148 research outputs found
Climate change track in river floods in Europe
proc-iahs.net/369/189/2015/ doi:10.5194/piahs-369-189-201
Extreme hydrological events and security
proc-iahs.net/369/181/2015/ doi:10.5194/piahs-369-181-201
Recommended from our members
Modelling flood damages under climate change conditions-a case study for Germany
The aim of the study is to analyze and discuss possible climate change impacts on flood damages in Germany. The study was initiated and supported by the German insurance sector whereby the main goal was to identify general climate-related trends in flood hazard and damages and to explore sensitivity of results to climate scenario uncertainty. The study makes use of climate scenarios regionalized for the main river basins in Germany. A hydrological model (SWIM) that had been calibrated and validated for the main river gauges, was applied to transform these scenarios into discharge for more than 5000 river reaches. Extreme value distribution has been fitted to the time series of river discharge to derive the flood frequency statistics. The hydrological results for each river reach have been linked using the flood statistics to related damage functions provided by the German Insurance Association, considering damages on buildings and small enterprises. The result is that, under the specific scenario conditions, a considerable increase in flood related losses can be expected in Germany in future, warmer, climate
Climate change and its effect on agriculture, water resources and human health sectors in Poland
Multi-model ensemble climate projections in the ENSEMBLES Project of the EU allowed the authors to quantify selected extreme-weather indices for Poland, of importance to climate impacts on systems and sectors. Among indices were: number of days in a year with high value of the heat index; with high maximum and minimum temperatures; length of vegetation period; and number of consecutive dry days. Agricultural, hydrological, and human health indices were applied to evaluate the changing risk of weather extremes in Poland in three sectors. To achieve this, model-based simulations were compared for two time horizons, a century apart, i.e., 1961â1990 and 2061â2090. Climate changes, and in particular increases in temperature and changes in rainfall, have strong impacts on agriculture via weather extremes â droughts and heat waves. The crop yield depends particularly on water availability in the plant development phase. To estimate the changes in present and future yield of two crops important for Polish agriculture i.e., potatoes and wheat, some simple empirical models were used. For these crops, decrease of yield is projected for most of the country, with national means of yield change being: â2.175 t/ha for potatoes and â0.539 t/ha for wheat. Already now, in most of Poland, evapotranspiration exceeds precipitation during summer, hence the water storage (in surface water bodies, soil and ground) decreases. Summer precipitation deficit is projected to increase considerably in the future. The additional water supplies (above precipitation) needed to use the agro-potential of the environment would increase by half. Analysis of water balance components (now and in the projected future) can corroborate such conclusions. As regards climate and health, a composite index, proposed in this paper, is a product of the number of senior discomfort days and the number of seniors (aged 65+). The value of this index is projected to increase over 8-fold during 100 years. This is an effect of both increase in the number of seniors (over twofold) and the number of senior-discomfort days (nearly fourfold)
Climate Change Impacts on Freshwater Wetland Hydrology and Vegetation Cover Cycling Along a Regional Aridity Gradient
Global mean temperature may increase up to 6°C by the end of this century and together with precipitation change may steepen regional aridity gradients. The hydrology, productivity, and ecosystem services from freshwater wetlands depend on their future water balance. We simulated the hydrology and vegetation dynamics of wetland complexes in the North American Prairie Pothole Region with the WETLANDSCAPE model. Simulations for 63 precipitation Ă temperature combinations spanning 6°C warming and â20% to +20% annual precipitation change at 19 locations along a mid-continental aridity gradient showed that aridity explained up to 99% of the variation in wetland stage and hydroperiod for all wetland permanence types, and in vegetation cycling for semipermanent wetlands. The magnitude and direction of hydrologic responses depended on whether climate changes increased or decreased water deficits. Warming to 6°C and 20% less precipitation increased wetland water deficits and more strongly decreased wetland stage and hydroperiod from historic levels at low aridity, especially in semipermanent wetlands, where peak vegetation cycling (Cover Cycle Index, CCI) also shifted to lower aridity. In contrast, 20% more precipitation decreased water deficits, increasing wetland stage and hydroperiod most strongly in shallow wetlands at high aridity, but filling semipermanent wetlands and reducing CCI at low aridity. All climate changes narrowed the range of aridity favorable to high productivity. Climate changes that reduce water deficits may help maintain wetlands at high aridity at the expense of those at low aridity, but with warming certain, increased deficits are more likely and will help maintain wetlands at lower aridity but exacerbate loss of wetlands at high aridity. Thus, there is likely not a universally applicable approach to mitigating climate change impacts on freshwater wetlands across regional aridity gradients. Conservation strategies need to account for aridity-specific effects of climate change on freshwater wetland ecosystems
CHASE-PL Climate Projection dataset over Poland â bias adjustment of EURO-CORDEX simulations
The CHASE-PL (Climate change impact assessment for selected sectors in
Poland) Climate Projections â Gridded Daily Precipitation and Temperature
dataset 5âŻkm (CPLCP-GDPT5) consists of projected daily minimum and
maximum air temperatures and precipitation totals of nine EURO-CORDEX
regional climate model outputs bias corrected and downscaled to
a 5âŻkmâŻâĂââŻ5âŻkm grid. Simulations of one historical period
(1971â2000) and two future horizons (2021â2050 and 2071â2100) assuming two
representative concentration pathways (RCP4.5 and RCP8.5) were produced. We
used the quantile mapping method and corrected any systematic seasonal bias
in these simulations before assessing the changes in annual and seasonal
means of precipitation and temperature over Poland. Projected changes
estimated from the multi-model ensemble mean showed that annual means of
temperature are expected to increase steadily by 1âŻÂ°C until
2021â2050 and by 2âŻÂ°C until 2071â2100 assuming the RCP4.5
emission scenario. Assuming the RCP8.5 emission
scenario, this can reach up to almost 4âŻÂ°C by 2071â2100.
