Modeling hydrologic processes and potential responses to climate change in an agro-silvo-pastoral watershed in the Mediterranean area

Abstract. Precipitation changes and water use patterns are two factors affecting the water quantity; obviously, hydrologic processes are always linked to many elements in the watershed scale, so to understand water management issues it is fundamental to analyze the different elements of hydrologic processes occurring in the watershed. In this study, the “SWAT” model (Soil and Water Assessment Tool) has been used to simulate the water balance for the present climate conditions on a semi arid watershed located in the central North of Morocco (R'dom). The study watershed covers an area of 1993 km2, and is hosting farming, pasture and forestry related activities. The water stress situation in the R'dom watershed can be summarized as limited resource facing increasing water demand. SWAT model was first run and calibrated under current climate; and was driven with downscaled climate simulations to generate future hydrological projections for R'dom watershed in the 2031 to 2050 horizon under two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The results of the study showed that the water balance in R'dom watershed is dominated by evapotranspiration and the water resources distribution within the watershed is uneven and follows a decreasing gradient matching the flow direction. The main results of climate change scenarios showed that R'dom watershed will undergo significant decrease of water resources availability with more economic impact under the scenario RCP8.5 as all areas hosting the economical activities will be affected and the highest changes of water yield should be under this scenario.

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Variability of Water Balance under Climate Change Scenarios. Implications for Sustainability in the Rhône River Basin

Sustainability ◽

10.3390/su12166402 ◽

2020 ◽

Vol 12 (16) ◽

pp. 6402

Author(s):

Pedro Pérez-Cutillas ◽

Pedro Baños Páez ◽

Isabel Banos-González

Keyword(s):

Climate Change ◽

Water Resources ◽

Water Balance ◽

Sustainable Management ◽

Hydrological Regime ◽

Water Yield ◽

Climate Change Scenarios ◽

Invest Model ◽

Discharge Water ◽

Vulnerability To Climate Change

The Rhône basin is considered a complex river socio-ecological system, which houses numerous socioeconomic activities closely linked to its river courses, as well as competition between the different users of these water resources. Likewise, its increasing vulnerability to climate change highlights the need to assess the potential effects of a set of climate scenarios to assist the management of these resources. With this aim, we have analysed the effects of five scenarios on different environmental zones of the basin characterised by altitudinal features, using the “Water Yield” hydrological module of the InVEST model. The model outputs show that the Rhône basin will have significant discharge water variations and changes in the seasonality of the hydrological regime, being able to trigger serious economic and environmental effects under the simulated scenarios. Regarding these altitudinal environmental zones, results show important differences in the final water balance, resulting in the mountain and subalpine zones being the most affected by these scenarios. The uncertainty in the availability of water resources and the need for its sustainable management will require the establishment of important adaptations to the new challenges imposed by these scenarios, particularly in alpine zones, due to its sensitivity and fragility to climate change.

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Water resources availability under different climate change scenarios in South East of Iran

Journal of Water and Climate Change ◽

10.2166/wcc.2021.373 ◽

2021 ◽

Author(s):

Reza Iranmanesh ◽

Navid Jalalkamali ◽

Omid Tayari

Keyword(s):

Climate Change ◽

Food Security ◽

Water Resources ◽

Water Balance ◽

Swat Model ◽

Green Water ◽

Climate Change Scenarios ◽

Available Water ◽

East Of Iran ◽

The Impact

Abstract The comprehensive large-scale assessment of future available water resources is crucial for food security in countries dealing with water shortages like Iran. Kerman province, located in the south east of Iran, is an agricultural hub and has vital importance for food security. This study attempts to project the impact of climate change on available water resources of this province and then, by defining different scenarios, to determine the amount of necessary reduction in cultivation areas to achieve water balance over the province. The GFDL-ESM2M climate change model, RCP scenarios, and the CCT (Climate Change Toolkit) were used to project changes in climatic variables, and the Soil and Water Assessment Tool (SWAT) was used for hydrological simulation. The future period for which forecasts are made is 2020–2050. Based on the coefficient of determination (R2) and Nash–Sutcliffe coefficient, the CCT demonstrates good performance in data downscaling. The results show that under all climate change scenarios, most parts of the province are likely to experience an increase in precipitation yet to achieve water balance a 10% decrease in the cultivation area is necessary under the RCP8.5 scenario. The results of the SWAT model show that green water storage in central and western parts of the province is higher than that in other parts.

