The affected area of the marshes extended to approximately 20,000 km² at its peak development in the early 1980s, with a considerable average water level of up to 2.5 m. In contrast, the average water level ranged from 0.1 to 0.7 m during the subsequent period, leading to the extinction of the marshes and a flattening of the landscape compared to the surrounding riverine and agricultural regions. Based on this aspect, three areas of the marshes were hypothesized in terms of auto-morphological wetness/dryness (i.e., a deep-water region as it still existed, a dry region representing a ruined marsh, and an intermediate region between these two as a transitional zone). The results indicate that water levels would still range between 0.6 and 3.3 m, and the total area covered would exceed 16,000 km², if none of the major irrigation and drainage constructions affecting the Tigris and Euphrates Rivers had occurred, which threaten such endemic wetlands. Detailed results will appear in upcoming publications.