A panel data analysis of a spatial measurement of green infrastructure and its potential effectiveness on peak streamflow

Research on the possible benefits of green infrastructure as a hazard mitigation strategy has been limited by the lack of effective tools for the identification and measurement of the specific dimensions of green infrastructure particularly within highly developed urban environments. Consequently, there has been little empirical research conducted on the potential benefits of green infrastructure for reducing streamflow, an indicator of runoff and potential flooding mitigation. This study seeks to further research green infrastructure as a potential tool for hazard mitigation by examining its consequences for streamflow over a 2-year period in 2004 and 2010 for two key urban areas subject to flooding in Texas, USA (Austin and Houston Metropolitan areas) in panel models to assess the effectiveness of green infrastructure for reducing runoff as assessed by using streamflow gage data predicting annual peak flow. The statistical models suggested that green infrastructure contributes to reduce annual peak flow in urbanized watersheds. The effect in the fixed effects model suggests that with every percent increase in green infrastructure within the 100-year floodplain, peak annual flow decreased by 7.7% ( R 2 = 0.6985). The effects of green infrastructure outside the floodplain appeared to be significant, and its magnitude in the fixed effects model was − 7.1% ( R 2 = 0.6447). These differences suggest slightly greater consequences for preserving green infrastructure within floodplains when it comes to peak annual flows. Moreover, the analyses explained that green infrastructure in Austin appears to be more effective on peak annual flow when, compared to Houston, suggesting that green infrastructure has elevated consequences in areas with greater topographical diversity. The effectiveness of green infrastructure in critical places will help make a guideline for the balanced urban development with implementation of green infrastructure.