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Understanding the Impacts of Climate Change in the Tana River Basin, Kenya

Proceedings of the International Association of Hydrological Sciences ◽

10.5194/piahs-379-37-2018 ◽

2018 ◽

Vol 379 ◽

pp. 37-42 ◽

Cited By ~ 1

Author(s):

Lal Muthuwatta ◽

Aditya Sood ◽

Matthew McCartney ◽

Nishchitha Sandeepana Silva ◽

Alfred Opere

Keyword(s):

Climate Change ◽

Water Resources ◽

River Basin ◽

Assessment Tool ◽

Swat Model ◽

Baseline Period ◽

Base Flow ◽

Water Yield ◽

Hydrological Characteristics ◽

Tana River

Abstract. In the Tana River Basin in Kenya, six Regional Circulation Models (RCMs) simulating two Representative Concentration Pathways (RCPs) (i.e., 4.5 and 8.5) were used as input to the Soil and Water Assessment Tool (SWAT) model to determine the possible implications for the hydrology and water resources of the basin. Four hydrological characteristics – water yield, groundwater recharge, base flow and flow regulation – were determined and mapped throughout the basin for three 30-year time periods: 2020–2049, 2040–2069 and 2070–2099. Results were compared with a baseline period, 1983–2011. All four hydrological characteristics show steady increases under both RCPs for the entire basin but with considerable spatial heterogeneity and greater increases under RCP 8.5 than RCP 4.5. The results have important implications for the way water resources in the basin are managed. It is imperative that water managers and policy makers take into account the additional challenges imposed by climate change in operating built infrastructure.

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Estimation of Hydrological Components under Current and Future Climate Scenarios in Guder Catchment, Upper Abbay Basin, Ethiopia, Using the SWAT

Sustainability ◽

10.3390/su13179689 ◽

2021 ◽

Vol 13 (17) ◽

pp. 9689

Author(s):

Tewekel Melese Gemechu ◽

Hongling Zhao ◽

Shanshan Bao ◽

Cidan Yangzong ◽

Yingying Liu ◽

...

Keyword(s):

Climate Change ◽

Hydrological Modeling ◽

Climate Model ◽

Assessment Tool ◽

Swat Model ◽

Future Climate ◽

Future Climate Change ◽

Water Yield ◽

Climate Change Scenarios ◽

Rcp 8.5

Changes in hydrological cycles and water resources will certainly be a direct consequence of climate change, making the forecast of hydrological components essential for water resource assessment and management. This research was thus carried out to estimate water balance components and water yield under current and future climate change scenarios and trends in the Guder Catchment of the Upper Blue Nile, Ethiopia, using the soil and water assessment tool (SWAT). Hydrological modeling was efficaciously calibrated and validated using the SUFI-2 algorithm of the SWAT model. The results showed that water yield varied from 926 mm to 1340 mm per year (1986–2016). Regional climate model (RCM) data showed, under representative concentration pathways (RCP 8.5), that the precipitation will decrease by up to 14.4% relative to the baseline (1986–2016) precipitation of 1228 mm/year, while the air temperature will rise under RCP 8.5 by +4.4 °C in the period from 2057 to 2086, possibly reducing the future basin water yield output, suggesting that the RCP 8.5 prediction will be warmer than RCP 4.5. Under RCP 8.5, the total water yield from 2024 to 2086 may be reduced by 3.2 mm per year, and a significant trend was observed. Local government agencies can arrange projects to solve community water-related issues based on these findings.

