Multi-Scale Periodic Variations in Soil Moisture in the Desert Steppe Environment of Inner Mongolia, China
Dandan Liu,
Yaowen Chang,
Lei Sun,
Yunpeng Wang,
Jiayu Guo,
Luyue Xu,
Xia Liu,
Zhaofei Fan
Affiliations
Dandan Liu
Water Resources Research Institute of Anhui Province and Huaihe River Commission, Ministry of Water Resources, Hefei 230088, China
Yaowen Chang
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Lei Sun
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Yunpeng Wang
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Jiayu Guo
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Luyue Xu
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Xia Liu
Jiangsu Key Laboratory of Soil and Water Conservation and Ecological Restoration, Collaborative Innovation Center of Sustainable Forestry in Southern China of Jiangsu Province, Forestry College of Nanjing Forestry University, Nanjing 210037, China
Zhaofei Fan
College of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849, USA
Uncovering the complex periodic variations in soil moisture can provide a significant reference for climate prediction and hydrological process simulation. We used wavelet analysis to quantify and identify the multi-scale periodic variations of soil moisture in the desert steppe of Inner Mongolia from 2009 to 2019 and analyzed the differences between the multi-scale periodic changes in soil moisture at the bottom (BS) and upper slope (US). The results show that the interannual variability in soil moisture at the BS and US has a significant upward trend. Moreover, the amount and volatility decrease with the increase in soil depth in the range of 0–30 cm, and the soil moisture at the BS is 26.4% higher than the US. The soil moisture has periodic changes of 0.5a, 1a, 2a, 3a and 3.5a in the desert steppe environment of Inner Mongolia. The periodic structure and intensity of different slope positions are greatly different. Soil moisture at the US has more complex multi-scale periodic changes, and the periodic oscillations of 3.5a, 3a, and 1a are dominant. The periodic oscillations of 0.5a and 1a are dominant at the BS. At the BS, the intensity of periodic oscillation of 1a after January 2015 has weakened. The weakening of soil moisture by temperature, rainfall and soil temperature caused the change in the multiple time-scale periodic oscillation of soil moisture.
