Priority Watersheds for Soil Conservation Works in Matatilla Catchment

The concept of priority watersheds has been introduced for soil conservation treatment works to imply watersheds that contribute to maximum silt at ion of a reservoir. The methodology for delineating priority watersheds comprises mapping of erosion units defined in terms of physiography, slope, soil characteristics, land use, vegetation and erosion. Weightage values are assigned to the mapping units corresponding to the resultant of the interaction of these factors in producing silt yield. Mapping is made on a base map with delineations and codifications of sub-catchments, watersheds, sub-watersheds. The silt yield index for each watershed is computed by summation of the product of the areas by the different units and their weightage values. The delivery of the eroded material to the reservoir is estimated by adjusted delivery ratio. The relevant factors of the delivery ratios are discussed in the paper. Estimations of priority watersheds by following this method for Matatilla catchment, Madhya Pradesh revealed that out of the total area of 5.56 lakh ha, 1.73 lakh ha, constituting about 30% of the total area falls under very high and high priority categories demanding immediate attention for soil conservation works.