A watershed is an area of land from which all the water drains to a common point into a stream, a channel, a lake, a reservoir, or other body of water. It is all land and water within the confines of a draining divide(SCSA, 1982).•Watershed, catchment, drainage area, river basin, and drainage basin, are all terms used interchangeably, however,
- Watershed, catchment, and drainage area: are terms used for small streams and rivers.
- Drainage basin and river basin: are terms used for large river systems with numerous sub-watersheds or sub-catchments nested within it.
Tributaries: a river or stream flowing into a larger river or lake.
Types of watershed
Negi(2003) classified watersheds into the following types:-
- Micro-watershed: catchment of a primary channel.
- Sub-watershed: catchment of a secondary channel, which consists of one or more micro watersheds.
- Watershed: catchment of a larger channel, stream or river which comprises of a number of micro watersheds and sub-watersheds.
- River basin: catchment of big rivers, comprises a number of larger watersheds.
Adopted after The World Bank 2008(Types along with sizes of the watershed)
|watershed unit||typical area(km^2)|
|Basin||more than 1,000|
- The main objective of watershed management is to manage land, water, and other natural resources within the watershed area on a sustainable basis.
Note: watershed management is the application of soil conservation measures in the watershed as a working unit. it is the implementation of a management system that ensures the preservation, conservation, and sustainable use of all land resources.
Why is Watershed taken as a management unit?
Because watersheds are the only landscape unit that allows for an adequate
quantification of the key components of the hydrological cycle e.g. precipitation, interception, soil moisture and ground storage, evapotranspiration, consumption by people and animals, and run-off and provides the information necessary to manage and allocate water more equitably and efficiently throughout the year hence taken as a management unit.
Why is integrated watershed management needed?
- Integrated watershed management is the process of guiding and organizing land and other resource use in a watershed to provide desired goods and services without adversely affecting soil and water resources.
- The integrated concepts of watershed management provide a framework for sustainable development, while watershed management practices provide the tools for making that framework operational, and for that various institutional mechanisms like public investment, regulations, etc are provided for implementing those practices.
- Integrated watershed management is imperative in view of the continuing increase in population in contrast with the static nature of land surfaces and resources. Water remains to be a critical resource in future therefore efficient management of water resources became essential for overall development, improving livelihoods, and maintaining food sufficiency.
- For integrated watershed management, a participatory, multidisciplinary, multisectoral approach is necessary which will ultimately help in effective and efficient management and recourses utilization.
- Integrated watershed management requires decentralization and linkages between the central, district, and local-level organizations and institutions.
- The success of a watershed management program depends on the simultaneous actions of several organizations, including the beneficiaries.
Note”Linkages with various organizations are crucial in order to achieve the goal of sustainable watershed management“
Generally, there are 3 types of linkage mechanism, relationship is as follow: