Research For Monitoring Of Wheat Take-all Disease Based On The Method Of Change Vector Analysis

In recent years,the prevalence of pests and diseases increased year by year,making the task of early prediction and real-time monitoring of pests and diseases more difficult.With the emergence of various types of remote sensing data sources,disease information using remote sensing technology to collect,monitor and predict the crop in a wide range,has become an important and effective way to visually check information,hand will gradually replace the traditional way.This paper mainly take all of wheat as the research object,focusing on studying the wheat disease regional monitoring,remote sensing satellites using Landsat series,with the sample data collected on the ground,carried out research on the monitoring of wheat take all disease,specific research contents and results are as follows:(1)In order to improve the accuracy of remote sensing monitoring of wheat disease severity,to avoid interference with other objects,this paper uses NDVI special sensitivity to vegetation,using a NDVI threshold vegetation area and non vegetation area;The grass in the near infrared reflectance is higher than that of crops and forests based on this point,by setting a threshold of Nir crops,forest and grassland will be further separated;by setting the DEM elevation threshold and slope threshold will leave to distinguish between crop and forest vegetation.Combined with support vector machine classification method and maximum likelihood method,wheat and non wheat crop regional separation,and by selecting better methods to verify the accuracy of classification,information acquisition study area of wheat planting areas.(2)In February 29 th,May 4th and May 11 th respectively corresponding wheat turning green stage and heading stage and filling stage of the three stage of growth,the three based on the remote sensing images were calculated for enhanced vegetation index EVI and normalized difference vegetation index,normalized NDVI chlorophyll NPCI ratio vegetation index,vegetation index NRI,nitrogen reflection and research the aging is not sensitive to PSRI and spectral reflectance index structure index SIPI with six wheat growth in response to the relationship between vegetation index is better,by analyzing the distribution information of vegetation index,combined with the wheat sample data collected on the spot,to judge the correlation between different vegetation index and disease severity of wheat.(3)Index is based on the 6 cultivation,constructing a multi-dimensional vector space,vegetation index in March 29 th,May 4th,May 11 th,the vector three image corresponding to a multidimensional.The change vector was constructed in March 29 th and in the year of May 4th and in the year of May 4th and in the year of May 11 th.The change vector analysis,to take all of Wheat by remote sensing monitoring,the damaged area and take all of wheat enhanced response relationship using vegetation index,redefined the vector construction,construction of wheat take all disease monitoring model of a multidimensional,by comparing the different vegetation index range,enhanced response relationship analysis the vegetation index of Wheat take all disease is more accurate,thereby establishing a monitoring model for the index of the wheat take all disease.Through the analysis of three different phases of disease monitoring,the study area of eastern and northern wheat growing is relatively good,the affected wheat take all of wheat production is relatively small,small amount,and the study area to the West and south the area wide,and situation was serious,severe reduction of wheat yield.According to the monitoring results,determine the spatial distribution and propagation of wheat take all disease,take appropriate preventive measures,can effectively reduce the effects of diseases of wheat take all disease,ensure the yield of wheat.