| 1. |
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| 2. |
- Ehlers, Todd A., et al.
(author)
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Past, present, and future geo-biosphere interactions on the Tibetan Plateau and implications for permafrost
- 2022
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In: Earth-Science Reviews. - : Elsevier BV. - 0012-8252. ; 234
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Journal article (peer-reviewed)abstract
- Interactions between the atmosphere, biosphere, cryosphere, hydrosphere, and geosphere are most active in the critical zone, a region extending from the tops of trees to the top of unweathered bedrock. Changes in one or more of these spheres can result in a cascade of changes throughout the system in ways that are often poorly understood. Here we investigate how past and present climate change have impacted permafrost, hydrology, and ecosystems on the Tibetan Plateau. We do this by compiling existing climate, hydrologic, cryosphere, biosphere, and geologic studies documenting change over decadal to glacial-interglacial timescales and longer. Our emphasis is on showing present-day trends in environmental change and how plateau ecosystems have largely flourished under warmer and wetter periods in the geologic past. We identify two future pathways that could lead to either a favorable greening or unfavorable degradation and desiccation of plateau ecosystems. Both paths are plausible given the available evidence. We contend that the key to which pathway future generations experience lies in what, if any, human intervention measures are implemented. We conclude with suggested management strategies that can be implemented to facilitate a future greening of the Tibetan Plateau.
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| 3. |
- Wartenburger, Richard, et al.
(author)
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Evapotranspiration simulations in ISIMIP2a-Evaluation of spatio-temporal characteristics with a comprehensive ensemble of independent datasets
- 2018
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In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 13:7
-
Journal article (peer-reviewed)abstract
- Actual land evapotranspiration (ET) is a key component of the global hydrological cycle and an essential variable determining the evolution of hydrological extreme events under different climate change scenarios. However, recently available ET products show persistent uncertainties that are impeding a precise attribution of human-induced climate change. Here, we aim at comparing a range of independent global monthly land ET estimates with historical model simulations from the global water, agriculture, and biomes sectors participating in the second phase of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2a). Among the independent estimates, we use the EartH2Observe Tier-1 dataset (E2O), two commonly used reanalyses, a pre-compiled ensemble product (LandFlux-EVAL), and an updated collection of recently published datasets that algorithmically derive ET from observations or observations-based estimates (diagnostic datasets). A cluster analysis is applied in order to identify spatio-temporal differences among all datasets and to thus identify factors that dominate overall uncertainties. The clustering is controlled by several factors including the model choice, the meteorological forcing used to drive the assessed models, the data category (models participating in the different sectors of ISIMIP2a, E2O models, diagnostic estimates, reanalysis-based estimates or composite products), the ET scheme, and the number of soil layers in the models. By using these factors to explain spatial and spatio-temporal variabilities in ET, we find that the model choice mostly dominates (24%-40% of variance explained), except for spatio-temporal patterns of total ET, where the forcing explains the largest fraction of the variance (29%). The most dominant clusters of datasets are further compared with individual diagnostic and reanalysis-based estimates to assess their representation of selected heat waves and droughts in the Great Plains, Central Europe and western Russia. Although most of the ET estimates capture these extreme events, the generally large spread among the entire ensemble indicates substantial uncertainties.
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| 4. |
- Arheimer, Berit, et al.
(author)
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The IAHS Science for Solutions decade, with Hydrology Engaging Local People IN a Global world (HELPING)
- 2024
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In: Hydrological Sciences Journal. - 0262-6667 .- 2150-3435.
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Journal article (peer-reviewed)abstract
- The new scientific decade (2023-2032) of the International Association of Hydrological Sciences (IAHS) aims at searching for sustainable solutions to undesired water conditions - may it be too little, too much or too polluted. Many of the current issues originate from global change, while solutions to problems must embrace local understanding and context. The decade will explore the current water crises by searching for actionable knowledge within three themes: global and local interactions, sustainable solutions and innovative cross-cutting methods. We capitalise on previous IAHS Scientific Decades shaping a trilogy; from Hydrological Predictions (PUB) to Change and Interdisciplinarity (Panta Rhei) to Solutions (HELPING). The vision is to solve fundamental water-related environmental and societal problems by engaging with other disciplines and local stakeholders. The decade endorses mutual learning and co-creation to progress towards UN sustainable development goals. Hence, HELPING is a vehicle for putting science in action, driven by scientists working on local hydrology in coordination with local, regional, and global processes.