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A Review of SWAT Model Application in Africa

Water ◽

10.3390/w13091313 ◽

2021 ◽

Vol 13 (9) ◽

pp. 1313

Author(s):

George Akoko ◽

Tu Hoang Le ◽

Takashi Gomi ◽

Tasuku Kato

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Hydrological Modeling ◽

Assessment Tool ◽

Swat Model ◽

Data Availability ◽

Mitigation Measures ◽

Model Parameterization ◽

Basin Scale

The soil and water assessment tool (SWAT) is a well-known hydrological modeling tool that has been applied in various hydrologic and environmental simulations. A total of 206 studies over a 15-year period (2005–2019) were identified from various peer-reviewed scientific journals listed on the SWAT website database, which is supported by the Centre for Agricultural and Rural Development (CARD). These studies were categorized into five areas, namely applications considering: water resources and streamflow, erosion and sedimentation, land-use management and agricultural-related contexts, climate-change contexts, and model parameterization and dataset inputs. Water resources studies were applied to understand hydrological processes and responses in various river basins. Land-use and agriculture-related context studies mainly analyzed impacts and mitigation measures on the environment and provided insights into better environmental management. Erosion and sedimentation studies using the SWAT model were done to quantify sediment yield and evaluate soil conservation measures. Climate-change context studies mainly demonstrated streamflow sensitivity to weather changes. The model parameterization studies highlighted parameter selection in streamflow analysis, model improvements, and basin scale calibrations. Dataset inputs mainly compared simulations with rain-gauge and global rainfall data sources. The challenges and advantages of the SWAT model’s applications, which range from data availability and prediction uncertainties to the model’s capability in various applications, are highlighted. Discussions on considerations for future simulations such as data sharing, and potential for better future analysis are also highlighted. Increased efforts in local data availability and a multidimensional approach in future simulations are recommended.

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Hydrological Alteration Index as an Indicator of the Calibration Complexity of Water Quantity and Quality Modeling in the Context of Global Change

Water ◽

10.3390/w12010115 ◽

2019 ◽

Vol 12 (1) ◽

pp. 115 ◽

Cited By ~ 3

Author(s):

Roxelane Cakir ◽

Mélanie Raimonet ◽

Sabine Sauvage ◽

Javier Paredes-Arquiola ◽

Youen Grusson ◽

...

Keyword(s):

Climate Change ◽

Water Quality ◽

Water Resources ◽

Stream Water ◽

Swat Model ◽

Water Yield ◽

Observation Data ◽

Hydrological Alteration ◽

Water Quality And Quantity ◽

The Impact

Modeling is a useful way to understand human and climate change impacts on the water resources of agricultural watersheds. Calibration and validation methodologies are crucial in forecasting assessments. This study explores the best calibration methodology depending on the level of hydrological alteration due to human-derived stressors. The Soil and Water Assessment Tool (SWAT) model is used to evaluate hydrology in South-West Europe in a context of intensive agriculture and water scarcity. The Index of Hydrological Alteration (IHA) is calculated using discharge observation data. A comparison of two SWAT calibration methodologies are done; a conventional calibration (CC) based on recorded in-stream water quality and quantity and an additional calibration (AC) adding crop managements practices. Even if the water quality and quantity trends are similar between CC and AC, water balance, irrigation and crop yields are different. In the context of rainfall decrease, water yield decreases in both CC and AC, while crop productions present opposite trends (+33% in CC and −31% in AC). Hydrological performance between CC and AC is correlated to IHA: When the level of IHA is under 80%, AC methodology is necessary. The combination of both calibrations appears essential to better constrain the model and to forecast the impact of climate change or anthropogenic influences on water resources.

