Integrated hydrological modelling of surface water and groundwater under climate change: the case of the Mygdonia basin in Greece

2019 ◽  
Vol 11 (4) ◽  
pp. 1429-1454 ◽  
Author(s):  
Dimitrios Malamataris ◽  
Elpida Kolokytha ◽  
Athanasios Loukas

Abstract Lakes Volvi and Koronia are located in the Mygdonia basin and constitute the second and fifth largest natural lakes in Greece, respectively. The lakes along with the Mygdonia basin aquifer have undergone severe quantitative and qualitative degradation, while Lake Koronia has been totally depleted in recent years. In this study, a fully integrated hydrological analysis of the Mygdonia basin for historical and future periods is carried out. Future climatic data were derived and analyzed from a Regional Climate Model, while the implications of climate change on the water balance of both lakes and the Mygdonia basin aquifer until 2100 were projected by developing a modelling system which includes coupled hydrological and hydraulic models, such as UTHBAL, MIKE SHE, MIKE HYDRO River and the MIKE HYDRO Basin. The results indicated that the precipitation is expected to decrease by 17%, the temperature to increase by 2.90 °C and as a result, the surface runoff is projected to decrease by 21% and the groundwater recharge to decrease by 38% in the Mygdonia basin at the end of the century. The above changes would have a direct negative impact on the Lakes Koronia and Volvi and the Mygdonia basin aquifer future water balance necessitating adaptation measures.

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1494
Author(s):  
Bernardo Teufel ◽  
Laxmi Sushama

Fluvial flooding in Canada is often snowmelt-driven, thus occurs mostly in spring, and has caused billions of dollars in damage in the past decade alone. In a warmer climate, increasing rainfall and changing snowmelt rates could lead to significant shifts in flood-generating mechanisms. Here, projected changes to flood-generating mechanisms in terms of the relative contribution of snowmelt and rainfall are assessed across Canada, based on an ensemble of transient climate change simulations performed using a state-of-the-art regional climate model. Changes to flood-generating mechanisms are assessed for both a late 21st century, high warming (i.e., Representative Concentration Pathway 8.5) scenario, and in a 2 °C global warming context. Under 2 °C of global warming, the relative contribution of snowmelt and rainfall to streamflow peaks is projected to remain close to that of the current climate, despite slightly increased rainfall contribution. In contrast, a high warming scenario leads to widespread increases in rainfall contribution and the emergence of hotspots of change in currently snowmelt-dominated regions across Canada. In addition, several regions in southern Canada would be projected to become rainfall dominated. These contrasting projections highlight the importance of climate change mitigation, as remaining below the 2 °C global warming threshold can avoid large changes over most regions, implying a low likelihood that expensive flood adaptation measures would be necessary.


Author(s):  
Vadim Yapiyev ◽  
Kanat Samarkhanov ◽  
Dauren Zhumabayev ◽  
Nazym Tulegenova ◽  
Saltanat Jumassultanova ◽  
...  

Both climate change and anthropogenic activities contribute to the deterioration of terrestrial water resources and ecosystems worldwide. Central Asian endorheic basins are among the most affected regions through both climate and human impacts. Here, we used a digital elevation model, digitized bathymetry maps and Landsat images to estimate the areal water cover extent and volumetric storage changes in small terminal lakes in Burabay National Nature Park (BNNP), located in Northern Central Asia (CA), for the period of 1986 to 2016. Based on the analysis of long-term climatic data from meteorological stations, short-term hydrometeorological network observations, gridded climate datasets (CRU) and global atmospheric reanalysis (ERA Interim), we have evaluated the impacts of historical climatic conditions on the water balance of BNNP lake catchments. We also discuss the future based on regional climate model projections. We attribute the overall decline of BNNP lakes to long-term deficit of water balance with lake evaporation loss exceeding precipitation inputs. Direct anthropogenic water abstraction has a minor importance in water balance. However, the changes in watersheds caused by the expansion of human settlements and roads disrupting water drainage may play a more significant role in lake water storage decline. More precise water resources assessment at the local scale will be facilitated by further development of freely available higher spatial resolution remote sensing products. In addition, the results of this work can be used for the development of lake/reservoir evaporation models driven by remote sensing and atmospheric reanalysis data without the direct use of ground observations.


2018 ◽  
Vol 9 (4) ◽  
pp. 657-671 ◽  
Author(s):  
Mirko Knežević ◽  
Ljubomir Zivotić ◽  
Nataša Čereković ◽  
Ana Topalović ◽  
Nikola Koković ◽  
...  

