Developing quantifiable approaches for delineating suitable options for irrigating fallow areas during dry season-a...

Area of Science:

• Environmental Science
• Water Resource Management
• Agricultural Engineering

Background:

• Water scarcity is a major challenge in agriculture-dominated regions of Odisha, India, despite extensive irrigation networks.
• Large agricultural areas remain fallow during dry seasons due to insufficient water availability.
• Rainwater harvesting (RWH) offers a viable solution to mitigate water scarcity and improve crop production.

Purpose of the Study:

• To delineate rainwater harvesting (RWH) potential zones in two districts of Odisha, India.
• To identify suitable locations for RWH structures like farm ponds, check dams, and percolation tanks.
• To support water resource management and enhance agricultural productivity through strategic RWH implementation.

Main Methods:

• A multi-criteria analysis-analytic hierarchy process (MCA-AHP) was employed for RWH zoning.
• Thematic layers including LU/LC, geomorphology, slope, stream density, soil type, and surface runoff were integrated.
• The Natural Resources Conservation Service-Curve Number method was used to derive surface runoff data.

Main Results:

• Nearly 40% of the study area exhibits very high RWH potential, concentrated in the eastern and central regions.
• Specific RWH structures are recommended: 73 check dams and 153 percolation tanks along 2nd- and 3rd-order streams.
• Significant areas were identified as suitable for percolation tanks (coarse soil) and farm ponds (fine soil) in Jajpur and Bhadrak districts, respectively.

Conclusions:

• The study provides spatially explicit maps to aid water resource managers in decision-making for RWH.
• Implementation of recommended RWH structures can mitigate flood, drought, and soil erosion, while enhancing soil moisture and cropping intensity.
• The GIS-based methodology is adaptable for application in larger regions, offering efficient RWH planning.