Assessing the impacts of climate change on water resources in the Srepok watershed, Central Highland of Vietnam

The Srepok watershed in the Central Highland of Vietnam plays an important role in the economic development of the region. Any harmful effects of climate change on natural resources may cause difficulties for social and economic development in this area. The present study aims to predict and evaluate changes of water resources in the Srepok watershed under the impact of climate change scenarios by using the soil and water assessment tool (SWAT) model. The study used observed weather data from 1990 to 2010 for the first period and climate change scenarios A1B and A2 from 2011 to 2039 for the second period and from 2040 to 2069 for the third period. According to the climate change scenarios of the studied watershed, future minimum and maximum daily average temperature will rise in all climate change scenarios and the amount of annual precipitation will fall in scenario A1B and go up in scenario A2. Based on the simulation results, the annual water discharge in scenario A1B decreased by 11.1% and 1.2% during the second and third periods, respectively, compared with the first. In scenario A2, annual water discharge increased by 2.4% during the second period but decreased by 1.8% during the third period.

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Unravelling Climate and Anthropogenic Forcings on the Evolution of Surface Water Resources in Southern France

Water ◽

10.3390/w12123581 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3581

Author(s):

Camille Labrousse ◽

Wolfgang Ludwig ◽

Sébastien Pinel ◽

Mahrez Sadaoui ◽

Guillaume Lacquement

Keyword(s):

Climate Change ◽

Land Use ◽

Surface Water ◽

Water Resources ◽

Water Discharge ◽

Study Region ◽

Southern France ◽

Surface Water Resources ◽

Annual Water ◽

Annual Water Discharge

In the Mediterranean, climate change and human pressures are expected to significantly impact the availability of surface water resources. In order to quantify these impacts during the last 60 years (1959–2018), we examined the hydro-climatic and land use change evolution in six coastal river basins of the Gulf of Lion in southern France. By combining observed water discharge, gridded climate, mapped land use and agricultural censuses data, we propose a statistical regression model which successfully reproduces the variability of annual water discharge in all basins. Our results clearly demonstrate that, despite important anthropogenic water withdrawals for irrigation, climate change is the major driver for the detected reduction of water discharge. The model can explain 78–88% of the variability of annual water discharge in the study catchments. It requires only two climatic indices that are solely computed from monthly temperature (T) and precipitation (P) data, thus allowing the estimation of the respective contributions of both parameters in the detected changes. According to our results, the study region experienced on average a warming trend of 1.6 °C during the last 60 years which alone was responsible for a reduction of almost 25% of surface water resources.

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Impact of climate change on superficial water resources in the South of France: statistical modelling over historical and future scenario periods

10.5194/egusphere-egu21-7132 ◽

2021 ◽

Author(s):

Camille Labrousse ◽

Sébastien Pinel ◽

Mahrez Sadaoui ◽

Wolfgang Ludwig ◽

Guillaume Lacquement

Keyword(s):

Climate Change ◽

Water Resources ◽

Large Scale ◽

Climate Models ◽

Water Discharge ◽

Strong Argument ◽

Study Region ◽

Climatic Indices ◽

Annual Water ◽

Annual Water Discharge

In the Mediterranean, climate change and human pressures are expected to significantly impact surface water resources. We studied these impacts on the water discharge of six coastal drainage basins of the Gulf of Lions in southern France over the sixty-years period 1959-2018. Our approach was based on statistical analyses of hydrological, climate, land use and water management data. Results suggested that the annual water discharge of the six rivers studied can be predicted with high confidence by only two climatic indices, exclusively calculated from monthly temperature and precipitation data. This is a strong argument that climate is clearly the dominant driver of water discharge trends in the study region. These models also easily allow individual testing of the role of temperatures and precipitations on the evolution of annual water discharge. The latter decreased with about 30-45% in the study catchments over the 1959-2018 period and 25% can be attributed solely to the annual temperatures increase. Considering future projections of different climate models under a RCP 8.5 scenario, which depicts the strongest climatic changes, the annual water discharge could still decrease about 49-87% during the 2006-2100 period. For all models, we furthermore examined the relationships between the observed and simulated climatologies, our climatic indices and the large scale teleconnection patterns in order to better understand the spatial and temporal variabilities in the predicted water discharge series.

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Evaluation of the Impact of Climate Change on Runoff Generation in an Andean Glacier Watershed

Water ◽

10.3390/w12123547 ◽

2020 ◽

Vol 12 (12) ◽

pp. 3547

Author(s):

Rossana Escanilla-Minchel ◽

Hernán Alcayaga ◽

Marco Soto-Alvarez ◽

Christophe Kinnard ◽

Roberto Urrutia

Keyword(s):

