Bernhard Lehner's research while affiliated with McGill University and other places

Publications (106)

Article
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Here we introduce the LakeATLAS dataset, which provides a broad range of hydro-environmental characteristics for more than 1.4 million lakes and reservoirs globally with an area of at least 10 ha. LakeATLAS forms part of the larger HydroATLAS data repository and expands the existing datasets of sub-basin and river reach descriptors by adding equiva...
Article
Rivers are the arteries of the planet, providing vital resources as they flow and pulse across landscapes in a vast global network. Rivers and streams convey sediments and nutrients to fertile valleys and river deltas, create habitat corridors and transportation routes, and deliver life-sustaining fresh water to aquatic and riparian ecosystems and...
Article
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The main objective of wastewater treatment plants (WWTPs) is to remove pathogens, nutrients, organics, and other pollutants from wastewater. After these contaminants are partially or fully removed through physical, biological, and/or chemical processes, the treated effluents are discharged into receiving waterbodies. However, since WWTPs cannot rem...
Conference Paper
The increased availability and accuracy of recent remote sensing data accelerates the development of data products for hydrological modelling. Most hydrological models rely on the accurate representation of the Earth’s terrestrial surface including all waterways from small mountain streams to great lowland rivers in order to compute discharge. In l...
Article
The fragmentation of free-flowing rivers (FFRs) through major infrastructure development remains a pivotal threat to global freshwater biodiversity. More than 3400 large hydropower dams (>1 MW) are either planned or under construction, posing threats to freshwater megafauna (i.e., freshwater animals that can reach 30 kg). Here, we investigate the g...
Article
Global wetlands and floodplains offer benefits and perils alike for human society. For example, humans rely on natural flood cycles for fisheries and agriculture, yet flooding also caused nearly one trillion USD in damage in the past 30 years and impacts millions of people every year. Looking forward, altered flow regimes or increased drought condi...
Article
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Dams, reservoirs, and other water management infrastructure provide benefits, but can also have negative impacts. Dam construction and removal affects progress toward the UN sustainable development goals at local to global scales. Yet, globally-consistent information on the location and characteristics of these structures are lacking, with informat...
Article
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Despite their importance for biodiversity and ecosystem services, wetlands are among the most threatened ecosystems globally. The conservation of many migratory waterbirds depends on the conservation of a network of key sites along their flyways. However, the suitability of these sites is changing under climate change, and it is important that mana...
Preprint
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The main objective of wastewater treatment plants (WWTPs) is to remove contaminants such as pathogens, nutrients, and organic and other pollutants from wastewaters using physical, biological and/or chemical processes prior to discharge into receiving waterbodies. However, since WWTPs cannot remove all contaminants, they inevitably represent concent...
Technical Report
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The report provides a global analysis of the current exposure of people and croplands to floods, the changing nature of floods towards the end of the 21st century, as well as current flood risk.
Technical Report
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The report highlights how nature-based solutions for flood risk management can be employed as multi-purpose solutions to mitigate the current and predicted future impacts of flooding.
Article
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Flowing waters have a unique role in supporting global biodiversity, biogeochemical cycles and human societies1–5. Although the importance of permanent watercourses is well recognized, the prevalence, value and fate of non-perennial rivers and streams that periodically cease to flow tend to be overlooked, if not ignored6–8. This oversight contribut...
Article
• This study aimed to develop an integrated analytical framework to identify candidate sites for surface water protection that is applicable at broad scales and in data scarce regions, using Zambia as a case study. • In the Zambian Water Resources Management Act of 2011, Water Resource Protection Areas are defined as areas where special measures ar...
Article
• Although the network of national parks in Zambia offers a degree of protection for freshwater diversity, the protection status of numerous systems outside of these parks requires further action. The biodiversity associated with its freshwater systems, both lotic and lentic, is unique, covering a climatic gradient from tropical to subtropical acro...
Article
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Climate change presents a particularly complex challenge in the context of flyway scale conservation of migratory bird species as it requires coordinated action by multiple countries along these species’ migratory routes. Coordinating conservation responses requires understanding the vulnerability of species and their habitats to climate change at...
Article
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Effectively conserving ecosystem services in order to maintain human wellbeing is a global need that requires an understanding of where ecosystem services are produced by ecosystems and where people benefit from these services. However, approaches to effectively identify key locations that have the capacity to supply ecosystem services and actually...
Article
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Non-technical summary There has been a long history of conflicts, studies, and debate over how to both protect rivers and develop them sustainably. With a pause in new developments caused by the global pandemic, anticipated further implementation of the Paris Agreement and high-level global climate and biodiversity meetings in 2021, now is an oppor...
Article
An atlas of European river barriers has been made, by curating and correcting existing records, and by surveying 2,700 kilometres of waterways. It reveals that rivers are fragmented by an amazing number of obstructions. At atlas of European river barriers.
