Method for assimilating remote sensing data of soil humidity in watershed scale

Abstract

The invention provides a method for assimilating remote sensing data of soil humidity in a watershed scale. The method comprises the following steps of: improving a watershed runoff producing calculation module and developing a distributed hydrological model which is suitable for assimilating remote sensing soil humidity information and describes a soil hydrodynamic process; introducing a particle filtering sequence data assimilation method of information science, and continuously merging and assimilating new remote sensing observation data in a dynamic operation process of distributed hydrological process numerical simulation so as to acquire updated watershed soil humidity assimilated data during sequential assimilation; feeding the updated watershed soil humidity assimilated data back to a distributed hydrological model platform; and gradually estimating the time and space distribution pattern of watershed soil moisture content. Practices prove that by the method, not only high-precision and physically consistent watershed soil humidity data can be provided for research on hydrology, zoology, environment and agriculture, but also the foundation is laid for performing four-dimensional data assimilation processing on soil humidity data of an upper soil layer acquired by using remote sensing retrieval, and improving the precision of the model.

Description

technical field [0001] The invention relates to a method for assimilating remote sensing data, more specifically a method for assimilating remote sensing data of soil moisture at the watershed scale. Background technique [0002] The state of soil moisture is not only the final result of the evolution of the climate and water resources system, but also exerts a strong feedback on the climate and soil vegetation atmospheric interaction system, which will profoundly affect its future changes. In the field of hydrology and water resources, obtaining accurate spatial distribution of soil moisture can be used as the initial value of soil moisture for flood simulation of hydrological models, improving the accuracy of flood forecasting. At the same time, the corrected continuous and accurate soil moisture data has potential application value for long-term hydrological process simulation, runoff forecasting and forecasting changes in water resources. Develop a distributed hydrologi...

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Problems solved by technology

However, the variational assimilation method also has some obvious defects. For example, the solution of the tangent linear adjoint equation necessary for this method is very time-consuming and error-prone, and even does not exist in theory.

Especially when the forecast model needs to be improved, its adjoint equations must be improved and tested more complicated, these characteristics restrict its application in land surface model assimilation

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