Spatio‐temporal variation of near‐surface soil water content in China from 1988 to 2016

Abstract

AbstractThe near‐surface soil water content (SWC) can reflect the agricultural drought levels. In addition, understanding the historical trends of near‐surface SWC change in China is an important step in combating climate change. The monthly near‐surface SWC data set during 1988–2016 published by the European Space Agency Climate Change Initiative were used in this study to analyse the variations of SWC in whole China and its seven natural divisions. Results indicated South and Central China had higher SWC than others because of their larger precipitation amounts. Significant (p < .05) decreasing trend in temporal SWC was found in Northeast China, which is related to the significant (p < .05) decreasing trend in the aridity index. However, significant (p < .01) increasing trends were found in Northwest China and Qing‐Tibet, which may be associated with the climate change (e.g., the ice and snow melting caused by increase of air temperature) and human activities (e.g., tillage and vegetation restoration). The monthly SWC in all divisions and whole China showed a main period scale (corresponding to peak values of wavelet variance) of about 225 months and 2 dry‐wet cycles. From 2016, the next 5–6 years are likely to be the wet years. The findings are of great significance to the management of soil water resources in China under global change.