Evaluation of impact of climate change and anthropogenic change on regional hydrology

Abstract. General circulation models (GCMs) have been widely used to simulate current and future climate at the global scale. However, the development of frameworks to apply GCMs to assess potential climate change impacts on regional hydrologic systems, ability to meet future water demand, and compliance with water resource regulations is more recent. In this study eight GCMs were bias-corrected and downscaled using the bias correction and stochastic analog (BCSA) downscaling method and then used, together with three ET0 methods and eight different water use scenarios, to drive an integrated hydrologic model previously developed for the Tampa Bay region in western central Florida. Variance-based sensitivity analysis showed that changes in projected streamflow were very sensitive to GCM selection, but relatively insensitive to ET0 method or water use scenario. Changes in projections of groundwater level were sensitive to both GCM and water use scenario, but relatively insensitive to ET0 method. Five of eight GCMs projected a decrease in streamflow and groundwater availability in the future regardless of water use scenario or ET method. For the business as usual water use scenario all eight GCMs indicated that, even with active water conservation programs, increases in public water demand projected for 2045 could not be met from ground and surface water supplies while achieving current groundwater level and surface water flow regulations. With adoption of 40 % wastewater reuse for public supply and active conservation four of the eight GCMs indicate that 2045 public water demand could be met while achieving current environmental regulations; however, drier climates would require a switch from groundwater to surface water use. These results indicate a high probability of a reduction in future freshwater supply in the Tampa Bay region if environmental regulations intended to protect current aquatic ecosystems do not adapt to the changing climate. Broad interpretation of the results of this study may be limited by the fact that all future water use scenarios assumed that increases in water demand would be the result of intensification of water use on existing agricultural, industrial, and urban lands. Future work should evaluate the impacts of a range of potential land use change scenarios, with associated water use change projections, over a larger number of GCMs.

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Impact of future climate change on water supply and irrigation demand in a small mediterranean catchment. Case study: Nebhana dam system, Tunisia

Journal of Water and Climate Change ◽

10.2166/wcc.2019.131 ◽

2019 ◽

Vol 11 (4) ◽

pp. 1724-1747 ◽

Cited By ~ 2

Author(s):

M. Allani ◽

R. Mezzi ◽

A. Zouabi ◽

R. Béji ◽

F. Joumade-Mansouri ◽

...

Keyword(s):

Climate Change ◽

Water Supply ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Annual Rainfall ◽

Future Climate Change ◽

Cycle Duration ◽

Climate Change Scenarios ◽

Time Periods

Abstract This study evaluates the impacts of climate change on water supply and demand of the Nebhana dam system. Future climate change scenarios were obtained from five general circulation models (GCMs) of CMIP5 under RCP 4.5 and 8.5 emission scenarios for the time periods, 2021–2040, 2041–2060 and 2061–2080. Statistical downscaling was applied using LARS-WG. The GR2M hydrological model was calibrated, validated and used as input to the WEAP model to assess future water availability. Expected crop growth cycle lengths were estimated using a growing degree days model. By means of the WEAP-MABIA method, projected crop and irrigation water requirements were estimated. Results show an average increase in annual ETo of 6.1% and a decrease in annual rainfall of 11.4%, leading to a 24% decrease in inflow. Also, crops' growing cycles will decrease from 5.4% for wheat to 31% for citrus trees. The same tendency is observed for ETc. Concerning irrigation requirement, variations are more moderated depending on RCPs and time periods, and is explained by rainfall and crop cycle duration variations. As for demand and supply, results currently show that supply does not meet the system demand. Climate change could worsen the situation unless better planning of water surface use is done.

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Estimation of hydrological response to future climate change in a cold watershed

Journal of Water and Climate Change ◽

10.2166/wcc.2018.026 ◽

2018 ◽

Vol 10 (1) ◽

pp. 78-88 ◽

Cited By ~ 1

Author(s):

Jian Sha ◽

Zhong-Liang Wang ◽

Yue Zhao ◽

Yan-Xue Xu ◽

Xue Li

Keyword(s):

Climate Change ◽

General Circulation ◽

Water System ◽

Coupled Model ◽

Weather Conditions ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Research Station ◽

Hydrological Process

Abstract The vulnerability of the natural water system in cold areas to future climate change is of great concern. A coupled model approach was applied in the headwater watershed area of Yalu River in the northeastern part of China to estimate the response of hydrological processes to future climate change with moderate data. The stochastic Long Ashton Research Station Weather Generator was used to downscale the results of general circulation models to generate synthetic daily weather series in the 2050s and 2080s under various projected scenarios, which were applied as input data of the Generalized Watershed Loading Functions hydrological model for future hydrological process estimations. The results showed that future wetter and hotter weather conditions would have positive impacts on the watershed runoff yields but negative impacts on the watershed groundwater flow yields. The freezing period in winter would be shortened with earlier snowmelt peaks in spring. These would result in less snow cover in winter and shift the monthly allocations of streamflow with more yields in March but less in April and May, which should be of great concern for future local management. The proposed approach of the coupled model application is effective and can be used in other similar areas.

