Impacts of climate change and rising atmospheric CO2 on future projected reference evapotranspiration in Emilia-Romagna (Italy)

AbstractThe continuous increase of atmospheric CO2 content mainly due to anthropogenic CO2 emissions is causing a rise in temperature on earth, altering the hydrological and meteorological processes and affecting crop physiology. Evapotranspiration is an important component of the hydrological cycle. Thus, understanding the change in evapotranspiration due to global warming is essential for better water resources planning and management and agricultural production. In this study, the effect of climate change with a focus on the combined effect of temperature and elevated CO2 concentrations on reference evapotranspiration (ETo) was evaluated using the Penman–Monteith equation. A EURO-CORDEX regional climate model (RCM) ensemble was used to estimate ETo in five locations in the Emilia-Romagna region (Northern Italy) during the period 2021–2050. Then, its projected changes in response to different CO2 concentrations (i.e., 372 ppm and 550 ppm) under two Representative Concentration Pathways (RCP) scenarios (i.e., RCP4.5 and RCP8.5) were analyzed. Simulation results with both scenarios, without increasing CO2 levels (372 ppm), showed that the annual and summertime ETo for all locations increased by an average of 4 to 5.4% with regard to the reference period 1981–2005, for an increase of air temperature by 1 to 1.5 °C. When the effect of elevated CO2 levels (550 ppm) was also considered in combination with projected changes in temperature, changes in both annual and summer ETo demand for all locations varied from − 1.1 to 2.2% during the 2021–2050 period with regard to the reference period 1981–2005. This shows that higher CO2 levels moderated the increase in ETo that accompanies an increase in air temperature.

Download Full-text

Projected Changes of Precipitation IDF Curves for Short Duration under Climate Change in Central Vietnam

Hydrology ◽

10.3390/hydrology5030033 ◽

2018 ◽

Vol 5 (3) ◽

pp. 33 ◽

Cited By ~ 7

Author(s):

Nguyen Tien Thanh ◽

Luca Dutto Aldo Remo

Keyword(s):

Climate Change ◽

Climate Model ◽

Southern Oscillation ◽

Regional Climate ◽

Extreme Weather Events ◽

Climate Data ◽

Rcp Scenarios ◽

Central Vietnam ◽

Idf Curves ◽

Projected Changes

In future years, extreme weather events are expected to frequently increase due to climate change, especially in the combination of climate change and events of El Niño–Southern Oscillation. This pays special attention to the construction of intensity–duration–frequency (IDF) curves at a tempo-spatial scale of sub-daily and sub-grid under a context of climate change. The reason for this is that IDF curves represent essential means to study effects on the performance of drainage systems, damps, dikes and reservoirs. Therefore, the objective of this study is to present an approach to construct future IDF curves with high temporo-spatial resolutions under climate change in central Vietnam, using the case of VuGia-ThuBon. The climate data of historical and future from a regional climate model RegCM4 forced by three global models MPI-ESM-MR, IPSL-CM5A-LR and ICHEC-EC-EARTH are used to re-grid the resolution of 10 km × 10 km grid spacing from 25 km × 25 km on the base of bilinear interpolation. A bias correction method is then applied to the finest resolution of a hydrostatic climate model for an ensemble of simulations. Furthermore, the IDF curves for short durations of precipitation are constructed for the historical climate and future climates under two representative concentration pathway (RCP) scenarios, RCP4.5 and RCP8.5, based on terms of correlation factors. The major findings show that the projected precipitation changes are expected to significantly increase by about 10 to 30% under the scenarios of RCP4.5 and RCP8.5. The projected changes of a maximum of 1-, 2-, and 3-days precipitation are expected to increase by about 30–300 mm/day. More importantly, for all return periods (i.e., 10, 20, 50, 100, and 200 years), IDF curves completely constructed for short durations of precipitation at sub-daily show an increase in intensities for the RCP4.5 and RCP8.5 scenarios.

