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Although the hydrologic cycle is a continuously renewable resource, the natural rate of water delivery is highly variable. Water is made available to our society on a consistent and reliable basis largely due to flow regulation by storage reservoirs. However, under current management, the reservoir storage capacity needed for flow regulation is a non-renewable resource because this capacity is steadily being lost to sedimentation. Today’s reservoirs occupy unique sites and may be considered largely irreplaceable, making the nation dependent on a non-sustainable resource. Sedimentation is steadily depleting storage capacity and progressively degrading the ability of reservoirs to fulfill their designated purposes. Sedimentation is also causing environmental impacts upstream and downstream of reservoirs. In the United States, the combined impacts of sedimentation and population growth have resulted in an estimated 35% decline in storage capacity per capita since this value peaked around 1970. In absolute terms, the estimated total reservoir storage capacity in the U.S. has dropped from a peak of 850 Gm3 in the late 1980s to 810 Gm3 today. Yet, sustaining the nation’s long-term reservoir storage capacity has not been a priority for many public or private dam owners, especially when they lack a reservoir sedimentation monitoring policy. In many regions, future reservoir storage will have to serve an important role in the mitigation of climate change to help ensure water, food, and energy, and the reduction of flood risk. There is an imperative need to preserve existing reservoir storage capacity due to rising demands associated with population growth, and increasing hydrologic variability associated with climate change, and the challenges and costs associated with either expanding existing capacity or decommissioning and developing new storage capacity. The trapping of sediment behind dams has also contributed to the decline of freshwater and coastal environments downstream of dams. Reversing these dangerous trends in storage capacity and environmental integrity will require increased monitoring of reservoirs, application of both established and emerging sediment management technologies, and a new paradigm for sustainable reservoir design and management. It requires moving from the traditional design life (reservoir life expectancy) approach to the adoption of sustainable use as the appropriate criteria for reservoir design and operation, achieving a sediment balance across reservoirs to permit the indefinite operation of this critical infrastructure.
Timothy J. Randle; Gregory L. Morris; Desirée D. Tullos; Frank H. Weirich; G. Mathias Kondolf; Daniel N. Moriasi; George W. Annandale; Jon Fripp; J. Toby Minear; David L. Wegner. Sustaining United States Reservoir Storage Capacity: Need for a New Paradigm. Journal of Hydrology 2021, 126686 .
AMA StyleTimothy J. Randle, Gregory L. Morris, Desirée D. Tullos, Frank H. Weirich, G. Mathias Kondolf, Daniel N. Moriasi, George W. Annandale, Jon Fripp, J. Toby Minear, David L. Wegner. Sustaining United States Reservoir Storage Capacity: Need for a New Paradigm. Journal of Hydrology. 2021; ():126686.
Chicago/Turabian StyleTimothy J. Randle; Gregory L. Morris; Desirée D. Tullos; Frank H. Weirich; G. Mathias Kondolf; Daniel N. Moriasi; George W. Annandale; Jon Fripp; J. Toby Minear; David L. Wegner. 2021. "Sustaining United States Reservoir Storage Capacity: Need for a New Paradigm." Journal of Hydrology , no. : 126686.
Sediment is an essential component of water and river systems. The anthropogenic alteration of sediment fluxes in the world’s rivers is one of the principal markers of the Anthropocene, the new geological epoch characterized by human influence at the planetary scale. In spite of its environmental and historical importance, water and river histories have surprisingly neglected sediment until recently. This introduction to the special issue “The Social Life of Sediment” argues for putting sediment at the center of social and historical inquiry and discusses the potential and value of such an approach. To do so, we introduce the concept of the “social life of sediment,” that is, the idea that the existence and movement of sediment is entwined with social needs, values, and activities, and needs to be appraised in his historical dimension. We review recent literature in fluvial geomorphology, social sciences, and history to assess to what extent the social and historical life of sediment has been taken into account. After this interdisciplinary review, we present the seven papers of the special issue and highlight their major insights to the study of social and historical lives of sediment. We conclude by outlining avenues for further research and by summarizing what we all can gain from putting sediment at the center of historical inquiries.
Giacomo Parrinello; G. Mathias Kondolf. The social life of sediment. Water History 2021, 13, 1 -12.
AMA StyleGiacomo Parrinello, G. Mathias Kondolf. The social life of sediment. Water History. 2021; 13 (1):1-12.
Chicago/Turabian StyleGiacomo Parrinello; G. Mathias Kondolf. 2021. "The social life of sediment." Water History 13, no. 1: 1-12.
