Journal Article

Spatial Downscaling of Soil Moisture Based on Fusion Methods in Complex Terrains

Tang, Xiaowen, Chen, Qingqing, Miao, Fang, Zeng, Qiangyu, Tang, Zhiya, Song, Guolin, Li, Biao, Yang, Ling, Wang, Hao

2023

Overview

Large-area soil moisture (SM) data with high resolution and precision are the foundation for the research and application of hydrological and meteorological models, water resource evaluation, agricultural management, and warning of geological disasters. It is still challenging to downscale SM products in complex terrains that require fine spatial details. In this study, SM data from the Soil Moisture Active and Passive (SMAP) satellite were downscaled from 36 to 1 km in the summer and autumn of 2017 in Sichuan Province, China. Genetic-algorithm-optimized backpropagation (GABP) neural network, random forest, and convolutional neural network were applied. A fusion model between SM and longitude, latitude, elevation, slope, aspect, land-cover type, land surface temperature, normalized difference vegetation index, enhanced vegetation index, evapotranspiration, day sequence, and AM/PM was established. After downscaling, the in situ information was fused through a geographical analysis combined with a spatial interpolation to improve the quality of the downscaled SM. The comparative results show that in complex terrains, the GABP neural network better captures the soil moisture variations in both time and space domains. The GDA_Kriging method is able to merge in situ information in the downscaled SM while simultaneously maintaining the dynamic range and spatial details.

• Publisher: MDPI AG
• Subject: Agricultural management / Algorithms / Artificial intelligence / Artificial neural networks / Artificial satellites in remote sensing / Atmospheric models / autumn / Back propagation networks / China / Comparative analysis / complex terrains / data fusion / Disaster management / Distribution / downscaling / Electronic data processing / Emergency warning programs / Environmental impact / Evapotranspiration / Genetic algorithms / Hydrology / Land cover / Land surface temperature / Landslides & mudslides / latitude / longitude / Machine learning / Measurement / Methods / Moisture effects / Mountains / Neural networks / Normalized difference vegetative index / Precipitation / Remote sensing / Resource evaluation / Satellites / Soil moisture / soil water / summer / surface temperature / Technology application / Topography / Vegetation / vegetation index / Water resources