Impacts of climate change on the frequency and severity of floods in the Châteauguay River basin, Canada

2007 ◽  
Vol 34 (9) ◽  
pp. 1048-1060 ◽  
Author(s):  
Arnaud Mareuil ◽  
Robert Leconte ◽  
François Brissette ◽  
Marie Minville

This study aims at evaluating the hydrologic impacts of climate change on the Châteauguay River basin in the province of Quebec, Canada. Three global climate models (GCMs) covering a range of climate sensitivities were selected, and their output was employed to adjust the parameters of a stochastic weather generator using simple transformation rules for precipitation and temperature. Values of monthly precipitation and temperature were extracted from the GCMs for the current (1960–1990) and future (2040–2060) climate. The International Panel on Climate Change emission scenario known as B2 was selected. It represents an average scenario and corresponds approximately to a doubling of the atmospheric CO2 concentration. Resorting to stochastically generated climate scenarios allowed assessing whether the modelled effects of climate change on flows were statistically significant. Results indicate that spring and summer–fall peak flows were reduced on average by 30% and 12%, respectively, using the Echam4 model derived scenarios. The Hadcm3 model produced a weaker signal that was not statistically significant. The CGCM2 model produced a statistically significant reduction in spring peak flows of 8% on average, whereas the simulated reduction in summer flows was not statistically significant for many of the return periods considered. Many sources of uncertainties were partially considered in this study. One is the downscaling of the GCM climatology at the watershed scale. The approach employed to generate the future climate scenarios changed the precipitation variability through an adjustment of the parameters of the Gamma distribution function used to model precipitation amounts. Whether this approach is truly typical of climate change effect remains to be ascertained. Using more physically based hydrological models would help reduce uncertainties in climate change impacts studies.Key words: climate change, weather generator, flood, frequency analysis, hydrological modelling.

2021 ◽  
Vol 16 (8) ◽  
pp. 1197-1206
Author(s):  
Sohaib Baig ◽  
Takahiro Sayama ◽  
Kaoru Takara ◽  
◽  
◽  
...  

The upper Indus River basin has large masses of glaciers that supply meltwater in the summer. Water resources from the upper Indus River basin are crucial for human activities and ecosystems in Pakistan, but they are vulnerable to climate change. This study focuses on the impacts of climate change, particularly the effects of receding glaciers on the water resources in a catchment of the upper Indus river basin. This study predicts river flow using a hydrologic model coupled with temperature-index snow and glacier melt models forced by observed climate data. The basin is divided into seven elevation zones so that the melt components and rainfall-runoff were calculated at each elevation zone. Hydrologic modeling revealed that glaciers contributed one-third of the total flow while snowmelt melt contributed about 40%; rainfall contributed to the remaining flow. Some climate scenarios based on CMIP5 and CORDEX were employed to quantify the impacts of climate change on annual river flows. The glacier retreat in the mid and late centuries is also considered based on climate change scenarios. Future river flows, simulated by the hydrologic model, project significant changes in their quantity and timing. In the mid-century, river flows will increase because of higher precipitation and glacier melt. Simulations projected that until 2050, the overall river flows will increase by 11%, and no change in the shape of the hydrograph is expected. However, this increasing trend in river flows will reverse in the late century because glaciers will not have enough mass to sustain the glacier melt flow. The change will result in a 4.5% decrease in flow, and the timing of the monthly peak flow will shift from June to May. This earlier shift in the streamflow will make water management more difficult in the future, requiring inclusive approaches in water resource management.


Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2825
Author(s):  
Xupu Li ◽  
Liwei Zhang ◽  
Patrick J. O’Connor ◽  
Junping Yan ◽  
Bin Wang ◽  
...  

Climate change can have critical impacts on ecosystem services (ESs) and their inter-relationships, especially for water-related services. However, there has been little work done on characterizing the current and future changes in these services and their inter-relationships under a changing climate. Based on the revised universal soil loss equation (RUSLE), the soil conservation service curve number model (SCS-CN), and the improved stochastic weather-generator-based statistical downscaled global climate models (GCMs), we examined two important water-related services, namely, the soil conservation (SC) service and the flood mitigation (FM) service, and their inter-relationship under baseline and future climate scenarios (Representative Concentration Pathways (RCPs) 4.5 and 8.5). We took the Upper Hanjiang River Basin (UHRB), which is the core water source area of the China’s South-to-North Water Diversion Project (S–NWDP), as an illustration. The findings revealed that (1) the SC and FM services will both decrease under the two climate scenarios examined; (2) the SC and FM services showed a significant synergistic inter-relationship and the synergy will be improved by 16.48% and 2.95% under RCP 4.5 and RCP 8.5, respectively, which provides an opportunity for management optimization; (3) the ecological degradation in the UHRB will likely have serious consequences for the middle and lower reaches of the Hanjiang river basin, and therefore impact the actual economic benefits of the S–NWDP. This study points to the necessity for understanding the dynamic changes and inter-relationships of ecosystem services under future climate change and provides information regarding the consequences of climate change, which is useful for policy and infrastructure investment.


