Influences of soil erosion susceptibility toward overloading vulnerability of the gully head bundhs in Mayurakshi River basin of eastern Chottanagpur Plateau

Soil erosion in the upper catchment of lateritic belt of the Mayurakshi River is one of the major problems. Excessive soil erosion leads the gully head bundhs (reservoir) hyper sedimented. These bundhs were constructed under Massanjore Dam projects for arresting soil erosion and reducing sedimentation rate in the reservoir of the Massanjore Dam. This paper intended to investigate the present state of gully head reservoirs in connection with sedimentation and find out whether these vulnerable gully head bundhs are located at the extremely soil erosion susceptible zone. Soil erosion and gully head over loading vulnerability models generated in this aim, and it is found that highly vulnerable gully head bunds are located at the excessive soil erosion zone and therefore these two models are spatially correlated. It is revealed that in the extremely susceptible soil erosion zone, 105 nos. or 52.5% to total extremely overloading vulnerable gully head bundhs are located and frequency density of them in the same area is 0.1204 nos./sq km. From this spatial adjacency, it can be stated that extreme soil erosion susceptibility and soil loss (19.62 Mg/ha/year) are principally responsible for making the reservoirs vulnerable. These reservoirs play vital role for arresting soil erosion, and as these are not evenly distributed even in the extremely soil erosion susceptible zone, more number of such reservoirs can be installed there.