Download Full-text

Hydrological Climate-Impact Projections for the Rhine River: GCM–RCM Uncertainty and Separate Temperature and Precipitation Effects*

Journal of Hydrometeorology ◽

10.1175/jhm-d-12-098.1 ◽

2014 ◽

Vol 15 (2) ◽

pp. 697-713 ◽

Cited By ~ 24

Author(s):

Thomas Bosshard ◽

Sven Kotlarski ◽

Massimiliano Zappa ◽

Christoph Schär

Keyword(s):

Climate Change ◽

Climate Model ◽

Hydrological Cycle ◽

Regional Climate ◽

Climate Impact ◽

Rhine River ◽

Supply Source ◽

Rhine Basin ◽

Projected Changes ◽

The Impact

Abstract Climate change is expected to affect the hydrological cycle, with considerable impacts on water resources. Climate-induced changes in the hydrology of the Rhine River (Europe) are of major importance for the riparian countries, as the Rhine River is the most important European waterway, serves as a freshwater supply source, and is prone to floods and droughts. Here regional climate model data from the Ensemble-Based Predictions of Climate Changes and their Impacts (ENSEMBLES) project is used to drive the hydrological model Precipitation–Runoff–Evapotranspiration–Hydrotope (PREVAH) and to assess the impact of climate change on the hydrology in the Rhine basin. Results suggest increases in monthly mean runoff during winter and decreases in summer. At the gauge Cologne and for the period 2070–99 under the A1B scenario of the Special Report on Emissions Scenarios, projected decreases in summer vary between −9% and −40% depending on the climate model used, while increases in winter are in the range of +4% to +51%. These projected changes in mean runoff are generally consistent with earlier studies, but the derived spread in the runoff projections appears to be larger. It is demonstrated that temperature effects (e.g., through altered snow processes) dominate in the Alpine tributaries, while precipitation effects dominate in the lower portion of the Rhine basin. Analyses are also presented for selected extreme runoff indices.

Download Full-text

Simulating the impact of future climate change on runoff processes in selected catchments of Slovakia

10.5194/egusphere-egu21-5074 ◽

2021 ◽

Author(s):

Roman Výleta ◽

Milica Aleksić ◽

Patrik Sleziak ◽

Kamila Hlavcova

Keyword(s):

Climate Change ◽

Air Temperature ◽

Climate Model ◽

Hydrological Cycle ◽

Future Climate Change ◽

Time Horizons ◽

The Future ◽

The Impact ◽

Impacts Of Climate Change

The future development of the runoff conditions, as a consequence of climate change, is of great interest for water managers. Information about the potential impacts of climate change on the hydrological regime is needed for long-term planning of water resources and flood protection.The aim of this study is to evaluate the possible impacts of climate change on the runoff regime in five selected catchments located in the territory of Slovakia. Changes in climatic characteristics (i.e., precipitation and air temperature) for future time horizons were prepared by a regional climate model KNMI using the A1B emission scenario. The selected climatic scenario predicts a general increase in air temperature and precipitation (higher in winter than in summer). For simulations of runoff under changed conditions, a lumped rainfall-runoff model (the TUW model) was used. This model belongs to a group of conceptual models and follows a structure of a widely used Swedish HBV model. The TUW model was calibrated for the period of 2011 &#8211; 2019. We assumed that this period would be similar (to recent/warmer climate) in terms of the average daily air temperatures and daily precipitation totals. The future changes in runoff due to climate change were evaluated by comparing the simulated long-term mean monthly runoff for the current state (1981-2010) and modelled scenarios in three time periods (2011-2040, 2041-2070, and 2071-2100). The results indicate that changes in the long-term runoff seasonality and extremality of hydrological cycle could be expected in the future. The runoff should increase in winter months compared to the reference period. This increase is probably related to a rise in temperature and anticipated snowmelt. Conversely, during the summer periods, a decrease in the long-term runoff could be assumed. According to modelling, these changes will be more pronounced in the later time horizons.It should be noted that the results of the simulation are dependent on the availability of the inputs, the hydrological/climate model used, the schematization of the simulated processes, etc. Therefore, they need to be interpreted with a sufficient degree of caution

