increasing from west to east. In this area, seasonally, soil moisture was the highest in summer, followed by autumn and then winter and spring. Northeast China, the Loess Plateau, and the Huang‐Huai‐Hai region are important grain‐producing areas in China. The soil moisture in these areas fluctuates widely with seasonal changes and shows an obvious drying trend.