A longitudinal analysis of green infrastructure conditions in Coastal Texan cities

Abstract

Green Infrastructure (GI) has gained attention as a strategy for minimizing flood damage and enhancing ecological services in developed and developing areas. Previous studies have investigated the positive effects of GI, focusing primarily on how the amount of GI impacts flood mitigation, but not its shape, connectivity, or quantity. Further, these studies have been mostly based on a single time period and not longitudinal. This paper explores GI conditions in high and low flood risk coastal Texan cities over time to identify the longitudinal effects of GI, controlling for a set of socio-economic, climate/biophysical, and development variables. The research examined sixty-eight coastal Texan cities of over 10,000 in population from 2001 to 2016, conducting spatial panel data models developed in 5-year intervals. Multiple landscape indices measuring size, shape, isolation, and connectivity of GI were used to measure its quantity and condition. Results indicate that GI conditions, especially amount and connectivity levels, appear to be improving in low-risk cities while worsening in high-risk cities. For control variables, a reduction in imperviousness was found to be more effective in managing GI quantity and landscape conditions in low-risk cities than in high-risk cities. These results suggest that planners should enhance efforts to improve current GI conditions, specifically in high flood risk cities. Additionally, conservation policies and transfer of development rights should be examined together with imperviousness regulations to increase current GI conditions.