The Study On The Extracting Area And Yield Estimate Of Cotton Based On RS And GIS

Cotton estimate system using remote sensing was established in Xinjiang,which can master plant area and growth of cotton fully, effectively and objectively.and has important meaning for agricultural administration section and economy administration section. to make decision .Take the 16 farm of Nongyishi of Production and Construction Group in Xinjiang as region of interest, the study has preliminary studied the yield estimate of cotton by remote sensing. the main contents were as follows:1 Optimum wave bands was studied. the result showed that the optimum wave bands of the remote sensing image of Landsat-7/ETM+ were 432.2.Light spectrum of cotton was analyzed in the essay.The differences between phenologic calendar and spectrum of cotton and other crops showed that the optimum time phase of cotton recognition is in second and last ten days of September.The differences between phenologic calender and spectrum of long staple-cotton and land cotton showed that the optimum time phase of cotton breed recognition is in first and second ten days of October.3.The essay abstracts plant area of cotton. Based on the optimum time phase of remote sensing image and using the maximum likelihood classification, information of cotton field and cotton breed(land cotton and long staple-cotton) was extracted.The result shows that the pixel precision of classification of cotton and rice reaches 97%. The result of classification of cotton breed shows: the area precision of long staple-cotton reaches 97.07% in 2001.The area precision of land cotton reaches 93.15% in 2001. The area precision of long staple-cotton reaches 90.87% in 2003.The area precision of land cotton reaches 82.87% in 2003.4.The essay grades cotton yield. analyzing growth habit, growth process and spectrum, the result shows that the time of the second ten days of July and the last ten days of august were the crux period for cotton yield. Using ASTER data of July in 2004 and in 2005 abstracted vegetation indicator(NDVI,RVI),and carried out density slicing. The result shows that relationship between density slicing of NDVI and cotton yield is better. Associating the image of density slicing of NDVI with the image classification of cotton breed and the information of soil salinization, high yield field,Middle,Low yield field can be divided.5.The essay estimates cotton yield. Based on the actual yield survey, the average yield per mu of high,middle and low can be got. The area of cotton breed multiples the average yield per mu is total yield. The production precision reaches 82.5% in 2004 and 84.9% in 2005.The precision of average yield is 83.7%.All these indicated that the method of supervised classification and density slicing...