Nature-based solutions for flood–drought mitigation using a composite framework: a case-based approach

Water-related hazards like floods and droughts are increasing due to climate change. The study aims towards balancing a double edge situation of the inevitable flood and drought. The Soil Conservation Service-Curve Number (SCS-CN) method is used to calculate the rainfall–runoff and the Topographic Wetness Index (TWI) is used for identifying potential water accumulation zones, whereas the Normalized Differential Water Index (NDWI) is used to calculate surface waterbody variations and the Soil Water Index (SWI) is used to identify zones varying in the range of dry-to-wet soil moisture. The study focuses on the use of nature-based solutions (NbS) for achieving mutual flood–drought mitigation for the pilot case of the Banaskantha district, Gujarat, and is validated for the study case of the Muzaffarpur district, Bihar. The application of the developed contingency plan in the form of an applicability rubric agrees to solve the issue by 44.44% for the pilot case and 22.22% for the study case. It suggests the application of NbS for the regions having similar situations of flood–drought as of the pilot case.