Article
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Protected areas (PAs) are an essential tool for freshwater biodiversity conservation. Given past and expected future global increases in dams and impacts of dams on freshwater ecosystems, we document the number of dams existing or planned within PAs, their history, and the extent of PA downgrading, downsizing, and degazettement (PADDD) proximally c...
Article
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Fresh water—the bloodstream of the biosphere—is at the center of the planetary drama of the Anthropocene. Water fluxes and stores regulate the Earth's climate and are essential for thriving aquatic and terrestrial ecosystems, as well as water, food, and energy security. But the water cycle is also being modified by humans at an unprecedented scale...
Article
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The planetary boundaries framework proposes quantified guardrails to human modification of global environmental processes that regulate the stability of the planet and has been considered in sustainability science, governance, and corporate management. However, the planetary boundary for human freshwater use has been critiqued as a singular measure...
Article
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The HydroATLAS database provides a standardized compendium of descriptive hydro-environmental information for all watersheds and rivers of the world at high spatial resolution. Version 1.0 of HydroATLAS offers data for 56 variables, partitioned into 281 individual attributes and organized in six categories: hydrology; physiography; climate; land co...
Article
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Natural lakes and reservoirs are important yet not well‐constrained sources of greenhouse gasses to the atmosphere. In particular for N2O emissions, a huge variability is observed in the few, observation‐driven flux estimates that have been published so far. Recently, a process‐based, spatially explicit model has been used to estimate global N2O em...
Article
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It is well recognized that there are currently limitations in the spatial and temporal resolution of environmental exposure models due to significant variabilities and uncertainties in model inputs and parameters. Here we present the updated Pangea multi-scale multimedia model based on the more spatially resolved, catchment-based hydrological Hydro...
Article
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Inland waters, including streams and rivers, are active components of the global carbon cycle. Despite the large areal extent of the world’s mountains, the role of mountain streams for global carbon fluxes remains elusive. Using recent insights from gas exchange in turbulent streams, we found that areal CO2 evasion fluxes from mountain streams equa...
Preprint
The planetary boundaries framework has proven useful for many global sustainability contexts, but is challenging to apply to freshwater, which is spatially heterogeneous, part of complex socio-ecological systems and often dominated by local dynamics. To date, the planetary boundary for water has been simplistically defined by as the global rate of...
Article
Full-text available
An Amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Climate change is altering the hydrology of Canadian rivers to an unprecedented degree. Consequently, sustainable freshwater management practices need to adapt, which include the development of integrated water resource strategies and environmental flow recommendations. A particular challenge arises for these assessments due to the highly diverse n...
Article
• Water insecurity is a defining feature of the Anthropocene, with degraded water quality and unreliable flows putting the well‐being of upstream and downstream communities, both human and aquatic, at risk. Within this context, the protection of drinking water at its source – ‘source water protection’ – is growing as a complementary water security...
Article
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Free-flowing rivers (FFRs) support diverse, complex and dynamic ecosystems globally, providing important societal and economic services. Infrastructure development threatens the ecosystem processes, biodiversity and services that these rivers support. Here we assess the connectivity status of 12 million kilometres of rivers globally and identify th...
Preprint
The planetary boundaries framework has proven useful for many global sustainability contexts, but is challenging to apply to freshwater, which is spatially heterogeneous, part of complex socio-ecological systems and often dominated by local dynamics. To date, the planetary boundary for water has been simplistically defined by as the global rate of...
Article
Full-text available
Groundwater, the largest available store of global freshwater¹, is relied upon by more than two billion people². It is therefore important to quantify the spatiotemporal interactions between groundwater and climate. However, current understanding of the global-scale sensitivity of groundwater systems to climate change3,4—as well as the resulting va...
Article
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Projected climate and environmental change are expected to increase the pressure on global freshwater resources. To prepare for and cope with the related risks, stakeholders need to devise plans for sustainable management of river systems, which in turn requires the identification of management-appropriate operational units, such as groups of river...
Article
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Governments, development banks, corporations, and nonprofits are increasingly considering the potential contribution of watershed conservation activities to secure clean water for cities and to reduce flood risk. These organizations, however, often lack decision-relevant, initial screening information across multiple cities to identify which specif...
Article
Several new satellite-derived and long-term surface water datasets at high-spatial resolution have recently become available at the global scale, showing different characteristics and abilities. They are either based on visible imagery from Landsat-the Global 3-second Water Body Map (G3WBM) and the Global Surface Water Explorer (GSWE)-or on the mer...
Article
The contamination of freshwater systems arises in many river basins due to industrialization and population growth, posing risks to ecosystems and human health. Despite these concerns, the fate and potential impact of many emerging pollutants are currently unknown, especially when the compounds are released into surface waters from populations dist...