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Hydrological responses to climate change conditioned by historic alterations of land-use and water-use

Hydrology and Earth System Sciences Discussions ◽

10.5194/hessd-8-7595-2011 ◽

2011 ◽

Vol 8 (4) ◽

pp. 7595-7620 ◽

Cited By ~ 3

Author(s):

J. Jarsjö ◽

S. M. Asokan ◽

C. Prieto ◽

A. Bring ◽

G. Destouni

Keyword(s):

Climate Change ◽

Water Loss ◽

Land Surface ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Aral Sea ◽

Future Climate Change ◽

Hydrological Responses ◽

Irrigation Practices

Abstract. This paper quantifies and conditions expected hydrological responses in the Aral Sea Drainage Basin (ASDB; occupying 1.3 % of the earth's land surface), Central Asia, to multi-model projections of climate change in the region from 20 general circulation models (GCMs). The aim is to investigate how uncertainties of future climate change interact with the effects of historic human re-distributions of water for land irrigation to influence future water fluxes and water resources. So far, historic irrigation changes have greatly amplified water losses by evapotranspiration (ET) in the ASDB, whereas the 20th century climate change has not much affected the regional net water loss to the atmosphere. Projected future climate change (for the period 2010–2039) however is here calculated to considerably increase the net water loss to the atmosphere. Furthermore, the ET response strength to any future temperature change will be further increased by maintained (or increased) irrigation practices. With such irrigation practices, the river runoff is likely to decrease to near-total depletion, with risk for cascading ecological regime shifts in aquatic ecosystems downstream of irrigated land areas. Without irrigation, the agricultural areas of the principal Syr Darya river basin could sustain a 50 % higher temperature increase (of 2.3 °C instead of the projected 1.5 °C until 2010–2039) before yielding the same consumptive ET increase and associated R decrease as with the present irrigation practices.

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Impact of Climate Change on Water Balance Components and Droughts in the Guajoyo River Basin (El Salvador)

Water ◽

10.3390/w11112360 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2360 ◽

Cited By ~ 5

Author(s):

Pablo Blanco-Gómez ◽

Patricia Jimeno-Sáez ◽

Javier Senent-Aparicio ◽

Julio Pérez-Sánchez

Keyword(s):

Climate Change ◽

El Salvador ◽

River Basin ◽

General Circulation ◽

Goodness Of Fit ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Climate Change Scenarios ◽

Historical Series

This study assessed how changes in terms of temperature and precipitation might translate into changes in water availability and droughts in an area in a developing country with environmental interest. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze the impacts of climate change on water resources of the Guajoyo River Basin in El Salvador. El Salvador is in one of the most vulnerable regions in Latin America to the effects of climate change. The predicted future climate change by two climate change scenarios (RCP 4.5 and RCP 8.5) and five general circulation models (GCMs) were considered. A statistical analysis was performed to identify which GCM was better in terms of goodness of fit to variation in means and standard deviations of the historical series. A significant decreasing trend in precipitation and a significant increase in annual average temperatures were projected by the middle and the end of the twenty–first century. The results indicated a decreasing trend of the amount of water available and more severe droughts for future climate scenarios with respect to the base period (1975–2004). These findings will provide local water management authorities useful information in the face of climate change to help decision making.

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Predictions of future climate change in the caribbean region using global general circulation models

International Journal of Climatology ◽

10.1002/joc.1416 ◽

2007 ◽

Vol 27 (5) ◽

pp. 555-569 ◽

Cited By ~ 56

Author(s):

Moises E. Angeles ◽

Jorge E. Gonzalez ◽

David J. Erickson ◽

José L. Hernández

Keyword(s):

Climate Change ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Caribbean Region ◽

The Caribbean

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Potential Climate Change Impacts on Water Resources in Egypt

Water ◽

10.3390/w13121715 ◽

2021 ◽

Vol 13 (12) ◽

pp. 1715

Author(s):

Soha M. Mostafa ◽

Osama Wahed ◽

Walaa Y. El-Nashar ◽

Samia M. El-Marsafawy ◽

Martina Zeleňáková ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Irrigation Water ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Impact Of Climate Change ◽

