ASSESSMENT OF ALBEDO-TEMPERATURE RELATIONSHIP IN CONTEXT OF LAND USE AND LAND COVER CHANGES

Abstract

One of the key important geophysical variables which control the surface radiation budget is surface albedo. Albedo denotes that amount of solar radiation which after incident on a surface, reflected back to the space in fraction. Surface albedo. measures the surface reflectivity of earth surface. Land surface albedo, can be defined as the ratio of solar radiation reflected back to sky and solar radiation incident on the earth surface. The application of shortwave surface albedo is very wide, and used to drive climatic and hydrological models. In last few decades, satellite data are continuously used to derive remotely sensed surface albedo products. However, some errors or problems are always remained associated with these products due to related instrument measurement inaccuracies and due to the failure of current retrieving procedures, which imposed some limits on their applications. This study mainly focuses on the assessment of the satellite surface albedo by using very simple method using weighted mean over the temporal satellite images is applied to simultaneously retrieve land surface albedo values calculated in various past studies. The second part is to assess the relationship between the surface albedo and temperature changes, using the remotely sensed albedo products, LULC change bases albedo product, remotely sensed land surface temperature and meteorological temperature data. The major contributions of this study are as follows: I) through this study individual effect of each land use class can be analyzed over the land surface albedo for a given region through satellite imagery: 2) surface albedo and temperature relationship are estimated and can be well understood and assess. considering the effect of various LULC changes for given satellite image; 3) temperature & albedo trends has been drawn and assessed for various LULC classes and changes has been analyzed temporally. The objective of this study is to draw trends for change in surtice albedo and temperature across different land covers using Landsat-7 ETM+ and Landsat- 5 TM satellite images.