Tackling climate change and human development challenges will require major global investments in renewable energy systems, including possibly into large hydropower. Despite well-known impacts of hydropower dams, most renewable energy assessments neither account for externalities of hydropower nor evaluate possible strategic alternatives. Here we demonstrate how integrating energy systems modeling and strategic hydropower planning can resolve conflicts between renewable energy and dam impacts on rivers. We apply these tools to Myanmar, whose rivers are the last free-flowing rivers of Asia, and where business-as-usual (BAU) plans call for up to 40 GW of new hydropower. We present alternative energy futures that rely more on scalable wind and solar, and less on hydropower (6.7–10.3 GW) than the BAU. Reduced reliance on hydropower allows us to use river basin models to strategically design dam portfolios for minimized impact. Thus, our alternative futures result in greatly reduced impacts on rivers in terms of sediment trapping and habitat fragmentation, and result in lower system costs ($8.4 billion compared to $11.7 billion for the BAU). Our results highlight specific opportunities for Myanmar but also demonstrate global techno-ecological synergies between climate action, equitable human development and conservation of riparian ecosystems and livelihoods.
Rafael J P Schmitt; Noah Kittner; G Mathias Kondolf; Daniel M Kammen. Joint strategic energy and river basin planning to reduce dam impacts on rivers in Myanmar. Environmental Research Letters 2021, 16, 054054 .
AMA StyleRafael J P Schmitt, Noah Kittner, G Mathias Kondolf, Daniel M Kammen. Joint strategic energy and river basin planning to reduce dam impacts on rivers in Myanmar. Environmental Research Letters. 2021; 16 (5):054054.
Chicago/Turabian StyleRafael J P Schmitt; Noah Kittner; G Mathias Kondolf; Daniel M Kammen. 2021. "Joint strategic energy and river basin planning to reduce dam impacts on rivers in Myanmar." Environmental Research Letters 16, no. 5: 054054.
The Mekong River in Southeast Asia, one of the world’s great rivers, has been facing disruption of its sediment balance and resultant impacts on nutrient fluxes, aquatic ecology, floodplains and the delta. Using monitoring data from 1993 to 2018, we estimated the temporal variability of sediment loads in Tonle Sap and Lower Mekong Rivers in Cambodia, assessing the sediment linkage between the Tonle Sap Lake and the Mekong mainstem, which are connected by a seasonally reversing flow through the Tonle Sap River. We estimated the annual sediment in the Mekong mainstem of 72 ± 38 Mt/year at Kratie (upstream) and 78 ± 22 Mt/year at Chroy Changvar from 1993 to 2018 (just upstream of the Chatumuk confluence). Our sediment load estimation of the Mekong River is consistent with other recent estimates of sediment load on the Lower Mekong. However, the result is lower than reported in some older studies (prior to the 2000s), which is consistent with sediment trapping by dams on Upper Mekong mainstem and major tributaries. Our analysis indicates that Tonle Sap Lake provided 0.65 ± 0.6 Mt/year of sediment annually to the Lower Mekong River from 1995 to 2000. However, since 2001, Tonle Sap Lake has become a sink for sediment, accumulating an average of 1.35 ± 0.7 Mt annually. Net storage of sediment in Tonle Sap Lake reduces the annual sediment transport to the delta, further compounding the effects of reduced sediment delivery to the delta resulting from upstream dam development and instream sand mining.
Ty Sok; Chantha Oeurng; Vinhteang Kaing; Sabine Sauvage; G. Mathias Kondolf; José Miguel Sánchez-Pérez. Assessment of suspended sediment load variability in the Tonle Sap and Lower Mekong Rivers, Cambodia. CATENA 2021, 202, 105291 .
AMA StyleTy Sok, Chantha Oeurng, Vinhteang Kaing, Sabine Sauvage, G. Mathias Kondolf, José Miguel Sánchez-Pérez. Assessment of suspended sediment load variability in the Tonle Sap and Lower Mekong Rivers, Cambodia. CATENA. 2021; 202 ():105291.
Chicago/Turabian StyleTy Sok; Chantha Oeurng; Vinhteang Kaing; Sabine Sauvage; G. Mathias Kondolf; José Miguel Sánchez-Pérez. 2021. "Assessment of suspended sediment load variability in the Tonle Sap and Lower Mekong Rivers, Cambodia." CATENA 202, no. : 105291.
On January 9, 2018 a series of debris flows killed 23 people and caused over a $1 billion in economic losses in Montecito, Santa Barbara County. The debris flows followed a classic pattern in mountainous areas of southern California: A large wildfire (the 2017 Thomas Fire) burned the headwaters of streams draining the Transverse Ranges southward to the Pacific, creating hydrophobic soil conditions that prevented infiltration of water, resulting in larger runoff during rains. A cell of intense precipitation over Montecito triggered debris flows, affecting areas along the stream channels.
The 2018 Montecito debris flows raise compelling questions about the role of scientific information in decision making generally, and specifically how hazardous areas along rivers and streams are mapped, how land use is regulated in these zones, and how best to respond in emergency situations.
This presentation analyzes the evacuation planning process during the emergency management (making emphasis on the maps used by public officials), the recovery planning strategies that the local government adopted after the event, and the evolution of houses in flood hazard areas since the beginning of the 20th century, to highlight the importance of exposure as a key element to reduce risk.
