Land Characterization Analysis of Surface Temperature of Semi-Arid Mountainous City Abha, Saudi Arabia Using Remote Sensing and GIS

Javed Mallick

doi:10.4236/jgis.2014.66055

Abstract

This knowledge of land surface temperature and its spatial variations within a city environment is of prime importance to the study of urban climate and human-environment interactions. Few studies have examined the influence of land use and terrain on the surface temperature effects of semi-arid mountainous urban areas. This study investigates the urban environment characterization and its effects on surface temperature using remote sensing. The methodologies adapted for this study are geometric and radiometric corrections of satellite data, extraction of land use/land cover and digital elevation model, estimation of vegetation density using Normalized Difference Vegetation Index (NDVI), and estimation of surface temperature and emissivity using temperature emissivity separation (TES) algorithm. Finally geospatial model and statistical techniques are used for assessing the overall impact of urban environmental characterization on urban climate of semi-arid region of Abha, Kingdom of Saudi Arabia. Herein, results reveal that the spatial distribution of surface temperature was affected by land use/land cover (LULC) and topography. The high dense built-up and commercial/industrial areas display higher surface temperature in comparison with surrounding lands. There is gradual decrease of LULC classes’ surface temperature with the increase in altitude. The cooling effect towards the surrounding urban built-up area is found increasing at the hill located vegetated area, the downward slope and valley terrain inside the recreational park. Therefore the spatial variation in surface temperature also reflected the effects of topography on LULC classes. Suitable mountainous land use utilization would help to expand the cooling effect. In the future, the outcomes of this study could be used to build environmentally sustainable urban planning suitable to semi-arid regions and to create practices that consider the local weather environment in urban planning.

Highlights

Land surface temperature is an important factor in global environmental change studies in estimating radiation budgets in heat balance studies and as a control for climate models [1]
Emissivity and surface temperature enables the better understanding of the overall urban land use/land cover classes and in turn helps in understanding the energy budget issues [13]
The objective of this study is to investigate the spatial distribution property of the Ts with spatial information related with land use/land cover, vegetation density, and altitudinal effects, in the semi-arid mountainous city Abha using ASTER remote sensing data and GIS spatial analysis

Summary

Introduction

Land surface temperature is an important factor in global environmental change studies in estimating radiation budgets in heat balance studies and as a control for climate models [1]. Thermal infrared (TIR) remote sensing data can provide important measurements of land surface heat fluxes and surface temperature which are integral to understanding landscape processes and responses [2]. There are many satellite sensors, which are able to sense thermal infrared radiation (TIR) with different spectral and spatial resolution [3]. Satellites with medium spatial resolutions are used at the regional scale For this purpose, medium resolution thermal infrared imagery/data, LANDSAT TM/ETM+, and ASTER have been extensively used to study surface temperature (Ts) variations and to relate them to land cover characteristics [12]. Emissivity and surface temperature enables the better understanding of the overall urban land use/land cover classes and in turn helps in understanding the energy budget issues [13]

Objectives

Findings

Discussion

Conclusion