Climate Change ◽

Water Resources ◽

Emission Scenario ◽

Water Discharge ◽

Climate Change Scenarios ◽

Climate Trend ◽

Snow Storage ◽

South Central ◽

Recent Climate ◽

The Impact

Excluding Antarctica and Greenland, 3.8% of the world’s glacier area is concentrated in Chile. The country has been strongly affected by the mega drought, which affects the south-central area and has produced an increase in dependence on water resources from snow and glacier melting in dry periods. Recent climate change has led to an elevation of the zero-degree isotherm, a decrease in solid-state precipitation amounts and an accelerated loss of glacier and snow storage in the Chilean Andes. This situation calls for a better understanding of future water discharge in Andean headwater catchments in order to improve water resources management in glacier-fed populated areas. The present study uses hydrological modeling to characterize the hydrological processes occurring in a glacio-nival watershed of the central Andes and to examine the impact of different climate change scenarios on discharge. The study site is the upper sub-watershed of the Tinguiririca River (area: 141 km2), of which nearly 20% is covered by Universidad Glacier. The semi-distributed Snowmelt Runoff Model + Glacier (SRM+G) was forced with local meteorological data to simulate catchment runoff. The model was calibrated on even years and validated on odd years during the 2008–2014 period and found to correctly reproduce daily runoff. The model was then forced with downscaled ensemble projected precipitation and temperature series under the RCP 4.5 and RCP 8.5 scenarios, and the glacier adjusted using a volume-area scaling relationship. The results obtained for 2050 indicate a decrease in mean annual discharge (MAD) of 18.1% for the lowest emission scenario and 43.3% for the most pessimistic emission scenario, while for 2100 the MAD decreases by 31.4 and 54.2%, respectively, for each emission scenario. Results show that decreasing precipitation lead to reduced rainfall and snowmelt contributions to discharge. Glacier melt thus partly buffers the drying climate trend, but our results show that the peak water occurs near 2040, after which glacier depletion leads to reducing discharge, threatening the long-term water resource availability in this region.

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QARABAĞ ÇAYLARININ SU EHTİYATLARI

“Water Problems: science and technologies” ◽

10.30546/wtst.2020.1.20 ◽

2021 ◽

Vol 1 (1) ◽

pp. 20-37

Author(s):

R.A. İsmayılov

Keyword(s):

Water Resources ◽

River Flow ◽

Water Discharge ◽

Atmospheric Precipitation ◽

Water Security ◽

Observation Data ◽

Management Measures ◽

Average Observation ◽

Annual Water ◽

Annual Water Discharge

Abstract. Karabakh is one of the main regions in Azerbaijan where local water resources are formed. The article calculated the water resources of the area using the data of hydrological observation stations operating on the Karabakh rivers before the occupation. For research and analysis of average annual water discharge, multiyear observation data of hydrological stations operating on the Karabakh rivers were collected and integrated into the SpSS Statistics program. For the study multi-year average observation data of 32 hydrological stations in 20 rivers were collected. In order to determine the exact location of the hydrological stations operating in the area, a map was compiled using the Geographic Information System with reference to the fund and archive materials. In addition, hydrological zoning of the flow was carried out depending on the orographic features of Karabakh. During the analysis, two hydrological regions were identified. The first hydrological region is the Tartarchay-Guruchay hydrological region, and the second region is hakari-Oлchuchay hydrological region. As a result of the study, it was determined that the water resources of the Karabakh rivers are 1.64 km3 , which is 5.31% of the total water resources of Azerbaijan. During the implementation of water management measures in the area, in order to ensure the water security of the area, the resource potential of atmospheric precipitation and river flow for the area was analyzed and maps were compiled. Keywords: Karabakh rivers, hydrological station, water catchment area, water resources, water balance, hydrological zoning

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Soil salinization under different climate change scenarios: A global scale analysis

10.5194/egusphere-egu21-13668 ◽

2021 ◽

Author(s):

Nima Shokri ◽

Amirhossein Hassani ◽

Adisa Azapagic

Keyword(s):

Climate Change ◽

Water Resources ◽

Soil Salinity ◽

Global Scale ◽

Soil Salinization ◽

Water Evaporation ◽

Climate Change Scenarios ◽

Spatio Temporal ◽

Salt Affected Soils

Population growth and climate change is projected to increase the pressure on land and water resources, especially in arid and semi-arid regions. This pressure is expected to affect all driving mechanisms of soil salinization comprising alteration in soil hydrological balance, sea salt intrusion, wet/dry deposition of wind-born saline aerosols &#8212; leading to an increase in soil salinity. Soil salinity influences soil stability, bio-diversity, ecosystem functioning and soil water evaporation (1). It can be a long-term threat to agricultural activities and food security. To devise sustainable action plan investments and policy interventions, it is crucial to know when and where salt-affected soils occur. However, current estimates on spatio-temporal variability of salt-affected soils are majorly localized and future projections in response to climate change are rare. Using Machine Learning (ML) algorithms, we related the available measured soil salinity values (represented by electrical conductivity of the saturated paste soil extract, ECe) to some environmental information (or predictors including outputs of Global Circulation Models, soil, crop, topographic, climatic, vegetative, and landscape properties of the sampling locations) to develop a set of data-driven predictive tools to enable the spatio-temporal predictions of soil salinity. The outputs of these tools helped us to estimate the extent and severity of the soil salinity under current and future climatic patterns at different geographical levels and identify the salinization hotspots by the end of the 21st century in response to climate change. Our analysis suggests that a soil area of 11.73 Mkm2 located in non-frigid zones has been salt-affected in at least three-fourths of the 1980 - 2018 period (2). At the country level, Brazil, Peru, Sudan, Colombia, and Namibia were estimated to have the highest rates of annual increase in the total area of soils with an ECe &#8805; 4 dS m-1. Additionally, the results indicate that by the end of the 21st century, drylands of South America, southern and Western Australia, Mexico, southwest United States, and South Africa will be the salinization hotspots (compared to the 1961 - 1990 period). The results of this study could inform decision-making and contribute to attaining the United Nation&#8217;s Sustainable Development Goals for land and water resources management.1. Shokri-Kuehni, S.M.S., Raaijmakers, B., Kurz, T., Or, D., Helmig, R., Shokri, N. (2020). Water Table Depth and Soil Salinization: From Pore-Scale Processes to Field-Scale Responses. Water Resour. Res., 56, e2019WR026707. https://doi.org/ 10.1029/2019WR0267072. Hassani, A., Azapagic, A., Shokri, N. (2020). Predicting Long-term Dynamics of Soil Salinity and Sodicity on a Global Scale, Proc. Nat. Acad. Sci., 117, 52, 33017&#8211;33027. https://doi.org/10.1073/pnas.2013771117