Anna Serra-Llobet; John Radke; Mathias Kondolf; Sarah Lindbergh. Planning for floods after fires: Lessons from the 2018 Montecito Debris Flow (California). 2021, 1 .
AMA StyleAnna Serra-Llobet, John Radke, Mathias Kondolf, Sarah Lindbergh. Planning for floods after fires: Lessons from the 2018 Montecito Debris Flow (California). . 2021; ():1.
Chicago/Turabian StyleAnna Serra-Llobet; John Radke; Mathias Kondolf; Sarah Lindbergh. 2021. "Planning for floods after fires: Lessons from the 2018 Montecito Debris Flow (California)." , no. : 1.
Eco-tourism is a growing part of the tourism industry. However, there are no agreed-upon criteria of what constitutes eco-tourism, so the industry is currently self-identified, with eco-lodges simply declaring themselves so. Here we present the first systematic comparison of eco-tourism versus conventional (or mass) tourism, using as our study area a set of 37 resorts along the southern Red Sea coast of Egypt, all constructed on similarly oriented parcels between the sea and the Red Sea Mountain Range. We compared resorts based on their water, energy, and waste management (all virtually equivalent), and based on mappable environmental parameters such as swimming pool surface area, distance from mangrove patches, conflict with flood plains, extent of lawn area, and means of access to deep water. We found that the self-identified eco-tourism establishments were not significantly different from the conventional tourism resorts in terms of their stress on environmental resources. We recommend that future eco-tourism operations be modified in two key ways. First, on the planning level, by modifying the regional master plan created by the central government tourism authorities. Second, on the site design level, by introducing significant improvements to the design approval processes for the developments to ensure compliance with environmental requirements.
Amir Gohar; G. Kondolf. How Eco is Eco-Tourism? A Systematic Assessment of Resorts on the Red Sea, Egypt. Sustainability 2020, 12, 10139 .
AMA StyleAmir Gohar, G. Kondolf. How Eco is Eco-Tourism? A Systematic Assessment of Resorts on the Red Sea, Egypt. Sustainability. 2020; 12 (23):10139.
Chicago/Turabian StyleAmir Gohar; G. Kondolf. 2020. "How Eco is Eco-Tourism? A Systematic Assessment of Resorts on the Red Sea, Egypt." Sustainability 12, no. 23: 10139.
Throughout the humid tropics, increased land disturbance and concomitant road construction increases erosion and sediment delivery to rivers. Building road networks in developing countries is commonly a priority for international development funding based on anticipated socio-economic benefits. Yet the resulting erosion from roads, which recent studies have shown result in at least ten-fold increases in erosion rates, is not fully accounted for. While effects of road-derived sediment on aquatic ecosystems have been documented in temperate climates, little has been published on the effects of road-induced sediment on aquatic ecosystems in developing countries of the tropics. We studied periphyton biomass and macroinvertebrate communities on the deltas of Río San Juan tributaries, comparing north-bank tributaries draining undisturbed rain forest with south-bank tributaries receiving runoff from a partially-built road experiencing rapid erosion. Periphyton biomass, richness and abundance of macroinvertebrates overall, and richness and abundance of Ephemeroptera, Plecoptera and Trichoptera were higher on the north-bank tributary deltas than the south-bank tributary deltas. These findings were consistent with prior studies in temperate climates showing detrimental effects of road-derived fine sediment on aquatic organisms. A Non-Metric Multidimensional Scaling (NMDS) analysis showed the impacted community on the south-bank deltas was influenced by poorly-sorted substrate with greater proportions of fine sediment and higher water temperatures.
Blanca Ríos Touma; G. Mathias Kondolf; Scott Walls. Impacts of sediment derived from erosion of partially-constructed road on aquatic organisms in a tropical river: The Río San Juan, Nicaragua and Costa Rica. PLOS ONE 2020, 15, e0242356 .
AMA StyleBlanca Ríos Touma, G. Mathias Kondolf, Scott Walls. Impacts of sediment derived from erosion of partially-constructed road on aquatic organisms in a tropical river: The Río San Juan, Nicaragua and Costa Rica. PLOS ONE. 2020; 15 (11):e0242356.
Chicago/Turabian StyleBlanca Ríos Touma; G. Mathias Kondolf; Scott Walls. 2020. "Impacts of sediment derived from erosion of partially-constructed road on aquatic organisms in a tropical river: The Río San Juan, Nicaragua and Costa Rica." PLOS ONE 15, no. 11: e0242356.
