Dataset of in situ Soil Moisture and Temperature in Genhe watershed (2016-2018) and Saihanba (2018-2019) area over China

The data presented in this article are related to our work on “Evaluation and Analysis of SMAP, AMSR2 and MEaSUREs Freeze/Thaw Products in China”. Soil temperature and moisture are two of important parameters of land-atmosphere energy exchange, monitoring vegetation growth, predicting drought disasters and climate and hydrological modelling. In this study, soil temperature and moisture data over Genhe watershed and Saihanba area were introduced. There are 22 sites data presented here from the continuous automatic soil temperature and moisture observation network in Genhe watershed as a representative of the complex surface heterogeneity in northeast China from March 2016 to February 2018. Another continuous automatic soil temperature and moisture measurement network included 29 sites in Saihanba area with unique alpine wetland and a complete aquatic ecosystem in the North China since August 2018. Soil temperature and permittivity data were measured by ECH2O EC-5TM probes (Decagon Devices, Inc., Washington, USA) and XST probes (BJ XST Co., Ltd., www.xingshitu.com) every 30 minutes at depths of 3 cm, 5 cm and 10 cm for Genhe watershed and depths of 5 cm and 10 cm for Saihanba area. The soil temperature and moisture were collected by EM50 data collection system by automatically converted permittivity to soil moisture over Genhe watershed, and soil temperature and permittivity were collected by XST data collection system over Saihanba area. The permittivity collected by XST data collector were transformed to soil moisture (volumetric water content, VWC). The data of Genhe watershed and Saihanba area consist of raw data acquired by data collector and valid data of soil temperature and moisture. Dataset for Saihanba area also included the calibration data based on soil texture. The long-term soil temperature and moisture data can provide important ground reference data for the validation and algorithm improvement of soil moisture and soil freeze/thaw by microwave remote sensing in China.

本文所呈现的数据与我们题为《中国区域SMAP、AMSR2与MEaSUREs冻融产品评估分析》的研究工作相关。土壤温度与土壤湿度是陆-气能量交换、植被生长监测、干旱灾害预测以及气候与水文模拟中的两类关键参数。本研究引入了根河流域（Genhe watershed）与塞罕坝地区（Saihanba area）的土壤温湿度数据：本次公开的22个站点数据来自根河流域的连续自动土壤温湿度观测网，该观测网代表了中国东北复杂的地表异质性，观测时段为2016年3月至2018年2月；另一组连续自动土壤温湿度观测网覆盖塞罕坝地区的29个站点，该区域拥有华北地区独特的高寒湿地与完整的水生生态系统，观测始于2018年8月。根河流域的土壤温度与介电常数数据由ECH2O EC-5TM传感器（美国华盛顿Decagon Devices公司）与XST传感器（北京XST有限公司，www.xingshitu.com）采集，观测频率为每30分钟一次，测量深度分别为3 cm、5 cm与10 cm；塞罕坝地区的观测深度则为5 cm与10 cm。根河流域的土壤温湿度数据由EM50数据采集系统采集，该系统可自动将介电常数转换为土壤湿度；塞罕坝地区的土壤温度与介电常数数据则由XST数据采集系统获取。XST数据采集器获取的介电常数会被转换为土壤湿度（体积含水量，Volumetric Water Content, VWC）。根河流域与塞罕坝地区的数据包含数据采集器获取的原始数据以及经过校验的土壤温湿度有效数据；塞罕坝地区的数据集还包含基于土壤质地的校正数据。这套长期土壤温湿度数据集可为中国区域微波遥感土壤湿度与冻融产品的验证及算法优化提供重要的地面参考数据。