PERSiST: the precipitation, evapotranspiration and runoff simulator for solute transport

Abstract

Abstract. While runoff is often a first-order control on water quality, runoff generation processes and pathways can vary widely between catchments. Credible simulations of solute and pollutant transport in surface waters are dependent on models which facilitate appropriate representations of perceptual models of the runoff generation process. With a few exceptions, models used in solute transport simulations enforce a single, potentially inappropriate representation of the runoff generation process. Here, we present a flexible, semi-distributed landscape scale rainfall-runoff model suitable for simulating a broad range of user-specified perceptual models of runoff generation and stream flow occurring in different climatic regions and landscape types. PERSiST, the Precipitation, Evapotranspiration and Runoff Simulator for Solute Transport; is designed for simulating present day conditions and projecting possible future effects of climate or land use change on runoff, catchment water storage and solute transport. PERSiST has limited data requirements and is calibrated using observed time series of precipitation, air temperature and runoff at one or more points in a river network. Here, we present a first application of the model to the Thames River in the UK and describe a Monte Carlo tool for parameter optimization and sensitivity analysis.