Five Water Supply Demand Management Scenarios for Rice Cultivation
1. Seasonal Tank Cultivation: Exploring the usage of tanks for both cultivation seasons in normal weather conditions, highlighting the challenges of meeting irrigation demands. Water shortages occur during specific months, such as March, May, June, and September.
2. Maha Season Tank Cultivation: Focusing on utilizing tanks exclusively for the Maha season, howcasing higher coverage in meeting irrigation requirements. However, some tanks experience water shortages in September, although more than 75% of tanks fulfill the demand.
3.Reservoir Supply in Normal Weather: Emphasizing the proposed use of reservoirs to meet irrigation, hydropower, and environmental flow requirements during a climatically normal year. This scenario demonstrates sufficient water supply to fulfill all demands.
4. Reservoir Supply in Extreme Dry Weather: Examining the reservoir's capability to meet demands with reduced monthly inflows at 20% of normal levels. The analysis reveals that alternative water allocations must be considered due to the reservoir's inability to accommodate the total irrigation demand. Water scarcity is observed in September.
5.Combined Tanks and Reservoir in Extreme Dry Year: Introducing a modeling approach that integrates the operation of ancient tanks and the new reservoir without constraints. This arrangement improves irrigation demand fulfillment, with a 90% coverage, yet a slight shortfall remains in September.
- These imaginative scenarios provide insights into different water supply demand management approaches for rice cultivation, addressing challenges, and offering potential solutions based on weather conditions and the combined use of tanks and reservoirs.
Water Demand Analysis and System Performance Evaluation
The water demand analysis was conducted for the D24 site, representing one of the ancient tank command areas, under the five mentioned scenarios. This estimation was performed for all 134 ancient irrigation tanks in the study.
The results help assess the system's performance and enable the development of a comprehensive water management strategy considering the new reservoir and individual ancient tanks.
- Refer to the next page for further details.