Vol. 9, Issue 10 (2020)

Author(s):
Abhishek Ranjan, DM Denis and H Mishra

Abstract:
This research prioritizes the parameters influencing evapotranspiration using a conceptual rainfall-runoff semi-distributed conceptual model, known as Hydrologiska Byråns Vattenbalansavedlning (HBV), for a small irrigated agricultural watershed in the northern semi-arid region of Uttar Pradesh, India. Lands in the watershed are mostly agricultural with wheat and paddy as the major crops. It also has pastures and orchards with a few ponds that run dry during summer. All parameters used by the model to simulate evapotranspiration are parameterized. The considered parameters are successfully modeled, calibrated, validated and their sensitivity obtained. The study prioritizes the parameters that influence evapotranspiration in descending order with the most sensitive the first and the least, last. The parameter “athorn” responsible for quantifying Evapotranspiration is identified as the most sensitive parameter. Objective functions as BIAS, RMSE, R², NSE, and RE are mostly minimum at a sensitivity range of -10% and +10% of “athorn” and its value ranges between from 0.83 to 0.083.