Assistant Professor FAMU-FSU College of Engineering
Changes in land use/land cover (LULC) and climate (CC) are expected to affect watershed hydrology in the future. Despite past research on estimating such changes, studies in urban watersheds have been limited. Urban watersheds have several important details such as underground infrastructure and land management practices that call for high-resolution watershed models to predict the impacts of LULC and CC. In this research, a high-resolution watershed model—Personal Computer Storm Water Management Model (PCSWMM)—was utilized to predict the impacts of LULC changes and CC on surface runoff peak and volume across 369.9 km2 Hillsborough Watershed in Midwest Florida. Our research question was how LULC and CC affect surface runoff volume and peak. The relationship between LULC, CC and runoff characteristics were also investigated to determine what stressors are most responsible for the changes. The study watershed was delineated into 3,800 sub-watersheds, which differ in terms of the drainage area, imperviousness and LULC distribution. We studied six synthetic rainfall events (5- to 500-year return periods) with 24-hour duration under historical and future (year 2070) climate and LULC. The case study results indicated that, overall, CC has a higher impact on runoff characteristics than LULC change. We also found that LULC and CC induced changes in runoff are more pronounced in greater return periods and watersheds with smaller drainage area and greater historical imperviousness.This research helps urban planners and floodplain managers identify the required actions and strategies to protect urban watersheds against future LULC change and CC.