Download Full-text

Modeling of climate change impact on hydrological regime in small headwater mountainous catchments in Slovakia

10.5194/egusphere-egu2020-21583 ◽

2020 ◽

Author(s):

Kamila Hlavcova ◽

Martin Kubán ◽

Patrik Sleziak ◽

Jan Szolgay

Keyword(s):

Climate Change ◽

Air Temperature ◽

Climate Changes ◽

Hydrological Cycle ◽

Differential Evolution Algorithm ◽

Hydrological Regime ◽

Model Parameters ◽

Climatic Data ◽

Reference Period

Assessment of the impacts of climate change on hydrological regime is important for sustainable water resources management. The objective of this study is to assess the impacts of future climate changes on the hydrological regime of the headwater catchment of the Vistucky Creek (area 9.8 km2) in south-western Slovakia. Changes in climatic characteristics (i.e. precipitation and air temperature) for periods 2022-2060 and 2062-2100 were prepared by two regional climate models KNMI and MPI using the A1B emission scenario (average related to fossil carbon production). Both climatic scenarios assume increase in the air temperature and precipitation (higher in winter than in summer). A lumped conceptual rainfall-runoff model (the HBV-based TUW model) was used to simulate the catchment hydrological behaviour. The TUW model was calibrated for the reference period of 1982 &#8211; 2008. The calibration of the model was performed 50 times with a differential evolution algorithm. After obtaining the collection of the 50 parameter sets, the best set (in terms of Nash-Sutcliffe efficiency and the volume error) was chosen. This set of model parameters was used for the simulation of long-term mean monthly runoff for the three periods (i.e. 1982-2008, 2022-2060, and 2062-2100). The results show that changes in the long-term runoff seasonality and extremality of hydrological cycle could be expected in the future if the climate changes as the scenarios assume. The runoff should increase in autumn and winter months (i.e. from September to February) and decrease in spring and summer months (i.e, from April to August) compared to the reference period. Peakflows should increase in period 2062-2100 while discharge minima should slightly decrease (only for the climatic data from the KNMI model). It indicates possible increase in flow extremality. Catchment water storage as expressed by the soil moisture index and baseflow should decrease in period 2062-2100, especially according to climatic data from the KNMI model. Our contribution will discuss these changes in hydrological regime in the climate change context.

Download Full-text

2 °C vs. High Warming: Transitions to Flood-Generating Mechanisms across Canada

Water ◽

10.3390/w13111494 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1494

Author(s):

Bernardo Teufel ◽

Laxmi Sushama

Keyword(s):

Climate Change ◽

Global Warming ◽

Climate Model ◽

Regional Climate ◽

Adaptation Measures ◽

Relative Contribution ◽

Late 21St Century ◽

Transient Climate Change ◽

Projected Changes ◽

Change Mitigation

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.

Download Full-text

Climate Change Projections over East Asia with BCC_CSM1.1 Climate Model under RCP Scenarios

Journal of the Meteorological Society of Japan Ser II ◽

10.2151/jmsj.2013-401 ◽

2013 ◽

Vol 91 (4) ◽

pp. 413-429 ◽

Cited By ~ 53

Author(s):

Xiaoge XIN ◽

Li ZHANG ◽

Jie ZHANG ◽

Tongwen WU ◽

Yongjie FANG

Keyword(s):

Climate Change ◽

East Asia ◽

Climate Model ◽

Climate Change Projections ◽

Rcp Scenarios

Download Full-text

Uncertainty in water resources availability in the Okavango River Basin as a result of climate change

