Comparison of optics and radar images to obtain vegetation cover in Zagros forests (study area: Yasuj)
الموضوعات : فصلنامه علمی پژوهشی سنجش از دور راداری و نوری و سیستم اطلاعات جغرافیایی
seyede_Razieh keshavarz
1
(Master of Science in Remote Sensing and GIS)
Seyyed Ali Almodaresi
2
(Associate professor, GIS and RS Department, Yazd Branch, Islamic Azad University, Yazd, Iran)
Mohamad Hosein Mokhtari
3
(Assistant Professor, Department of Natural Resources and Desert, Yazd University, Iran)
الکلمات المفتاحية: Fire, Landsat 8, Sentinel, NDVI, Backscatter,
ملخص المقالة :
Forests in the Zagros region have undergone many changes in recent years due to the uncontrolled interference of humans and the dependence of people on these resources. The use of remote sensing and geographic information systems is widely used in many scientific and research fields and it is important to use this science to obtain vegetation cover. In this study, we tried to use optical images including Landsat 8 OLI satellite imagery, sentinel 2 and Power Sentinel 1 radar images (GRDH) on dates 30/05/2017 to 23/10/2017 to obtain vegetation cover before and after from the fires of the region on the specified dates, then with the comparison between the backscatter values, the power and power values and the values of the normalized vegetation index (NDVI), from the optical images, the precision of the images used for Obtaining coverage was discussed.Further, the specified fire areas were determined by creating a buffer of 200metre away, and the average NDVI and Backscatter were calculated from the desired optics and radar images. The results showed that Landsat 8 and Sentinel 2 images are complementary, and both images can be used to calculate vegetation and can be used for studying low-lying forests such as Yasouj forests, NDVI indexes for obtaining The amount of vegetation is appropriate. Also, the use of Powerline images of Sentinel 1 due to C bandwidth can show us the amount of coating variation.
