Estimation of Water Balance Components Using Evapoclimatonomy Model (Case Study: Ciliwung Upstream Sub-watershed).

Abstract

Evapoclimatonomy modeling is used to calculate water balance components for the Ciliwung Hulu sub-watershed and the potential effect of land use changes on the components. Present condition of Ciliwung Hulu sub-watershed may be represented by a set of climatonomic parameters, namely, np = 0.2; PN = 100 mm/month; ep = 0.5, ϑE = 0.146 to 0.215/month; and ϑN = 0.328 to 0.462/month. Monthly patterns of run off values obtained from model calculation resemble run off data from observations very closely, with a correlation coefficient of 0.98. Within a conceptual framework of forcing-response relationship, scenario analysis is conducted by assuming that changes in the physical characteristics of the watershed may be represented by changes in the model parameters. The behavior of response functions is also evaluated by, tentatively, modifying rainfall input (based on their theoretical statistical distributions). In this study, climatonomic parameters np and ep are used to illustrate the effect of parameters modification on response functions.