Abstrait

Performance Evaluation of Rehabilitated Irrigation Tanks using Hydrological Modelling

E Arivoli, N K Ambujam

Tank irrigation is considered as one of the ancient irrigation system. Since the age of south Indian tanks are century years old and had started to decline progressively. Due to inadequate rainfall, improper maintenance of tank components the tank irrigation system follows a declining trend, almost all the command area under any tank irrigation system depends on the wells located in the fields. By knowing this, the government of Tamil Nadu is trying to rejuvenate the existing irrigation tanks. One such rehabilitation programme is TN – IAMWARM. This paper focused on evaluating the performance of rehabilitated tanks for the past fifteen year (2000-2015) through hydrological simulation using MS-Excel as a tool and to study the impact of rehabilitation on tank performance. Gomukhi sub basin of vellar basin, Tamil Nadu, India is selected for the study, in which one non-system tank and a system tank is chosen. Monthly runoff to the tank and rainfed on the tank is taken as inflow, crop water requirement, evaporation and seepage is taken as monthly outflow. The monthly change in storage is used to simulate the ayacut area of the selected tanks which is taken as the performance of the tanks.