Modeling Flood Extent of a Large Wetland in a Data-Scarce Region Using Hydrodynamic and Empirical Models

Md Mominul Haque, University, My, University, My
2020
Wetlands are dynamic ecosystems and important sources of natural resources that provide a large array of ecosystem services. Unfortunately, most wetlands are threatened by human and natural stressors, such as damming, irrigation, water abstraction, climate change and variability that compromise the sustainability of the whole system. The Inner Niger Delta (IND), Mali, West Africa, is one of the biggest floodplains in the world, has a vast natural resource that attracts many people to live in
more » ... around the delta. The IND is considered a hub of human activities that include agriculture, fishing, transport, and tourism and plays an important role in promoting sustainable development for food security, water management, and the environment. As for most wetlands in the world, the very existence of the IND is at stake with the ever-increasing number of dams and irrigation schemes that are built to feed the growing population in the region. Given the fragility of the system and the multiplicity of water uses in the IND, the current knowledge of the flood dynamics and its relation to ecosystem services and the productivity of economic activity is insufficient. There is no operational hydrodynamic model of the IND, and the Malian authorities rely on simplified models and empirical relations for water resources management in the area. This thesis contributes to a better water resources management of the IND by a) developing the first 2D hydrodynamic model based on a triangular adaptative mesh of the IND that performs well despite the poor quality of available topographic/bathymetric data b) developing an innovative way of accounting for the strong hysteresis phenomenon in the IND in the hydrodynamic modeling that allowed a better reproduction of the hydraulic connectivity between important lakes and the main river and c) developing the first non-stationary relationship between the water levels at a reference station and the flooded area in the IND. The first part of the thesis deals with the challenge of developing a hydr [...]
doi:10.20381/ruor-24347 fatcat:bod3r35g65f7ri3yhlaii6vnk4