scholarly journals Application of an Integrated SWAT–MODFLOW Model to Evaluate Potential Impacts of Climate Change and Water Withdrawals on Groundwater–Surface Water Interactions in West-Central Alberta

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 110 ◽  
Author(s):  
David Chunn ◽  
Monireh Faramarzi ◽  
Brian Smerdon ◽  
Daniel Alessi

It has become imperative that surface and groundwater resources be managed as a holistic system. This study applies a coupled groundwater–surface water (GW–SW) model, SWAT–MODFLOW, to study the hydrogeological conditions and the potential impacts of climate change and groundwater withdrawals on GW–SW interactions at a regional scale in western Canada. Model components were calibrated and validated using monthly river flow and hydraulic head data for the 1986–2007 period. Downscaled climate projections from five General Circulation Models (GCMs), under the RCP 8.5, for the 2010–2034 period, were incorporated into the calibrated model. The results demonstrated that GW–SW exchange in the upstream areas had the most pronounced fluctuation between the wet and dry months under historical conditions. While climate change was revealed to have a negligible impact in the GW–SW exchange pattern for the 2010–2034 period, the addition of pumping 21 wells at a rate of 4680 m3/d per well to support hypothetical high-volume water use by the energy sector significantly impacted the exchange pattern. The results showed that the total average discharge into the rivers was only slightly reduced from 1294 m3/d to 1174 m3/d; however, localized flowrate differences varied from under 5 m3/d to over 3000 m3/d in 320 of the 405 river cells. The combined potential impact is that intensive groundwater use may have more immediate effects on river flow than those of climate change, which has important implications for water resources management and for energy supply in the future.

2008 ◽  
Vol 12 (2) ◽  
pp. 449-463 ◽  
Author(s):  
M. Posch ◽  
J. Aherne ◽  
M. Forsius ◽  
S. Fronzek ◽  
N. Veijalainen

Abstract. The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC) was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically) feasible reductions (MFR). Future climate (temperature and precipitation) was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under two global scenarios of the Intergovernmental Panel on Climate Change (IPCC: A2 and B2). The combinations resulting in the widest range of future changes were used for simulations, i.e., the A2 scenario results from ECHAM4/OPYC3 (highest predicted change) and B2 results from HadAM3 (lowest predicted change). Future scenarios for catchment runoff were obtained from the Finnish watershed simulation and forecasting system. The potential influence of future changes in surface water organic carbon concentrations was also explored using simple empirical relationships based on temperature and sulphate deposition. Surprisingly, current emission reduction policies hardly show any future recovery; however, significant chemical recovery of soil and surface water from acidification was predicted under the MFR emission scenario. The direct influence of climate change (temperate and precipitation) on recovery was negligible, as runoff hardly changed; greater precipitation is offset by increased evapotranspiration due to higher temperatures. However, two exploratory empirical DOC models indicated that changes in sulphur deposition or temperature could have a confounding influence on the recovery of surface waters from acidification, and that the corresponding increases in DOC concentrations may offset the recovery in pH due to reductions in acidifying depositions.


2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Vimal Mishra ◽  
Udit Bhatia ◽  
Amar Deep Tiwari

Abstract Climate change is likely to pose enormous challenges for agriculture, water resources, infrastructure, and livelihood of millions of people living in South Asia. Here, we develop daily bias-corrected data of precipitation, maximum and minimum temperatures at 0.25° spatial resolution for South Asia (India, Pakistan, Bangladesh, Nepal, Bhutan, and Sri Lanka) and 18 river basins located in the Indian sub-continent. The bias-corrected dataset is developed using Empirical Quantile Mapping (EQM) for the historic (1951–2014) and projected (2015–2100) climate for the four scenarios (SSP126, SSP245, SSP370, SSP585) using output from 13 General Circulation Models (GCMs) from Coupled Model Intercomparison Project-6 (CMIP6). The bias-corrected dataset was evaluated against the observations for both mean and extremes of precipitation, maximum and minimum temperatures. Bias corrected projections from 13 CMIP6-GCMs project a warmer (3–5°C) and wetter (13–30%) climate in South Asia in the 21st century. The bias-corrected projections from CMIP6-GCMs can be used for climate change impact assessment in South Asia and hydrologic impact assessment in the sub-continental river basins.


Author(s):  
H. M. S. M. Herath ◽  
P. R. Sarukkalige ◽  
V. T. V. Nguyen

Abstract. Downscaling of climate projections is the most adopted method to assess the impacts of climate change at regional and local scale. In the last decade, downscaling techniques which provide reasonable improvement to resolution of General Circulation Models' (GCMs) output are developed in notable manner. Most of these techniques are limited to spatial downscaling of GCMs' output and still there is a high demand to develop temporal downscaling approaches. As the main objective of this study, combined approach of spatial and temporal downscaling is developed to improve the resolution of rainfall predicted by GCMs. Canberra airport region is subjected to this study and the applicability of proposed downscaling approach is evaluated for Sydney, Melbourne, Brisbane, Adelaide, Perth and Darwin regions. Statistical Downscaling Model (SDSM) is used to spatial downscaling and numerical model based on scaling invariant concept is used to temporal downscaling of rainfalls. National Centre of Environmental Prediction (NCEP) data is used in SDSM model calibration and validation. Regression based bias correction function is used to improve the accuracy of downscaled annual maximum rainfalls using HadCM3-A2. By analysing the non-central moments of observed rainfalls, single time regime (from 30 min to 24 h) is identified which exist scaling behaviour and it is used to estimate the sub daily extreme rainfall depths from daily downscaled rainfalls. Finally, as the major output of this study, Intensity Duration Frequency (IDF) relations are developed for the future periods of 2020s, 2050s and 2080s in the context of climate change.


