Basin-scale impacts of hydropower development on the Mompos Depression wetlands, Colombia
Basin-scale impacts of hydropower development on the Mompos Depression wetlands, Colombia
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DOI：
10.5194/hess-22-2839-2018
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发表时间：
2018-05-08
影响因子：
6.3
通讯作者：
Purkey, David
中科院分区：
文献类型：
--
作者：
Angarita, Hector;Wickel, Albertus J.;Purkey, David
哥伦比亚马格达莱纳河流域的一些大型水电站大坝目前正在开发中或处于规划的后期阶段，这给蒙波斯洼地湿地带来了不确定性，蒙波斯洼地湿地是南美洲最大的湿地系统之一，面积为3400公里（2）。洪泛区及其相关湿地每年的大规模淹没调节了水、养分和沉积物的循环，这反过来又维持了丰富的生态过程和生态系统服务，包括关键的粮食供应。在这项研究中，我们实施了一种综合方法，重点关注生态功能洪泛区的关键属性：（1）河流和洪泛区之间以及上游和下游部分之间的水文连通性;（2）水文变异模式及其与当地和区域过程的联系;（3）维持洪泛区相关过程和利益所需的空间尺度，如洄游鱼类生物多样性。实施的框架提供了一个明确的量化的非线性或直接的响应关系，这些考虑与水电开发。拟议的框架被用来对满足预计的2050年电力需求所需的水电扩建的潜在影响进行比较分析。作为这项研究的一部分，我们开发了一个增强的水资源评估和规划系统（WEAP），允许在中等规模（类似于1000至10000 km（2））的洪泛区水平衡的决议和上游水资源管理实践的潜在影响的评估。在蒙波斯洼地湿地的情况下，我们的研究结果表明，新的水电基础设施相对于基线条件的潜在额外影响的范围可以高达一个数量级的情景之间的能源容量方面是可比的。低地洪泛区和上游产卵生境之间连通走廊的破碎化以及沉积物负荷的减少显示出最大的影响，与坝前条件相比，可能分别减少97.6%和80%。在某些发展情景中，上游基础设施调节和截留的水量与干旱年份洪泛区阶段性淹没所涉及的现有通量具有相似的量级，因此，也可能导致蒙波斯凹陷某些地区从平旱年到干旱年洪泛区季节动态的重大变化。
A number of large hydropower dams are currently under development or in an advanced stage of planning in the Magdalena River basin, Colombia, spelling uncertainty for the Mompos Depression wetlands, one of the largest wetland systems in South America at 3400 km(2). Annual large-scale inundation of floodplains and their associated wetlands regulates water, nutrient, and sediment cycles, which in turn sustain a wealth of ecological processes and ecosystem services, including critical food supplies. In this study, we implemented an integrated approach focused on key attributes of ecologically functional floodplains: (1) hydrologic connectivity between the river and the floodplain, and between upstream and downstream sections; (2) hydrologic variability patterns and their links to local and regional processes; and (3) the spatial scale required to sustain floodplain-associated processes and benefits, like migratory fish biodiversity. The implemented framework provides an explicit quantification of the nonlinear or direct response relationship of those considerations with hydropower development. The proposed framework was used to develop a comparative analysis of the potential effects of the hydropower expansion necessary to meet projected 2050 electricity requirements. As part of this study, we developed an enhancement of the Water Evaluation and Planning system (WEAP) that allows resolution of the floodplains water balance at a medium scale (similar to 1000 to 10 000 km(2)) and evaluation of the potential impacts of upstream water management practices. In the case of the Mompos Depression wetlands, our results indicate that the potential additional impacts of new hydropower infrastructure with respect to baseline conditions can range up to one order of magnitude between scenarios that are comparable in terms of energy capacity. Fragmentation of connectivity corridors between lowland floodplains and upstream spawning habitats and reduction of sediment loads show the greatest impacts, with potential reductions of up to 97.6 and 80 %, respectively, from pre-dam conditions. In some development scenarios, the amount of water regulated and withheld by upstream infrastructure is of similar magnitude to existing fluxes involved in the episodic inundation of the floodplain during dry years and, thus, can also induce substantial changes in floodplain seasonal dynamics of average-to-dry years in some areas of the Mompos Depression.