Assessing the significance of wetland restoration scenarios on sediment mitigation plan
Assessing the significance of wetland restoration scenarios on sediment mitigation plan
复制标题
DOI：
10.1016/j.ecoleng.2014.11.031
复制
发表时间：
2015-04-01
影响因子：
3.8
通讯作者：
Giri, Subhasis
中科院分区：
文献类型：
--
作者：
Martinez-Martinez, Edwin;Nejadhashemi, A. Pouyan;Giri, Subhasis
湿地具有许多环境、社会和经济价值。然而，由于土地利用的加速变化和对湿地生态系统功能的认识不足，湿地生态系统在世界许多地区即使没有消失，也已经恶化。同时，目前的功能湿地评价技术只提供了粗略的估计，并且在大多数情况下是具体的和定性的。该项目的总体目标是在次流域和流域尺度上研究湿地实施方案的减沙效益。我们使用了两组模型来实现这一目标。首先，利用流域模型—水土评估工具（SWAT）估算流域尺度下的泥沙负荷。然而，由于SWAT的湿地功能的局限性，我们使用了第二个模型——城市雨水处理和分析集成系统（SUSTAIN）。每个子盆地产生的泥沙负荷被纳入SUSTAIN模型。这样就可以在次流域水平评价湿地的减沙能力。接下来，一部分未经过湿地处理的沉积物被反馈到SWAT模型，并被输送到流域出口。在位于密歇根州东南部和俄亥俄州东北部的Raisin河流域内的所有子流域中，逐一研究了四种不同湿地表面积（0.40、0.81、2和4公顷）对泥沙负荷减缓的影响。对比不同湿地恢复方案的减沙量，揭示了湿地在流域中的重要性。总体而言，实施湿地导致的径流减少率高于次流域水平的泥沙减少率，但在流域水平上更具可比性。此外，在距离出水口150-200流公里处设置的湿地集群在更近和更远的距离上表现优于其他集群湿地。与一级溪流相关的湿地在次流域水平上表现较好，而位于四级溪流的湿地在流域水平上表现较好。考虑湿地恢复方案的环境和经济问题，发现0.4 ha湿地因其减沙效率和显著降低的安装和维护成本而最适合在次流域和流域层面实施。(C) 2015 Elsevier B.V.版权所有
Wetlands have many environmental, social, and economic values. However, due to accelerated land use change and lack of understanding of the functions of wetland ecosystems, they have deteriorated, if not been lost in many areas worldwide. Meanwhile, current functional wetland assessment techniques only provide rough estimations, and are in most cases site specific and qualitative. The overall goal of this project is to examine the sediment reduction benefit of wetland implementation scenarios both at subbasin and watershed scales. Two sets of models were used to accomplish this goal. First, a watershed model - the Soil and Water Assessment Tool (SWAT), was employed to estimate sediment load at the subbasin scale. However, due to limitations of wetland functions of SWAT, a second model - the System for Urban Stormwater Treatment and Analysis Integration (SUSTAIN) was used. The sediment load generated for each subbasin was incorporated in the SUSTAIN model. This allows for evaluating sediment reduction capability of wetlands at subbasin level. Next, a portion of sediment not treated by a wetland was fed back to the SWAT model and routed to the watershed outlet. The impacts of four different wetland surface areas (0.40, 0.81, 2, and 4 ha) on sediment load mitigation were examined one-at-a-time for all subbasins within the River Raisin watershed located in southeastern Michigan and northeastern Ohio. Comparison of the sediment reductions due to different wetland restoration scenarios reveals the importance of wetland placement in a watershed. In general, the rate of streamflow reduction resulting from wetland implementation is higher than sediment reduction at the subbasin level but more comparable at the watershed level. In addition, clusters of wetlands installed at the distance of 150-200 stream km from the outlet outperformed other clustered wetlands at closer and farther distances. Wetlands associated with 1st order streams performed better at the subbasin level, while wetlands located at 4th order streams performed better at the watershed level. Considering environmental and economic issues of wetland restoration scenarios revealed that the 0.4 ha wetlands were the most suitable for subbasin and watershed level implementation due to its sediment reduction efficiency and significantly lower cost of installation and maintenance. (C) 2015 Elsevier B.V. All rights reserved.