2020 ◽  
Vol 30 (1) ◽  
pp. 85-102 ◽  
Author(s):  
Qihui Chen ◽  
Hua Chen ◽  
Jun Zhang ◽  
Yukun Hou ◽  
Mingxi Shen ◽  
...  

2014 ◽  
Vol 11 (5) ◽  
pp. 4579-4638 ◽  
Author(s):  
M. C. Peel ◽  
R. Srikanthan ◽  
T. A. McMahon ◽  
D. J. Karoly

Abstract. Two key sources of uncertainty in projections of future runoff for climate change impact assessments are uncertainty between Global Climate Models (GCMs) and within a GCM. Within-GCM uncertainty is the variability in GCM output that occurs when running a scenario multiple times but each run has slightly different, but equally plausible, initial conditions. The limited number of runs available for each GCM and scenario combination within the Coupled Model Intercomparison Project phase 3 (CMIP3) and phase 5 (CMIP5) datasets, limits the assessment of within-GCM uncertainty. In this second of two companion papers, the primary aim is to approximate within-GCM uncertainty of monthly precipitation and temperature projections and assess its impact on modelled runoff for climate change impact assessments. A secondary aim is to assess the impact of between-GCM uncertainty on modelled runoff. Here we approximate within-GCM uncertainty by developing non-stationary stochastic replicates of GCM monthly precipitation and temperature data. These replicates are input to an off-line hydrologic model to assess the impact of within-GCM uncertainty on projected annual runoff and reservoir yield. To-date within-GCM uncertainty has received little attention in the hydrologic climate change impact literature and this analysis provides an approximation of the uncertainty in projected runoff, and reservoir yield, due to within- and between-GCM uncertainty of precipitation and temperature projections. In the companion paper, McMahon et al. (2014) sought to reduce between-GCM uncertainty by removing poorly performing GCMs, resulting in a selection of five better performing GCMs from CMIP3 for use in this paper. Here we present within- and between-GCM uncertainty results in mean annual precipitation (MAP), temperature (MAT) and runoff (MAR), the standard deviation of annual precipitation (SDP) and runoff (SDR) and reservoir yield for five CMIP3 GCMs at 17 world-wide catchments. Based on 100 stochastic replicates of each GCM run at each catchment, within-GCM uncertainty was assessed in relative form as the standard deviation expressed as a percentage of the mean of the 100 replicate values of each variable. The average relative within-GCM uncertainty from the 17 catchments and 5 GCMs for 2015–2044 (A1B) were: MAP 4.2%, SDP 14.2%, MAT 0.7%, MAR 10.1% and SDR 17.6%. The Gould–Dincer Gamma procedure was applied to each annual runoff time-series for hypothetical reservoir capacities of 1× MAR and 3× MAR and the average uncertainty in reservoir yield due to within-GCM uncertainty from the 17 catchments and 5 GCMs were: 25.1% (1× MAR) and 11.9% (3× MAR). Our approximation of within-GCM uncertainty is expected to be an underestimate due to not replicating the GCM trend. However, our results indicate that within-GCM uncertainty is important when interpreting climate change impact assessments. Approximately 95% of values of MAP, SDP, MAT, MAR, SDR and reservoir yield from 1× MAR or 3× MAR capacity reservoirs are expected to fall within twice their respective relative uncertainty (standard deviation/mean). Within-GCM uncertainty has significant implications for interpreting climate change impact assessments that report future changes within our range of uncertainty for a given variable – these projected changes may be due solely to within-GCM uncertainty. Since within-GCM variability is amplified from precipitation to runoff and then to reservoir yield, climate change impact assessments that do not take into account within-GCM uncertainty risk providing water resources management decision makers with a sense of certainty that is unjustified.


2021 ◽  
Vol 6 (2) ◽  
pp. p55
Author(s):  
Wilawan Boonsri Prathaithep ◽  
Vilas Nitivattananon

Traditionally, flood management has concentrated on providing protection against floods using technical measures, but there is currently an international shift towards a more integrated system of flood risk management, whereby flood risk is defined as the probability of flooding multiplied by the potential consequences. Climate change is a great challenge to sustainable development and the Millennium Development Goals (MDGs) in Thailand. The main purpose of this paper is to highlight the challenges associated with the current situation and projected impacts of climate change on the disasters and the human environment in Thailand, to review and explore the potential of Strategic Environmental Assessment (SEA), and to propose SEA in making informed decisions relevant to the implementation of the new adaptation framework in a flood management plan. Thus, current measures on how Thailand is responding to the recent impacts of climate change in river basin planning are presented. It is imperative that an appropriate environmental assessment tool, such as SEA be employed in making rational decisions regarding adaptation frameworks. SEA offers a structured and proactive environmental tool for integrating of climate change adaption into formulating Policies, Plans, and Programs (PPPs) among relevant sectors.


2016 ◽  
Vol 141 (3) ◽  
pp. 533-546 ◽  
Author(s):  
Buda Su ◽  
Jinlong Huang ◽  
Xiaofan Zeng ◽  
Chao Gao ◽  
Tong Jiang

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