the efficiency of landsat tm and etm+ thermal data for extracting soil information in arid regions
نویسندگان
چکیده
a knowledge of soil surface conditions, especially desert crust, salt crust and desert varnish is useful for improving classification of remotely sensed data. desert crust can generate high levels of reflectance, similar to those areas with high salt concentration and non-saline soil. therefore, soil surface crusts might bias thematic remote sensing of soils. in this study, we evaluated the efficiency of the thematic mapper (tm) and enhanced thematic mapper plus (etm+) reflective and thermal bands in detecting crusted surfaces and soil salinity conditions. the study areas were ardakan, damghan, lut desert, qom, and abarkooh which are located in arid regions of iran. to assess the landsat tm ther-mal data for detecting land cover types, the following steps were taken: 1) determination of correlation coefficients between tm wavebands, 2) assessment of the relationship be-tween tm thermal and tm reflective bands on land cover types, 3) assessment of the rela-tionship between soil salinity and tm digital numbers (dn), 4) two dimensional feature space (fs) analysis of the training samples, 5) field sampling, 6) image classification and accuracy assessment, and 7) comparison of surface reflectance of different soil surface types. the results show that the trend of correlation coefficients of tm6 with reflective bands is completely different from the correlation between reflective bands. the behav-iour of the thermal band on gypsiferous soils is completely different from that on saline soils. moreover, with an increasing correlation between soil salinity and reflective bands, the correlation between soil salinity and the thermal band decreases. in image classifica-tion, the thermal band improved the separability of the crusted and gravely classes. therefore the tm/etm+ regions of the electro-magnetic spectrum have complementary capabilities for spectral separability of gravely and crusted surfaces. in general, selection of the tm/etm+ thermal band combination is an important step for classifying the re-mote sensing data and for securing class separability of gravely and crusted surfaces in arid regions. we also concluded that tm/etm+ thermal bands may contain information complementary to the tm/etm+ reflective bands and therefore this combination of the tm/etm+ thermal and reflective bands provide a viable method for soil salinity studies in arid regions.
منابع مشابه
Investigation of the Possibility of Forest Type Mapping in Arid and Semi-arid Regions Using Landsat Etm+ Data
Landsat ETM+ data from the National Park of Khabr in Kerman province, dating May 2000, were analyzed to investigate the possibility of forest type mapping in arid and semi-arid regions.Quality evaluation of the image showed any radiometric distortion. Orthorectification was implemented to reduce relief displacement. The RMS error obtained was less than half a pixel. The ground truth map allocat...
متن کاملSoil Clay Content Mapping Using a Time Series of Landsat TM Data in Semi-Arid Lands
Clay content (fraction < 2 μm) is one of the most important soil properties. It controls soil hydraulic properties like wilting point, field capacity and saturated hydraulic conductivity, which in turn control the various fluxes of water in the unsaturated zone. In our study site, the Kairouan plain in central Tunisia, existing soil maps are neither exhaustive nor sufficiently precise for water...
متن کاملImprovement in absolute calibration accuracy of Landsat-5 TM with Landsat-7 ETM+ data
The ability to detect and quantify changes in the Earth’s environment depends on satellites sensors that can provide calibrated, consistent measurements of Earth’s surface features through time. A critical step in this process is to put image data from subsequent generations of sensors onto a common radiometric scale. To evaluate Landsat-5 (L5) Thematic Mapper’s (TM) utility in this role, image...
متن کاملrelationship between the landsat tm, mss data and soil salinity
to use remote sensing data effectively, one must understand the spectral characteristics of the particular features under investigations. to study the relationship between soil salinity and soil reflectance, four multispectral scanners (mss) and seven thematic mappers (tm bands) over the ardakan playa located on the central iranian desert margins were selected. in this study soil map, soil ...
متن کاملA C++ program for retrieving land surface temperature from the data of Landsat TM/ETM+ band6
A C++ language-based software tool for retrieving land surface temperature (LST) from the data of Landsat TM/ ETM+ band6 is developed. It has two main functional modules: (1) Three methods to compute the ground emissivity based on land use/cover classification image, NDVI image and the ratio values of vegetation and bare ground and (2) Converting digital numbers (DNs) from TM/ETM+ band6 to LST....
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
journal of agricultural science and technologyناشر: tarbiat modares university
ISSN 1680-7073
دوره 10
شماره Supplementary Issue 2010
کلمات کلیدی
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023