2012 ◽  
Vol 9 (5) ◽  
pp. 6569-6614 ◽  
Author(s):  
H. Lauri ◽  
H. de Moel ◽  
P. J. Ward ◽  
T. A. Räsänen ◽  
M. Keskinen ◽  
...  

Abstract. The transboundary Mekong River is facing two on-going changes that are estimated to significantly impact its hydrology and the characteristics of its exceptional flood pulse. The rapid economic development of the riparian countries has led to massive plans for hydropower construction, and the projected climate change is expected to alter the monsoon patterns and increase temperature in the basin. The aim of this study is to assess the cumulative impact of these factors on the hydrology of the Mekong within next 20–30 yr. We downscaled output of five General Circulation Models (GCMs) that were found to perform well in the Mekong region. For the simulation of reservoir operation, we used an optimisation approach to estimate the operation of multiple reservoirs, including both existing and planned hydropower reservoirs. For hydrological assessment, we used a distributed hydrological model, VMod, with a grid resolution of 5 km × 5 km. In terms of climate change's impact to hydrology, we found a high variation in the discharge results depending on which of the GCMs is used as input. The simulated change in discharge at Kratie (Cambodia) between the baseline (1982–1992) and projected time period (2032–2042) ranges from −11% to +15% for the wet season and −10% to +13% for the dry season. Our analysis also shows that the changes in discharge due to planned reservoir operations are clearly larger than those simulated due to climate change: 25–160% higher dry season flows and 5–24% lower flood peaks in Kratie. The projected cumulative impacts follow rather closely the reservoir operation impacts, with an envelope around them induced by the different GCMs. Our results thus indicate that within the coming 20–30 yr, the operation of planned hydropower reservoirs is likely to have a larger impact on the Mekong hydrograph than the impacts of climate change, particularly during the dry season. On the other hand, climate change will increase the uncertainty of the estimated hydropower impacts. Consequently, both dam planners and dam operators should pay better attention to the cumulative impacts of climate change and reservoir operation to the aquatic ecosystems, including the multibillion-dollar Mekong fisheries.


MAUSAM ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 229-244
Author(s):  
K. RUPA KUMAR ◽  
R. G. ASHRIT

The regional climatic impacts associated with global climatic change and their assessment are very important since agriculture, water resources, ecology etc., are all vulnerable to climatic changes on regional scale. Coupled Atmosphere-Ocean general circulation model (AOGCM) simulations provide a range of scenarios, which can be used, for the assessment of impacts and development of adaptive or mitigative strategies. Validation of the models against the observations and establishing the sensitivity to climate change forcing are essential before the model projections are used for assessment of possible impacts. Moreover model simulated climate projections are often of coarse resolution while the models used for impact assessment, (e.g. crop simulation models, or river runoff models etc.) operate on a higher spatial resolution. This spatial mismatch can be overcome by adopting an appropriate strategy of downscaling the GCM output.   This study examines two AOGCM (ECHAM4/OPYC3 and HadCM2) climate change simulations for their performance in the simulation of monsoon climate over India and the sensitivity of the simulated monsoon climate to transient changes in the atmospheric concentrations of greenhouse gases and sulfate aerosols. The results show that the two models simulate the gross features of climate over India reasonably well. However the inter-model differences in simulation of mean characteristics, sensitivity to forcing and in the simulation of climate change suggest need for caution. Further an empirical downscaling approach in used to assess the possibility of using GCM projections for preparation of regional climate change scenario for India.


2013 ◽  
Vol 16 (4) ◽  
pp. 872-889 ◽  
Author(s):  
Chi Zhang ◽  
Xueping Zhu ◽  
Guangtao Fu ◽  
Huicheng Zhou ◽  
Hao Wang

This paper presents an assessment framework that analyses the impacts of climate change on the water diversion strategies of a water transfer project in China. A water diversion strategy consists of high and low water levels as well as related diversion flows in four operating periods: pre-flood, flood, post-flood and non-flood periods. The optimal water diversion problem is defined as a multi-objective problem with two conflicting objectives: minimising human and ecological water supply shortages, and solved by the popular non-dominated sorting genetic algorithm II (NSGA-II). The derived Pareto-optimal solutions are then evaluated using the predicted runoffs based on an ensemble of three general circulation models under three climate scenarios. Results obtained from the study catchment show that intra-annual distribution of future runoff changes. The optimal solutions on the Pareto front have greatly varying performance under a climate scenario. It is critical to reveal the different impacts of climate change on the water shortages over the four operating periods, in particular when an increase of water shortage in one period is masked by a reduction in one or more periods. This study illustrates that the framework can be used to identify resilient water diversion strategies to mitigate the potential impacts of climate change on the operation of a water transfer project.