Similarly to temperature, projected changes in regional annual means of
precipitation are expected to increase by 6 to 10âŻ% and by 8 to
16âŻ% for the two future horizons and RCPs, respectively. Similarly,
individual model simulations also exhibited warmer and wetter conditions on
an annual scale, showing an intensification of the magnitude of the change at
the end of the 21st century. The same applied for projected changes in
seasonal means of temperature showing a higher winter warming rate by up to
0.5âŻÂ°C compared to the other seasons. However, projected
changes in seasonal means of precipitation by the individual models largely
differ and are sometimes inconsistent, exhibiting spatial variations which
depend on the selected season, location, future horizon, and RCP. The overall
range of the 90âŻ% confidence interval predicted by the ensemble of
multi-model simulations was found to likely vary between â7âŻ%
(projected for summer assuming the RCP4.5 emission scenario) and
+40âŻ% (projected for winter assuming the RCP8.5 emission scenario) by
the end of the 21st century. Finally, this high-resolution bias-corrected
product can serve as a basis for climate change impact and adaptation studies
for many sectors over Poland. The CPLCP-GDPT5 dataset is publicly available
at http://dx.doi.org/10.4121/uuid:e940ec1a-71a0-449e-bbe3-29217f2ba31d
The European Union approach to flood risk management and improving societal resilience: lessons from the implementation of the Floods Directive in six European countries
Diversity in flood risk management approaches is often considered to be a strength. However in some national settings, and especially for transboundary rivers, variability and the incompatibility of approaches can reduce the effectiveness of flood risk management. Placed in the context of increasing flood risks, as well as the potential for flooding to undermine the European Union's sustainable development goals, a desire to increase societal resilience to flooding has prompted the introduction of a common European Framework. This paper provides a legal and policy analysis of the implementation of the Floods Directive (2007/60/EC) in six countries; Belgium (Flemish Region), England, France, the Netherlands, Poland and Sweden. Evaluation criteria from existing legal and policy literature frame the study of the Directive and its impact on enhancing or constraining societal resilience by using an adaptive governance approach. These criteria are initially used to analyze the key components of the EU approach, before providing insight of the implementation of the Directive at a national level. Similarities and differences in the legal translation of European goals into existing flood risk management are analyzed alongside their relative influence on policy and practice. The research highlights that the impact of the Floods Directive on increasing societal resilience has been nationally variable, in part due to its focus on procedural obligations, rather than on more substantive requirements. Analysis shows that despite a focus on transboundary river basin management, in some cases existing traditions of flood risk management, have overridden objectives to harmonize flood risk management. This could be strengthened by requiring more stringent cooperation and providing the competent authorities in International River Basins Districts with more power. Despite some shortcomings in directly impacting flood risk outcomes, the Directive has positively stimulated discussion and flood risk management planning in countries that were perhaps lagging behind
Competition for water for the food system
Although the global agricultural system will need to provide more food for a growing and wealthier population in decades to come, increasing demands for water and potential impacts of climate change pose threats to food systems. We review the primary threats to agricultural water availability, and model the potential effects of increases in municipal and industrial (M&I) water demands, environmental flow requirements (EFRs) and changing water supplies given climate change. Our models show that, together, these factors cause an 18 per cent reduction in the availability of worldwide water for agriculture by 2050. Meeting EFRs, which can necessitate more than 50 per cent of the mean annual run-off in a basin depending on its hydrograph, presents the single biggest threat to agricultural water availability. Next are increases in M&I demands, which are projected to increase upwards of 200 per cent by 2050 in developing countries with rapidly increasing populations and incomes. Climate change will affect the spatial and temporal distribution of run-off, and thus affect availability from the supply side. The combined effect of these factors can be dramatic in particular hotspots, which include northern Africa, India, China, parts of Europe, the western US and eastern Australia, among others
Partial costs of global climate change adaptation for the supply of raw industrial and municipal water: a methodology and application
Despite growing recognition of the importance of climate change adaptation, few global estimates of the costs involved are available for the water supply sector. We present a methodology for estimating partial global and regional adaptation costs for raw industrial and domestic water supply, for a limited number of adaptation strategies, and apply the method using results of two climate models. In this paper, adaptation costs are defined as those for providing enough raw water to meet future industrial and municipal water demand, based on country-level demand projections to 2050. We first estimate costs for a baseline scenario excluding climate change, and then additional climate change adaptation costs. Increased demand is assumed to be met through a combination of increased reservoir yield and alternative backstop measures. Under such controversial measures, we project global adaptation costs of 73 bn p.a.), which supports the notion of mainstreaming climate change adaptation into broader policy aims. The method provides a tool for estimating broad costs at the global and regional scale; such information is of key importance in international negotiations. © 2010 IOP Publishing Ltd
- âŠ