The Dataset of Dense Soil Moisture Monitoring Network in the Qinghai Lake Basin on the Qinghai–Tibetan Plateau

Soil moisture (SM) is a relatively active surface parameters that are significant to the sustainable development of the water–land–air–plant–human nexus. In response to the requirements of multiscale product validation and multisource uncertainty tracking, a soil moisture monitoring network in the Qinghai Lake Basin (QLB-NET) was established in September 2019. The QLB-NET is characterized by densely distributed in situ sites (82 sites) measuring SM and ST at 5-, 10-, and 30-cm depths, with 60 sites in a large-scale network in a heterogeneous area of 36 km × 40 km, which covers the SMAP, AMSR2, SMOS pixel footprint, and 22 sites evenly distributed across two small-scale 1 km × 1 km networks for sub-grid analysis. The site deployment strategy, the installation and maintenance, the sensor calibration, and the characteristics and quality of the in situ SM measurements of QLB-NET will be introduced in detail. Quantitative analyses of the in situ measurements was carried out, which shows that the QLB-NET can provide stable and reliable ground truth for SM over coarse grid scales, facilitating product validation and uncertainty tracking, spatiotemporal analysis of SM change optimization of the SM retrieving algorithms and scaling methods in heterogeneous regions.