Water Demands ◽

The Impact

This paper presents a comprehensive study to assess the impact of climate change on Egypt’s water resources, focusing on irrigation water for agricultural crops, considering that the agriculture sector is the largest consumer of water in Egypt. The study aims to estimate future climate conditions using general circulation models (GCMs), to assess the impact of climate change and temperature increase on water demands for irrigation using the CROPWAT 8 model, and to determine the suitable irrigation type to adapt with future climate change. A case study was selected in the Middle part of Egypt. The study area includes Giza, Bani-Sweif, Al-Fayoum, and Minya governorates. The irrigation water requirements for major crops under current weather conditions and future climatic changes were estimated. Under the conditions of the four selected models CCSM-30, GFDLCM20, GFDLCM21, and GISS-EH, as well as the chosen scenario of A1BAIM, climate model (MAGICC/ScenGen) was applied in 2050 and 2100 to estimate the potential rise in the annual mean temperature in Middle Egypt. The results of the MAGICC/SceGen model indicated that the potential rise in temperature in the study area will be 2.12 °C in 2050, and 3.96 °C in 2100. The percentage of increase in irrigation water demands for winter crops under study ranged from 6.1 to 7.3% in 2050, and from 11.7 to 13.2% in 2100. At the same time, the increase in irrigation water demands for summer crops ranged from 4.9 to 5.8% in 2050, and from 9.3 to 10.9% in 2100. For Nili crops, the increase ranged from 5.0 to 5.1% in 2050, and from 9.6 to 9.9% in 2100. The increase in water demands due to climate change will affect the water security in Egypt, as the available water resources are limited, and population growth is another challenge which requires a proper management of water resources.

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Simulating Future Distributions of Northern Permafrost Peatlands

10.5194/egusphere-egu21-7450 ◽

2021 ◽

Author(s):

Richard Fewster ◽

Paul Morris ◽

Ruza Ivanovic ◽

Graeme Swindles ◽

Anna Peregon ◽

...

Keyword(s):

Climate Change ◽

Northern Hemisphere ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Organic Soils ◽

Climate Projections ◽

Cold Temperatures ◽

Peat Plateaus

Northern permafrost peatlands represent one of Earth&#8217;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 (CO2) and methane (CH4) 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. &#160;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 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.&#160;

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Climate change inspector with intentionally biased bootstrapping (CCIIBB ver. 1.0) – methodology development

Geoscientific Model Development ◽

10.5194/gmd-10-525-2017 ◽

2017 ◽

Vol 10 (2) ◽

pp. 525-536 ◽

Cited By ~ 5

Author(s):

Taesam Lee

Keyword(s):

Climate Change ◽

Global Warming ◽

General Circulation ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Precipitation Data ◽

Temperature Variable ◽

Temperature Scenario ◽

Hydrological Variables

Abstract. The outputs from general circulation models (GCMs) provide useful information about the rate and magnitude of future climate change. The temperature variable is more reliable than other variables in GCM outputs. However, hydrological variables (e.g., precipitation) from GCM outputs for future climate change possess an uncertainty that is too high for practical use. Therefore, a method called intentionally biased bootstrapping (IBB), which simulates the increase of the temperature variable by a certain level as ascertained from observed global warming data, is proposed. In addition, precipitation data were resampled by employing a block-wise sampling technique associated with the temperature simulation. In summary, a warming temperature scenario is simulated, along with the corresponding precipitation values whose time indices are the same as those of the simulated warming temperature scenario. The proposed method was validated with annual precipitation data by truncating the recent years of the record. The proposed model was also employed to assess the future changes in seasonal precipitation in South Korea within a global warming scenario as well as in weekly timescales. The results illustrate that the proposed method is a good alternative for assessing the variation of hydrological variables such as precipitation under the warming condition.

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Modeling the Impacts of Future Climate Change on Irrigation over China: Sensitivity to Adjusted Projections

Journal of Hydrometeorology ◽

10.1175/jhm-d-13-0182.1 ◽

2014 ◽

Vol 15 (5) ◽

pp. 2085-2103 ◽

Cited By ~ 18

Author(s):

Guoyong Leng ◽

Qiuhong Tang

Keyword(s):

Climate Change ◽

Climate Variability ◽

General Circulation ◽

Southern China ◽

Climate Change Impacts ◽

General Circulation Models ◽

Future Climate ◽

Future Climate Change ◽

Community Land Model ◽

The Impact

Abstract Because of the limitations of coarse-resolution general circulation models (GCMs), delta change (DC) methods are generally used to derive scenarios of future climate as inputs into impact models. In this paper, the impact of future climate change on irrigation was investigated over China using the Community Land Model, version 4 (CLM4), which was calibrated against observed irrigation water demand (IWD) at the provincial level. The results show large differences in projected changes of IWD variability, extremes, timing, and regional responses between the DC and bias-corrected (BC) methods. For example, 95th-percentile IWD increased by 62% in the BC method compared to only a 28% increase in the DC method. In addition, a shift of seasonal IWD peaks (averaged over the country) to one month later in the year was projected when using the BC method, whereas no evident changes were predicted when using the DC method. Furthermore, low-percentile runoff has larger impacts in the BC method compared with proportional changes in the DC method, indicating that hydrological droughts seem to be exacerbated by increased climate variability. The discrepancies between the two methods were potentially due to the inability of the DC method to capture the changes in precipitation variability. Therefore, the authors highlight the potential effects of climate variability and the sensitivity to the choice of particular strategy-adjusting climate projection in assessing climate change impacts on irrigation. Some caveats, however, should be placed around interpretation of simulated percentage changes for all of China since a large model bias was found in southern China.

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