Urban riverfront interventions are ubiquitous throughout the developed world, and increasingly also in the Global South. Many have failed spectacularly. We conducted a systematic review of failed riverfront interventions to draw lessons that could improve future projects. Learning from past mistakes may be more important than observing successes, because successful elements in one city may not be repeatable elsewhere, as the context and opportunity could be specific to that one city. Recognizing what did not work elsewhere may provide clues needed to improve future projects. Our results show that poorly designed riverfront interventions typically fail on several levels: a bad program, with the wrong budget and timing, no concern for local needs or context, results in an unattractive and costly intervention, with reduced to no social or environmental benefit. To create more successful interventions in the future, we should acknowledge the local context, the morphology of the river valley, the time and budget a set of solutions entail, and select uses and functions that work for a diverse crowd and provide multiple benefits, including good flood management performance and the restoration of the rivers’ natural connectivity.
Pedro Janela Pinto; G. Mathias Kondolf. The Fit of Urban Waterfront Interventions: Matters of Size, Money and Function. Sustainability 2020, 12, 4079 .
AMA StylePedro Janela Pinto, G. Mathias Kondolf. The Fit of Urban Waterfront Interventions: Matters of Size, Money and Function. Sustainability. 2020; 12 (10):4079.
Chicago/Turabian StylePedro Janela Pinto; G. Mathias Kondolf. 2020. "The Fit of Urban Waterfront Interventions: Matters of Size, Money and Function." Sustainability 12, no. 10: 4079.
Anthropogenic impacts in large rivers are widely studied, but studies of recovery once a disturbance has stopped are uncommon. This study examines the biogeomorphic recovery of a 40‐km river corridor on the mid‐Apalachicola River, Florida following the cessation of dredging, disposal and snag removal in 2002. This failed navigation project resulted in vegetation losses (~166 ha between 1941 and 2004), river widening and increased point bar areas. We used paired sets of imagery for a ten‐year period during the recovery process at two different flow levels to assess sand bar change, land cover change, and their spatial variations. Most large sand bars significantly decreased in area due to growth of pioneer species, typically from the bankside of the bar. Mean bar area shrank 0.17 ha and 0.20 ha for the 30th and 1st percentile flows, respectively. For the entire study area, both water level comparisons showed gains in vegetation (23.36 ha, 15.83 ha), compensated by losses in the extent of water (16.83 ha, 8.55 ha) and sand bar losses (6.53 ha, 7.28 ha). Overall, these gains during the 10‐year passive recovery period are equivalent to ~15% of the vegetation losses that resulted from the navigational dredging. As found in other studies, most of the pioneer vegetation grew approximately 2 m relative elevation above the low water surface. The initial length of the tree line and the area of herbaceous growth both had a significant and positive relationship with the area of new vegetation growth over the study interval. As parts of the river are healing, reduced channel capacity from narrowing and tree growth will benefit the floodplain. As elsewhere, understanding of a river's biogeomorphology, hydrology, and disturbance history can help in selecting appropriate recovery metrics to further advance the understanding and management of disturbed floodplains.
Joann Mossa; Yin‐Hsuen Chen; G. Mathias Kondolf; Scott Porter Walls. Channel and vegetation recovery from dredging of a large river in the Gulf coastal plain, USA. Earth Surface Processes and Landforms 2020, 45, 1926 -1944.
AMA StyleJoann Mossa, Yin‐Hsuen Chen, G. Mathias Kondolf, Scott Porter Walls. Channel and vegetation recovery from dredging of a large river in the Gulf coastal plain, USA. Earth Surface Processes and Landforms. 2020; 45 (9):1926-1944.
Chicago/Turabian StyleJoann Mossa; Yin‐Hsuen Chen; G. Mathias Kondolf; Scott Porter Walls. 2020. "Channel and vegetation recovery from dredging of a large river in the Gulf coastal plain, USA." Earth Surface Processes and Landforms 45, no. 9: 1926-1944.
Cairo is a congested city with high rate of urbanization and very limited public space. Cairo has one of the lowest rates of parkland per capita of any major city. Moreover, the banks of the Nile, formerly alive with activities such as washing, fishing, and felucca landings, were by the end of the twentieth century largely cutoff from free public access by a wall of busy roads, private clubs, luxury hotels, restaurants, nurseries, and police/military stations, roads. The need for open space for people from lower income who could not afford the expensive options along the Nile banks, has resulted in use of the sidewalks of the main bridges as public spaces. Families, couples, and friends tolerate the noise and fumes of traffic to enjoy the expansive views and breezes over the Nile. As a result of this extraordinary re-purposing of the bridges, new small businesses have formed to cater to the uses, and a new interaction with the river has emerged. We studied the patterns of use, characteristics of the user population, and stated preferences of users. We identify a set of characteristics contributing to the popularity of the bridges as public space, including affordability, accessibility, openness to the river and visual connection with the other bank. We propose that these characteristics be taken into account when developing future projects along the river water front to address the need for public space and access to the Nile.
Amir Gohar; G. Mathias Kondolf. Bridges Over the Nile. Transportation Corridors Transformed into Public Spaces. The Journal of Public Space 2020, 5, 5 -20.