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| 5. |
- Blösch, Günter, et al.
(author)
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Twenty-three unsolved problems in hydrology (UPH) - a community perspective
- 2019
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In: Hydrological Sciences Journal. - : Informa UK Limited. - 0262-6667 .- 2150-3435. ; 64:10, s. 1141-1158
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Journal article (peer-reviewed)abstract
- This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through online media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focused on the process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come.
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| 6. |
- Campana, Pietro Elia, et al.
(author)
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Optimal grassland locations for sustainable photovoltaic water pumping systems in China
- 2015
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In: CLEAN, EFFICIENT AND AFFORDABLE ENERGY FOR A SUSTAINABLE FUTURE. - : Elsevier. ; 75, s. 301-307
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Conference paper (peer-reviewed)abstract
- Grassland is of strategic importance for food security of China because of the high number of livestock raised in those areas. Grassland degradation due to climate change and overgrazing is thus regarded as severe environmental and economic threat for a sustainable future development of China. Photovoltaic water pumping (PVWP) systems for irrigation can play an important role for the conservation of grassland areas, halting degradation, improving its productivity and farmers' income and living conditions. The aim of this paper is to identify the technically suitable grassland areas for the implementation of PVWP systems by assessing spatial data on land cover and slope, precipitation, potential evapotranspiration and water stress index. Furthermore, the optimal locations for installing PVWP systems have been assessed using a spatially explicit renewable energy systems optimization model based on the minimization of the cost of the whole supply chain. The results indicate that the PVWP-supported grassland areas show high potential in terms of improving forage productivity to contribute to supplying the local demand. Nevertheless, the optimal areas are highly sensitive to several environmental and economic parameters such as ground water depth, forage water requirements, forage price and CO2 emission costs. These parameters need to be carefully considered in the planning process to meet the forage yield potentials. (C) 2015 The Authors. Published by Elsevier Ltd.
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| 7. |
- Caretta, Martina Angela, et al.
(author)
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Water
- 2022
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In: Climate Change 2022: Impacts, Adaptation and Vulnerability : Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change - Contribution of Working Group II to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change.
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Book chapter (other academic/artistic)
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| 8. |
- Guan, Yanlong, et al.
(author)
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Elevation Regulates the Response of Climate Heterogeneity to Climate Change
- 2024
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In: GEOPHYSICAL RESEARCH LETTERS. - 0094-8276 .- 1944-8007. ; 51:12
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Journal article (peer-reviewed)abstract
- Climate change represents a profound threat to the diversity and stability of global climate zones. However, the complex interplay between climate change and elevation in shaping climate heterogeneity is not yet fully understood. Here, we combine Shannon's diversity index (SHDI) with the K & ouml;ppen-Geiger climate classification to explore the altitudinal distributions of global climate heterogeneity; and their responses to climate change. The study reveals a distinctive pattern: SHDI, a proxy for climate heterogeneity tends to slow down or decline at lower elevations with increasing temperatures, while at higher elevations, it continues to rise due to continuing cold conditions. Examination of climate simulations, both with and without anthropogenic forcing, confirms that observed changes in climate heterogeneity are primarily attributable to anthropogenic climate change within these high-elevation regions. This study underscores the importance of high-elevation regions as not only custodians of diverse climate types but also potential refuges for species fleeing warmer climates. Climate change is threatening the diversity and stability of global climate patterns. But we're still not completely sure how climate change interacts with elevation to affect climate heterogeneity. In this study, we looked at how climate heterogeneity changes with altitude and responds to climate change. We found that as temperatures rise, the climate diversity tends to decrease at lower elevations, but it increases at higher elevations. We used climate simulations to show that these changes can be attributed to anthropogenic climate change. This study shows that high-elevation regions are important because they can sustain diverse climates and are likely to be a safe haven for plants and animals when climate diversity continues to decline at lower elevations. We employed a high-resolution climate data set to analyze changes in global climate heterogeneity With increasing temperatures, global climate heterogeneity amplifies at higher elevations, while diminishing at lower altitudes Anthropogenic climate change primarily drives alterations in climate heterogeneity at higher elevations
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| 9. |
- Hou, Xuejiao, et al.