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-7-5737-2010 ◽

2010 ◽

Vol 7 (4) ◽

pp. 5737-5768 ◽

Cited By ~ 13

Author(s):

D. A. Hughes ◽

D. G. Kingston ◽

M. C. Todd

Keyword(s):

Climate Change ◽

Water Resource Management ◽

Climate Models ◽

Climate Model ◽

Management Policy ◽

Mean Flow ◽

Considerable Uncertainty ◽

Okavango River ◽

Projected Changes ◽

Change In Mean

Abstract. This paper assesses the hydrological response to scenarios of climate change in the Okavango River catchment in Southern Africa. Climate scenarios are constructed representing different changes in global mean temperature from an ensemble of 7 climate models assessed in the IPCC AR4. The results show a substantial change in mean flow associated with a global warming of 2 °C. However, there is considerable uncertainty in the sign and magnitude of the projected changes between different climate models, implying that the ensemble mean is not an appropriate generalised indicator of impact. The uncertainty in response between different climate model patterns is considerably greater than the range due to uncertainty in hydrological model parameterisation. There is also a clear need to evaluate the physical mechanisms associated with the model projected changes in this region. The implications for water resource management policy are considered.

Download Full-text

Hydrological impacts of climate change on small ungauged catchments – results from a global climate model–regional climate model–hydrologic model chain

Natural Hazards and Earth System Science ◽

10.5194/nhess-20-2133-2020 ◽

2020 ◽

Vol 20 (8) ◽

pp. 2133-2155

Author(s):

Aynalem T. Tsegaw ◽

Marie Pontoppidan ◽

Erle Kristvik ◽

Knut Alfredsen ◽

Tone M. Muthanna

Keyword(s):

Climate Change ◽

Hydrological Model ◽

Climate Model ◽

Regional Climate ◽

Reference Period ◽

Future Period ◽

The Mean ◽

Model Chain ◽

Small Catchments ◽

Impacts Of Climate Change

Abstract. Climate change is one of the greatest threats currently facing the world's environment. In Norway, a change in climate will strongly affect the pattern, frequency, and magnitudes of stream flows. However, it is challenging to quantify to what extent the change will affect the flow patterns and floods from small rural catchments due to the unavailability or inadequacy of hydro-meteorological data for the calibration of hydrological models and due to the tailoring of methods to a small-scale level. To provide meaningful climate impact studies at the level of small catchments, it is therefore beneficial to use high-spatial- and high-temporal-resolution climate projections as input to a high-resolution hydrological model. In this study, we used such a model chain to assess the impacts of climate change on the flow patterns and frequency of floods in small ungauged rural catchments in western Norway. We used a new high-resolution regional climate projection, with improved performance regarding the precipitation distribution, and a regionalized hydrological model (distance distribution dynamics) between a reference period (1981–2011) and a future period (2070–2100). The flow-duration curves for all study catchments show more wet periods in the future than during the reference period. The results also show that in the future period, the mean annual flow increases by 16 % to 33 %. The mean annual maximum floods increase by 29 % to 38 %, and floods of 2- to 200-year return periods increase by 16 % to 43 %. The results are based on the RCP8.5 scenario from a single climate model simulation tailored to the Bergen region in western Norway, and the results should be interpreted in this context. The results should therefore be seen in consideration of other scenarios for the region to address the uncertainty. Nevertheless, the study increases our knowledge and understanding of the hydrological impacts of climate change on small catchments in the Bergen area in the western part of Norway.

Download Full-text

An update of IPCC climate reference regions for subcontinental analysis of climate model data: definition and aggregated datasets

Earth System Science Data ◽

10.5194/essd-12-2959-2020 ◽

2020 ◽

Vol 12 (4) ◽

pp. 2959-2970

Author(s):

Maialen Iturbide ◽

José M. Gutiérrez ◽

Lincoln M. Alves ◽

Joaquín Bedia ◽

Ruth Cerezo-Mota ◽

...

