Method for estimating global vegetation coverage

Abstract

The invention provides a method for estimating global vegetation coverage. The method comprises the following steps: firstly, selecting a plurality of global land surface space sampling points according to distribution of global vegetation types; acquiring a first earth surface reflectivity data with a high space resolution and a second earth surface reflectivity data with a low space resolution in satellite remote sensing data at the sampling points, and then acquiring a vegetation coverage training sample by using the first earth surface reflectivity data through a dimidiate pixel model; subsequently extracting the second earth surface reflectivity data and the vegetation coverage which is calculated according to the first earth surface reflectivity data with the space corresponding to the space of the second earth surface reflectivity data at the sampling points, respectively taking the second earth surface reflectivity data and the vegetation coverage as input and output of the training sample so as to train a generalized regression neural network; and finally estimating the global land surface vegetation coverage according to the second earth surface reflectivity data by using the trained model. The method for estimating the global vegetation coverage makes full use of ground actual measurement data, remote sensing observation data with high space resolution and artificial intelligence learning algorithm, and has the advantages of good stability, high adaptability, high accuracy, easiness in operation and the like.

Description

technical field [0001] The invention relates to environmental science, in particular to a method for estimating global vegetation coverage. Background technique [0002] Vegetation is the most basic part of terrestrial ecosystems, and all other organisms depend on vegetation. Vegetation coverage is defined as the percentage of the vertical projected area of ​​green vegetation on the ground to the total area of ​​the statistical area. It is an important parameter to describe the vegetation coverage on the ground, and it is also a basic and objective indicator indicating the change of the ecological environment. Occupy an important position in the sphere, hydrosphere and biosphere. In addition, from the perspective of general application, vegetation coverage has a wide range of applications in agriculture, forestry, resource and environment management, land use, hydrology, disaster risk monitoring, drought monitoring and other fields. Therefore, it is of great significance t...

AI Technical Summary

Problems solved by technology

However, this method requires a large amount of data. The application of existing satellite remote sensing data needs to consider time, space, angle, spectral response, etc., and the amount of data is often insufficient.

On the other hand, how to choose a model is in a dilemma: if the model is complex, there are many parameters to be estimated and it is difficult to calculate; if the model is simple, there is still a large error between the existing radiative transfer model and the actual situation

Therefore, problems in both data and models limit the application of physical methods

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