Validation and Calibration of HRLDAS Soil Moisture Products in Nebraska
Validation and Calibration of HRLDAS Soil Moisture Products in Nebraska
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DOI：
10.1109/agro-geoinformatics55649.2022.9858974
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发表时间：
2022-07
期刊：
影响因子：
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通讯作者：
Haoteng Zhao;L. Di;Ziheng Sun;E. Yu;Chen Zhang;Li Lin
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文献类型：
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作者：
Haoteng Zhao;L. Di;Ziheng Sun;E. Yu;Chen Zhang;Li Lin
作物生长取决于根区土壤水分（RZSM）（~顶部1米）。RZSM的准确估计对于优化灌溉管理，在保持作物产量的同时节约用水和能源至关重要。NCAR的高分辨率土地同化系统（HRLDAS）可以生成农田尺度的RZSM，用于灌溉管理。土壤水分数据来自AmeriFlux网络，美国气候参考网络（USCRN）和土壤气候分析网络（SCAN）中的各个农业站点，用于验证HRLDAS生成的土壤水分产品。虽然HRLDAS产品不是特定于位置的，可以在全国范围内应用，但本研究将重点放在内布拉斯加州进行评估、验证和进一步校准。我们还比较了美国宇航局的SMAP表层土壤水分产品HRLDAS表层土壤水分。由于SMAP产品的准确性是已知的，这种比较直接验证HRLDAS表层土壤水分产品，并间接验证其RZSM产品。这两种验证方法的结果表明，HRLDAS土壤水分产品具有良好的准确性。HRLDAS和SMAP产品之间的显着差异表明，HRLDAS省略了灌溉活动，因为它的模拟是基于天气变量和能量平衡。HRLDAS很难将灌溉作用考虑和包含在其结果中，而SMAP产品远程感知土壤水分，可以清楚地反映灌溉引起的变化。因此，通过将灌溉量作为其变量，对HRLDAS产品进行了简单的校准。
Crop growth depends on the root-zone soil moisture (RZSM) (~top 1m). Accurate estimation of RZSM is vital to optimize irrigation management for saving water and energy while sustaining crop yield. The High-Resolution Land Assimilation System (HRLDAS) from NCAR can generate RZSM at field scales for irrigation management. The soil moisture data from various agriculture sites in the AmeriFlux network, U.S. Climate Reference Network (USCRN), and Soil Climate Analysis Network (SCAN) are used to verify the soil moisture products generated by HRLDAS. Although the HRLDAS products is not location specific and could be applied nationwide, this study will focus on Nebraska for evaluation, validation, and further calibration. We also compared NASA's SMAP surface soil moisture products to HRLDAS surface layer soil moisture. Since the accuracy of the SMAP product is known, this comparison directly validates the HRLDAS surface soil moisture product and indirectly validate its RZSM products. Results from these two validation methods show a good accuracy of HRLDAS soil moisture products. The conspicuous differences between HRLDAS and SMAP products indicate that HRLDAS omits the irrigation activities as its simulation is based on weather variables and energy balance. It's hard for HRLDAS to consider and include the irrigation actions in its results, while as SMAP products remotely sense the soil moisture as it is, the changes caused by irrigation are clearly reflected. Therefore, a simple calibration is applied to the HRLDAS products by including irrigation amount as its variables.