Abstract The impact of climate change on potato cultivation in Montenegro was assessed. Three scenarios (A1B, A1Bs and A2) for 2001–2030, 2071–2100 and 2071–2100, respectively, were generated by a regional climate model and compared with the baseline period 1961–1990. The results indicated an increase of temperature during the summer season from 1.3 to 4.8 °C in the mountain region and from 1 to 3.4 °C in the coastal zone. The precipitation decreased between 5 and 50% depending on the scenario, region and season. The changes in temperature and precipitation influenced phenology, yield and water needs. The impact was more pronounced in the coastal areas than in the mountain regions. The growing season was shortened 13.6, 22.9 and 29.7 days for A1B, A1Bs and A2, respectively. The increase of irrigation requirement was 4.0, 19.5 and 7.3 mm for A1B, A1Bs and A2, respectively. For the baseline conditions, yield reduction under rainfed cultivation was lower than 30%. For A1B, A1Bs and A2 scenarios, yield reductions were 31.0 ± 8.2, 36.3 ± 11.6 and 34.1 ± 10.9%, respectively. Possible adaptation measures include shifting of production to the mountain (colder) areas and irrigation application. Rainfed cultivation remains a viable solution when the anticipation of sowing is adopted.


2021 ◽  
Vol 24 (s1) ◽  
pp. 20-26
Author(s):  
Lia Megrelidze ◽  
Nato Kutaladze ◽  
Gizo Gogichaishvili ◽  
Marina Shvangiradze

Abstract Under the increase of the concern for food security in the world, mainly caused by water resources shortages, the forecast and determination of crop yield at regional scale has been considered as a strategic topic. This study has been conducted to assess the possible impacts of the climate change on cereal crops productivity and irrigation requirement for two main producing regions of Georgia, according to the current crop pattern, and for the 2050s periods. With this aim, water-driven FAO-AquaCrop model has been used. Furthermore, ongoing and forecasted changes, up to the end of the century, in agro-climatic zones relevant for cereals production have been assessed. The climate change data was generated for RCP4.5 scenario through the global circulation model ECHAM4.1, dynamically downscaled on the region via regional climate model (RegCM4.1). Results show overall increase in cereal crop yields, but also enhancement in water shortages even considering optimum management practices under rainfed conditions. Based on the results obtained, recommendations have been developed for adaptation measures to the climate change for the Georgia Agriculture sector.


2017 ◽  
Vol 10 (5) ◽  
pp. 1849-1872 ◽  
Author(s):  
Benoit P. Guillod ◽  
Richard G. Jones ◽  
Andy Bowery ◽  
Karsten Haustein ◽  
Neil R. Massey ◽  
...  

Abstract. Extreme weather events can have large impacts on society and, in many regions, are expected to change in frequency and intensity with climate change. Owing to the relatively short observational record, climate models are useful tools as they allow for generation of a larger sample of extreme events, to attribute recent events to anthropogenic climate change, and to project changes in such events into the future. The modelling system known as weather@home, consisting of a global climate model (GCM) with a nested regional climate model (RCM) and driven by sea surface temperatures, allows one to generate a very large ensemble with the help of volunteer distributed computing. This is a key tool to understanding many aspects of extreme events. Here, a new version of the weather@home system (weather@home 2) with a higher-resolution RCM over Europe is documented and a broad validation of the climate is performed. The new model includes a more recent land-surface scheme in both GCM and RCM, where subgrid-scale land-surface heterogeneity is newly represented using tiles, and an increase in RCM resolution from 50 to 25 km. The GCM performs similarly to the previous version, with some improvements in the representation of mean climate. The European RCM temperature biases are overall reduced, in particular the warm bias over eastern Europe, but large biases remain. Precipitation is improved over the Alps in summer, with mixed changes in other regions and seasons. The model is shown to represent the main classes of regional extreme events reasonably well and shows a good sensitivity to its drivers. In particular, given the improvements in this version of the weather@home system, it is likely that more reliable statements can be made with regards to impact statements, especially at more localized scales.


2021 ◽  
Author(s):  
Klaus Haslinger ◽  
Gregor Laaha ◽  
Wolfgang Schöner ◽  
Andre Konrad ◽  
Marc Olefs ◽  
...  

