| Abstract: |
We examined the relationship between the built environment, landscape configuration, and water quality of streams across three physiographic provinces of the State of Maryland and in southern New England. We used image data products capable of discriminating fine-scale information of the land surface, including proportional impervious, tree, grass and crop cover, and then developed a range of statistical models that relate land cover information to stream biotic integrity within watersheds. The stream biota measurements included number of sensitive taxa (NEPT), biotic indices of biological integrity (BIBI), and the Hilsenhoff Biotic Index (HBI), each of which provides unique information. Impervious and tree cover were found to be the primary predictors of stream biota, although this varied with physiographic province and the response variable of interest. In Maryland, the best multivariate models predicted 65% of variability in BIBI and 62% of NEPT (N=59). In New England the best models predicted 76% of NEPT and 69% of HBI (N=83). We also tested the effectiveness of weighting land cover variables within a watershed based on distance from the stream channel and the presence of forest cover. These indices of landscape configuration were important in many, but not all cases, for improving the predictive quality of statistical models estimating stream biota metrics. |