CHANGE DETECTIONS IN MARSH AREAS, SOUTH IRAQ, USING REMOTE SENSING AND GIS APPLICATIONS

Abstract

The marshes of the southern part of Iraq are considered the most outstanding feature in the area. They are developed within the Mesopotamian Plain forming natural balance between the Tigris and Euphrates Rivers and Shat Al-Arab that leads to the Arabian Gulf. The marshes that are locally called "Ahwar" have suffered from drying processes, since early eighties of the last century. During the late nineties, large parts were dried leaving barren salty (Sabkha) lands devoid of all types of life, especially those related to the large water bodies, beside human activities. Moreover, hydrological and climatic changes that clearly could be observed in the areas involved.To detect the considerable changes, in land use and land cover, remote sensing techniques and GIS applications were used; among these are Landsat images in three different intervals: MSS in 1973, TM in 1990 and ETM in 2000. These were used in the changes detection method. Moreover, different digital image processing techniques that are available in ERDAS program were applied. Normalized Difference Vegetation Index (NDVI) was also used to recognize the vegetation cover. The classified images were converted to vector shape in GIS media in each class; the area of each class is determined as percentage from the total coverage area of the marshes. The current study revealed that large changes took place between 1973 and 2000 in land cover and land use. The barren land is increased; while the water bodies are decreased drastically, consequently desertification is increased causing large environmental and hydrological changes that affected on the physical and chemical properties of the soil. The soil became unfertile and not suitable for agricultural purposes. The marsh areas were also abandoned by the local people due to the mentioned changes.Since 2004, great efforts are carried on in the marsh areas to rehabilitate and reactivate the marshes. Therefore, considerable parts of the marshes have grown again; local people started to reconstruct their communities. Some types of birds, fishes and vegetation reappeared again. The coverage area of the marshes is about 50% of the original marsh areas, hitherto.