scholarly journals Assessment of impacts of climate change on surface water availability using coupled SWAT and WEAP models: case of upper Pangani River Basin, Tanzania

2018 ◽  
Vol 378 ◽  
pp. 23-27 ◽  
Author(s):  
Peter Kishiwa ◽  
Joel Nobert ◽  
Victor Kongo ◽  
Preksedis Ndomba
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
River Basin ◽  
Water Use ◽  
Water Availability ◽  
Swat Model ◽  
Economic Activities ◽  
Peak Flows ◽  
Global Circulation Models ◽  
The Impact

Abstract. This study was designed to investigate the dynamics of current and future surface water availability for different water users in the upper Pangani River Basin under changing climate. A multi-tier modeling technique was used in the study, by coupling the Soil and Water Assessment Tool (SWAT) and Water Evaluation And Planning (WEAP) models, to simulate streamflows under climate change and assess scenarios of future water availability to different socio-economic activities by year 2060. Six common Global Circulation Models (GCMs) from WCRP-CMIP3 with emissions Scenario A2 were selected. These are HadCM3, HadGEM1, ECHAM5, MIROC3.2MED, GFDLCM2.1 and CSIROMK3. They were downscaled by using LARS-WG to station scale. The SWAT model was calibrated with observed data and utilized the LARS-WG outputs to generate future streamflows before being used as input to WEAP model to assess future water availability to different socio-economic activities. GCMs results show future rainfall increase in upper Pangani River Basin between 16–18 % in 2050s relative to 1980–1999 periods. Temperature is projected to increase by an average of 2 ∘C in 2050s, relative to baseline period. Long-term mean streamflows is expected to increase by approximately 10 %. However, future peak flows are estimated to be lower than the prevailing average peak flows. Nevertheless, the overall annual water demand in Pangani basin will increase from 1879.73 Mm3 at present (2011) to 3249.69 Mm3 in the future (2060s), resulting to unmet demand of 1673.8 Mm3 (51.5 %). The impact of future shortage will be more severe in irrigation where 71.12 % of its future demand will be unmet. Future water demands of Hydropower and Livestock will be unmet by 27.47 and 1.41 % respectively. However, future domestic water use will have no shortage. This calls for planning of current and future surface water use in the upper Pangani River Basin.

scholarly journals SIMULAÇÃO HIDROLÓGICA FERRAMENTA PARA GESTÃO DOS RECURSOS HÍDRICOS EM FUNÇÃO DE MUDANÇAS CLIMÁTICAS NA BACIA DO RIO RIACHÃO, MG, BRASIL

Nativa ◽  
2019 ◽  
Vol 7 (6) ◽  
pp. 718
Author(s):  
Rafael Alexandre Sá ◽  
Marcos Koiti Kondo ◽  
Edson De Oliveira Vieira ◽  
Silvânio Rodrigues Dos Santos ◽  
Nayara Paula Andrade Vieira ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Air Temperature ◽  
Water Availability ◽  
Swat Model ◽  
Minas Gerais ◽  
Hydrologic Model ◽  
Hydrological Simulation ◽  
The Impact