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Hydrologic response to climate change: a case study for the Be River Catchment, Vietnam

Journal of Water and Climate Change ◽

10.2166/wcc.2012.035 ◽

2012 ◽

Vol 3 (3) ◽

pp. 207-224 ◽

Cited By ~ 17

Author(s):

Dao Nguyen Khoi ◽

Tadashi Suetsugi

Keyword(s):

Climate Change ◽

General Circulation ◽

Assessment Tool ◽

Swat Model ◽

General Circulation Models ◽

Climate Change Scenarios ◽

River Catchment ◽

Calibration And Validation ◽

Daily Streamflow ◽

The Impact

The Be River Catchment was studied to quantify the potential impact of climate change on the streamflow using a multi-model ensemble approach. Climate change scenarios (A1B and B1) were developed from an ensemble of four GCMs (general circulation models) (CGCM3.1 (T63), CM2.0, CM2.1 and HadCM3) that showed good performance for the Be River Catchment through statistical evaluations between 15 GCM control simulations and the corresponding time series of observations at annual and monthly levels. The Soil and Water Assessment Tool (SWAT) was used to investigate the impact on streamflow under climate change scenarios. The model was calibrated and validated using daily streamflow records. The calibration and validation results indicated that the SWAT model was able to simulate the streamflow well, with Nash–Sutcliffe efficiency exceeding 0.78 for the Phuoc Long station and 0.65 for the Phuoc Hoa station, for both calibration and validation at daily and monthly steps. Their differences in simulating the streamflow under future climate scenarios were also investigated. The results indicate a 1.0–2.9 °C increase in annual temperature and a −4.0 to 0.7% change in annual precipitation corresponding to a change in streamflow of −6.0 to −0.4%. Large decreases in precipitation and runoff are observed in the dry season.

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The Impact of Land Use/Land Cover Change (LULCC) on Water Resources in a Tropical Catchment in Tanzania under Different Climate Change Scenarios

Sustainability ◽

10.3390/su11247083 ◽

2019 ◽

Vol 11 (24) ◽

pp. 7083 ◽

Cited By ~ 4

Author(s):

Kristian Näschen ◽

Bernd Diekkrüger ◽

Mariele Evers ◽

Britta Höllermann ◽

Stefanie Steinbach ◽

...

Keyword(s):

Climate Change ◽

Land Use ◽

Water Resources ◽

Land Cover ◽

Water Balance ◽

Land Cover Change ◽

Sub Saharan Africa ◽

Climate Change Scenarios ◽

Land Use Land Cover ◽

The Impact

Many parts of sub-Saharan Africa (SSA) are prone to land use and land cover change (LULCC). In many cases, natural systems are converted into agricultural land to feed the growing population. However, despite climate change being a major focus nowadays, the impacts of these conversions on water resources, which are essential for agricultural production, is still often neglected, jeopardizing the sustainability of the socio-ecological system. This study investigates historic land use/land cover (LULC) patterns as well as potential future LULCC and its effect on water quantities in a complex tropical catchment in Tanzania. It then compares the results using two climate change scenarios. The Land Change Modeler (LCM) is used to analyze and to project LULC patterns until 2030 and the Soil and Water Assessment Tool (SWAT) is utilized to simulate the water balance under various LULC conditions. Results show decreasing low flows by 6–8% for the LULC scenarios, whereas high flows increase by up to 84% for the combined LULC and climate change scenarios. The effect of climate change is stronger compared to the effect of LULCC, but also contains higher uncertainties. The effects of LULCC are more distinct, although crop specific effects show diverging effects on water balance components. This study develops a methodology for quantifying the impact of land use and climate change and therefore contributes to the sustainable management of the investigated catchment, as it shows the impact of environmental change on hydrological extremes (low flow and floods) and determines hot spots, which are critical for environmental development.