AMA StyleAmir Gohar, G. Mathias Kondolf. Bridges Over the Nile. Transportation Corridors Transformed into Public Spaces. The Journal of Public Space. 2020; 5 (1):5-20.
Chicago/Turabian StyleAmir Gohar; G. Mathias Kondolf. 2020. "Bridges Over the Nile. Transportation Corridors Transformed into Public Spaces." The Journal of Public Space 5, no. 1: 5-20.
In many countries of the Global South, aquatic ecosystems such as streams, rivers, lakes, and wetlands are severely impacted by several simultaneous environmental stressors, associated with accelerated urban development, and extreme climate. However, this problem receives little attention. Applying a DPSIR approach (Drivers, Pressures, State, Impacts, Responses), we analyzed the environmental impacts and their effects on urban hydrosystems (including stagnant waters), and suggest possible solutions from a series of case studies worldwide. We find that rivers in the Global South, with their distinctive geographical and socio-political setting, display significant differences from the Urban Stream Syndrome described so far in temperate zones. We introduce the term of ‘Southern Urban Hydrosystem Syndrome’ for the biophysical problems as well as the social interactions, including the perception of water bodies by the urbanites, the interactions of actors (e.g., top-down, bottom-up), and the motivations that drive urban hydrosystem restoration projects of the Global South. Supported by a synthesis of case studies (with a focus on Brazilian restoration projects), this paper summarizes the state of the art, highlights the currently existing lacunae for research, and delivers examples of practical solutions that may inform UNESCO’s North–South–South dialogue to solve these urgent problems. Two elements appear to be specifically important for the success of restoration projects in the Global South, namely the broad acceptance and commitment of local populations beyond merely ‘ecological’ justifications, e.g., healthy living environments and ecosystems with cultural linkages (‘River Culture’). To make it possible implementable/practical solutions must be extended to (often poor) people having settled along river banks and wetlands.
Karl Wantzen; Carlos Alves; Sidia Badiane; Raita Bala; Martín Blettler; Marcos Callisto; Yixin Cao; Melanie Kolb; G. Kondolf; Marina Leite; Diego Macedo; Obaidullah Mahdi; Moana Neves; M. Peralta; Vincent Rotgé; Guillermo Rueda-Delgado; Andres Scharager; Anna Serra-Llobet; Jean-Louis Yengué; Aude Zingraff-Hamed. Urban Stream and Wetland Restoration in the Global South—A DPSIR Analysis. Sustainability 2019, 11, 4975 .
AMA StyleKarl Wantzen, Carlos Alves, Sidia Badiane, Raita Bala, Martín Blettler, Marcos Callisto, Yixin Cao, Melanie Kolb, G. Kondolf, Marina Leite, Diego Macedo, Obaidullah Mahdi, Moana Neves, M. Peralta, Vincent Rotgé, Guillermo Rueda-Delgado, Andres Scharager, Anna Serra-Llobet, Jean-Louis Yengué, Aude Zingraff-Hamed. Urban Stream and Wetland Restoration in the Global South—A DPSIR Analysis. Sustainability. 2019; 11 (18):4975.
Chicago/Turabian StyleKarl Wantzen; Carlos Alves; Sidia Badiane; Raita Bala; Martín Blettler; Marcos Callisto; Yixin Cao; Melanie Kolb; G. Kondolf; Marina Leite; Diego Macedo; Obaidullah Mahdi; Moana Neves; M. Peralta; Vincent Rotgé; Guillermo Rueda-Delgado; Andres Scharager; Anna Serra-Llobet; Jean-Louis Yengué; Aude Zingraff-Hamed. 2019. "Urban Stream and Wetland Restoration in the Global South—A DPSIR Analysis." Sustainability 11, no. 18: 4975.
River management based solely on physical science has proven to be unsustainable and unsuccessful, evidenced by the fact that the problems this approach intended to solve (e.g., flood hazards, water scarcity, and channel instability) have not been solved and long‐term deterioration in river environments has reduced the capacity of rivers to continue meeting the needs of society. In response, there has been a paradigm shift in management over the past few decades, towards river restoration. But the ecological, morphological, and societal benefits of river restoration have, on the whole, been disappointing. We believe that this stems from the fact that restoration overrelies on the same physical analyses and approaches, with flowing water still regarded as the universally predominant driver of channel form and structural intervention seen as essential to influencing fluvial processes. We argue that if river restoration is to reverse long‐standing declines in river functions, it is necessary to recognize the influence of biology on river forms and processes and re‐envisage what it means to restore a river. This entails shifting the focus of river restoration from designing and constructing stable channels that mimic natural forms to reconnecting streams within balanced and healthy biomes, and so levering the power of biology to influence river processes. We define this new approach as biomic river restoration.
Matthew F. Johnson; Colin R. Thorne; Janine M. Castro; G. Mathias Kondolf; Celeste Searles Mazzacano; Stewart B. Rood; Cherie Westbrook. Biomic river restoration: A new focus for river management. River Research and Applications 2019, 36, 3 -12.