A simulação hidrológica de bacias hidrográficas tem se tornado uma ferramenta importante de planejamento e gestão de recursos hídricos, projetando-se inclusive a disponibilidade hídrica a partir das mudanças climáticas. Dessa forma, objetivou-se avaliar a eficiência do modelo hidrológico SWAT na simulação da vazão da bacia hidrográfica do rio Riachão, no Norte de Minas Gerais, sob impacto de cenários alternativos de elevação da temperatura média do ar. O modelo SWAT foi ajustado para o período de 01/01/2008 a 31/12/2014 e calibrado com os dados das vazões hidrometradas obtendo valores do coeficiente de eficiência Nash-Sutcliffe (NSE) de 0,74 e 0,79 e tendência percentual (PBIAS) 15,45% e 16,72%, nas fases de calibração e validação, respectivamente. A disponibilidade de água superficial da bacia hidrográfica para comparação dos cenários foi calculada por meio da curva de permanência da vazão de referência Q90, obtendo-se o valor de 0,081 m3 s-1 para o modelo calibrado. Os cenários de aumento da temperatura média da bacia em 1,5; 2,0; 3,0; 4,0 e 5,0 °C levaram ao decréscimo da Q90 em 7,66; 8,98; 10,49; 14,06 e 17,76%, respectivamente.Palavras-chave: escoamento superficial; modelo SWAT; cenários climáticos; gerenciamento de recursos hídricos. HYDROLOGICAL SIMULATION TOOL FOR MANAGEMENT OF WATER RESOURCES IN THE FUNCTION OF CLIMATE CHANGE IN THE RIACHÃO RIVER BASIN, MG, BRAZIL ABSTRACT: The hydrological simulation of watersheds becomes a major tool for planning and management of water resources, including water availability prediction from global climate change. Thus, the objective was to evaluate the efficiency of the SWAT hydrologic model to simulate the stream flow of Riachão river basin, North of Minas Gerais State, Brazil, under the impact of alternative scenarios with the increase in mean surface air temperature. The SWAT model was adjusted for 1/1/2008 to 12/31/2014 period and calibrated with data measurement obtaining values the Nash-Sutcliffe efficiency (NSE) of 0.74 and 0.79 and percent bias (PBIAS) of 15.45 and 16.72% was found to calibration and validation period, respectively. The surface water availability in the hydrographic basin was calculated by Q90 streamflow, with calibrated value of 0.081 m³s-1. The scenarios of increase in mean air temperature (1.5, 2.0, 3.0, 4.0 and 5.0 ºC) reduced Q90 by 7.66, 8.98, 10.49, 14.06 and 17.76%, respectively.Keywords: runoff; SWAT model; climate scenarios; water resource management.

scholarly journals Application of SWAT in Hydrological Simulation of Complex Mountainous River Basin (Part II: Climate Change Impact Assessment)

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1548
Author(s):  
Suresh Marahatta ◽  
Deepak Aryal ◽  
Laxmi Prasad Devkota ◽  
Utsav Bhattarai ◽  
Dibesh Shrestha
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Climate Models ◽  
Assessment Tool ◽  
Swat Model ◽  
Global Climate Models ◽  
Climate Data ◽  
The Future ◽  
The Impact ◽  
Mountainous River

This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day-maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience.

Impact of climate change on streamflow and water quality in the upper Dong Nai river basin, Vietnam

2018 ◽  
pp. 70-79 ◽  
Author(s):  
Le Viet Thang ◽  
Dao Nguyen Khoi ◽  
Ho Long Phi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
River Basin ◽  
Sediment Load ◽  
Swat Model ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Nutrient Load ◽  
Impact Of Climate Change ◽  
The Impact

In this study, we investigated the impact of climate change on streamflow and water quality (TSS, T-N, and T-P loads) in the upper Dong Nai River Basin using the Soil and Water Assessment Tool (SWAT) hydrological model. The calibration and validation results indicated that the SWAT model is a reasonable tool for simulating streamflow and water quality for this basin. Based on the well-calibrated SWAT model, the responses of streamflow, sediment load, and nutrient load to climate change were simulated. Climate change scenarios (RCP 4.5 and RCP 8.5) were developed from five GCM simulations (CanESM2, CNRM-CM5, HadGEM2-AO, IPSL-CM5A-LR, and MPI-ESM-MR) using the delta change method. The results indicated that climate in the study area would become warmer and wetter in the future. Climate change leads to increases in streamflow, sediment load, T-N load, and T-P load. Besides that, the impacts of climate change would exacerbate serious problems related to water shortage in the dry season and soil erosion and degradation in the wet season. In addition, it is indicated that changes in sediment yield and nutrient load due to climate change are larger than the corresponding changes in streamflow.

scholarly journals Assessment of the impact of climate change on the freshwater availability of Kaduna River basin, Nigeria

