Climate Change and Water Cycle - Some Lessons from the Geological Past

Author(s):  
Volker Mosbrugger
2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yukiko Hirabayashi ◽  
Haireti Alifu ◽  
Dai Yamazaki ◽  
Yukiko Imada ◽  
Hideo Shiogama ◽  
...  

AbstractThe ongoing increases in anthropogenic radiative forcing have changed the global water cycle and are expected to lead to more intense precipitation extremes and associated floods. However, given the limitations of observations and model simulations, evidence of the impact of anthropogenic climate change on past extreme river discharge is scarce. Here, a large ensemble numerical simulation revealed that 64% (14 of 22 events) of floods analyzed during 2010-2013 were affected by anthropogenic climate change. Four flood events in Asia, Europe, and South America were enhanced within the 90% likelihood range. Of eight snow-induced floods analyzed, three were enhanced and four events were suppressed, indicating that the effects of climate change are more likely to be seen in the snow-induced floods. A global-scale analysis of flood frequency revealed that anthropogenic climate change enhanced the occurrence of floods during 2010-2013 in wide area of northern Eurasia, part of northwestern India, and central Africa, while suppressing the occurrence of floods in part of northeastern Eurasia, southern Africa, central to eastern North America and South America. Since the changes in the occurrence of flooding are the results of several hydrological processes, such as snow melt and changes in seasonal and extreme precipitation, and because a climate change signal is often not detectable from limited observation records, large ensemble discharge simulation provides insights into anthropogenic effects on past fluvial floods.


2021 ◽  
Author(s):  
Itxaso Ruiz ◽  
María José Sanz

<p>Rural areas of the Mediterranean watersheds face great environmental challenges, where climate change impacts the water cycle, the soil, and biodiversity, which are often priority issues for adaptation. These, have been aggravated by historical land management practices trends. In this context, we propose Nature Based Solutions (NBS) in the form of Sustainable Land Management (SLM) actions at the watershed scale to achieve climate change adaptation and mitigation while promoting other ecosystem services.</p><p>SLM actions are local adaptation practices that promote sustainable rural development. Thus, we seek the combination of several actions to achieve regional (watershed scale) more integrated approaches. With this study, we aim at proving that NBS, and thus SLM, is a successful tool for alleviating climate change impacts (i.e. water scarcity, enhanced erosion, biodiversity decline) while promoting the role of land in mitigation and enhancing biodiversity in the rural Mediterranean areas.</p><p>For this, we propose a novel conceptualization of SLM actions that moves from their local application and evaluation to the regional more systemic approaches through their combination. Results show synergies in the atmosphere, biosphere, and hydrosphere, allow for the upscaling of SLM through systemic approaches and point at direct contributions to several Sustainable Development Goals.</p>


Author(s):  
Salley Alhassan ◽  
Wade Hadwen

Climate change threatens water, sanitation and hygiene (WaSH) facilities and services, as these are intimately linked to the water cycle and are vulnerable to changes in the quantity and quality of available water resources. Floods and droughts, which pollute and reduce water delivery respectively, have now become a perennial issue to deal with in the northern regions of the country, including the Bolgatanga Municipality. This study aimed to assess the degree to which climate change adaptation measures are mainstreamed into the WaSH development planning process in Ghana. Stakeholders from government and non-government agencies were interviewed to gain perspectives on the threat of climate change, the inclusion of climate change in WaSH planning and the barriers preventing mainstreaming. In general, despite awareness and concern about climate change, adaptation measures have been regarded to be far away from the immediate concerns of WaSH development planning. Most of the current measures are reactive and respond to environmental issues rather than to climate change stressors. In essence, stakeholders expressed the view that the adaptive capacity of the Municipality was low and that mainstreaming has not yet occurred. Despite the lack of progress, there are great opportunities for mainstreaming climate change adaptation into planning through increasing awareness and capacity, legislative and institutional changes and the development of participatory systems to provide early warning systems and disaster risk analyses that will inform future planning.


