The Study Of Remote Sensing Monitoring For The Damage Of Apocheima Cinerius Erschoff On Tugayi Forest In Tarim River Basin

Based on GF 1 WFV data,Landsat 8 OLI data and HJ 1 A/B CCD data extraction Tugai forest,the extraction capacity of sparse vegetation was compared and analyzed.Studied the applicability of sparse vegetation information extraction method in arid and semi-arid areas.Based on the results of optimal distribution of Tugai forest,the accuracy of coverage of Tugai forest was calculated by vegetation index fitting binomial and dimidiate pixel model.Combined with the characteristics of pests and diseases in the study area,established a detection model to detect the spatial distribution of diseases and pests in Tugai forest in the study area,and to extract the abnormal growth area of Tugai forest.According to the classification of different image vegetation,the area of non-vegetation covered areas such as bare land is the largest in the study area.The Tugai forest is mainly distributed along the river channel,some of the cultivated land is distributed along the river channel,and the other part is distributed in the area of residential area.Compared with the classification results of the three images,the classification accuracy of GF 1 WFV data is slightly higher than that of Landsat 8 OLI data,and the HJ image is relatively lowest.The Landsat 8 OLI data has higher separation accuracy of the Tugai forest classification,and its user accuracy and producer precision are the highest.GF 1 WFV data classification of cultivated land classification is the highest,and its user accuracy and producer precision are also the highest.Therefore,Landsat 8OLI data is more suitable for vegetation extraction in sparse riparian forest.The results of vegetation cover inversion showed that the area of bare land was the largest in the study area,and the results showed that vegetation coverage in most areas was concentrated within 20%.The Tugai forest in the study area is mainly distributed along the river channel,the vegetation coverage along the river is relatively high,the vegetation coverage far away from the river is low,the arable land has some low coverage vegetation distribution on the edge of the arable land,and the other areas are mostly bare land.Through the comparison of vegetation coverage inversion method,it is considered that the inversion accuracy of dimidiate pixel model is higher than that of NDVI fitting binomial.It can be seen from the verification that the inversion accuracy of Landsat 8 OLI data based on dimidiate pixel model is R~2=0.608(RMES=0.124,P<0.05).The correlation between Landsat 8 OLI data NDVI vegetation index and GF1 WFV data as well as the correlation between Landsat 8 OLI data NDVI vegetation index and HJ 1 A/B CCD NDVI is significantly lower than GF 1 WFV data and HJ 1A/B CCD NDVI correlation.In April 2017,NDVI average value of Tugai forest increased first,decreased in late April,and shortly afterwards the NDVI began to rise again;From middle of April to early May,when the larva of spring geometrid was mainly at the 3rd instar,4th instar and 5th instar,the forest of Apocheima cinerarius was seriously damaged,and its monitoring accuracy was as high as 85%.However,from late March to early April,when the first instar and 2nd instar were the dominant larvae,Populus euphratica was less harmful and its monitoring accuracy was lower than 5.The result showed that the forest of Populus euphratica in Luntai County,west of the study area,was damaged first,then the east part of Yuli County was damaged afterwards.Conclusion China's HJ satellite can effectively monitor the damage of Apocheima cinerarius on Tugai forest in middle reaches area of the Tarim River,but only when the Tugai forest damage is serious,the accuracy is high.From the time point of view,from mid-April to early May,the larvae of Apocheima cinerarius were 3,4 and 5 years old,this was the main period of the serious harm of the spring inchworm.From a spatial point of view,because of the earlier spring moth in the west of the study area,the Tugai forest was damaged first,and because the spring geometrid occurred relatively late in Yuli County on the east side,the Tugai forest was damaged later by the Apocheima cinerarius.