2018 ◽  
Vol 38 (1) ◽  
pp. 105-114 ◽  
Author(s):  
Gloria C. Okafor ◽  
Kingsley N. Ogbu
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Water Availability ◽  
Hydrological Cycle ◽  
Temporal Trends ◽  
Kendall Test ◽  
Well Being ◽  
Trend Test ◽  
Climate Indices ◽  
The Impact

AbstractChanges in runoff trends have caused severe water shortages and ecological problems in agriculture and human well-being in Nigeria. Understanding the long-term (inter-annual to decadal) variations of water availability in river basins is paramount for water resources management and climate change adaptation. Climate change in Northern Nigeria could lead to change of the hydrological cycle and water availability. Moreover, the linkage between climatic changes and streamflow fluctuations is poorly documented in this area. Therefore, this study examined temporal trends in rainfall, temperature and runoff records of Kaduna River basin. Using appropriate statistical tools and participatory survey, trends in streamflow and their linkages with the climate indices were explored to determine their amplifying impacts on water availability and impacts on livelihoods downstream the basin. Analysis indicate variable rainfall trend with significant wet and dry periods. Unlike rainfall, temperature showed annual and seasonal scale statistically increasing trend. Runoff exhibit increasing tendency but only statistically significant on annual scale as investigated with Mann–Kendall trend test. Sen’s estimator values stood in agreement with Mann–Kendall test for all variables. Kendall tau and partial correlation results revealed the influence of climatic variables on runoff. Based on the survey, some of the hydrological implications and current water stress conditions of these fluctuations for the downstream inhabitants were itemized. With increasing risk of climate change and demand for water, we therefore recommend developing adaptive measures in seasonal regime of water availability and future work on modelling of the diverse hydrological characteristics of the entire basin.

scholarly journals Variations of Drought Tendency, Frequency, and Characteristics and Their Responses to Climate Change under CMIP5 RCP Scenarios in Huai River Basin, China

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2174 ◽  
Author(s):  
Jingcai Wang ◽  
Hui Lin ◽  
Jinbai Huang ◽  
Chenjuan Jiang ◽  
Yangyang Xie ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Eastern China ◽  
Cmip5 Models ◽  
Drought Severity ◽  
Global Circulation Models ◽  
Huai River Basin ◽  
Huai River ◽  
The Future ◽  
The Impact

Huai River Basin (HRB) is an important food and industrial production area and a frequently drought-affected basin in eastern China. It is necessary to consider the future drought development for reducing the impact of drought disasters. Three global circulation models (GCMs) from Coupled Model Intercomparison Project phase 5 (CMIP5), such as CNRM-CM5 (CNR), HadGEM2-ES (Had) and MIROC5 (MIR), were used to assessment the future drought conditions under two Representative Concentration Pathways (RCPs) scenarios, namely, RCP4.5 and RCP8.5. The standardized precipitation evapotranspiration index (SPEI), statistical method, Mann-Kendall test, and run theory were carried out to study the variations of drought tendency, frequency, and characteristics and their responses to climate change. The research showed that the three CMIP5 models differ in describing the future seasonal and annual variations of precipitation and temperature in the basin and thus lead to the differences in describing drought trends, frequency, and drought characteristics, such as drought severity, drought duration, and drought intensity. However, the drought trend, frequency, and characteristics in the future are more serious than the history. The drought frequency and characteristics tend to be strengthened under the scenario of high concentration of RCP8.5, and the drought trend is larger than that of low concentration of RCP4.5. The lower precipitation and the higher temperature are the main factors affecting the occurrence of drought. All three CMIP5 models show that precipitation would increase in the future, but it could not offset the evapotranspiration loss caused by significant temperature rise. The serious risk of drought in the future is still higher. Considering the uncertainty of climate models for simulation and prediction, attention should be paid to distinguish the effects of different models in the future drought assessment.

scholarly journals Simulating the Impact of Climate Change on the Hydrological Regimes of a Sparsely Gauged Mountainous Basin, Northern Pakistan