(author)
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Anthropogenic transformation of Yangtze Plain freshwater lakes: patterns, drivers and impacts
- 2020
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In: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257. ; 248
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Journal article (peer-reviewed)abstract
- Over the past half century, the Yangtze Plain of China has experienced rapid economic development. Lake reclamation (i.e., conversion of natural lake/wetland areas to agricultural/urban land or aquaculture, thereby reducing the area of natural waters) in particular has greatly contributed to meeting the increasing demands for food and urban development. However, until now, a comprehensive quantification and understanding of historical anthropogenic lacustrine exploitation in this region has been lacking, prohibiting assessment of the impacts of these activities. We used Landsat observations from 1973 to 2018 to track reclamation-induced changes in 112 large lakes (97.8% of the total lake area) in the Yangtze Plain. We show that 41.6% (6056.9 km2) of the total lake area has been reclaimed since the 1970s. The expansion of agricultural and built-up lands dominated the reclamation activities in the 1970s, while the increase of aquaculture zones has prevailed since the mid-1980s. Reclamation activities were closely connected to government policies and major socio-economic events and had strong impacts on lake hydrology, flood risk mitigation capacity, and water quality as revealed by satellite and in situ observations. This new quantitative understanding of anthropogenic reclamation and its associated impacts on Yangtze Plain freshwater lakes can underpin the development of strategies to reduce the impacts of lake reclamation on environmental quality. The study has also demonstrated the unique strength of using long-term series satellite images in tracking historical environmental changes in a substantial region of the world, and the methods used here are potentially extendable to other inland and coastal areas to understand similar human-environment interaction problems.
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| 10. |
- Hou, Xuejiao, et al.
(author)
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Global mapping reveals increase in lacustrine algal blooms over the past decade
- 2022
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In: Nature Geoscience. - : Springer Science and Business Media LLC. - 1752-0894 .- 1752-0908. ; 15:2, s. 130-134
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Journal article (peer-reviewed)abstract
- Algal blooms constitute an emerging threat to global inland water quality, yet their spatial and temporal distribution at the global scale remains largely unknown. Here we establish a global bloom database, using 2.91 million Landsat satellite images from 1982 to 2019 to characterize algal blooms in 248,243 freshwater lakes, representing 57.1% of the global lake area. We show that 21,878 lakes (8.8%) spread across six continents have experienced algal blooms. The median bloom occurrence of affected lakes was 4.6%, but this frequency is increasing; we found increased bloom risks in the 2010s, globally (except for Oceania). The most pronounced increases were found in Asia and Africa, mostly in developing countries that remain reliant on agricultural fertilizer. As algal blooms continue to expand in scale and magnitude, this baseline census will be vital towards future risk assessments and mitigation efforts.
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| 11. |
- Irannezhad, Masoud, et al.
