scholarly journals Projected changes in Rhine River flood seasonality under global warming

2021 ◽  
Vol 25 (5) ◽  
pp. 2353-2371
Author(s):  
Erwin Rottler ◽  
Axel Bronstert ◽  
Gerd Bürger ◽  
Oldrich Rakovec
Keyword(s):  
Global Warming ◽  
River Basin ◽  
General Circulation ◽  
General Circulation Models ◽  
Cold Season ◽  
Rhine River ◽  
Climate Conditions ◽  
Antecedent Precipitation ◽  
Projected Changes ◽  
Liquid Precipitation

Abstract. Climatic change alters the frequency and intensity of natural hazards. In order to assess potential future changes in flood seasonality in the Rhine River basin, we analyse changes in streamflow, snowmelt, precipitation and evapotranspiration at 1.5, 2.0 and 3.0 ∘C global warming levels. The mesoscale hydrological model (mHM) forced with an ensemble of climate projection scenarios (five general circulation models under three representative concentration pathways) is used to simulate the present and future climate conditions of both pluvial and nival hydrological regimes. Our results indicate that future changes in flood characteristics in the Rhine River basin are controlled by increases in antecedent precipitation and diminishing snowpacks. In the pluvial-type sub-basin of the Moselle River, an increasing flood potential due to increased antecedent precipitation encounters declining snowpacks during winter. The decrease in snowmelt seems to counterbalance increasing precipitation, resulting in only small and transient changes in streamflow maxima. For the Rhine Basin at Basel, rising temperatures cause changes from solid to liquid precipitation, which enhance the overall increase in precipitation sums, particularly in the cold season. At the gauge at Basel, the strongest increases in streamflow maxima show up during winter, when strong increases in liquid precipitation encounter almost unchanged snowmelt-driven runoff. The analysis of snowmelt events for the gauge at Basel suggests that at no point in time during the snowmelt season does a warming climate result in an increase in the risk of snowmelt-driven flooding. Snowpacks are increasingly depleted with the course of the snowmelt season. We do not find indications of a transient merging of pluvial and nival floods due to climate warming. To refine attained results, next steps need to be the representation of glaciers and lakes in the model set-up, the coupling of simulations to a streamflow component model and an independent validation of the snow routine using satellite-based snow cover maps.

scholarly journals Projected changes in Rhine River flood seasonality under global warming

2020 ◽  
Author(s):  
Erwin Rottler ◽  
Axel Bronstert ◽  
Gerd Bürger ◽  
Oldrich Rakovec
Keyword(s):  
Global Warming ◽  
General Circulation ◽  
General Circulation Models ◽  
Climate Projections ◽  
Rhine River ◽  
Climate Conditions ◽  
Projected Changes ◽  
Liquid Precipitation ◽  
Flood Characteristics ◽  
Precipitation Events

Abstract. Climatic change alters the frequency and intensity of natural hazards. In order to assess potential future changes in flood seasonality in the Rhine River Basin, we analyse changes in streamflow, snowmelt, precipitation, and evapotranspiration at 1.5, 2.0 and 3.0 °C global warming levels. The mesoscale Hydrological Model (mHM) forced with an ensemble of climate projection scenarios (five general circulation models under three representative concentration pathways) is used to simulate the present and future climate conditions of both, pluvial and nival hydrological regimes. Our results indicate that the interplay between changes in snowmelt- and rainfall-driven runoff is crucial to understand changes in streamflow maxima in the Rhine River. Climate projections suggest that future changes in flood characteristics in the entire Rhine River are controlled by both, more intense precipitation events and diminishing snow packs. The nature of this interplay defines the type of change in runoff peaks. On the sub-basin level (the Moselle River), more intense rainfall during winter is mostly counterbalanced by reduced snowmelt contribution to the streamflow. In the High Rhine (gauge at Basel), the strongest increases in streamflow maxima show up during winter, when strong increases in liquid precipitation intensity encounter almost unchanged snowmelt-driven runoff. The analysis of snowmelt events suggests that at no point in time during the snowmelt season, a warming climate results in an increase in the risk of snowmelt-driven flooding. We do not find indications of a transient merging of pluvial and nival floods due to climate warming.

