Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 4/15/2007
Publication Date: 7/15/2007
Citation: Venteris, E., Pachinkin, K., McCarty, G.W., Doraiswamy, P.C. 2007. An assessment of the potential use of SRTM DEMs in terrain analysis for the efficient mapping of soils in the drylands regions of Kazakhstan. In: Lal, R., Suleimenov, M., Stewart, B.A., Hansen, D.O., and Doraiswamy, P. editors. Climate change and terrestrial carbon sequestration in Central Asia. London, United Kingdom: Taylor & Francis. p. 401-412. Interpretive Summary: The dry lands region of Kazakhstan has excellent potential for SOC accumulation through the adoption of management practices to reverse losses caused by Khrushchev’s Virgin Lands programs of the 1950s. The modeling of SOC in space is needed to set baselines and verify soil C sequestration. Modeling in space and time is needed to forecast gains and compare potential benefits between various management practices. These modeling efforts need to consider interaction between soil forming processes and topography. The association between soil type and terrain is a fundamental concept in pedology. A soils position relative to landform has been a recognized factor in soil formation from the very earliest scientific work on the distribution of soils. The shape of the land affects how water and sediment are transported, deposited and stored as well as the aspect of the landform, which affects sun light interception. These landform processes in turn affect moisture balance, plant growth, and geochemistry, leading to great diversity in soils even over relatively short distances. An understanding of these processes and how they lead to soil diversity is the main basis for the qualitative mapping of soils by traditional soil survey techniques. This report concentrates on the use of the newly available digital elevation data set (generated by Space Shuttle mission) and illustrates the calculation of a key terrain derivative that has proven useful for SOC prediction at other locations.
Technical Abstract: The relationship between soil properties and hill slope position is well established. Potential variations in the amount of soil organic carbon (SOC) with topographic position must be considered in any mapping or inventory scheme. It is possible to establish statistical, geostatistical, and/ or physical models to relate point measurements of SOC to continuous spatial data such as remotely sensed images and terrain derivatives from digital elevations models (DEMs). Such models can be used to map SOC over large areas accurately and efficiently. The viability of using quantitative soil mapping techniques in the dry lands region of Kazakhstan is greatly increased with the release of DEMs from the Shuttle Radar Topography Mission. This paper presents a worked example of terrain analysis techniques as applied to an SRTM DEM in the vicinity of the settlement of Aksu Ayuly, in Kazakhstan.