STUDY OF SEASONAL SPATIAL VARIABILITY OF SURFACE TEMPERATURE IN THE NORTH OF NEUQUEN USING SATELLITE IMAGES
Marisa Gloria Cogliati
Facultad de Humanidades, Universidad Nacional del Comahue, Neuquén, Argentina
Manuscript received on 30 March 2013, in final form on 29 July 2014
This paper presents a study of the spatial distribution of surface temperature using Landsat 7 ETM+ thermal channel for a complex terrain area in the northern of Neuquen province during scenes in cool (autumn-winter) and warm (spring-summer) periods. This region is used with farming purposes, but the arid or semi-arid systems are vulnerable to desertification and land overuse. This paper is part of a project to study the land geo-ecology characteristics using Landsat images. Studies of the spatial variability of surface temperature in areas with complex terrain are scarce due the need to count with data networks that incorporate a greater spatial density of observations following the altitudinal gradient. Sometimes the density of meteorological network is not adequate because of the high cost of installation and maintenance of weather stations. Remote sensing gives a great amount of information on different spatial resolutions with less cost. The present paper presents calculation of surface temperature from Landsat images in an area where surface meteorological data are unavailable. The atmospheric correction involved forward calculations with the MODTRAN radiative transport model and reanalysis data. Six cloudless scenes were considered. Surface temperature patterns were correlated with topography mainly in the cool period, showing a poorer relationship in summer. The 273 K (0 oC) isotherm was located at heights greater than 1900 m and was restricted to elevations above 3700 m in summer scenes. The areas with temperature below 273 K presented greatest differences between warm and cool periods.
Keywords: topo climatology, surface temperature, satellite images.