Article
To develop meaningful land use scenarios, drivers that affect changes in the landscape are required. In this study, driving factors that influence farmers to change crops on their farm were determined. A questionnaire was administered to four independent groups of farmers who identified and ranked influencing factors pertaining to their choices of...
Article
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The parameter uncertainty in the eco-hydrological model Soil and Water Assessment Tool (SWAT) was estimated using non-unique parameter sets for the Altmühl watershed (Bavaria, Germany). The Sequential Uncertainty Fitting Algorithm (SUFI-2) was used to calibrate SWAT. The non-unique parameter sets found were subsequently applied to SWAT concurrently...
Presentation
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Migratory waterbirds highly depend on a network of key wetlands across their flyways to complete their annual migration. These wetlands are not only threatened by changes in local climate but also by the long-distance hydrological effects of climate change. We use high resolution inundation models and Species Distribution Models (SDMs) to assess th...
Preprint
The parameter uncertainty in the eco-hydrological model Soil and Water Assessment Tool (SWAT) was estimated using non-unique parameter sets for the Altmühl watershed (Bavaria, Germany). The Sequential Uncertainty Fitting Algorithm (SUFI-2) was used to calibrate SWAT. The non-unique parameter sets found were subsequently applied to SWAT concurrently...
Article
Wetlands have been extensively modified by human activities worldwide. We provide a global-scale portrait of the threats and protection status of the world's inland wetlands by combining a global map of inundation extent derived from satellite images with data on threats from human influence and on protected areas. Currently, seasonal inland wetlan...
Presentation
The Global Inundation Extent from Multi-Satellites (GIEMS) provides multi-year monthly variations of the global surface water extent at 25kmx25km resolution. It is derived from multiple satellite observations. Its spatial resolution is usually compatible with climate model outputs and with global land surface model grids but is clearly not adequate...
Article
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A new procedure is introduced to downscale low-spatial-resolution inundation extents from Global Inundation Extent from Multi-Satellites (GIEMS) to a 3-arc-s (90 m) dataset (known as GIEMS-D3). The methodology is based on topography and hydrography information from the HydroSHEDS database. A new floodability index is introduced and an innovative sm...
Chapter
Lakes, ponds, and lacustrine environments are characterized by standing water in depressions of the landscape left by glacier scouring or impoundments along river networks. Depending on their origin and climatic conditions, lakes can be ancient (e.g., African rift lakes) or very young (e.g., recent landslides). The age of most of today’s lakes are...
Article
Full-text available
Lakes are key components of biogeochemical and ecological processes, thus knowledge about their distribution, volume and residence time is crucial in understanding their properties and interactions within the Earth system. However, global information is scarce and inconsistent across spatial scales and regions. Here we develop a geo-statistical mod...
Data
Supplementary Figures 1-6, Supplementary Tables 1-5, Supplementary Discussion and Supplementary References.
Article
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Protected areas are a cornerstone strategy for terrestrial and increasingly marine biodiversity conservation, but their use for conserving inland waters has received comparatively scant attention. In 2010, the Convention on Biological Diversity (CBD) included a target of 17% protection for inland waters, yet there has been no meaningful way of meas...
Article
Full-text available
The hydrological model SWAT was applied to the upper Altmühl watershed to examine the simulated 10th and 90th percentiles of streamflow, nitrate nitrogen (NO3⁻-N), and total phosphorus loads (TP), using an ensemble of reference climate (1975–2000) and future climate (2046–2070) simulations. A comparison between the two periods showed that in the fu...
Chapter
Lakes, ponds, and lacustrine environments are characterized by standing water in depressions of the landscape left by glacier scouring or impoundments along river networks. Depending on their origin and climatic conditions, lakes can be ancient (e.g., African rift lakes) or very young (e.g., recent landslides). The age of most of today’s lakes are...
Article
Full-text available
Chemicals released into freshwater systems threaten ecological functioning and may put aquatic life and the health of humans at risk. We developed a new contaminant fate model (CFM) that follows simple, well-established methodologies and is unique in its cross-border, seamless hydrological and geospatial framework, including lake routing, a critica...
Article
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Study region: Bavaria, Germany. Study focus: The Altmühl River is prone to nutrient inputs from agricultural activities. Quantifying nitrate nitrogen (NO3−-N) and total phosphorus (TP) concentrations due to potential future changes in the watershed is necessary for managing water quality and adhering to water policy directives. The Soil and Water A...
Article
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Modelling land surface water flow is of critical im-portance for simulating land surface fluxes, predicting runoff and water table dynamics and for many other applications of Land Surface Models. Many approaches are based on the popular hydrology model TOPMODEL (TOPography-based hydrological MODEL), and the most important parameter of this model is...
Article
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The global number of dam constructions has increased dramatically over the past six decades and is forecast to continue to rise, particularly in less industrialized regions. Identifying development path-ways that can deliver the benefits of new infrastructure while also maintaining healthy and productive river systems is a great challenge that requ...