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2141 ◽  
Author(s):  
Saddique ◽  
Usman ◽  
Bernhofer
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Assessment Tool ◽  
High Elevation ◽  
Climate Simulation ◽  
Water Yield ◽  
Research Station ◽  
Impact Of Climate Change ◽  
Global Circulation Models ◽  
The Impact

Projected climate changes for the 21st century may cause great uncertainties on the hydrology of a river basin. This study explored the impacts of climate change on the water balance and hydrological regime of the Jhelum River Basin using the Soil and Water Assessment Tool (SWAT). Two downscaling methods (SDSM, Statistical Downscaling Model and LARS-WG, Long Ashton Research Station Weather Generator), three Global Circulation Models (GCMs), and two representative concentration pathways (RCP4.5 and RCP8.5) for three future periods (2030s, 2050s, and 2090s) were used to assess the climate change impacts on flow regimes. The results exhibited that both downscaling methods suggested an increase in annual streamflow over the river basin. There is generally an increasing trend of winter and autumn discharge, whereas it is complicated for summer and spring to conclude if the trend is increasing or decreasing depending on the downscaling methods. Therefore, the uncertainty associated with the downscaling of climate simulation needs to consider, for the best estimate, the impact of climate change, with its uncertainty, on a particular basin. The study also resulted that water yield and evapotranspiration in the eastern part of the basin (sub-basins at high elevation) would be most affected by climate change. The outcomes of this study would be useful for providing guidance in water management and planning for the river basin under climate change.

scholarly journals Understanding Future Water Challenges in a Highly Regulated Indian River Basin—Modelling the Impact of Climate Change on the Hydrology of the Upper Narmada

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1762 ◽  
Author(s):  
Nathan Rickards ◽  
Thomas Thomas ◽  
Alexandra Kaelin ◽  
Helen Houghton-Carr ◽  
Sharad K. Jain ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Large Scale ◽  
Monsoon Season ◽  
Future Climate Change ◽  
Impact Of Climate Change ◽  
Global Circulation Models ◽  
The Impact ◽  
Availability Assessment

The Narmada river basin is a highly regulated catchment in central India, supporting a population of over 16 million people. In such extensively modified hydrological systems, the influence of anthropogenic alterations is often underrepresented or excluded entirely by large-scale hydrological models. The Global Water Availability Assessment (GWAVA) model is applied to the Upper Narmada, with all major dams, water abstractions and irrigation command areas included, which allows for the development of a holistic methodology for the assessment of water resources in the basin. The model is driven with 17 Global Circulation Models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) ensemble to assess the impact of climate change on water resources in the basin for the period 2031–2060. The study finds that the hydrological regime within the basin is likely to intensify over the next half-century as a result of future climate change, causing long-term increases in monsoon season flow across the Upper Narmada. Climate is expected to have little impact on dry season flows, in comparison to water demand intensification over the same period, which may lead to increased water stress in parts of the basin.

Climate change vs. human impact. A look into Austrian groundwater

2020 ◽  
Author(s):  
Johannes Christoph Haas ◽  
Steffen Birk
Keyword(s):  
Climate Change ◽  
Surface Water ◽  
Water Supply ◽  
Human Impact ◽  
Water Use ◽  
Special Role ◽  
European Alps ◽  
Groundwater Levels ◽  
Human Use ◽  
The Impact