Optimal white spruce breeding zones for Ontario under current and future climates

2010 ◽  
Vol 40 (8) ◽  
pp. 1576-1587 ◽  
Author(s):  
Ashley M. Thomson ◽  
Kevin A. Crowe ◽  
William H. Parker
Keyword(s):  
Picea Glauca ◽  
General Circulation ◽  
Circulation Model ◽  
White Spruce ◽  
General Circulation Models ◽  
Future Climate ◽  
Decision Support Model ◽  
Climate Conditions ◽  
Seed Transfer ◽  
Significant Difference

Optimal breeding zones were developed for white spruce ( Picea glauca (Moench) Voss) in Ontario under present and future climate conditions to examine potential shifts due to climate change. These zones were developed by (i) determining a set of candidate breeding zones based on the relationship between measured performance variables and climate and (ii) employing a decision support model to select subsets of breeding zones that maximize geographic coverage subject to a constraint on the maximum number of zones. Current optimal breeding zones were based on 1961–1990 climate normals, and future breeding zones were based on three general circulation model (CGCM2, HADCM3, and CSIRO) predictions of 2041–2070 climate. Based on a maximum adaptive distance of 2.0 least significant difference values between sites within zones, 14 zones were required to cover the Ontario range of white spruce for the 1961–1990 data. Compared with breeding zones of other boreal conifers, current optimal breeding zones for white spruce were quite large, spanning up to 3° latitude and 10°–12° longitude and indicating large distances of effective seed transfer. Of the three general circulation models used to simulate future climate, HADCM3 B2 and CGCM2 B2 predicted 2041–2070 breeding zones that largely coincide with 1961–1990 zones. In contrast, CSIRO B2 indicated much narrower 2041–2070 breeding zones.

scholarly journals Comparison of Statistical Downscaling Methods for Monthly Total Precipitation: Case Study for the Paute River Basin in Southern Ecuador

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
L. Campozano ◽  
D. Tenelanda ◽  
E. Sanchez ◽  
E. Samaniego ◽  
J. Feyen
Keyword(s):  
River Basin ◽  
Statistical Downscaling ◽  
General Circulation ◽  
General Circulation Models ◽  
Support Vector ◽  
Monthly Precipitation ◽  
Local Conditions ◽  
Southern Ecuador ◽  
Monthly Total Precipitation ◽  
Precipitation Estimates

Downscaling improves considerably the results of General Circulation Models (GCMs). However, little information is available on the performance of downscaling methods in the Andean mountain region. The paper presents the downscaling of monthly precipitation estimates of the NCEP/NCAR reanalysis 1 applying the statistical downscaling model (SDSM), artificial neural networks (ANNs), and the least squares support vector machines (LS-SVM) approach. Downscaled monthly precipitation estimates after bias and variance correction were compared to the median and variance of the 30-year observations of 5 climate stations in the Paute River basin in southern Ecuador, one of Ecuador’s main river basins. A preliminary comparison revealed that both artificial intelligence methods, ANN and LS-SVM, performed equally. Results disclosed that ANN and LS-SVM methods depict, in general, better skills in comparison to SDSM. However, in some months, SDSM estimates matched the median and variance of the observed monthly precipitation depths better. Since synoptic variables do not always present local conditions, particularly in the period going from September to December, it is recommended for future studies to refine estimates of downscaling, for example, by combining dynamic and statistical methods, or to select sets of synoptic predictors for specific months or seasons.

scholarly journals Northern Hemispheric Trends of Pressure Indices and Atmospheric Circulation Patterns in Observations, Reconstructions, and Coupled GCM Simulations

2005 ◽  
Vol 18 (19) ◽  
pp. 3968-3982 ◽  
Author(s):  
C. C. Raible ◽  
T. F. Stocker ◽  
M. Yoshimori ◽  
M. Renold ◽  
U. Beyerle ◽  
...  
Keyword(s):  
Atmospheric Circulation ◽  
General Circulation ◽  
Southern Oscillation ◽  
Storm Track ◽  
General Circulation Models ◽  
Aleutian Low ◽  
Climate Conditions ◽  
Atmospheric Circulation Patterns ◽  
The North ◽  
Decadal Trend

Abstract The decadal trend behavior of the Northern Hemisphere atmospheric circulation is investigated utilizing long-term simulations with different state-of-the-art coupled general circulation models (GCMs) for present-day climate conditions (1990), reconstructions of the past 500 yr, and observations. The multimodel simulations show that strong positive winter North Atlantic Oscillation (NAO) trends are connected with the underlying sea surface temperature (SST) and exhibit an SST tripole trend pattern and a northward shift of the storm-track tail. Strong negative winter trends of the Aleutian low are associated with SST changes in the El Niño–Southern Oscillation (ENSO) region and a westward shift of the storm track in the North Pacific. The observed simultaneous appearance of strong positive NAO and negative Aleutian low trends is very unlikely to occur by chance in the unforced simulations and reconstructions. The positive winter NAO trend of the last 50 yr is not statistically different from the level of internal atmosphere–ocean variability. The unforced simulations also show a strong link between positive SST trends in the ENSO region and negative Aleutian low trends. With much larger observed SST trends in the ENSO region, this suggests that the observed negative Aleutian low trend is possibly influenced by external forcing, for example, global warming, volcanism, and/or solar activity change.

