Strengthening agricultural sustainability in the Ganges Delta polders: A stakeholder-centric approach to hydrological modeling

By Mahesh Jampani, Syed Adil Mizan, Dipaka Ranjan Sena, Karthikeyan Matheswaran

Dhaka, Bangladesh (March 5, 2024) – A collaborative workshop brought together water management experts to tackle water and agricultural challenges in the Ganges Delta polders. These low-lying, protected areas are vital for agriculture but face threats from salinity intrusion and waterlogging.

The workshop, organized by the International Water Management Institute (IWMI), International Rice Research Institute (IRRI), and Institute for Water Modelling (IWM) Bangladesh, focused on using local-scale hydrological modeling to forecast salinity and inform agricultural decisions.

The workshop aimed to develop a collaborative approach using advanced hydrological modeling techniques alongside local knowledge and field data. This integrated approach is seen as crucial for managing the complexities of water and agriculture in the polders.

The workshop opened with remarks from Mr. Md Zahirul Haque Khan, Executive Director of IWM Bangladesh. He highlighted the critical challenges of water and salinity dynamics in Coastal Bangladesh and how this collaborative modeling, with consensus from key stakeholders, can shape better management of polder systems.

The workshop featured two main sessions. The first session included presentations from local experts who discussed the broad challenges and ongoing efforts in managing water resources (groundwater and surface water) and irrigation infrastructure development in polders. The second session highlighted the specific impacts of salinity on crop water productivity and the role of hydrological modeling in sustainable water management.

The experts highlighted the importance of considering factors like irrigation practices and social dynamics within the models. Overreliance on remote sensing data was cautioned against, with a balanced approach incorporating field data and model calibration being advocated.

Experts attended represent surface water and groundwater departments of Bangladesh Water Division (BWD), Bangladesh Agricultural Research Council (BARC), Bangladesh University of Engineering and Technology (BUET), Wageningen University and Research (WUR), IWM Bangladesh, IRRI and IWMI.

The workshop concluded with a consensus on the need for a comprehensive approach. This will involve combining local knowledge, field data, and advanced modeling techniques.

IWMI is currently developing a salinity forecasting system for the Rupsa River, which impacts water management in Polder 34/2p. Piloting this system for the upcoming agricultural season is under discussion. Additionally, IWMI and IWM are co-developing a comprehensive model to assess water management scenarios in the polders.

As part of the CGIAR Initiative on Asian Mega-Deltas, this workshop marks a significant step in addressing critical modeling gaps and paves the way for developing sustainable water management strategies for the Ganges Delta polders.

Further Reading
Jampani, M., Sena, D.R., Matheswaran, K. 2023. Framework for advancing water resource sustainability and climate resilience through local-scale hydrological modeling in the Ganges Delta. Colombo, Sri Lanka: International Water Management Institute (IWMI). CGIAR Initiative on Asian Mega-Deltas. 8p.