2019 ◽  
Vol 55 (1) ◽  
pp. 260
Author(s):  
Constantinos Perisoratis

The climate changes are necessarily related to the increase of the Earth’s temperature, resulting in a sea level rise. Such continuous events, were taking place with minor and greater intensity, during the alternation of warm and cool periods in the Earth during the Late Quaternary and the Holocene periods. However, a particularly significant awareness has taken place in the scientific community, and consequently in the greater public, in the last decades: that a climatic change will take place soon, or it is on-going, and that therefore it is important to undertake drastic actions. However, such a climatic change has not been recorded yet, and hence the necessary actions are not required, for the time being.


2016 ◽  
Vol 2016 (4) ◽  
pp. 23
Author(s):  
Basem Shomar
Keyword(s):  

2021 ◽  
Author(s):  
Ronan Abhervé ◽  
Clément Roques ◽  
Laurent Longuevergne ◽  
Stéphane Louaisil ◽  
Jean-Raynald de Dreuzy ◽  
...  

<p>While it is well understood and accepted that climate change and growing water needs affect the availability of water resources, the identification of the main physical processes involved remains challenging. It notably requires to filter interannual to interdecadal fluctuations and extreme events to isolate the underlying trends. Metropolitan areas are specifically subject to growing pressures because of the significant and increasing demand, combined with the strong anthropization of land uses.</p><p>The Meu-Chèze-Canut catchment supplies the city of Rennes with drinking water (680 km² - 500 000 users, Brittany, France). In this field laboratory, we explore the dynamics of the water cycle and water resources availability. In this context, water supply is mostly coming from reservoir storage for which levels shows a medium-term vulnerability in response to frequent relatively dry years. Based on retrospective data analysis, we describe the relationship between climatic forcing (precipitation, temperature) and water availability (aquifer storage, river discharge and reservoir storage) in different parts of the catchment that are characterized by distinct lithological and topographical settings. We then evaluate the resilience of both surface and groundwater resources, their past evolution and their resilience to climate change and increasing societal needs.</p><p>Water resources availability in these catchments relies on two geological formations with distinct hydrodynamics properties: the Armorican sandstone and Brioverian schist. To assess the resilience of the system, we specifically analyzed the relationships between monthly effective precipitation and stream discharge within nine sub-catchments over the past 30 years. We observe annual hysteresis relationships - that is, a time lag between precipitation and discharge highlighting the capacity of the landscape to temporarily store water - with significant variability in shapes across the catchments. We argue that topographic and lithological factors play key roles in controlling this variability through their impacts on subsurface storage capacity and characteristic drainage timescales. We propose perspectives based on the complementary use of calibrated groundwater models to leverage these results and provide adaptive water management strategies.</p>


Atmosphere ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 509
Author(s):  
Jingwen Wu ◽  
Haiyan Zheng ◽  
Yang Xi

Runoff in snowy alpine regions is sensitive to climate change in the context of global warming. Exploring the impact of climate change on the runoff in these regions is critical to understand the dynamics of the water cycle and for the improvement of water resources management. In this study, we analyzed the long-term variations in annual runoff in the headwaters region of the Yellow River (HRYR) (a typical snowy mountain region) during the period of 1956–2012. The Soil and Water Assessment Tool (SWAT) with different elevation bands was employed to assess the performance of monthly runoff simulations, and then to evaluate the impacts of climate change on runoff. The results show that the observed runoff for the hydrological stations at lower relative elevations (i.e., Maqu and Tangnaihai stations) had a downward trend, with rates of 1.91 and 1.55 mm/10 years, while a slight upward trend with a rate of 0.26 mm/10 years was observed for the hydrological station at higher elevation (i.e., Huangheyan station). We also found that the inclusion of five elevation bands could lead to more accurate runoff estimates as compared to simulation without elevation bands at monthly time steps. In addition, the dominant cause of the runoff decline across the whole HRYR was precipitation (which explained 64.2% of the decrease), rather than temperature (25.93%).


