Annual soil moisture predictions across conterminous United States using remote sensing and terrain analysis across 1 km grids (1991-2016)

We provide 26 annual soil moisture predictions across conterminous United States for the years 1991-2016. These predictions are provided in raster files with a geographical (lat, long) projection system and a spatial resolution of 1 x 1 km grids (folder: soil_moisture_annual_grids_1991_2016). These raster files were populated with soil moisture data based on multiple kernel based machine learning models for coupling hydrologically meaningful terrain parameters (the explanatory variables) with soil moisture microwave records (the response variable) from the European Space Agency Climate Change Initiative. We provide a raster stack with the annual training data from satellite soil moisture estimates (file: annual_means_of _ESA_CCI_soil_moiture_1991_2016.tif) and the explanatory variables (terrain) calculated on SAGA GIS (System of Automated Geoscientific Analysis) using digital terrain analysis (folder: explanatory_variables_dem). The explained variance for all models-years was >70% (10-fold cross-validation). The 1 km soil moisture grids (compared to the original satellite soil moisture estimates) had higher correlations with field soil moisture observations from the North American Soil Moisture Database (n=668 locations with available data between 1991-2013; 0-5 cm depth) than soil moisture microwave records. For further information refer to our preprint in bioRxiv: https://www.biorxiv.org/content/biorxiv/early/2019/07/01/688846.full.pdf

本数据集提供美国大陆1991至2016年间26年的土壤水分预测数据。这些预测数据以栅格文件形式呈现，采用地理坐标（纬度、经度）投影系统，并具有1 x 1公里的空间分辨率（文件夹：soil_moisture_annual_grids_1991_2016）。栅格文件中填充了基于多个核机器学习模型的数据，这些模型将水文上有意义的地形参数（解释变量）与欧洲空间局气候变化倡议的土壤水分微波记录（响应变量）相结合。数据集包含从卫星土壤水分估计得到的年度训练数据栅格堆叠（文件：annual_means_of_ESA_CCI_soil_moiture_1991_2016.tif）以及在地形分析（文件夹：explanatory_variables_dem）中基于SAGA GIS（自动地球科学分析系统）计算的解释变量（地形）。所有模型-年份的解释方差均超过70%（10折交叉验证）。1公里土壤水分栅格（与原始卫星土壤水分估计值相比）与北美土壤水分数据库中的田间土壤水分观测值（n=668个地点，1991-2013年间有可用数据；0-5厘米深度）的相关性高于土壤水分微波记录。更详细的信息请参阅我们于bioRxiv上发表的预印本：https://www.biorxiv.org/content/biorxiv/early/2019/07/01/688846.full.pdf