Agricultural drought monitoring method based on SMAP L waveband brightness temperature

Abstract

The invention discloses an agricultural drought monitoring method based on an SMAP L waveband brightness temperature, and the method employs the soil moisture, soil temperature and vegetation information carried in the L waveband brightness temperature to represent a drought state, builds a standardized microwave brightness temperature drought index (SMTBDI). The method is a quick, convenient and near-real-time monitoring method. And agricultural drought can be effectively forecasted and early warned. The method comprises the following steps: acquiring SMAP brightness temperature time series data of each grid in a certain time scale of a month for many years in an area; performing Gaussian distribution inspection on the time sequence data, and judging whether an independent sample corresponding to each grid conforms to Gaussian distribution or not; calculating SMTBDI for the grid passing through the Gaussian distribution test; and judging the drought degree according to the SMTBDI score, wherein the smaller the index value is, the more drought the index value is.

Description

technical field [0001] The invention belongs to the technical field of drought monitoring, in particular, a drought monitoring method based on SMAP L-band brightness temperature is invented. This method uses the soil moisture, soil temperature and vegetation information carried in the L-band brightness temperature to characterize the drought state, and constructs the Standardized Microwave brightness temperature drought index (SMTBDI), which is a fast, convenient and near real-time monitoring method. This method can effectively forecast and warn agricultural drought. Background technique [0002] Soil moisture is an important data source for agricultural drought monitoring. The lack of soil moisture caused by lack of rainfall will prevent plants from absorbing sufficient water, and the healthy growth of plants will be threatened. Therefore, soil moisture, as the first sign of drought, is a key and timely monitoring indicator. Among the soil moisture products, the microwav...

AI Technical Summary

Problems solved by technology

However, drought monitoring using only SMAP soil moisture also has certain limitations, mainly reflected in the penetration depth of SMAP brightness temperature and the retrieval accuracy of SMAP soil moisture.

The inversion accuracy of soil moisture based on microwave brightness temperature is poor in open water areas, steep terrain, dense vegetation areas, snow-covered areas, etc. Auxiliary information such as vegetation and roughness also affect the inversion accuracy of soil moisture

For example, in the southern part of my country, the vegetation coverage is higher, the clay content is larger, and the penetration depth of microwave brightness temperature is lower.

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