2020 ◽  
Vol 12 (7) ◽  
pp. 2936
Author(s):  
Denis Jean Sonwa ◽  
Mfochivé Oumarou Farikou ◽  
Gapia Martial ◽  
Fiyo Losembe Félix

Humid conditions and equatorial forest in the Congo Basin have allowed for the maintenance of significant biodiversity and carbon stock. The ecological services and products of this forest are of high importance, particularly for smallholders living in forest landscapes and watersheds. Unfortunately, in addition to deforestation and forest degradation, climate change/variability are impacting this region, including both forests and populations. We developed three case studies based on field observations in Cameroon, the Central African Republic, and the Democratic Republic of Congo, as well as information from the literature. Our key findings are: (1) the forest-related water cycle of the Congo Basin is not stable, and is gradually changing; (2) climate change is impacting the water cycle of the basin; and, (3) the slow modification of the water cycle is affecting livelihoods in the Congo Basin. Developmental and environmental actions in the Congo Basin need to properly consider the slight modification of this water cycle in watersheds that affect products and services from the forest.


2018 ◽  
Vol 7 (2) ◽  
pp. 35-56
Author(s):  
Fransje Lucretia Hooimeijer ◽  
Ignace van Campenhout

Although severely altered, the urban subsurface is the base of the natural system, and is crucial for a stable, green, healthy, and liveable city. It is also the technical space, the engine room of the city where vital functions such as water, electricity, sewers, and drainage are located. This hybrid state needs to be recognized when designing resilient and durable (subsurface) infrastructure within urban renewal projects, so as to properly employ the parameters of both natural and technical systems. Interdisciplinary work is needed in order to be able to link natural systems (a) the water cycle, (b) soil and subsurface conditions, (c) soil improvement technology, and (d) opportunities for urban renewal (e.g. urban growth or shrinkage) in an efficient way. The importance of implementing “boundary spanning” when doing interdisciplinary work that deals with the effects of climate change is a widely recognized method, and has been an object of study in the city of Rotterdam in the past decade. The particular need for a “distributed agency” became clear during several research projects dealing with climate change, because it enables different actors to contribute to the development of the project at different phases. The representation of the city as both a natural and technical construction has been tested through the use of 2D and 3D information, which has played a significant role in enabling designs to incorporate the dimension of the subsurface. 2D and 3D information needs to anticipate different scales of specific planning and/or design phases, and they must also address various topics of the subsurface. For each phase of urban development, the distributed agency between 2D and 3D information is investigated and reflected upon. Conclusions are then drawn on the relationship between 2D and 3D information, and how it could relate in a productive, boundary spanning act that is inclusive of the subsurface. Based on these potential connections, the design of a new concept which implements boundary spanning as a facilitator is presented.


2018 ◽  
Vol 99 (11) ◽  
pp. 2341-2359 ◽  
Author(s):  
M. J. Roberts ◽  
P. L. Vidale ◽  
C. Senior ◽  
H. T. Hewitt ◽  
C. Bates ◽  
...  

AbstractThe time scales of the Paris Climate Agreement indicate urgent action is required on climate policies over the next few decades, in order to avoid the worst risks posed by climate change. On these relatively short time scales the combined effect of climate variability and change are both key drivers of extreme events, with decadal time scales also important for infrastructure planning. Hence, in order to assess climate risk on such time scales, we require climate models to be able to represent key aspects of both internally driven climate variability and the response to changing forcings. In this paper we argue that we now have the modeling capability to address these requirements—specifically with global models having horizontal resolutions considerably enhanced from those typically used in previous Intergovernmental Panel on Climate Change (IPCC) and Coupled Model Intercomparison Project (CMIP) exercises. The improved representation of weather and climate processes in such models underpins our enhanced confidence in predictions and projections, as well as providing improved forcing to regional models, which are better able to represent local-scale extremes (such as convective precipitation). We choose the global water cycle as an illustrative example because it is governed by a chain of processes for which there is growing evidence of the benefits of higher resolution. At the same time it comprises key processes involved in many of the expected future climate extremes (e.g., flooding, drought, tropical and midlatitude storms).


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