Developing an ArcGIS Pro Toolkit for Assessing Bridge Construction Effects on Sediment Regime and Aquatic Habitat

Eroded materials released from bridge construction sites can alter sediment regime and geomorphological conditions of receiving streams and may have short- and long-term impacts on aquatic habitat. One of the biggest inconsistencies in construction-related stream assessments is the delineation of the impacted area. Environmental agencies usually define the minimum buffer length for habitat surveys. This length comprises the entire project footprint and buffers for areas of the potential impact that include a minimum length upstream and downstream of the project footprint. It is unknown whether these buffer lengths adequately protect aquatic species. Field monitoring and numerical modeling efforts have been reported in various road and bridge construction projects where attempts are made to assess construction impacts on the stream sediment regime and aquatic habitat. However, no predictive model is available to quantify the potential release of sediment during the construction of bridges. A GIS-based Predictive Sediment Toolkit is developed to estimate overland erosion, determine the potential depositional area and suspended sediment concentration downstream of bridges, and assess the impact of construction activities on aquatic life. The development of the toolkit and its application in a bridge construction site are presented in this paper.

Keywords:

Overland erosion , Sediment transport , Particle Tracking , Advection-dispersion , Stochastic Lagrangian Approach