(author)
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Influential Climate Teleconnections for Spatiotemporal Precipitation Variability in the Lancang-Mekong River Basin From 1952 to 2015
- 2020
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In: Journal of Geophysical Research: Atmospheres. - 2169-897X .- 2169-8996. ; 125:21
-
Journal article (peer-reviewed)abstract
- ©2020. The Authors. The Lancang-Mekong River Basin (LMRB) in Mainland Southeast Asia is home to ~70 million people, mostly living in poverty and typically working in primary freshwater-related sectors, particularly agriculture and fishery. Understanding the mechanisms of the historical variability in precipitation (as the crucial water source) plays a key role in regional sustainable development throughout the LMRB. Herein, the spatiotemporal variability in interannual and intra-annual precipitation over the LMRB was analyzed using the Global Precipitation Climatology Centre (GPCC) data for the period 1952–2015. The empirical orthogonal function (EOF) and wavelet transform coherence methods were utilized to investigate the relationships of such historical variations in annual (water year: November–October), dry season (November–May), and wet season (June–October) precipitation with 13 different climate teleconnections (eight large-scale oceanic-atmospheric circulation patterns and five summer monsoons). On the basin scale, only a significant (p<0.05) wetting trend in the dry season precipitation (DSP) was uncovered. Spatially, significant wetting (drying) trends in annual precipitation detected over the northeastern (most western) parts of the Mekong River Basin during the water years 1952–2015, largely contributed by the substantial increases (decreases) in historical wet season precipitation. The most important precipitation pattern (EOF1) was identified as a strong (relatively weak) positive center in the eastern (southwestern) Mekong River Basin accompanying by a significantly high (relatively low) positive value for the first EOF mode of the dry season precipitation (wet season precipitation). Precipitation variability in the LMRB was significantly associated with the South Asian Summer Monsoon Index, Southern Oscillation Index, and Indian Summer Monsoon Index.
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| 12. |
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| 13. |
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| 14. |
- McMillan, Hilary, et al.
(author)
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Panta Rhei 2013-2015 : global perspectives on hydrology, society and change
- 2016
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In: Hydrological Sciences Journal. - : Taylor & Francis Group. - 0262-6667 .- 2150-3435. ; 61:7, s. 1174-1191
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Journal article (peer-reviewed)abstract
- In 2013, the International Association of Hydrological Sciences (IAHS) launched the hydrological decade 2013-2022 with the theme "Panta Rhei: Change in Hydrology and Society". The decade recognizes the urgency of hydrological research to understand and predict the interactions of society and water, to support sustainable water resource use under changing climatic and environmental conditions. This paper reports on the first Panta Rhei biennium 2013-2015, providing a comprehensive resource that describes the scope and direction of Panta Rhei. We bring together the knowledge of all the Panta Rhei working groups, to summarize the most pressing research questions and how the hydrological community is progressing towards those goals. We draw out interconnections between different strands of research, and reflect on the need to take a global view on hydrology in the current era of human impacts and environmental change. Finally, we look back to the six driving science questions identified at the outset of Panta Rhei, to quantify progress towards those aims.
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| 15. |
- Pi, Xuehui, et al.
(author)
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Mapping global lake dynamics reveals the emerging roles of small lakes
- 2022
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 13:1
-
Journal article (peer-reviewed)abstract
- Lakes are important natural resources and carbon gas emitters and are undergoing rapid changes worldwide in response to climate change and human activities. A detailed global characterization of lakes and their long-term dynamics does not exist, which is however crucial for evaluating the associated impacts on water availability and carbon emissions. Here, we map 3.4 million lakes on a global scale, including their explicit maximum extents and probability-weighted area changes over the past four decades. From the beginning period (1984–1999) to the end (2010–2019), the lake area increased across all six continents analyzed, with a net change of +46,278 km2, and 56% of the expansion was attributed to reservoirs. Interestingly, although small lakes (<1 km2) accounted for just 15% of the global lake area, they dominated the variability in total lake size in half of the global inland lake regions. The identified lake area increase over time led to higher lacustrine carbon emissions, mostly attributed to small lakes. Our findings illustrate the emerging roles of small lakes in regulating not only local inland water variability, but also the global trends of surface water extent and carbon emissions.
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| 16. |
- Qi, Wei, et al.
