Reservoir sedimentation issue in Pillur reservoir in Nilgiris basin (India): Field reconnaissance and numerical modelling using Delft3D

摘要

The sediment management issue in many reservoirs in India has become acute due to not only loss of storage capacity, but also the threat of malfunctioning of power intakes, sluices and other apparatuses. The major complexities are associated with sediment removal activities given the cascade scheme of dams and reservoirs as well as the fact that some of the reservoirs are located in neighbourhood of the preserved forest and eco-sensitive areas. Besides, some of the reservoirs also serve for water supply, irrigation as well as recreational purposes, so the upstream and downstream effects are of the major concerns. Within a scope of this study, we have carried out a brief field reconnaissance to explore reservoir sedimentation issue and desiltation possibility at Pillur reservoir in Nilgiris basin (in South India). Furthermore, morphological analysis has been carried out, particularly downstream effect of the sediment removal activity based on computational modelling of some synthetic scenarios. We have demonstrated the possibility to apply computational modelling to address some basic morphological issues when data is scarce.