AMA StyleMatthew F. Johnson, Colin R. Thorne, Janine M. Castro, G. Mathias Kondolf, Celeste Searles Mazzacano, Stewart B. Rood, Cherie Westbrook. Biomic river restoration: A new focus for river management. River Research and Applications. 2019; 36 (1):3-12.
Chicago/Turabian StyleMatthew F. Johnson; Colin R. Thorne; Janine M. Castro; G. Mathias Kondolf; Celeste Searles Mazzacano; Stewart B. Rood; Cherie Westbrook. 2019. "Biomic river restoration: A new focus for river management." River Research and Applications 36, no. 1: 3-12.
Rivers flow across national borders, unfettered by political distinctions, and the ecological health of rivers is closely linked to their degree of connectivity. River research today is more global than it has ever been, but we show that river research, engineering, and management still operate within homegrown local paradigms. As a basis for this discussion, we studied the citation networks surrounding the most widely cited papers in our field, assessing the degree to which researchers have collaborated across geographical boundaries and fully drawn from the international literature. Despite gains over time, our field remains surprisingly and pervasively provincial. The likely explanation for provincial bias is that researchers are generally more familiar and comfortable with their own research methods, sites, and agendas. However, local focus has tangible consequences. For example, contrasting paradigms and differing approaches to river restoration and to flood‐risk management show that opportunities are lost when we fail to learn from the successes and failures of other regions. As we look to the future, increased engagement across political and intellectual and physical borders should propel the field of river science into new and exciting directions.
Nicholas Pinter; James Brasington; Angela Gurnell; G. Mathias Kondolf; Klement Tockner; Geraldene Wharton; Sarah M. Yarnell. River research and applications across borders. River Research and Applications 2019, 1 .
AMA StyleNicholas Pinter, James Brasington, Angela Gurnell, G. Mathias Kondolf, Klement Tockner, Geraldene Wharton, Sarah M. Yarnell. River research and applications across borders. River Research and Applications. 2019; ():1.
Chicago/Turabian StyleNicholas Pinter; James Brasington; Angela Gurnell; G. Mathias Kondolf; Klement Tockner; Geraldene Wharton; Sarah M. Yarnell. 2019. "River research and applications across borders." River Research and Applications , no. : 1.
The Tonle Sap is the most fertile and diverse freshwater ecosystem in Southeast Asia, receiving nurturing water flows from the Mekong and its immediate basin. In addition to rapid development in the Tonle Sap basin, climate change may threaten natural flow patterns that sustain its diversity. The impacts of climate change on river flows in 11 sub-basins contributing to the Tonle Sap Lake were assessed using the Soil and Water Assessment Tool (SWAT) model to quantify the potential magnitude of future hydrological alterations. Projected river flows from three General Circulation Models (GFDL-CM3, GISS-E2-R-CC and IPSL-CM5A-MR) for three time horizons (2030s, 2060s and 2090s) indicate a likely decrease in both the wet and dry season flows. The mean annual projected flow reductions range from 9 to 29%, 10 to 35% and 7 to 41% for the 2030s, 2060s and 2090s projections, respectively. Moreover, a decrease in extreme river flows (Q5 and Q95) was also found, which implies there could be a decline in flood magnitudes and an increase in drought occurrences throughout the basin. The results of this study provide insight for water resources planning and adaptation strategies for the river ecosystems during the dry season, when water flows are projected to decrease.
Chantha Oeurng; Thomas A. Cochrane; Sarit Chung; Mathias G. Kondolf; Thanapon Piman; Mauricio E. Arias. Assessing Climate Change Impacts on River Flows in the Tonle Sap Lake Basin, Cambodia. Water 2019, 11, 618 .
AMA StyleChantha Oeurng, Thomas A. Cochrane, Sarit Chung, Mathias G. Kondolf, Thanapon Piman, Mauricio E. Arias. Assessing Climate Change Impacts on River Flows in the Tonle Sap Lake Basin, Cambodia. Water. 2019; 11 (3):618.
Chicago/Turabian StyleChantha Oeurng; Thomas A. Cochrane; Sarit Chung; Mathias G. Kondolf; Thanapon Piman; Mauricio E. Arias. 2019. "Assessing Climate Change Impacts on River Flows in the Tonle Sap Lake Basin, Cambodia." Water 11, no. 3: 618.
