The Characteristics and Impacts of Imperviousness From a GIS-based Hydrological Perspective

Abstract

With the concern that imperviousness can be quantified differently depending on data sources and methods, regression equations to translate between imperviousness estimates using land use and land cover were developed. In addition, this study examined how quantitatively different imperviousness estimates affect the prediction of hydrological response. The regressions between indicators of hydrological response and imperviousness-descriptors were evaluated by examining goodness-of-fit measures such as explained variance or relative standard errors. The results show that imperviousness estimates using land use are better predictors of hydrological response than imperviousness estimates using land cover. Also, this study reveals that flow variability is more sensitive to spatially distributed models than lumped models, while thermal variability is equally responsive to both models. The findings from this study can be further examined from a policy perspective with regard to policies that are based on a threshold concept for imperviousness impacts on the ecological and hydrological system.