(author)
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Divergent sensitivity of surface water and energy variables to precipitation product uncertainty in the Tibetan Plateau
- 2020
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In: Journal of Hydrology. - : Elsevier BV. - 0022-1694. ; 581
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Journal article (peer-reviewed)abstract
- © 2019 Elsevier B.V. Precipitation is a major driving factor for land surface water and energy balances. Uncertainty in global precipitation products over observation sparse regions such as the Tibetan Plateau (TP) is generally large. Sensitivity of surface water and energy variables to precipitation uncertainty can provide clues for confidence that can be assigned to simulated water and energy variables in such regions. In this study, the sensitivities of surface water and energy variables to global precipitation product uncertainty over four large river basins in the TP are quantified and inter-compared based on a newly developed sensitivity analysis approach. A water and energy budget-based distributed hydrological model including biosphere is utilized after calibration and validation against observed runoff and Land Surface Temperatures (LSTs) from Moderate Resolution Imaging Spectroradiometer (MODIS). Eight global precipitation products are used to represent the precipitation uncertainty. Results show that Canopy interception loss (CIE) and runoff are highly sensitive to the uncertainty in general, whereas LSTs are not sensitive. Therefore, confidence in simulated CIE and runoff can be considered relatively low when using global precipitation products in the four basins. These results imply that other simulated variables may have large uncertainty even when LSTs simulation performs well, and accurate simulations of CIE and runoff require high accuracy in precipitation. Because CIE has profound influence on local hydrological cycle, the results also imply that utilizing the most accurate precipitation product is critical for local scale hydrological cycle research.
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| 17. |
- Qi, Wei, et al.
(author)
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Evaluations and Improvements of GLDAS2.0 and GLDAS2.1 Forcing Data's Applicability for Basin Scale Hydrological Simulations in the Tibetan Plateau
- 2018
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In: Journal of Geophysical Research: Atmospheres. - 2169-897X .- 2169-8996. ; 123:23
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Journal article (peer-reviewed)abstract
- ©2018. The Authors. Hydroclimatic data are of importance to understand the water cycle and therefore for water resource assessment. Such data are of paramount importance for the Tibetan Plateau (TP), which is the source region of several large rivers in Asia. The Global Land Data Assimilation System (GLDAS) 2.0 and 2.1 provide abundant fine resolution hydroclimatic data. However, evaluations on their applicability have not been carried out for the TP. This study aims to evaluate and improve their applicability in basin-scale hydrological applications in the TP. Gauge-based data, a hydrological model including biosphere and seven state-of-the-art global precipitation products are utilized to carry out the study in four large basins in the TP. We find that GLDAS2.1 shows significant warming trends from 2001 to 2010, whereas GLDAS2.0 shows cooling trends, although only significant in the Upper Yellow River basin. The contrasting trends imply that caution should be taken when using them to analyze climate change impacts. On a monthly scale, GLDAS2.1 precipitation on average is closer to the gauge-based data than GLDAS2.0, but both of them have high uncertainty. Therefore, further quality improvements in precipitation are of importance. We also find CMORPH-BLD has better performance than other products in terms of Nash-Sutcliffe Efficiency (NSE), Relative Bias (RB), and root-mean-square error. Combining CMORPH-BLD with GLDAS2.0 forcing data generates more realistic runoff simulation than GLDAS2.1, with NSE and RB being 0.85 and 16% on average. The results provide unique insights into the studied data and are beneficial for water resource assessment in the TP.
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| 18. |
- Wang, Xinchi, et al.
(author)
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Continuous Loss of Global Lake Ice Across Two Centuries Revealed by Satellite Observations and Numerical Modeling
- 2022
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In: Geophysical Research Letters. - 0094-8276. ; 49:12
-
Journal article (peer-reviewed)abstract
- Lake ice loss has been detected worldwide due to recent climate warming, yet spatially and temporally detailed information on the changes in global ice phenology does not exist. Here, we build a global lake ice phenology database comprising three lake ice phenologies—freeze-up, break-up, and ice duration—for each year across two centuries (1900–2099). The timing of all three phenologies experienced mild but statistically significant warming trends in the 20th century; continued warming trends were detected in ∼60% of the lakes from 2001 to 2020. Under a high emissions scenario (RCP 8.5), future global median ice duration would be shortened by 49.9 days by the end of the 21st century; such change can be substantially reduced under lower emission scenarios. We revealed continuous loss of global lake ice during the observed period, our generated database provides critical baseline information to evaluate the consequences of historical and future lake ice changes.
