SR-SA v2 (Simplified Risk–Score Aggregation, Version 2) is a deterministic, multi-parameter evaluation algorithm designed to assess water-related risks at the panchayat level. The algorithm integrates hydrological variability and land-use characteristics into a single composite risk score.
Instead of relying on prediction models, SR-SA v2 focuses on observed deviations, ensuring interpretability, transparency, and academic defensibility.
Rainfall impact is computed using the percentage deviation between long-term normal rainfall and the current observed rainfall. This captures abnormal excess or deficit conditions.
This normalized representation allows rainfall variability to be compared uniformly across regions.
Groundwater stress is evaluated using the absolute change between previous and current groundwater levels, normalized against a 3m reference maximum.
Result is scaled to 0–100. Larger fluctuations indicate increased vulnerability, particularly in water scarcity scenarios.
Land-use characteristics affect both surface runoff and groundwater recharge. Urban areas increase runoff, while forest cover improves infiltration. Both factors contribute equally to the land-use risk score.
Result is always 0–100. A fully urbanized, deforested area scores 100; a fully forested rural area scores ~0.
SR-SA v2 uses weighted aggregation, where parameter importance varies depending on the selected risk model.
G_rise: Only counts if groundwater level rose (depth decreased).
Flood_Boost: Water_Body% × 1.2 (Lake proximity increases risk).
Panchayats adjacent to significant water bodies (lakes, backwaters, reservoirs) have markedly reduced water scarcity risk.
A panchayat with 35% water body coverage (e.g. Perumon) has SWF = 0.30, reducing scarcity by 70%.
Flood Model
Water Scarcity Model
The final composite score (0–100) is mapped to qualitative risk levels to support interpretability.
Example: Rainfall Dev = 20%, GW change = 1.5m, Urban = 25%, Forest = 30%
Flood Risk = (0.4 × 20) + (0.4 × 47.5) + (0.2 × 50)