The practice of enhancing existing rivers and creating entirely new waterscapes has exploded in China over the past two decades. In our study of 104 randomly selected cities across China, we identified 14 types of river projects based on grey literature reports and their appearance on sequential aerial imagery, falling into three categories: ‘engineering’, ‘waterfront spaces’ and ‘ecological’ projects. ‘Waterfront spaces’ is the most common (60.5%), followed by ‘engineering’ (28.7%) and ‘ecological’ (10.8%). Using multiple stepwise regression, we found that the types of projects undertaken were strongly influenced by factors such as climate, social-economic setting, and ‘Landscape Garden City’ designation. Designation as a ‘Landscape Garden City’ was correlated with ‘waterfront spaces’, but not ‘engineering’ and ‘ecological’ projects. We found that cities in drier climates (as measured by ‘precipitation minus evaporation’) constructed more projects and they included many projects that impounded seasonal rivers to create year-round water bodies. Based on our results, we conclude that Chinese cities are still in the process of ‘decorating’ rivers, and that the ‘Landscape Garden City’ designation promoted such ‘decorating’ projects, especially ‘linear greening’ projects and ‘public spaces along rivers’. The results also demonstrate that the new river projects in China are often at odds with the local climate.
Shuhan Shi; G. Mathias Kondolf; Dihua Li. Urban River Transformation and the Landscape Garden City Movement in China. Sustainability 2018, 10, 4103 .
AMA StyleShuhan Shi, G. Mathias Kondolf, Dihua Li. Urban River Transformation and the Landscape Garden City Movement in China. Sustainability. 2018; 10 (11):4103.
Chicago/Turabian StyleShuhan Shi; G. Mathias Kondolf; Dihua Li. 2018. "Urban River Transformation and the Landscape Garden City Movement in China." Sustainability 10, no. 11: 4103.
Reservoirs play a critically important role in supplying water for human uses. However, sedimentation limits storage capabilities and increases risk for aging infrastructure. The objectives of this paper are to synthesize both general sediment management strategies and past sediment management efforts in Taiwan in order to identify the barriers to more effective sediment management in reservoirs globally. A review of the broader literature and six Taiwan case studies was conducted to examine the characteristics, limitations, costs, and effectiveness of different sediment management strategies. Results highlight how social barriers play an important role in limiting reservoir sustainability, particularly the crisis-response approach to addressing sedimentation and the low priority for sediment management relative to competing objectives, such as tourism. Technical barriers are driven primarily by the engineering and costs of retrofitting existing dams and site conditions that may inhibit particular practices at any given site. Results also highlight tradeoffs in the effectiveness, costs, and time efficiency of various sediment management strategies in restoring storage capacity. The high sediment loads and rapid filling of reservoirs in Taiwan provide early insight into the management issues that are emerging worldwide, and these results emphasize the need for proactive engineering and management of sediment in reservoirs globally.
Hsiao-Wen Wang; Mathias Kondolf; Desiree Tullos; Wei-Cheng Kuo. Sediment Management in Taiwan’s Reservoirs and Barriers to Implementation. Water 2018, 10, 1034 .
AMA StyleHsiao-Wen Wang, Mathias Kondolf, Desiree Tullos, Wei-Cheng Kuo. Sediment Management in Taiwan’s Reservoirs and Barriers to Implementation. Water. 2018; 10 (8):1034.
Chicago/Turabian StyleHsiao-Wen Wang; Mathias Kondolf; Desiree Tullos; Wei-Cheng Kuo. 2018. "Sediment Management in Taiwan’s Reservoirs and Barriers to Implementation." Water 10, no. 8: 1034.
Two decades after the construction of the first major dam, the Mekong basin and its six riparian countries have seen rapid economic growth and development of the river system. Hydropower dams, aggregate mines, flood-control dykes, and groundwater-irrigated agriculture have all provided short-term economic benefits throughout the basin. However, it is becoming evident that anthropic changes are significantly affecting the natural functioning of the river and its floodplains. We now ask if these changes are risking major adverse impacts for the 70 million people living in the Mekong Basin. Many livelihoods in the basin depend on ecosystem services that will be strongly impacted by alterations of the sediment transport processes that drive river and delta morpho-dynamics, which underpin a sustainable future for the Mekong basin and Delta. Drawing upon ongoing and recently published research, we provide an overview of key drivers of change (hydropower development, sand mining, dyking and water infrastructures, climate change, and accelerated subsidence from pumping) for the Mekong's sediment budget, and their likely individual and cumulative impacts on the river system. Our results quantify the degree to which the Mekong delta, which receives the impacts from the entire connected river basin, is increasingly vulnerable in the face of declining sediment loads, rising seas and subsiding land. Without concerted action, it is likely that nearly half of the Delta's land surface will be below sea level by 2100, with the remaining areas impacted by salinization and frequent flooding. The threat to the Delta can be understood only in the context of processes in the entire river basin. The Mekong River case can serve to raise awareness of how the connected functions of river systems in general depend on undisturbed sediment transport, thereby informing planning for other large river basins currently embarking on rapid economic development.
G. Mathias Kondolf; Rafael J.P. Schmitt; Paul Carling; Stephen Darby; Mauricio E. Arias; Simone Bizzi; Andrea Castelletti; Thomas A. Cochrane; Stanford Gibson; Matti Kummu; Chantha Oeurng; Zan Rubin; Thomas Wild. Changing sediment budget of the Mekong: Cumulative threats and management strategies for a large river basin. Science of The Total Environment 2018, 625, 114 -134.
