基于土壤水分的农业干旱监测研究进展

Advances in agricultural drought monitoring based on soil moisture

土壤水分是评估农业干旱的关键变量。然而长期以来,由于缺乏大范围、高精度、长时间的土壤水分观测数据,基于土壤水分的农业干旱监测在实际应用中受到限制。近年来,随着遥感观测技术的发展,土壤水分数据的时空覆盖度和产品精度显著提升,基于土壤水分的农业干旱监测逐渐吸引更多的关注。论文系统归纳了站点观测与微波遥感观测的土壤水分数据特性,综述了目前基于土壤水分的3种农业干旱监测指标:基于长时间土壤水分序列的干旱指标、基于土壤水分与土壤水力学参数的干旱指标和基于土壤水分等多变量综合的干旱指标。最后,论文从提高土壤水分数据空间分辨率、加强农业干旱机制研究与完善农业干旱监测体系三方面提出基于土壤水分的农业干旱监测所面临的挑战与机遇,以期为未来的相关研究提供参考。

Soil moisture(SM) is a key variable for assessing agricultural drought. For a long time, due to the lack of large-scale, high-precision, continuous SM measurements, SM-based agricultural drought monitoring has been limited in application. With the recent development of remote sensing technologies, the spatial-temporal coverage and accuracy of SM data have been improved significantly. Agricultural drought monitoring indicators using SM have received increasing attention. This study systematically summarized the main characteristics of the SM data sets from multiple sources including in-situ measurements and microwave remote sensing, and further reviewed the three categories of agricultural drought indicators based on SM: 1) drought indicators based on long-term SM;2) drought indicators based on both SM and soil hydraulic parameters;and 3) integrated drought indicators based on multiple variables including SM. Finally, with the aim of providing some reference for future research, we envisioned the challenges and opportunities for agricultural drought monitoring from the perspectives of 1) the development of SM data;2) the strengthening of agricultural drought mechanism research;and 3) the improvement of agricultural drought monitoring systems.