2016 ◽  
Vol 21 (5) ◽  
pp. 581-602 ◽  
Author(s):  
Juliano Assunção ◽  
Flávia Chein

AbstractThis paper evaluates the impact of climate change on agricultural productivity. Cross-sectional variation in climate among Brazilian municipalities is used to estimate an equation in which geographical attributes determine agricultural productivity. The Intergovernmental Panel on Climate Change (IPCC) predictions based on atmosphere–ocean, coupled with general circulation models (for 2030–2049), are used to simulate the impacts of climate change. Our estimates suggest that global warming under the current technological standards is expected to decrease the agricultural output per hectare in Brazil by 18 per cent, with the effects on municipalities ranging from−40 to+15 per cent.


2007 ◽  
Vol 4 (5) ◽  
pp. 3209-3248 ◽  
Author(s):  
M. Posch ◽  
J. Aherne ◽  
M. Forsius ◽  
S. Fronzek ◽  
N. Veijalainen

Abstract. The dynamic hydro-chemical Model of Acidification of Groundwater in Catchments (MAGIC) was used to predict the response of 163 Finnish lake catchments to future acidic deposition and climatic change scenarios. Future deposition was assumed to follow current European emission reduction policies and a scenario based on maximum (technologically) feasible reductions (MFR). Future climate (temperature and precipitation) was derived from the HadAM3 and ECHAM4/OPYC3 general circulation models under two global scenarios of the Intergovernmental Panel on Climate Change (IPCC: A2 and B2). The combinations resulting in the widest range of future changes were used for simulations, i.e., the A2 scenario results from ECHAM4/OPYC3 (highest predicted change) and B2 results from HadAM3 (lowest predicted change). Future scenarios for catchment runoff were obtained from the Finnish watershed simulation and forecasting system. The potential influence of future changes in surface water organic carbon concentrations was also explored using simple empirical relationships based on temperature and sulphate deposition. Surprisingly, current emission reduction policies hardly show any future recovery; however, significant chemical recovery of soil and surface water from acidification was predicted under the MFR emission scenario. The direct influence of climate change (temperate and precipitation) on recovery was negligible, as runoff hardly changed; greater precipitation is offset by increased evapotranspiration due to higher temperatures. Predicted changes in dissolved organic carbon induced by reductions in acid deposition or increases in temperature may potentially influence the recovery of surface waters from acidification and may offset the increase in pH resulting from S deposition reductions. However, many climate-induced changes in processes are generally not incorporated in current versions of acidification models. To allow more reliable forecasts, the mechanisms by which climate changes affect key biogeochemical processes need to be incorporated directly into process-oriented models such as MAGIC.


2021 ◽  
Author(s):  
Richard Fewster ◽  
Paul Morris ◽  
Ruza Ivanovic ◽  
Graeme Swindles ◽  
Anna Peregon ◽  
...  

<p>Northern permafrost peatlands represent one of Earth’s largest terrestrial carbon stores and are highly sensitive to climate change. Whilst frozen, peatland carbon fluxes are restricted by cold temperatures, but once permafrost thaws and saturated surficial conditions develop, emissions of carbon dioxide (CO<sub>2</sub>) and methane (CH<sub>4</sub>) substantially increase. This positive feedback mechanism threatens to accelerate future climate change globally. Whilst future permafrost distributions in mineral soils have been modelled extensively, the insulating properties of organic soils mean that peatland permafrost responses are highly uncertain. Peatland permafrost is commonly evidenced by frost mounds, termed palsas/peat plateaus, or by polygonal patterning in more northerly regions. Although the distribution of palsas in northern Fennoscandia is well-studied, the extent of palsas/peat plateaus and polygon mires elsewhere remains poorly constrained, which currently restricts predictions of their future persistence under climate change.  </p><p>Here, we present the first pan-Arctic analyses of the modern climate envelopes and future distributions of permafrost peatland landforms in North America, Fennoscandia, and Western Siberia. We relate a novel hemispheric-scale catalogue of palsas/peat plateaus and polygon mires (>2,100<strong> </strong>individual sites) to modern climate data using one-vs-all (OVA) binary logistic regression. We predict future distributions of permafrost peatland landforms across the northern hemisphere under four Shared Socioeconomic Pathway (SSP) scenarios, using future climate projections from an ensemble of 12 general circulation models included in the Coupled Model Intercomparison Project 6 (CMIP6). We then combine our simulations with recent soil organic carbon maps to estimate how northern peatland carbon stocks may be affected by future permafrost redistribution. These novel analyses will improve our understanding of future peatland trajectories across the northern hemisphere and assist predictions of climate feedbacks resulting from peatland permafrost thaw. </p>


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