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E. Aksoy 1, K. Demirel 2, M. S. Dirim 1, G. Özsoy 1, Z. Tümsavaş 1 1 Uludağ University, Faculty of Agriculture, Department of Soil Science, Bursa, Turkey 2 Rural Services Provincal Directorate, Bursa, Turkey Introduction Only 24 % or 3,2 billion ha of the World's total ice-free area is potentially arable, i.e. land that can be cultivated and/or maintained in productive pasture of these about 40 % or 1,3 billion ha is high to moderately productive and 60 % is of low productivity currently the best of these lands are already used for cropland, i.e. 1,5 billion ha, and the remainder are in permanent pasture, forest and woodland (Buringh and Dudal, 1987). Increasing demands for food and material expectations of growing population can only be meet by integrated land resources planning and management rather than from bringing new lands into cultivation if considered currently used land coverage for cropland. Soil surveys are the base-stone activity in integrated land recourses planning and management practices. To describe actual condition or states and to detect changes of the soils have vital importance for their sustainable use and management. In the past these data could only be collected in the field but advances in computer technology and techniques have introduced new group of tools, methods, instrument and systems especially for to improve acquisition, processing, transforming, displaying, mapping and use of geo-information (or spatial data). In order to describe actual condition, to detect changes and find out characteristics and distribution of the soils that one of the most important unrenewable resources, for sustainable use and management, soil surveys are the best and essential way especially in developing countries. Used base maps and applied methods can be varied due to available instruments, data, experienced person, hardware and software, etc. In our work, available base maps were topographical maps in 1:25.000 scale and Landsat TM data, while software program was ILWIS 1.4 (Integrated Land and Water Information System developed by ITC, in 1993) Remote Sensing and GIS program. That is why during the soil survey and mapping works the false color composite image (Landsat TM 357 bands used for RGB) superimposed DEM were used to delineate the physiographic units and to find out the characteristics and distribution of the different soil types. In this study, our objectives were to produce soil map by using integrated satellite and Digital Terrain data and to evaluate the use of slope class map derived from 10 m. DEM overlied color composite images for detailed soil survey in the hilly terrain. A DEM can be manipulated to provide many kinds of data that can assist the soil surveyor in mapping and giving a quantitative description of landform and of soil variability. By itself the DEM can yield maps of slopes, aspects, rate of change of slope, drainage networks on catchment areas. Computers have been used for extracting terrain information from digital elevation model (DEM) for at least last 20 years. Dikau et al. (1991) developed automated processes that essentially simulate Hammond's manual methods which are based on quantitative procedures that use slope, relative relief and profile to define different landform and tested them in New Mexico using a 200 m cell size DEM. Brabyn (1997) developed a new automated landform classification processes to eliminate classification problem caused by microrelief effect of Dikau's automated processes. Brabyn used a circle neighborhood analysis window effect (NAW) and a 500 m cell size. Hammer et al. (1995) used 10 m DEMs and 30 m DEMs with GIS to investigate precision and accuracy of computer generated slope class map for soil survey and land use planning. They suggested that slope class maps produced from the 10 m DEM appear to have great potential use for soil survey and land use planning. Bayramin (2001) tested the use of non-soil data (DEMs satellite images, digital geological data) for improving mapping efficiency and quality of soil maps and developed a pre-model for soil mapping for countries that conventional soil surveys are not being finished. Material and Methods GDRS was decided to establish upland irrigation project for the Arız-Doğla villages' agricultural lands in 1998. Due to this project, detailed soil survey and mapping works using by satellite and digital terrain data were applied in order to produce soil, land capability classification and irrigation suitability classification maps and to test the usage probability of slope class map overlied color composite images as a preliminary map for soil survey in hilly terrain. The study area located 4455000-4460000 m north latitude and 593000-596000 m east longitude. It is at the north west of Bursa and it covers an area of 7500 decares. Materials used for the study include; i- Topographic maps, scale 1:25.000, 1977, ii- Landsat TM, June 1993, iii- Soil map of the Bursa province, scale 1:100.000, GDRS, 1995. The satellite data was geo-referenced to UTM map projection through ILWIS 1.4 and subsequently enhanced for improving the visual aspect of the images (ITC, 1993). The color composites were prepared by Landsat 