Method for monitoring soil moisture status in whole growth period of large-area crops on basis of modified NDVI (normalized difference vegetation index) time sequence

Abstract

The invention relates to the technical field of remote monitoring of soil moisture status, in particular to a method for monitoring soil moisture status in whole growth period of large-area crops on the basis of the modified NDVI (normalized difference vegetation index) time sequence. Firstly, region division of farmland, division of the crop growth period and source data acquisition and processing are performed; with the NDVI as a basic soil moisture status index, corresponding factors are introduced for different regions and at different growth periods, and self-adaptive modification is performed on the NDVI; a modified NDVI time sequence growth curve of the crops in the whole growth period is established on the basis of correlation verification of the modified NDVI and actually measured soil moisture status; anomaly analysis is performed on the modified NDVI curve of a monitored year and the average value curve of ordinary years, space-time distribution conditions of the relative soil moisture status, compared with the ordinary years, of the farmland in the monitored year are obtained, the soil moisture status of the farmland and the space-time distribution of the soil moisture status are effectively monitored, and the technical problem of failure in monitoring and back analysis of soil moisture status in whole growth period of large-area crops due to the fact that single NDVI cannot accurately reflect the growth states and the root soil moisture status of the crops in the whole growth period is solved.

Description

technical field [0001] The invention relates to the technical field of remote sensing moisture monitoring, in particular to a method for monitoring moisture in the whole growth period of large-scale crops based on corrected NDVI time series. Background technique [0002] Remote sensing moisture monitoring is the frontier field of remote sensing technology application, and it is also recognized as one of the worldwide research problems. The reason is that from an ecological point of view, the surface ecosystem is a nonlinear complex giant system involving many factors. As far as soil moisture is concerned, its influencing factors include soil type, precipitation, solar altitude, atmosphere, plant growth, surface conditions, and field management, etc., making remote sensing retrieval of soil moisture extremely difficult; from the perspective of remote sensing technology, there are currently spatial and temporal The resolution of the "two rates contradictory" contradiction. O...

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Problems solved by technology

[0005] The present invention proposes a method based on the modified NDVI time series moisture monitoring method for the whole growth period of crops in a large area. Taking NDVI as the basic moisture index, the corresponding factors are introduced for different regions and different growth stages for adaptive improvement, and the correction of the whole growth period of crops is constructed. NDVI time series growth curve, based on the verification of the correlation with the measured moisture, analyzed the anomaly vegetation index between the modified vegetation index of the monitoring year and its average annual value, and obtained the relative moisture spatio-temporal distribution of the monitoring year compared with the normal year, and then Realize effective monitoring of farmland moisture and its temporal and spatial distribution, and solve the problem that the single vegetation index NDVI cannot accurately reflect the growth status and root moisture status of crops throughout the growth period, and thus cannot monitor and invert the moisture content of crops throughout the growth period in large areas technical problems

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