<p>Climate change is mostly associated with the term of “global warming” and thus conjures images of a hotter and dryer future. Indeed, the Alpine region already has seen much higher warming compared to the average of the northern hemisphere [1]. However, because of the impact of other climate variables (e.g. precipitation) and vegetation responses, warming does not necessarily have to mean higher evapotranspiration and dryer conditions [2]. This matter is further complicated as groundwater is closely interlinked with surface water. While surface water is of course related to precipitation, it is also one of the major pathways for humans to have a large and direct impact on the water cycle, e.g. by the construction of run-of-river powerplants. A further direct human impact is the abstraction of groundwater. For this factor, it is generally understood that water use increased with economic activity until the rise of environmentalism in the 1980s and more efficient water use stopped this trend and turned it into a decrease in many industrialized countries.</p><p> </p><p>Assessing impacts of climate change on groundwater resources therefore is a challenging task. In order to assess these, as well as direct human impacts on groundwater, we analyzed a large dataset (1017 groundwater level-, 426 stream stage- and 646 precipitation time series) covering Austria from earlier than 1930 until 2015, with the majority of the data from the 1970s on.</p><p> </p><p>It is shown that groundwater shows a strong falling trend, followed by a rise, fitting the human water use, whereas precipitation shows a more moderate trend. River stages show a completely deviating behavior before the 1980s but also follow the rising trend afterwards [3]. While this does not yet prove a causal link, it does highlight the possibility that human use could affect groundwater levels more than the climate, especially since Austria almost exclusively uses groundwater for human use and the wells in the dataset are all located in the populated lowlands.</p><p> </p><p>Going beyond [3], we take a closer look at the history and future of the human factor, namely water abstraction for public water supply and the effects of humans on rivers. We show that Austria has a very particular form of water supply, mainly due to the special role of the capital, Vienna, whose history could see a repeat in the near future. Under a changing climate, there is also a possibility for further changes in Austria’s rivers. In addition to effects of such changes on groundwater levels, we try to address potential impacts on the chemical quality and ecological status of groundwater.</p><p> </p><p>References:</p><p>[1] Gobiet et al., 2014, 21<sup>st</sup> century climate change in the European alps-a review. Sci. Total. Environ. 493, 1138 – 1151.</p><p>[2] Pangle et al., 2014, Rainfall seasonality and an ecohydrological feedback offset the potential impact of climate warming on evapotranspiration and groundwater recharge, Water Resour. Res., 50, 1308–1321</p><p>[3] Haas & Birk, 2019, Trends in Austrian groundwater – climate or human impact? J. Hydrol.: Reg. Stud. 22, 100597</p>

scholarly journals Relative Importance of Land Use and Climate Change on Hydrology in Agricultural Watershed of Southern China

2020 ◽  
Vol 12 (16) ◽  
pp. 6423
Author(s):  
Lanhua Luo ◽  
Qing Zhou ◽  
Hong S. He ◽  
Liangxia Duan ◽  
Gaoling Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Land Use Change ◽  
River Basin ◽  
Laboratory Experiments ◽  
Southern China ◽  
Swat Model ◽  
Efficiency Coefficient ◽  
Soil Database ◽  
The Impact

Quantitative assessment of the impact of land use and climate change on hydrological processes is of great importance to water resources planning and management. The main objective of this study was to quantitatively assess the response of runoff to land use and climate change in the Zhengshui River Basin of Southern China, a heavily used agricultural basin. The Soil and Water Assessment Tool (SWAT) was used to simulate the river runoff for the Zhengshui River Basin. Specifically, a soil database was constructed based on field work and laboratory experiments as input data for the SWAT model. Following SWAT calibration, simulated results were compared with observed runoff data for the period 2006 to 2013. The Nash-Sutcliffe Efficiency Coefficient (NSE) and the correlation coefficient (R2) for the comparisons were greater than 0.80, indicating close agreement. The calibrated models were applied to simulate monthly runoff in 1990 and 2010 for four scenarios with different land use and climate conditions. Climate change played a dominant role affecting runoff of this basin, with climate change decreasing simulated runoff by −100.22% in 2010 compared to that of 1990, land use change increasing runoff in this basin by 0.20% and the combination of climate change and land use change decreasing runoff by 60.8m3/s. The decrease of forestland area and the corresponding increase of developed land and cultivated land area led to the small increase in runoff associated with land use change. The influence of precipitation on runoff was greater than temperature. The soil database used to model runoff with the SWAT model for the basin was constructed using a combination of field investigation and laboratory experiments, and simulations of runoff based on that new soil database more closely matched observations of runoff than simulations based on the generic Harmonized World Soil Database (HWSD). This study may provide an important reference to guide management decisions for this and similar watersheds.

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