مشخصات پژوهش

Residue burning is usual in some agricultural regions of Iran, which creates negative impacts on agricultural soils obviously. Present research was carried out for finding an accurate and fast method for monitoring of residue management. In this research the ability of Landsat-8 sensor imagery for monitoring of burned fields was evaluated using Spectral indices and analysis of linear spectral separation. For this purpose, spectral indices include; Normalized Difference of Vegetation Index (NDVI), Burned Area Index (BAI), Normalized Burn Ratio (NBR), Normalized Burn Ratio Thermal ( NBRT) was created for experimental lands and four soil surface condition as experimental plots were considered include; no planted field, residue covered field, green vegetation field and burned residue field. The comparison among means of indices was conducted using Duncan's multiple range test at a 1% probability level. In order to validate the ability of linear spectral separation in segmentation and determination of burned fields area, the area of burned fields was determined manually (ground-based method) in the farm and was represented as a function of linear spectral separation data. Result showed, there is the significant difference between four soil surface conditions about means of studied indices. And the mean of BAI index for no planted field (soil), residue covered field, green vegetation field and burned residue field (ash) was 10.86, 4.50, 4.84 and 148.1 respectively and BAI index was stronger than other indices in separation of burned fields from other fields. Considering standard deviation of BAI index, the range of 88.41 to 207.79 was determined as a threshold range for separation of burned residue from other field conditions. The area average of burned fields that had been separated from other fields by using BAI index had high correlation (R2=0.89) with ground-based obtained area. Also area of burned fields that had been estimated by analysis of linear spectral separati