AMA StyleG. Mathias Kondolf, Rafael J.P. Schmitt, Paul Carling, Stephen Darby, Mauricio E. Arias, Simone Bizzi, Andrea Castelletti, Thomas A. Cochrane, Stanford Gibson, Matti Kummu, Chantha Oeurng, Zan Rubin, Thomas Wild. Changing sediment budget of the Mekong: Cumulative threats and management strategies for a large river basin. Science of The Total Environment. 2018; 625 ():114-134.
Chicago/Turabian StyleG. Mathias Kondolf; Rafael J.P. Schmitt; Paul Carling; Stephen Darby; Mauricio E. Arias; Simone Bizzi; Andrea Castelletti; Thomas A. Cochrane; Stanford Gibson; Matti Kummu; Chantha Oeurng; Zan Rubin; Thomas Wild. 2018. "Changing sediment budget of the Mekong: Cumulative threats and management strategies for a large river basin." Science of The Total Environment 625, no. : 114-134.
The Mississippi River was the first theater in which the federal government sought to control floods and improve navigation through the efforts of the US Army Corps of Engineers, initially under a “levees only” philosophy, later revised (after the disastrous 1927 flood) to include multiple approaches, such as backwater areas and flood bypasses. The Mississippi River and Tributaries Project successfully conveyed the 2011 flood (with more rainfall than fell in 1927), but operation of critical bypasses was threatened by encroachment of buildings within the bypasses, permitted by local governments. Structures designed to concentrate flow for the benefit of navigation can result in higher flood stages and thus can undermine flood control efforts. Allowing floodplains to flood naturally, as much as possible, can have benefits not only for the ecosystem but also for managing floods to minimize inundation of cities.
Charles E. Shadie; Pilar Lopez-Llompart; Melissa Samet; Todd Strole; G. Mathias Kondolf. Managing Floods in Large River Basins in the USA: The Mississippi River. Managing Flood Risk 2018, 11 -41.
AMA StyleCharles E. Shadie, Pilar Lopez-Llompart, Melissa Samet, Todd Strole, G. Mathias Kondolf. Managing Floods in Large River Basins in the USA: The Mississippi River. Managing Flood Risk. 2018; ():11-41.
Chicago/Turabian StyleCharles E. Shadie; Pilar Lopez-Llompart; Melissa Samet; Todd Strole; G. Mathias Kondolf. 2018. "Managing Floods in Large River Basins in the USA: The Mississippi River." Managing Flood Risk , no. : 11-41.
Sedimentation is a major issue for water systems worldwide, but the need for sustainable sediment management is rarely addressed. This article surveys the problem of sedimentation in the contemporary sphere in addition to drawing on archaeological evidence of past unsustainable and sustainable sedimentation management practices. A compact characterization scheme is presented for identifying the scale of sedimentation management, both past and present. The results of the research illustrate that communities have grappled with issues of sedimentation for as long as water storage has existed. System failure from sedimentation is therefore not inevitable, but arises from a combination of social and biophysical factors.
G. Mathias Kondolf; Alan Farahani. Sustainably Managing Reservoir Storage: Ancient Roots of a Modern Challenge. Water 2018, 10, 117 .
AMA StyleG. Mathias Kondolf, Alan Farahani. Sustainably Managing Reservoir Storage: Ancient Roots of a Modern Challenge. Water. 2018; 10 (2):117.
Chicago/Turabian StyleG. Mathias Kondolf; Alan Farahani. 2018. "Sustainably Managing Reservoir Storage: Ancient Roots of a Modern Challenge." Water 10, no. 2: 117.
R. J. P. Schmitt; S. Bizzi; A. F. Castelletti; G. M. Kondolf. Stochastic Modeling of Sediment Connectivity for Reconstructing Sand Fluxes and Origins in the Unmonitored Se Kong, Se San, and Sre Pok Tributaries of the Mekong River. Journal of Geophysical Research: Earth Surface 2018, 123, 2 -25.
AMA StyleR. J. P. Schmitt, S. Bizzi, A. F. Castelletti, G. M. Kondolf. Stochastic Modeling of Sediment Connectivity for Reconstructing Sand Fluxes and Origins in the Unmonitored Se Kong, Se San, and Sre Pok Tributaries of the Mekong River. Journal of Geophysical Research: Earth Surface. 2018; 123 (1):2-25.
Chicago/Turabian StyleR. J. P. Schmitt; S. Bizzi; A. F. Castelletti; G. M. Kondolf. 2018. "Stochastic Modeling of Sediment Connectivity for Reconstructing Sand Fluxes and Origins in the Unmonitored Se Kong, Se San, and Sre Pok Tributaries of the Mekong River." Journal of Geophysical Research: Earth Surface 123, no. 1: 2-25.