Index of wetland condition development and application for evaluating ecological functions of detention ponds
Journal
Journal of Taiwan Agricultural Engineering
Journal Volume
62
Journal Issue
3
Date Issued
2016-09-01
Author(s)
Abstract
Detention ponds are engineered facilities for flood detention with the primary pur-poses to reduce the peak discharge and delay the arrival time of flood peaks during the flood period. The detention wetland (DW) is defined as a composite facility combining detention pond and free water surface (FWS) wetland, designed to serve as ecological functions, such as wastewater treatment and wildlife habitats, in addition to its flood detention function. This study aims to evaluate the ecological function of DW and provide improvement strategy according to the field survey, model simulation and wetland scores calculation. The ecological investigations were conducted every season during the project executing. Both biotic and abiotic items were included. They are benthos, vegetation, birds, fish as biotic items and water quality, water surface elevation, water connectivity and bank erosion by wind-induced wave propagation representing abiotic factors. We also established a new model named as index of wetland condition (IWC), to quantify the ecological importance of DW based on a scoring system. The IWC consists of five sub-indices, such as hydrology (HY), water quality (WQ), physical environment (PF), riparian vegetation (SID), and aquatic animal (BI). Four DWs including Dago pond (DG) and Dahu pond (DH) in Taipei City and Hsinwen-south pond (HS) and Hsinwen-north pond (HN) in Chiayi County were selected as our study sites to evaluate ecological functions of DW systems in urban areas. The IWC scores for DG, DH, HS and HN were 76, 70, 74 and 74 respectively, and this indicated that all study DW sites were able to provide marginal to good ecological functions. Possible methods and techniques for enhancing the ecological functions of DW systems were also suggested and discussed to provide insights on management strategies for DW in Taiwan.
Subjects
Detention pond | Detention wetland | Ecological function | IWC
Type
journal article