Digital Analysis of Flood Scenarios of the Tigris River between the Two Zab Rivers and the Assessment of Their Impacts on Land Use

Abstract

    This study investigates the digital simulation of flood scenarios of the Tigris River in the reach between the Upper and Lower Zab, based on remote sensing data, digital elevation models (DEMs), and geographic information systems (GIS) techniques. The Simulate Water-Level Rise/Flooding tool in Global Mapper was employed to model water levels from the current stage up to (+10 m) and to analyze their impacts on land uses (agricultural, residential, roads, and quarries).

   The results revealed that 1988 was the wettest year, with a rise of (7–8 m) inundating an area of (145.3 km²), while 2008 represented the driest year, with an inundated area not exceeding (39.5 km²). In contrast, 2019 recorded a moderate flood with an inundated area of (86.7 km²), whereas 2013 was relatively balanced at (68.2 km²). Discharge analysis indicated a peak flow of (2078 m³/s) in 1988 compared to a minimum of (32 m³/s) in 2008.

   Simulation results showed that flood damage begins at level (+2 m), affecting one settlement and inundating (0.6 km²) of agricultural land and (1.3 km²) of residential land. The impacts gradually intensify, peaking at level (+10 m), where (310.4 km²) are inundated, (55 settlements) are affected, along with (91.9 km²) of agricultural land, (59.1 km²) of residential land, (7 quarries), and (235.8 km) of roads. The findings confirm that the maximum realistic flood risk is concentrated at level (+7 m), inundating (219.3 km²), whereas levels (+8–10 m) represent hypothetical scenarios designed to test the limits of potential maximum risk. These insights provide a basis for producing accurate flood hazard maps and guiding water management and mitigation strategies.