No abstract

The Al-Shewicha Trough represents a real flood hazard to Kut City (capital of Wasit Province, Iraq) as well as to the other cities along the Tigris River downstream Kut Barrage, especially heavy monsoon years. Under the acute lack of water resources around the world, many modern techniques in unconventional innovative water resources management were developed. In this study, ArcGIS was used in the morphologic analysis of six river basins which represent the main sources of feed for the Al-Shewicha Trough. The results show that the high value of the greatest length of a basin 1,5 and 6 indicate that these watersheds have high value of concentration time (tc) which delays the peak flow. All basins consisted of very coarse and permeable subsurface strata, and were of coarse texture. Circularity ratio Form factor and elongation ratio shows an elongated shape of all basins with lower peak flow and long duration. Analyses of soil data demonstrate that the soil type that covers a large area is loam soil within the hydrologic soil group type B, which indicates that all basins have low permeability and high runoff. The most predominant land use was bare soil and all basins have a covering of poor vegetation which highlights the basins that are most susceptible to erosion, thus resulting in the generation of higher sedimentation.

A flood happens when water floods wet land. In Iraq, there have been floods several times in the Tigris River, but the flood in 2019 was one of the major events that have greatly affected Maysan city. This paper shows the study of Maysan’s extreme flood with hydraulic models. HEC-RAS two dimensional has been utilized to model the action of the study area from the downstream of Kut Barrage to Al-Musandaq escape, at the Tigris River. The model includes descriptions of simulated temporal parameters such as water depth and flow velocity. HEC-RAS Validation of simulated flood outcomes was done by correlation coefficient (r) Equation Between simulated and observed data, where the coefficient of r for calibrating the Tigris River and the Al-Musandaq escape was 0.995 and 0.991 in an appropriate range, respectively. The validation results demonstrated that the HEC-RAS model performance is highly efficient and can be implemented for design and production by hydrologists or water resources engineers.

The Al-Shewicha Trough represents a serious flood hazard to Kut City (the capital of Wasit Province, Iraq) and to the other cities along the Tigris River downstream Kut Barrage, especially in heavy monsoon years. In this study, The Geographic Information System software ArcGIS was used in the morphologic analysis of six river basins that represent the main feeding sources for the Al-Shewicha Trough. The results revealed that the high values for the greatest length of Basins 1, 5, and 6 meant that these watersheds had high concentration time (tc) values, which delay peak flow. All basins consisted of very coarse and permeable subsurface strata that were of coarse texture. Circularity ratio form factor and elongation ratio suggested an elongated shape for all basins with lower peak flow and long duration. Analyses of soil data demonstrated that the soil type that covered a large area was loam soil (classified as hydrologic soil group B), which indicates that all basins had low permeability and high runoff. The predominant land use was bare soil, and all basins had a covering of poor vegetation, which highlighted the fact that basins were highly susceptible to erosion, thus resulting in the generation of higher sedimentation.

Soil functions such as water storage, soil filtration, and reducing reservoir life due to sediment load are directly affected by the process of “soil erosion.” The Universal Soil Loss Equation was adopted to predict the erodibility factor for watersheds feeding the Al-Shewicha trough. The K-average factor’s determined value was 0.156, indicating that the K-factor had substantial variability. The K-factor for erodibility values was linked to the high sand content in the topsoil of the study area because of the high sand content of the topsoil. The topsoil is coarse-textured and then permeable. ArcGIS (geographic information system) was used to obtain the distribution of soil types as well as the erodibility factor distribution.