- Award ID(s):
- Publication Date:
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- Journal Name:
- Stochastic Environmental Research and Risk Assessment
- Sponsoring Org:
- National Science Foundation
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The nexus of food, energy, and water systems offers a meaningful lens to evaluate hydroelectric dam removal decisions. Maintaining adequate power supplies and flourishing fish populations hangs on the balance of managing the tradeoffs of water resource management. Aside from energy adequacy, substituting hydropower with other renewable energy sources impacts the overall energy dispatch behavior of the grid, including emissions of existing fossil fuels. This study extends earlier work in the literature to evaluate the adequacy impact to the power supply by removing four Lower Snake River dams in the Columbia River Basin in favor of supporting migratory salmon populations. The authors explore the climate performance, i.e., fossil fuel dispatch changes, of simulated renewable substitution portfolios to supplement performance metrics alongside adequacy and initial investment metrics. The study finds that including the climate metric greatly influences the favorability of some alternative portfolios that would otherwise be overlooked, with some portfolios improving climate mitigation efforts by reducing emissions over the baseline scenario. The contribution is in advancing a straightforward and supplementary climate performance method that can accompany any energy portfolio analysis.
A Meta-Analysis of Environmental Tradeoffs of Hydropower Dams in the Sekong, Sesan, and Srepok (3S) Rivers of the Lower Mekong BasinIn Mekong riparian countries, hydropower development provides energy, but also threatens biodiversity, ecosystems, food security, and an unparalleled freshwater fishery. The Sekong, Sesan, and Srepok Rivers (3S Basin) are major tributaries to the Lower Mekong River (LMB), making up 10% of the Mekong watershed but supporting nearly 40% of the fish species of the LMB. Forty-five dams have been built, are under construction, or are planned in the 3S Basin. We completed a meta-analysis of aquatic and riparian environmental losses from current, planned, and proposed hydropower dams in the 3S and LMB using 46 papers and reports from the past three decades. Proposed mainstem Stung Treng and Sambor dams were not included in our analysis because Cambodia recently announced a moratorium on mainstem Mekong River dams. More than 50% of studies evaluated hydrologic change from dam development, 33% quantified sediment alteration, and 30% estimated fish production changes. Freshwater fish diversity, non-fish species, primary production, trophic ecology, and nutrient loading objectives were less commonly studied. We visualized human and environmental tradeoffs of 3S dams from the reviewed papers. Overall, Lower Sesan 2, the proposed Sekong Dam, and planned Lower Srepok 3A and Lower Sesan 3 have considerable environmental impacts. Tradeoff analysesmore »
Carbon dioxide (CO 2 ) concentrations and emission in the newly constructed Belo Monte hydropower complex in the Xingu River, AmazoniaAbstract. The Belo Monte hydropower complex located in the Xingu River is the largestrun-of-the-river (ROR) hydroelectric system in the world and has one of thehighest energy production capacities among dams. Its construction receivedsignificant media attention due to its potential social and environmentalimpacts. It is composed of two ROR reservoirs: the Xingu Reservoir (XR) inthe Xingu's main branch and the Intermediate Reservoir (IR), an artificialreservoir fed by waters diverted from the Xingu River with longer waterresidence time compared to XR. We aimed to evaluate spatiotemporalvariations in CO2 partial pressure (pCO2) and CO2 fluxes(FCO2) during the first 2 years after the Xingu River impoundmentunder the hypothesis that each reservoir has contrasting FCO2 andpCO2 as vegetation clearing reduces flooded area emissions. Time ofthe year had a significant influence on pCO2 with the highest averagevalues observed during the high-water season. Spatial heterogeneitythroughout the entire study area was observed for pCO2 during both low-and high-water seasons. FCO2, on the other hand, only showed significantspatial heterogeneity during the high-water period. FCO2 (0.90±0.47 and 1.08±0.62 µmol m2 d−1 for XR and IR,respectively) and pCO2 (1647±698 and 1676±323 µatm for XR and IR, respectively) measured during the high-water season wereon the same order of magnitude as previous observations in other Amazonianclearwater rivers unaffectedmore »
Despite efforts to understand the hydrologic impact of hydropower dams, their influence on downstream river temperatures has gone unnoticed in data limited regions. Using 30 years of Landsat thermal infrared observations (1988–2018), we identified a relationship between dry season water temperature cooling trends and dam development in the 3S Basin, a major tributary of the Mekong River. Within a year of the beginning of operations of major dams in the 3S River Basin, rapid decreases in annual average dry season river temperature were observed ranging between 0.7 ° C and 2 ° C. Furthermore,
in situwater temperature observations confirmed decreasing river temperature for two major dam development events. Evidence was found that the 3S outflow has been cooling the Mekong River downstream of the confluence, by as much as 0.8 ° C in recent years. Our findings are critically important for understanding how fish and aquatic ecosystems will behave in the future as more hydropower dams are built in the Mekong River Basin.
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