5 TM bands (in combination 3,5,7 band as RGB). The contour lines 10 m interval of the topographic map were digitized and slope map with six slope classes (0-2, 2-5 ,5-8, 8-15, 15-30, >30 %) was made by ILWIS using a DEM 5*5 smooth filter was applied to eliminate speckle effect, and then slope classes map produced with screen digitizing in vector format. The vectorized slope class map overlied color composite image was used to delineate soil boundaries and other land features as preliminary soil map. DEM data were also used to produce 3D-view with slope class boundaries superimposed Landsat image and shaded relief map as a color map in order to select possible site of soil profile and to define physiographic units. After extensive field checking/sampling and corrections of the preliminary soil map, final soil map was produced and published in 1:25.000 scale. The soil series and their important phases, in this case these were slope, texture, depth and stoniness, were considered as a basic mapping units. 27 mapping units were determined after the fieldwork. Soil profiles were described and sampled according to Soil Taxonomy (1975). Necessary analysis for classifying and determining physical and chemical properties were done according to Soil Conservation Service (1972). On the basis of morphological and physicochemical characteristics, the soil profile classified according to Soil Taxonomy (1994). Results and Discussion After field work which is applied by using slope classes map overlied color composite image as a preliminary soil map, six soil series formed on two different physiographic units were determined and mapped in 27 mapping units. Due to fact that, the Arız and Turgut soil series usually located on summit position with nearly flat to gentle slope, they have moderately deep, well developed profiles with A, B, C horizon designation and CO3 accumulation with the depth. In spite of these, Behzat, soil series located on back slope position with moderate to steep slope. So it has shallow, weak developed profile due to severely erosion with A, C horizon designation and high amount CaCO3 throughout to profile. The Çal and Karakuş Soil Series have very deep, weak developed profile with A, C horizon designation and in clayey texture while Kışladere series has very deep to, moderately well developed profile with A, B, C horizon designation and loamy clay in texture. Based on morphological and physicochemical properties, the soils of the Karacabey-Arız and Doğla agricultural lands have been classified as Entisol, Mollisol, Vertisol and Inceptisol according to Soil Taxonomy (1994). Agricultural potential of the soils restricted by the steep slope, shallow soil depth, and high amount of CaCO3 content of the subsurface horizon. The major photo-interpretation elements such as land forms, relief, slope etc. are the base-stones of the both monoscopic and stereoscopic interpretation of satellite images as well as aerial photographs for delineation of soil boundaries. The disadvantages caused by the absence of stereovision of the Landsat images during the image interpretation for soil survey were eliminated by using slope classes map and shaded relief map derived from 10-m DEM. The slope classes map from 10-m DEM overlied Landsat images can easily be used for soil survey with extensive ground truth where there are proven close relationships between soils and topography and soils are situated hilly terrain. 3D-View with slope classes boundaries overlied Landsat images or shaded relief map as a color map, can be used to define physiographic units, to select possible site of soil profile pits and to distinguish distribution of the soils. The soil survey efficiency can be increased by using large-scale geological map, high-resolution satellite data or black and white aerial photographs. References . Bayramin, I., 2001. Using Geographic Information System And Remote Sensing Techniques In Making Pre-Soil Survey.International Symposium On Desertification ISD. 13-17 June 2000, Konya, Turkey. . Brabyn, L., 1997. Classification Of Macro Landforms Using GIS. ITC Journal 97-1, pp. 26-40. . Buringh, P. & Dudal, R., 1987. Agricultural Land Use In Space At Time. In M. G. Wolman and F. G. A. Fournier (Eds.) Land Transformation In Agriculture. John Wiley and Sons, New York, pp. 9-45. . Dikau, R., Brabb, E.E. & Mark, R.M., 1991. Landform Classification Of New Mexico By Computer. U. S. Department Of The Interior, U. S. Geo. Open File Report 91-634, 26 pp. . Hammer , R.D., Young, N.C., Wolenhaupt, T.L., Barney T.L.& Haithcoate, T.W., 1995. Slope Class Maps Form Soil Survey and Digital Elevation Models. Soil Sci. Soc. Am. J. 59:509-519. . ITC, 1993. ILWIS Version 1.4 User's Manual. ITC Computer Department, ITC, Enschede, The Netherlands. . Soil Conservation Service, 1972. Soil survey Laboratory Methods and Procedures For Collecting Soil Samples. USDA Ssir, Us.Govt. Printing Office Washington D.C. . Soil Survey Staff,1975. Soil Taxonomy. A Basic System Of Soil Classification For Making And Interpreting Soil Surveys. USDA Soil Cons. Serv. Agr. Handbook 436, Washington, USA, 754 pp. . Soil Survey Staff, 1994. Keys To Soil Taxonomy. 8th Edition, US Govt. 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