Identifying the Effects of the Gulf War on the Geomorphic Features of Kuwait by Remote Sensing and GIs Magaly Koch and Farouk El-Baz Abstract Satellite images combined with landform/su$ace maps are used to identify and characterize changes in the desert sur- face of Kuwait resulting from military activities during and after the Gulf War of 1991. These changes are producing al- terations to the surface sediment and morphological features that lead to environmental degradation. A geographic information system (GIS) is used to inte- grate and analyze multi-source and multi-scale data derived from satellite images, maps, and field observations. The GIs is used to identify, describe, and characterize changes occur- ring in the landform patterns, the nature and extent of land surface change, and their potential impacts on the environ- ment. Postwar satellite images are correlated with prewar field maps, allowing identification of changes in surface sedi- ment types and geomorphic units, focusing on areas showing changes in su$ace dynamics. Such areas are identified and classified in terms of alterations in the extent of surface sand [postwar sand encroachment) and the impact of oil pollution (formation of layers of tarcrete). The GIS analysis shows that 21.6 percent of Kuwait's area has been affected by the Gulf War, of which 4.4 percent is due to oil pollution and 17.2 percent is due to remobilized sand sheets. These results sug- gest that a reclassification of Kuwait's geomorphic features is needed to take into account these war-related su$ace changes. Introduction Kuwait is located in the northwestern corner of the Arabian (Persian) Gulf. It covers an area of 17,818 kmz, and its land surface is a generally flat to gently undulating desert plain. Its climate is arid to semi-arid, with an average annual pre- cipitation of 115 mm. Eolian sand deposits are the most frequent type of recent surface deposits and cover most of Kuwait's surface (Khalaf et al., 1984). The desert surface of Kuwait was severely disturbed dur- ing and after the Gulf War due to military activities and postwar clearance of land mines (Al-Ajmi et al., 1994). Three types of major surface changes are particularly evident: (1) disturbance of the desert pavement (a layer of pebbles, one particle thick, that protects the sandy soil from wind ero- sion), destruction of the sparse vegetation cover by military activities (El-Baz, 1992a), and excavation and trenching by troops, (2) deposition of oil and soot on the desert surface from the plumes of the oil well fires, which mixed with sand Center for Remote Sensing, Boston University, 725 Common- wealth Ave., Boston, MA 02215. M. Koch is presently with the Instituto de Ciencias de la Tierra (Jaume Almera), CSIC, Barcelona 08028, Spain (mkoch8ija.csic.e~). PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING and gravel and hardened into a layer of "tarcrete" (El-Baz, 1994), and (3) formation of over 300 inland oil lakes from damaged oil wells (El-Baz, 1992b; El-Baz and Al-Ajmi, 1993). Figures l a and l b show a prewar (1989) and postwar (1991) Landsat TM image of Kuwait City and the Greater Bur- gan oil field. A comparison of these images shows the magni- tude and type of surface changes that occurred in this part of Kuwait. These changes are mainly reflected by the tarcrete layer that extends from the oil field towards the southeast, in the direction of the prevailing wind. Bright areas in Figure l b correspond to a thin layer of active sand or sand sheets, which suggest the mobilization of sand and its movement from northwest to southeast following the main wind direc- tion. Previous studies have focused on mapping of these sur- face changes in terms of assessing the damage caused to the environment (Koch and El-Baz, 1993; El-Baz et al., 1994a). However, it is expected that the remobilization of vast amounts of sand, and the surface cover of tarcrete, is having a major impact on the geomorphology and the distribution of surface sediments in Kuwait (Al-Ajmi et al., 1994). Desert environments are very fragile ecosystems which react to sur- face disturbances with changes in their erosional/deposi- tional dynamic setting. Factors that have a severe effect on desert surfaces are well known, and are mainly due to dam- age caused by off-road vehicle traffic (Webb and Wilshire, 1983), as well as the construction of trenches, pits, and sand walls for military purposes (El-Baz, 1994). Satellite images (e.g., Landsat TM multispectral and SPOT panchromatic) have, because of their high spatial and tempo- ral resolution, been used increasingly to identify surfaces disrupted by military activities. Their regional scale coverage allows rapid and regular monitoring of the effects of such military activities. Most studies deal with relatively small- scale surface disturbances, and are generally based on identi- fying the level of surface disturbance in military training ar- eas by calculating the total number of vehicle tracks per unit area for selected test areas (Linn and Gordon, 1993; McCarthy et al., 1996). The present work, however, differs in that it presents a computer-based methodology to establish the geo- morphic impact of military maneuvers on desert surfaces at regional scales (> 10,000 kmz),and to relate types of distur- bance to their effect on geomorphic surfaces and surface sed- iment properties. To establish the nature, extent, and effect of war-inducea Photogrammetric Engineering & Remote Sensing, Vol. 64, No. 7, July 1998, pp. 739-747. 0099-1112/98/6407-739$3.00/0 O 1998 American Society for Photogrammetry 79 and Remote Sensing