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A Hydrological Modeling Approach for Assessing the Impacts of Climate Change on Runoff Regimes in Slovakia

Water ◽

10.3390/w13233358 ◽

2021 ◽

Vol 13 (23) ◽

pp. 3358

Author(s):

Patrik Sleziak ◽

Roman Výleta ◽

Kamila Hlavčová ◽

Michaela Danáčová ◽

Milica Aleksić ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Hydrological Modeling ◽

Performance Metrics ◽

Climate Change Scenarios ◽

Reference Period ◽

Changing Climate ◽

Time Horizons ◽

The Future

The changing climate is a concern with regard to sustainable water resources. Projections of the runoff in future climate conditions are needed for long-term planning of water resources and flood protection. In this study, we evaluate the possible climate change impacts on the runoff regime in eight selected basins located in the whole territory of Slovakia. The projected runoff in the basins studied for the reference period (1981–2010) and three future time horizons (2011–2040, 2041–2070, and 2071–2100) was simulated using the HBV (Hydrologiska Byråns Vattenbalansavdelning) bucket-type model (the TUW (Technische Universität Wien) model). A calibration strategy based on the selection of the most suitable decade in the observation period for the parameterization of the model was applied. The model was first calibrated using observations, and then was driven by the precipitation and air temperatures projected by the KNMI (Koninklijk Nederlands Meteorologisch Instituut) and MPI (Max Planck Institute) regional climate models (RCM) under the A1B emission scenario. The model’s performance metrics and a visual inspection showed that the simulated runoff using downscaled inputs from both RCM models for the reference period represents the simulated hydrological regimes well. An evaluation of the future, which was performed by considering the representative climate change scenarios, indicated that changes in the long-term runoff’s seasonality and extremality could be expected in the future. In the winter months, the runoff should increase, and decrease in the summer months compared to the reference period. The maximum annual daily runoff could be more extreme for the later time horizons (according to the KNMI scenario for 2071–2100). The results from this study could be useful for policymakers and river basin authorities for the optimum planning and management of water resources under a changing climate.

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Contrasting climate change impact on river flows from high-altitude catchments in the Himalayan and Andes Mountains

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1606526113 ◽

2016 ◽

Vol 113 (33) ◽

pp. 9222-9227 ◽

Cited By ~ 67

Author(s):

Silvan Ragettli ◽

Walter W. Immerzeel ◽

Francesca Pellicciotti

Keyword(s):

Climate Change ◽

Water Resources ◽

High Altitude ◽

Water Availability ◽

Climate Change Impact ◽

River Flow ◽

Climate Change Scenarios ◽

Glacier Area ◽

Spatiotemporal Resolution ◽

Change Impact

Mountain ranges are the world’s natural water towers and provide water resources for millions of people. However, their hydrological balance and possible future changes in river flow remain poorly understood because of high meteorological variability, physical inaccessibility, and the complex interplay between climate, cryosphere, and hydrological processes. Here, we use a state-of-the art glacio-hydrological model informed by data from high-altitude observations and the latest climate change scenarios to quantify the climate change impact on water resources of two contrasting catchments vulnerable to changes in the cryosphere. The two study catchments are located in the Central Andes of Chile and in the Nepalese Himalaya in close vicinity of densely populated areas. Although both sites reveal a strong decrease in glacier area, they show a remarkably different hydrological response to projected climate change. In the Juncal catchment in Chile, runoff is likely to sharply decrease in the future and the runoff seasonality is sensitive to projected climatic changes. In the Langtang catchment in Nepal, future water availability is on the rise for decades to come with limited shifts between seasons. Owing to the high spatiotemporal resolution of the simulations and process complexity included in the modeling, the response times and the mechanisms underlying the variations in glacier area and river flow can be well constrained. The projections indicate that climate change adaptation in Central Chile should focus on dealing with a reduction in water availability, whereas in Nepal preparedness for flood extremes should be the policy priority.

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