A Framework to Regionalize Flow Information in a Catchment with Limited Hydrological Data

Abstract

This paper describes a framework for mapping flow information from a single gauge to the 9-ungauged river basins with distinct attributes. To establish the basic watershed characteristics at the gauged site, a hydrologic model was calibrated and validated against the historical continuous discharge dataset. The framework was then applied to account for the two watersheds' proportionality in their similarity, such as the influence of land use on transplanting flow signatures to the ungauged site. Three land-use scenarios-discharges at the ungauged and gauged sites formed the basis of an equation mapping the gauged discharge signal to the ungauged site. In comparison with intermittent observed data, the framework prediction attained a precision of 0.85 ≥ NSE ≤ 0.95, 0.80 ≥ R 2 ≤ 0.94, 0.56 ≥ bR 2 ≤ 0.89. Despite considerable differences in the watershed area, slope, soils, and land cover, the framework satisfactorily depicted the variation in flow pulses at each of the 9 ungauged discharge sites. In the absence of sufficient hydrological information, for example, the presence of a single gauge, the framework provides an alternative method to estimate flow at ungauged sites, reducing uncertainties in the regionalization of model parameters.