scholarly journals Assessing the response of groundwater quantity and travel time distribution to 1.5, 2 and 3 degrees global warming in a mesoscale central German basin

2019 ◽  
Author(s):  
Miao Jing ◽  
Rohini Kumar ◽  
Falk Heße ◽  
Stephan Thober ◽  
Oldrich Rakovec ◽  
...  
Keyword(s):  
Global Warming ◽  
Travel Time ◽  
General Circulation ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Groundwater Model ◽  
Groundwater System ◽  
Ensemble Simulations ◽  
Regional Groundwater ◽  
German Basin

Abstract. Groundwater is the biggest single source of high-quality fresh water worldwide, which is also continuously threatened by the changing climate. This paper is designed to investigate the response of regional groundwater system to the climate change under three global warming levels (1.5, 2, and 3 °C) in a central German basin (Nägelstedt). This investigation is conducted by deploying an integrated modeling workflow that consists of a mesoscale Hydrologic Model (mHM) and a fully-distributed groundwater model OpenGeoSys (OGS). mHM is forced by five general circulation models under three representative concentration pathways. The diffuse recharges estimated by mHM are used as outer forcings of the OGS groundwater model to compute changes in groundwater levels and travel time distributions. Simulation results indicate that under future climate scenarios, groundwater recharges and levels are expected to increase slightly. Meanwhile, the mean travel time is expected to decrease compared to the historical average. However, the ensemble simulations do not all agree on the sign of relative change. The ensemble simulations do not show a systematic relationship between the predicted change and the warming level, but they indicate an increased variability in predicted changes with the enhanced warming level from 1.5 to 3 °C. This study indicates that a higher warming level may introduce more uncertain and extreme events for the studied regional groundwater system.

scholarly journals Contrasting dynamics of hydrological processes in the Volta River basin under global warming

2021 ◽  
Author(s):  
Moctar Dembélé ◽  
Mathieu Vrac ◽  
Natalie Ceperley ◽  
Sander J. Zwart ◽  
Josh Larsen ◽  
...  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
River Basin ◽  
General Circulation ◽  
Climate Models ◽  
Greenhouse Gas Emission ◽  
Local Population ◽  
Hydrologic Model ◽  
Mitigation Strategies ◽  
Low Flow

Abstract. A comprehensive evaluation of the impacts of climate change on water resources of the West Africa Volta River basin is conducted in this study, as the region is expected to be hardest hit by global warming. A large ensemble of twelve general circulation models (GCM) from CMIP5 that are dynamically downscaled by five regional climate models (RCM) from CORDEX-Africa is used. In total, 43 RCM-GCM combinations are considered under three representative concentration pathways (RCP2.6, RCP4.5 and RCP8.5). The reliability of each of the climate datasets is first evaluated with satellite and reanalysis reference datasets. Subsequently, the Rank Resampling for Distributions and Dependences (R2D2) multivariate bias correction method is applied to the climate datasets. The corrected simulations are then used as input to the fully distributed mesoscale Hydrologic Model (mHM) for hydrological projections over the twenty-first century (1991–2100). Results reveal contrasting changes in the seasonality of rainfall depending on the selected greenhouse gas emission scenarios and the future projection periods. Although air temperature and potential evaporation increase under all RCPs, an increase in the magnitude of all hydrological variables (actual evaporation, total runoff, groundwater recharge, soil moisture and terrestrial water storage) is only projected under RCP8.5. High and low flow analysis suggests an increased flood risk under RCP8.5, particularly in the Black Volta, while hydrological droughts would be recurrent under RCP2.6 and RCP4.5, particularly in the White Volta. Disparities are observed in the spatial patterns of hydroclimatic variables across climatic zones, with higher warming in the Sahelian zone. Therefore, climate change would have severe implications for future water availability with concerns for rain-fed agriculture, thereby weakening the water-energy-food security nexus and amplifying the vulnerability of the local population. The variability between climate models highlights uncertainties in the projections and indicates a need to better represent complex climate features in regional models. These findings could serve as a guideline for both the scientific community to improve climate change projections and for decision makers to elaborate adaptation and mitigation strategies to cope with the consequences of climate change and strengthen regional socio-economic development.

