What is prioritization?
Prioritization is done to select the area of interest.
Prioritization is a process of identifying areas of main concern based on single or many parameters
Selection of one or few watersheds out of many watersheds by using predefined set of criteria.
4. What is prioritization
Concept of Priority Watersheds
Factors Influencing Prioritizing Watersheds
Basics and Methods of Watershed Prioritization
Purpose and Benefits of Watershed Prioritizations
CONTENTS
5. What is prioritization?
Prioritization is done to select the area of interest.
Prioritization is a process of identifying areas of main concern
based on single or many parameters
Selection of one or few watersheds out of many watersheds by
using predefined set of criteria.
6. Concept of Priority Watersheds
Identification and selection of few areas or sub-watersheds having relatively
more degradation problem.
For development, planning and implementation of conservation activities
according to level of need and status of degradation, are required.
These few selected areas or sub-watersheds within a large watershed are called
the priority watersheds.
In this process, collection of sufficient bio-physical and socio-economic
information is required for integrated watershed management planning.
7. • Alpha-Numeric symbolic codes consisting alternative Arabic numbers and
English alphabet letters are used to designate different stages of delineation.
• In the eighth stage of delineation small letter English alphabet has been
used by KSRSAC to indicate the least area of the watershed.
• WRR’s are assigned Arabic number 1,2,3,…..
• Basins are assigned alphabet capital letters A,B,C,…..
• Catchments are assigned Arabic numbers 1,2,3,…..
• Sub-catchments are assigned alphabet capitol letters A,B,C,…..
• Watersheds are assigned Arabic number 1,2,3,…..
• Sub-watersheds are assigned alphabet capital letters A,B,C,…..
• Mini-watersheds are assigned Arabic number 1,2,3,…..
• Micro-watersheds are assigned alphabet small letters a,b,c,….
Example,
• Sub-watershed will have the code 4D3D6A.
• Mini-watershed will have the code 4D3D6A1.
• Micro-watershed will have the code 4D3D6A1a.
WATERSHED CODIFICATION
8. All characteristics affect the disposal of water.
SIZE: It helps in computing parameters like precipitation received, retained &
drained off.
SHAPE: Different shapes based on morphological parameters like geology and
structure, eg. pear, elongated etc.
PHISIOGRAPHY: Lands altitude and physical disposition.
SLOPE: It controls the rainfall distribution and movement:
CLIMATE: It decides the quantitative approach.
DRAINAGE: It determines the flow characteristics and so the erosion behavior.
CHARACTERISTICS OF WATERSHEDS
9. VEGETATION: Information of species gives a sure ground for selection plants and crops.
GEOLOGY AND SOILS: Their nature determines size, shape, physiographic, drainage
and groundwater conditions. Soils, derivative of rocks are the basic to greenery
HYDROLOGY: Basic to final goal of growing greenery in a watershed. It helps in
quantification of water available.
HYDROGEOLOGY: Availability of groundwater.
SOCIOECONOMICS: Statistics on people and their health, hygiene, wants and wishes
are important in managing water
CONTINUE…
10. Sediment Yield Index (SYI) Method
Watershed delineation based on Morphometric
Parameters
Methods of Watershed prioritization
12. Morphometric analysis could be used for prioritization of micro-watersheds by studying
different linear and aerial parameters of the watershed even without the availability of soil
maps.
Morphometric analysis of a drainage system requires delineation of all existing streams.
The stream delineation is done in GIS environment using Digital Elevation Model (DEM)
The various morphometric parameters such as area, perimeter, stream order, stream
length, stream number, bifurcation ratio, drainage density, stream frequency, drainage
texture, length of basin, form factor, circulatory ratio, elongation ratio, length of overland
flow, compactness coefficient, shape factor, texture ratio are computed.
Watershed delineation based on Morphometric Parameters
14. This approach is simple to adapt and useful for managers, as it combines the best
available information from scientific investigations with the knowledge and
intentions of local stakeholders.
While comparing among watersheds or varying condition within the same cluster
type or across cluster types, this approach generates a relevant list of prioritized
watersheds.
It assists the users in developing a profile of watersheds of interest, by graphically
locating a watershed and obtaining relevant information about its vulnerability.
The contemplative process used to locate multiple watersheds is helpful in deciding
upon a course of action with regard to prioritizing watershed protection and
restoration.
Benefits of Watershed Prioritization