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Climate change impacts on nutrient loads in the Yorkshire Ouse catchment (UK)

Hydrology and Earth System Sciences ◽

10.5194/hess-6-197-2002 ◽

2002 ◽

Vol 6 (2) ◽

pp. 197-209 ◽

Cited By ~ 70

Author(s):

F. Bouraoui ◽

L. Galbiati ◽

G. Bidoglio

Keyword(s):

Climate Change ◽

Assessment Tool ◽

Swat Model ◽

Climate Change Impacts ◽

Climate Change Scenarios ◽

Baseline Scenario ◽

Nutrient Loads ◽

Nitrogen And Phosphorus ◽

Temperature And Precipitation ◽

The Impact

Abstract. This study assessed the impact of potential climate change on the nutrient loads to surface and sub-surface waters from agricultural areas and was conducted using the Soil and Water Assessment Tool (SWAT) model. The study focused on a 3500 km2 catchment located in northern England, the Yorkshire Ouse. The SWAT model was calibrated and validated using sets of five years' measurements of nitrate and ortho-phosphorus concentrations and water flow. To increase the reliability of the hydrological model predictions, an uncertainty analysis was conducted by perturbing input parameters using a Monte-Carlo technique. The SWAT model was then run using a baseline scenario corresponding to an actual measured time series of daily temperature and precipitation, and six climate change scenarios. Because of the increase in temperature, all climate scenarios introduced an increase of actual evapotranspiration. Faster crop growth and an increased nutrient uptake resulted, as did an increase of annual losses of total nitrogen and phosphorus, however, with strong seasonal differences. Keywords: SWAT model, climate change, nutrient loads

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Predicting hydrologic responses to climate changes in highly glacierized and mountainous region Upper Indus Basin

Royal Society Open Science ◽

10.1098/rsos.191957 ◽

2020 ◽

Vol 7 (8) ◽

pp. 191957 ◽

Cited By ~ 2

Author(s):

Muhammad Izhar Shah ◽

Asif Khan ◽

Tahir Ali Akbar ◽

Quazi K. Hassan ◽

Asim Jahangir Khan ◽

...

Keyword(s):

Climate Change ◽

Water Resources ◽

Climate Model ◽

Assessment Tool ◽

Model Simulation ◽

Global Climate ◽

Meteorological Data ◽

Swat Model ◽

Indus Basin ◽

Upper Indus Basin

The Upper Indus Basin (UIB) is a major source of supplying water to different areas because of snow and glaciers melt and is also enduring the regional impacts of global climate change. The expected changes in temperature, precipitation and snowmelt could be reasons for further escalation of the problem. Therefore, estimation of hydrological processes is critical for UIB. The objectives of this paper were to estimate the impacts of climate change on water resources and future projection for surface water under different climatic scenarios using soil and water assessment tool (SWAT). The methodology includes: (i) development of SWAT model using land cover, soil and meteorological data; (ii) calibration of the model using daily flow data from 1978 to 1993; (iii) model validation for the time 1994–2003; (iv) bias correction of regional climate model (RCM), and (v) utilization of bias-corrected RCM for future assessment under representative concentration pathways RCP4.5 and RCP8.5 for mid (2041–2070) and late century (2071–2100). The results of the study revealed a strong correlation between simulated and observed flow with R 2 and Nash–Sutcliff efficiency (NSE) equal to 0.85 each for daily flow. For validation, R 2 and NSE were found to be 0.84 and 0.80, respectively. Compared to baseline period (1976–2005), the result of RCM showed an increase in temperature ranging from 2.36°C to 3.50°C and 2.92°C to 5.23°C for RCP4.5 and RCP8.5 respectively, till the end of the twenty-first century. Likewise, the increase in annual average precipitation is 2.4% to 2.5% and 6.0% to 4.6% (mid to late century) under RCP4.5 and RCP8.5, respectively. The model simulation results for RCP4.5 showed increase in flow by 19.24% and 16.78% for mid and late century, respectively. For RCP8.5, the increase in flow is 20.13% and 15.86% during mid and late century, respectively. The model was more sensitive towards available moisture and snowmelt parameters. Thus, SWAT model could be used as effective tool for climate change valuation and for sustainable management of water resources in future.

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