EVALUATION OF GENERAL CIRCULATION MODELS IN PREDICTING MONTHLY RAINFALL FOR THE SANFRANCISCO RIVER BASIN

2019 ◽  
Author(s):  
EDUARDO E. DE FIGUEIREDO ◽  
RICARDO DE ARAGÃO ◽  
MARCOS A. S. CRUZ ◽  
ANDRÉ Q ALMEIDA ◽  
VAJAPEYAM S SRINIVASAN
Keyword(s):  
River Basin ◽  
General Circulation ◽  
General Circulation Models ◽  
Monthly Rainfall

Potential Changes in Extreme Events Under Global Climate Change

2008 ◽  
Vol 3 (1) ◽  
pp. 39-50 ◽  
Author(s):  
Koji Dairaku ◽  
◽  
Seita Emori ◽  
Hironori Higashi ◽  
Keyword(s):  
Climate Change ◽  
Global Warming ◽  
Summer Monsoon ◽  
Extreme Events ◽  
Extreme Precipitation ◽  
General Circulation ◽  
Asian Summer Monsoon ◽  
Climate Conditions ◽  
Asian Summer ◽  
A1b Scenario

Climate-related disasters are a serious problem in Asia. Advances in the understanding of meteorology and in the development of monitoring and forecasting systems have enhanced early warning systems, contributing immensely to reducing fatalities resulting from typhoons, cyclones, and floods. The frequency of extreme events causing water-related disasters has increased, however, over the last decade and may grow in the future due to anthropogenic activity. The sections that follow introduce two recent efforts in hydrologic projection in Asia. Time-slice ensemble experiments using a high-resolution (T106) atmospheric general circulation model (AGCM) on the earth simulator revealed changes in the South Asian summer monsoon resulting from climate change. Model results under global warming conditions suggest increases in mean and extreme precipitation during the Asian summer monsoon. increases generally attributed to greater atmospheric moisture content. a thermodynamic change. Dynamic changes limit the intensification of mean precipitation. Enhanced extreme precipitation over land in South Asia arises from dynamic rather than thermodynamic changes. The impact of global warming on heavy precipitation features and flood risks in the Tama River basin in Japan is addressed using 12 atmosphere-ocean coupled general circulation models (AOGCMs). Multi-model ensemble average 200-year quantiles in Tokyo from 2050 to 2300 under Intergovernmental Panel on Climate Changes (IPCC) Special Reports on Emissions Scenarios (SRES) A1B scenario climate conditions were 1.07-1.20 times greater than that under present climate conditions. A 200-year quantile extreme event in the present occurs in much shorter return periods in the A1B scenario. High-water discharge in the basin rose by 10%-26% and flood volume increased by 46%-131% for precipitation in a 200-year return period. The risk of flooding in the basin is thus, even though the increase of extreme precipitation is not substantial, projected to be much higher than that presently estimated.

scholarly journals Seasonality of the hydrological cycle in major South and Southeast Asian River Basins as simulated by PCMDI/CMIP3 experiments

2013 ◽  
Vol 4 (2) ◽  
pp. 627-675 ◽  
Author(s):  
S. Hasson ◽  
V. Lucarini ◽  
S. Pascale ◽  
J. Böhner
Keyword(s):  
General Circulation ◽  
Hydrological Cycle ◽  
Monsoon Season ◽  
General Circulation Models ◽  
River Basins ◽  
Southeast Asian ◽  
Indus Basin ◽  
Precipitation Regime ◽  
Precipitation Regimes ◽  
Projected Changes

Abstract. In this study, we investigate how PCMDI/CMIP3 general circulation models (GCMs) represent the seasonal properties of the hydrological cycle in four major South and Southeast Asian river basins (Indus, Ganges, and Brahmaputra and Mekong). First, we examine the skill of GCMs by analysing their simulations for the XX century climate (1961–2000) under present-day forcing, and then we analyse the projected changes for the corresponding XXI and XXII century climates under SRESA1B scenario. CMIP3 GCMs show a varying degree of skill in simulating the basic characteristics of the monsoonal precipitation regimes of the Ganges, Brahmaputra and Mekong basins, while the representation of the hydrological cycle over the Indus basin is poor in most cases, with few GCMs not capturing the monsoon signal at all. Although the models' outputs feature a remarkable spread for the monsoonal precipitations, a satisfactory representation of the western mid-latitude precipitation regime is instead observed. Similarly, most of the models exhibit a satisfactory agreement for the basin-integrated runoff in winter and spring, while the spread is large for the runoff during the monsoon season. For future climate scenarios, winter (spring) P − E decreases over all four (Indus and Ganges) basins due to decrease in precipitation associated with the western mid-latitude disturbances. Consequently, the spring (winter) runoff drops (rises) for the Indus and Ganges basins. Such changes indicate a shift from rather glacial and nival to more pluvial runoff regimes, particularly for the Indus basin. Furthermore, the rise in the projected runoff along with the increase in precipitations during summer and autumn indicates an intensification of the summer monsoon regime for all study basins.

Sign in / Sign up

Export Citation Format

Share Document