<p>In this contribution future changes of surface water availability over the Austrian domain is investigated. We use an ensemble of downscaled and bias-corrected regional climate model simulations of the EURO-CORDEX initiative under moderate mitigation (RCP4.5) and Paris agreement (RCP2.6) emission scenarios. The climatic water balance and its components (rainfall, snow melt, glacier melt and potential evapotranspiration) are used as indicators for surface water availability and we focus on different altitudinal classes (lowland, mountainous and high alpine) to depict a variety of processes in complex terrain. Apart from analysing the mean changes of these quantities we also pursue a hazard risk approach by estimating changes in return periods of drought events of a given magnitude as observed in the reference period. The results show in general wetter conditions over the course of the 21<sup>st</sup> century over Austria. Considering seasonal differences, winter and spring will be getting wetter due to an increase in precipitation along with a higher rainfall/snowfall fraction as a consequence of rising temperatures. In summer only little changes in the ensemble median of the climatic water balance are visible, hence uncertainties are large due to a considerable ensemble spread. However, by analysing changes in return periods of drought events, a robust signal of increasing risk of moderate and extreme drought events during summer is apparent. It emerges from an increase in interannual variability of the climatic water balance, which likely stems from intensified land-atmosphere coupling under climate change sustaining and intensifying spring preconditions towards even wetter or dryer summers.</p>


2016 ◽  
Author(s):  
Benoit P. Guillod ◽  
Andy Bowery ◽  
Karsten Haustein ◽  
Richard G. Jones ◽  
Neil R. Massey ◽  
...  

Abstract. Extreme weather events can have large impacts on society and, in many regions, are expected to change in frequency and intensity with climate change. Owing to the relatively short observational record, climate models are useful tools as they allow for generation of a larger sample of extreme events, to attribute recent events to anthropogenic climate change, and to project changes of such events into the future. The modelling system known as weather@home, consisting of a global climate model (GCM) with a nested regional climate model (RCM) and driven by sea surface temperatures, allows to generate very large ensemble with the help of volunteer distributed computing. This is a key tool to understanding many aspects of extreme events. Here, a new version of weather@home system (weather@home 2) with a higher resolution RCM over Europe is documented and a broad validation of the climate is performed. The new model includes a more recent land-surface scheme in both GCM and RCM, where subgrid scale land surface heterogeneity is newly represented using tiles, and an increase in RCM resolution from 50 km to 25 km. The GCM performs similarly to the previous version, with some improvements in the representation of mean climate. The European RCM biases are overall reduced, in particular the warm and dry bias over eastern Europe, but large biases remain. The model is shown to represent main classes of regional extreme events reasonably well and shows a good sensitivity to its drivers. In particular, given the improvements in this version of the weather@home system, it is likely that more reliable statements can be made with regards to impact statements, especially at more localized scales.


2012 ◽  
Vol 16 (12) ◽  
pp. 4637-4649 ◽  
Author(s):  
P. D. T. Van ◽  
I. Popescu ◽  
A. van Griensven ◽  
D. P. Solomatine ◽  
N. H. Trung ◽  
...  

Abstract. The present paper investigated the extent of the flood propagation in the Vietnamese Mekong Delta under different projected flood hydrographs, considering the 2000 flood event (the 20-yr return period event, T. V. H. Le et al., 2007) as the basis for computation. The analysis herein was done to demonstrate the particular complexity of the flood dynamics, which was simulated by the 1-D modelling system ISIS used by the Mekong River Commission. The floods of the year 2050 are simulated using a projected sea level rise of +30 cm. The future flood hydrograph changes at Kratie, Cambodia, were also applied for the upstream boundary condition by using an adjusted regional climate model. Two future flood hydrographs were applied at the upstream part of the delta, the first one in a scenario of climate change without considering developments in the Mekong Basin,and the second one in a scenario of climate change taking into account future development of the delta. Analyses were done to identify the areas sensitive to floods, considering the uncertainty of the projection of both the upstream and downstream boundary conditions. In addition, due to the rice-dominated culture in the Vietnamese Mekong Delta, possible impacts of floods on the rice-based farming systems were also analysed.


2014 ◽  
Vol 5 (4) ◽  
pp. 633-651
Author(s):  
D. González-Zeas ◽  
L. Garrote ◽  
A. Iglesias

This paper provides and tests a methodology to compute surface water (SW) availability for irrigation on regulated systems at large scale, considering different alternatives of streamflow monthly time series derived from regional climate models. SW availability for consumptive use for a river basin is estimated through the concept of maximum potential water withdrawal (MPWW). MPWW is defined as the maximum demand that can be supplied at a given point in the river network under certain conditions: management restrictions (such as ecological flows), demand priorities, monthly distribution of demand and required reliability. Calculation was applied in 567 basins that cover the entirety of mainland Spain to evaluate adaptation needs for agriculture by comparing MPWW for irrigation in the current situation and under climate change projections. The results show that streamflow monthly time series obtained from the regional climate model simulations and bias corrected by University of New Hampshire/Global Runoff Data Centre (UNH/GRDC) dataset and Schreiber's formula provide MPWW values similar to those obtained with the observed data under current situations. Under climate change projections, the capability to satisfy water requirements for agricultural production is significantly reduced and adaptation measures are necessary to mitigate the expected long-term impact.


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