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| 19. |
- Wang, Xinchi, et al.
(author)
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High-Resolution Mapping of Ice Cover Changes in Over 33,000 Lakes Across the North Temperate Zone
- 2021
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In: Geophysical Research Letters. - 0094-8276. ; 48:18
-
Journal article (peer-reviewed)abstract
- More than 50% of global lakes periodically freeze, and their lake ice phenology is sensitive to climate change. However, spatially detailed quantification of the changes in lake ice at the global scale is not available. Here, we map ice cover in >33,000 lakes throughout the North Temperate Zone (23.5°–66.5°N) using 0.55 million Landsat images from 1985 to 2020. Over this period, we found a remarkable reduction in median ice cover occurrence (ICO) (61% to 43%), which was strongly related to warming terrestrial mean surface temperatures (R2 = 0.94, p < 0.05). Lakes in Europe showed the most pronounced ice loss (median ICO decreased from 50% to 24%), and extensive lake ice losses were also detected in the northern US, and central and eastern Asia. An overall increase in ice cover was identified from P2 (1999–2006) to P3 (2007–2014) due to regional decreased temperatures associated with the “global warming hiatus.” Thehigh-resolution mapping of lake ice here provides essentialbaseline information whichcan be used to elucidate ice loss-induced environmental and societal impacts.
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| 20. |
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| 21. |
- Xi, Qiaojuan, et al.
(author)
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中国主要流域灰-绿-蓝蓄水能力时空演变 : [Spatio-temporal variation of gray-green-blue storage capacity in nine major basins of China]
- 2021
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In: Chinese Science Bulletin-Chinese. - 0023-074X .- 2095-9419. ; 66:34, s. 4437-4448
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Journal article (peer-reviewed)abstract
- Most of China's territory is influenced by the East Asia monsoon, and thus, the spatio-temporal distribution of surface water resources in China is extremely uneven, causing many water-related issues, e.g.. water scarcity and flooding. As the basis and essential condition of economic and social development, water-related infrastructures provide the material basis and guarantee for regulating and storing surface water resources and solving multi-dimensional water problems. The infrastructures that play an important role in surface water resource regulation and storage mainly include three types: Gray (such as dams), green (such as forests), and blue infrastructures (such as lakes). Gray infrastructures can reduce the flood peak and increase water supply during dry seasons by regulating and storing water so that the seasonal and inter-annual fluctuation of runoff is reduced, which plays an important role in water storage, water supply, flood control, and disaster mitigation. However, excessive gray infrastructures would have adverse effects on the social economy and environmental ecology. Unlike gray infrastructures, green and blue infrastructures can not only benefit water resource management but also have ecological functions, such as improving water quality and enhancing ecosystem services. Thus. it is significant to couple gray, green, and blue infrastructures to regulate the spatio-temporal distribution of water resources. However, research on the spatial distribution and temporal variation of water storage capacity is still lacking, which hinders the coordinated regulation and comprehensive management of surface water resources. Therefore, in the present study, the spatio-temporal distribution of the three aforementioned infrastructures was compared and analyzed on basin scale, based on the latest data of darns, root zone storage capacity, natural lakes, and so on. Results indicated the following: (1) Gray water storage capacity has exceeded that of the natural terrestrial surface ecosystem in the Yangtze River Basin and the Southeast Basins, where human activities are intense. (2) Gray water storage capacity has increased significantly in nine major basins from 1955 to 2020, but the timing of construction varies in different basins. (3) Green water storage capacity did not change much, the Songhua-Liaohe River Basin and the Huaihe River Basin increased slightly. (4) Blue water storage capacity shows a constantly increasing trend on the whole, in which the water storage capacity in the inland river basin (including the endorheic basin on the Tibetan Plateau) significantly increased. Our study revealed the basic information and spatio-temporal variation of gray-green-blue water storage capacities in nine major basins of China, which could lead to better coordination between natural and artificial water infrastructures and provide support for multidimensional optimization of water resource allocation.
