River space: A hydro-bio-geomorphic framework for sustainable river-floodplain management

Area of Science:

• River ecology and geomorphology
• Hydrology and hydro-meteorology
• Sustainable resource management

Background:

• Alluvial river floodplains provide vital ecosystem services and resources.
• Over-utilization of floodplain resources adversely impacts river system functions.
• Effective management strategies are needed to balance human needs and ecological health.

Purpose of the Study:

• To formulate a hydro-bio-geomorphological framework for assessing river systems.
• To define and assess
• river space
• for sustainable river-floodplain management.
• To establish a minimum river space criterion for ecological restoration.

Main Methods:

• Flood frequency analysis to determine inundation widths for various return periods.
• Utilizing rating curves and satellite-derived cross-sections for hydrological assessment.
• Integrating bio-geomorphological data to corroborate hydrologically assessed river widths.

Main Results:

• The study assessed river space across seven hydro-meteorological sites on the Ganga River (~750 km stretch).
• Minimum river space was proposed to equal the lateral width of a 1-year return period flood.
• Measured river space ranged from 2 to 21 km in the middle Ganga plains.

Conclusions:

• A simple, logical framework for assessing river space has been presented.
• The proposed minimum river space criterion can aid in biomic restoration efforts.
• This approach supports sustainable management of river-floodplain systems.