An integrated modelling toolbox for water resources assessment and management in highland catchments: Sensitivity analysis and testing

Abstract

An earlier companion paper developed a framework for river basin management to assess trade-offs among economic, social and environmental factors and their spatiotemporal variability (Letcher, R.A., Merritt, W.S., Jakeman, A.J., Croke, B.F., this issue. An integrated modelling toolbox for water resources assessment and management in Northern Thailand: model description, Agricultural Systems). That paper discussed an integrated modelling toolbox (IMT) that has been developed for highland catchments with specific application to the Mae Chaem catchment in Northern Thailand. The aim of the IMT is to provide information on these types of trade-offs. The toolbox uses a scenario modelling approach that translates policy and uncontrollable drivers into scenario inputs to the biophysical toolbox, a component of the integrated modelling toolbox. The biophysical toolbox (BPT) outputs indicators from models of crop growth, erosion and rainfall-runoff, whereas socioeconomic decision-making and impact models are complementary components of the IMT. This paper presents results from a sensitivity analysis of the model to changes in various input assumptions. These results show that policy recommendations based on socioeconomic or flow impacts are not likely to be affected by small levels of uncertainty in prices or costs, or recent variability in climate. Erosion is the most sensitive output, and is strongly sensitive to a change in price. But the direction of change in erosion appears to be consistent across different price assumptions. Overall the model shows plausible levels and patterns of sensitivity to changes in input parameters.