CHANGE IN HYDROLOGIC AND WATER QUALITY RESPONSES DUE TO URBANIZATION

Urbanization involves the conversion of forest or agriculture lands to an infrastructure intensive urban landscape through the construction of transportation, residential, and commercial developments. These changes in landuse alter the natural hydrological, biogeochemical, and morphological processes of a watershed due to increased runoff volume and storm peakflow, decreased baseflow and evapotranspiration, elevated nutrients and contaminants loading, and altered channel morphology and stability. To maintain the predevelopment hydrologic and water quality conditions stormwater BMPs and stream restoration practices are undertaken. Stream restoration increases the transient storage, reduces travel time, and reduces flow velocity by enhancing complexity of the in-stream geomorphic structures and connecting floodplains to the stream channel, which can help in establishing the natural stream ecosystem for sustaining the physical, chemical, and biological activities to retain, degrade, and uptake pollutants (Meyer et al. 2003; Bukaveckas 2007; and Kaushal 2008). However, there are instances, where complete stream restorations were identified as the disturbances rather than cure for declining stream health (Palmer et al. 2009). Therefore, comparisons of restored and natural stream processes in receiving water inputs from different landuses are important to identify strategies to enhance biogeochemical processes in lotic systems. Here we present a long-term study of changes in hydrologic and water quality responses from the forested and urban watersheds as well as the in-stream transport dynamics of sediments, nutrients, and DOC in natural and restored stream reaches draining both forested and urbanizing watersheds.