Abstract:
The identification of environmentally stressed areas for planning soil conservation
measures requires an efficient decision support tool to provide appropriate weights for various
topographical, morphological, climatological and management factors responsible for soil
erosion. In the present study, Saaty’s analytical hierarchy process (SAHP) with nine erosion
hazards parameters (EHPs) including soil loss (SL), sediment yield (SY), sediment production
rate (SPR), sediment transport index (STI), slope (Slp), Drainage density (Dd), channel
frequency (Cf), form factor (Rf), circulatory ratio (Rc) has been used as a decision support
system for identification of environmentally stressed sub-watersheds in Benisagar dam catchment
of Bundelkhand region (Madhya Pradesh, India). The SAHP is a structured technique for
dealing with complex decisions which involves building a hierarchy of decision elements,
making comparisons between each possible pair in each cluster, provides weighting for each
element within a cluster and checking the consistency of the decision based on a consistency
ratio. The Benisagar dam catchment having excessive erosion due to undulating topography,
limitation of soil depth and absence of conservation measures affects reservoir storages due to
silting problems. For prioritization purposes, the Benisagar dam catchment has been divided in
to 36 sub-watersheds with their areas ranging from 0.77 to 6.53 km2 and all nine EHPs for
various sub-watersheds have been computed. The pair wise comparison matrix and final
weights for all the EHPs have been determined using SAHP with the acceptable limit of
consistency ratio. The final priority ranks for sub-watersheds have been computed by summing
the multiplication of SAHP weights and their corresponding normalized values of EHPs. From
the analysis, it has been observed that eight sub-watersheds covering 20.15 km2 and seven subwatersheds
covering 19.41 km2 areas fall under very high and high priority respectively.