Keyword(s):

Climate Change ◽

Climate Model ◽

Climate Adaptation ◽

Regional Climate ◽

Atmospheric Model ◽

Future Climate Change ◽

Intergovernmental Panel ◽

Temperature And Precipitation ◽

Scatter Plots ◽

Projected Changes

Abstract. Several sets of reference regions have been used in the literature for the regional synthesis of observed and modelled climate and climate change information. A popular example is the series of reference regions used in the Intergovernmental Panel on Climate Change (IPCC) Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Adaptation (SREX). The SREX regions were slightly modified for the Fifth Assessment Report of the IPCC and used for reporting subcontinental observed and projected changes over a reduced number (33) of climatologically consistent regions encompassing a representative number of grid boxes. These regions are intended to allow analysis of atmospheric data over broad land or ocean regions and have been used as the basis for several popular spatially aggregated datasets, such as the Seasonal Mean Temperature and Precipitation in IPCC Regions for CMIP5 dataset. We present an updated version of the reference regions for the analysis of new observed and simulated datasets (including CMIP6) which offer an opportunity for refinement due to the higher atmospheric model resolution. As a result, the number of land and ocean regions is increased to 46 and 15, respectively, better representing consistent regional climate features. The paper describes the rationale for the definition of the new regions and analyses their homogeneity. The regions are defined as polygons and are provided as coordinates and a shapefile together with companion R and Python notebooks to illustrate their use in practical problems (e.g. calculating regional averages). We also describe the generation of a new dataset with monthly temperature and precipitation, spatially aggregated in the new regions, currently for CMIP5 and CMIP6, to be extended to other datasets in the future (including observations). The use of these reference regions, dataset and code is illustrated through a worked example using scatter plots to offer guidance on the likely range of future climate change at the scale of the reference regions. The regions, datasets and code (R and Python notebooks) are freely available at the ATLAS GitHub repository: https://github.com/SantanderMetGroup/ATLAS (last access: 24 August 2020), https://doi.org/10.5281/zenodo.3998463 (Iturbide et al., 2020).

Download Full-text

Flood risk assessment methodology for planning under climate change scenarios and the corresponding change in land cover

Journal of Water and Climate Change ◽

10.2166/wcc.2019.016 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1370-1382 ◽

Cited By ~ 1

Author(s):

Asma Hanif ◽

Ashwin Dhanasekar ◽

Anthony Keene ◽

Huishu Li ◽

Kenneth Carlson

Keyword(s):

Climate Change ◽

Climate Model ◽

Global Climate Model ◽

The United States ◽

Army Corps ◽

Climate Projections ◽

Climate Change Scenarios ◽

Rcp Scenarios ◽

Daily Precipitation Data ◽

Time Frames

Abstract Projected climate change impacts on the hydrological regime and corresponding flood risks were examined for the years 2030 (near-term) and 2050 (long-term), under representative concentration pathways (RCP) 4.5 (moderate) and 8.5 (high) emission scenarios. The United States Army Corps of Engineers' (USACE) Hydrologic Engineering Center's Hydrologic Modeling System was used to simulate the complete hydrologic processes of the various dendritic watershed systems and USACEs' Hydrologic Engineering Center's River Analysis System hydraulic model was used for the two-dimensional unsteady flow flood calculations. Climate projections are based on recent global climate model simulations developed for the International Panel on Climate Change, Coupled Model Inter-comparison Project Phase 5. Hydrographs for frequent (high-recurrence interval) storms were derived from 30-year historical daily precipitation data and decadal projections for both time frames and RCP scenarios. Since the climate projections for each scenario only represented ten years of data, 100-year or 500-year storms cannot be derived. Hence, this novel approach of identifying frequent storms is used as an indicator to compare across the various time frames and climate scenarios. Hydrographs were used to generate inundation maps and results are used to identify vulnerabilities and formulate adaptation strategies to flooding at 43 locations worldwide.

Download Full-text