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| 22. |
- Zhang, Shuyu, et al.
(author)
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Moisture Sources and Pathways of Annual Maximum Precipitation in the Lancang-Mekong River Basin
- 2024
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In: GEOPHYSICAL RESEARCH LETTERS. - 0094-8276 .- 1944-8007. ; 51:6
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Journal article (peer-reviewed)abstract
- Recent extremely heavy precipitation has led to substantial economic losses and affected millions of residences in the Lancang-Mekong River Basin (LMRB). This study analyzed the spatial-temporal characteristics of the annual maximum precipitation (R1X) of the LMRB and identified the moisture sources and pathways conducive to R1Xs using a Lagrangian back trajectory model. Results show that India Ocean and Bay of Bengal (IO/BOB), local evapotranspiration, and West Pacific Ocean and East China (WP/EC) are the three main moisture transport pathways of the R1Xs in LMRB, contributing 68.3%, 20.4% and 11.3% of the trajectories, respectively. R1Xs in the downstream eastern area are affected by tropical cyclones bringing large amounts of moisture from the WP/EC. As tropical cyclones shifted northward under climate change impact, more extreme precipitation occurred over the LMRB due to moisture coming from WP/EC, but those from the IO/BOB had decreased because of the slowdown of flows across the Equator. Recent extremely heavy precipitation has led to more frequent floods, storm surges, and other natural hazards in the Lancang-Mekong River Basin, resulting in substantial economic losses and affecting millions of residences. This study used annual maximum precipitation to represent the extreme precipitation and analyzed its spatial-temporal characteristics and the moisture sources and pathways. Results show that the extreme precipitation of the upstream region mainly occurred in July, while that of the downstream region mainly occurred in August-September. The moisture pathways of the historical extreme precipitation were identified using a physical-based model, and are classified into three clusters using a machine-learning model. West Pacific Ocean and East China, local evapotranspiration, and Indian Ocean and Bay of Bengal (IO/BOB) are the three moisture transport pathways with contributions of 68.3%, 20.4%, and 11.3% to the total pathways. The tropical cyclones bring large amounts of moisture and mainly affect R1Xs in the downstream eastern area. Tropical cyclones shifted northward under climate change impact, and more extreme precipitation occurred over the LMRB due to moisture coming from the West Pacific Ocean and East China, but those from the IO and BOB had decreased because of the slowdown of flows across the Equator. The timing of the annual maximum precipitation of the Lancang-Mekong River Basin (LMRB) varies from July to September The extreme precipitation of the LMRB mainly received moisture from the Indian Ocean to the West Pacific Ocean Tropical cyclones will bring more extreme precipitation to the LMRB under climate change
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| 23. |
- Zhang, Xinxin, et al.
(author)
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China's coal-fired power plants impose pressure on water resources
- 2017
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In: Journal of Cleaner Production. - : ELSEVIER SCI LTD. - 0959-6526 .- 1879-1786. ; 161, s. 1171-1179
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Journal article (peer-reviewed)abstract
- Coal is the dominant fuel for electricity generation around the world. This type of electricity generation uses large amounts of water, increasing pressure on water resources. This calls for an in-depth investigation in the water-energy nexus of coal-fired electricity generation. In China, coal-fired power plants play an important role in the energy supply. Here we assessed water consumption of coal-fired power plants (CPPs) in China using four cooling technologies: closed-cycle cooling, once-through cooling, air cooling, and seawater cooling. The results show that water consumption of CPPs was 3.5 km(3), accounting for 11% of total industrial water consumption in China. Eighty-four percent of this water consumption was from plants with closed-cycle cooling. China's average water intensity of CPPs was 1.15 l/kWh, while the intensity for closed-cycle cooling was 3-10 times higher than that for other cooling technologies. About 75% of water consumption of CPPs was from regions with absolute or chronic water scarcity. The results imply that the development of CPPs needs to explicitly consider their impacts on regional water resources.
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