Acta Geographica Sinica ›› 2019, Vol. 74 ›› Issue (1): 117-130.doi: 10.11821/dlxb201901009

• Climate Change and Surface Processes • Previous Articles     Next Articles

Spatial and temporal variations of relative soil moisture in China's farmland

PAN Hanxiong1(),ZHU Guofeng1,2,3(),ZHANG Yu1,GUO Huiwen1,YONG Leilei1,WAN Qiaozhuo1,MA Huiying1,LI Sen4   

  1. 1. College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China
    2. State Key Laboratory of Cryospheric Sciences, Northwest Institute of Eco-Environment and Resources, CAS, Lanzhou 730000, China
    3. Gansu Engineering Research Center of Land Utilization and Comprehension Consolidation, Lanzhou 730070, China
    4. State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China
  • Received:2017-10-31 Online:2019-01-18 Published:2019-01-18
  • Supported by:
    National Natural Science Foundation of China, No.41661005, No.41867030;Chinese Postdoctoral Science Foundation, No.2016 T90961;National Natural Science Foundation Innovation Research Group Science Foundation of China, No.41421061;Autonomous Project of the State Key Laboratory of Cryosphere Sciences, No.SKLCS-ZZ-2017;Remote Sensing Monitoring Special Project of Rotation and Fallow System in Pilot Regions under Ministry of Agriculture and Rural Affairs of the People's Republic of China, No.SCZG2017-ZB-2187/1-HT

Abstract:

Based on the data of relative soil moisture obtained from 653 agricultural meteorological stations in China during the period of 1993-2013, the spatial and temporal differentiations of relative soil moisture in China's farmland were analyzed and discussed by using geostatistical methods. The results show that the relative soil moisture of China's farmland has fluctuated and increased since 1993, exceeding 60% in general. The distribution area has been expanding to the north and west with the summer monsoon since mid-April, and in late October, the region began to shrink to the east and south. The value of relative soil moisture increases with the increase of soil depth, and the distribution of farmland in high-value area increases with the increase of soil depth. The relative soil moisture of farmland increases fastest in summer and autumn, and the range of change decreases with the increase of soil depth. There is a strong positive correlation between relative soil moisture and precipitation. Relative soil moisture has a strong negative correlation with potential evaporation and temperature. The annual mean value of relative soil moisture in paddy field is higher than that in dry land, and the difference between the annual mean values of relative soil moisture of two types of farmland increases with the increase of soil depth.

Key words: relative soil moisture, farmland, Kriging interpolation, correlation analysis, spatial and temporal variation