Developing interception and root uptake systems in conceptual hydrological modelling

This research aimed at developing a conceptual hydrological model (tank model) with interception and root uptake. It was conducted in a sub-watershed of Coban Rondo located in an area with 89% forest and plantation land. 10-year rainfall and discharge data were used to perform calibration, verification and simulation. The calibration utilised a hybrid optimisation method of random search and genetic algorithm. A water balance equation was developed. The effect of interception and root uptake parameters on the modelling procedure was evaluated using the Nash-Sutcliffe efficiency (NSE) coefficient and paired sample t test. Results showed that, at a significance level of 5%, the interception and root uptake parameters had a significant effect on modelling (t Stat = 8.457 > t critical two-tail = 1.980). The modelling performance increased by 26.98% with an NSE value of 0.91.