scholarly journals Modelling streamflow response to climate change in data-scarce White Volta River basin of West Africa using a semi-distributed hydrologic model

2018 ◽  
Vol 10 (4) ◽  
pp. 907-930 ◽  
Author(s):  
Sulemana Abubakari ◽  
Xiaohua Dong ◽  
Bob Su ◽  
Xiaonong Hu ◽  
Ji Liu ◽  
...  
Keyword(s):  
Climate Change ◽  
West Africa ◽  
General Circulation ◽  
Management Practices ◽  
Evaluation Criteria ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Volta Basin ◽  
Monthly Streamflow ◽  
The Future

Abstract This study uses high resolution Climate Forecast System Reanalysis (CFSR), SWAT and two IPCC climate change (CC) scenarios (A1B and B1) combined with two general circulation models (GCMs) (HADCM3 and MPEH5) to evaluate impact of CC on streamflow in the White Volta basin of West Africa. The evaluation criteria (R2 and NSE > 0.70 and PBIAS within ±25%) during calibration and validation showed good simulation of the basin hydrology. Using average streamflow from 1979 to 2008 as a baseline, there were uncertainties over the sign of variation of annual streamflow in the 2020s. Annually, streamflow change is projected to be within −4.00% to +13.00% in the 2020s and +3.00% to +16.00% in the 2050s. Monthly streamflow changes for most months vary between −13.00% and +32.00%. A shift in monthly maximum streamflow from September to August is projected, while the driest months (December, January and February) show no change in the future. Based on the model results, the White Volta basin will likely experience an increase in streamflow by the mid-21st century. This would call for appropriate investment into cost-effective adaptive water management practices to cater for the likely impact of CC on the future hydrology of the basin.

scholarly journals High-Resolution Solar Climate Atlas for Greece under Climate Change Using the Weather Research and Forecasting (WRF) Model

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 761 ◽  
Author(s):  
Theodoros Katopodis ◽  
Iason Markantonis ◽  
Nadia Politi ◽  
Diamando Vlachogiannis ◽  
Athanasios Sfetsos
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
Energy Demand ◽  
General Circulation ◽  
Wrf Model ◽  
General Circulation Models ◽  
Weather Research And Forecasting ◽  
Clear Sky ◽  
The Future ◽  
Weather Research

In the context of climate change and growing energy demand, solar technologies are considered promising solutions to mitigate Greenhouse Gas (GHG) emissions and support sustainable adaptation. In Greece, solar power is the second major renewable energy, constituting an increasingly important component of the future low-carbon energy portfolio. In this work, we propose the use of a high-resolution regional climate model (Weather Research and Forecasting model, WRF) to generate a solar climate atlas for the near-term climatological future under the Representative Concentration Pathway (RCPs) 4.5 and 8.5 scenarios. The model is set up with a 5 × 5 km2 spatial resolution, forced by the ERA-INTERIM for the historic (1980–2004) period and by the EC-EARTH General Circulation Models (GCM) for the future (2020–2044). Results reaffirm the high quality of solar energy potential in Greece and highlight the ability of the WRF model to produce a highly reliable future climate solar atlas. Projected changes between the annual historic and future RCPs scenarios indicate changes of the annual Global Horizontal Irradiance (GHI) in the range of ±5.0%. Seasonal analysis of the GHI values indicates percentage changes in the range of ±12% for both scenarios, with winter exhibiting the highest seasonal increases in the order of 10%, and autumn the largest decreases. Clear-sky fraction fclear projects increases in the range of ±4.0% in eastern and north continental Greece in the future, while most of the Greek marine areas might expect above 220 clear-sky days per year.

scholarly journals A Simplistic Approach for Assessing Hydroclimatic Vulnerability of Lakes and Reservoirs with Regulated Superficial Outflow

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 61 ◽  
Author(s):  
Kleoniki Demertzi ◽  
Dimitris Papadimos ◽  
Vassilis Aschonitis ◽  
Dimitris Papamichail
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Drainage Basin ◽  
Management Strategies ◽  
General Circulation Models ◽  
Climatic Conditions ◽  
Modified Model ◽  
Natural Lakes ◽  
The Future ◽  
The Impact

This study proposes a simplistic model for assessing the hydroclimatic vulnerability of lakes/reservoirs (LRs) that preserve their steady-state conditions based on regulated superficial discharge (Qd) out of the LR drainage basin. The model is a modification of the Bracht-Flyr et al. method that was initially proposed for natural lakes in closed basins with no superficial discharge outside the basin (Qd = 0) and under water-limited environmental conditions {mean annual ratio of potential/reference evapotranspiration (ETo) versus rainfall (P) greater than 1}. In the proposed modified approach, an additional Qd function is included. The modified model is applied using as a case study the Oreastiada Lake, which is located inside the Kastoria basin in Greece. Six years of observed data of P, ETo, Qd, and lake topography were used to calibrate the modified model based on the current conditions. The calibrated model was also used to assess the future lake conditions based on the future climatic projections (mean conditions of 2061-2080) derived by 19 general circulation models (GCMs) for three cases of climate change (three cases of Representative Concentration Pathways: RCP2.6, RCP4.5 and RCP8.5). The modified method can be used as a diagnostic tool in water-limited environments for analyzing the superficial discharge changes of LRs under different climatic conditions and to support the design of new management strategies for mitigating the impact of climate change on (a) flooding conditions, (b) hydroelectric production, (c) irrigation/industrial/domestic use and (d) minimum ecological flows to downstream rivers.

scholarly journals Future Changes in Precipitation and Drought Characteristics over Bangladesh Under CMIP5 Climatological Projections

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2219 ◽  
Author(s):  
Kamruzzaman ◽  
Jang ◽  
Cho ◽  
Hwang
Keyword(s):  
Climate Change ◽  
21St Century ◽  
General Circulation ◽  
General Circulation Models ◽  
Northern Region ◽  
Medium Term ◽  
Rcp Scenarios ◽  
Drought Characteristics ◽  
The Future ◽  
Northwestern Region

: The impacts of climate change on precipitation and drought characteristics over Bangladesh were examined by using the daily precipitation outputs from 29 bias-corrected general circulation models (GCMs) under the representative concentration pathway (RCP) 4.5 and 8.5 scenarios. A precipitation-based drought estimator, namely, the Effective Drought Index (EDI), was applied to quantify the characteristics of drought events in terms of the severity and duration. The changes in drought characteristics were assessed for the beginning (2010–2039), middle (2040–2069), and end of this century (2070–2099) relative to the 1976–2005 baseline. The GCMs were limited in regard to forecasting the occurrence of future extreme droughts. Overall, the findings showed that the annual precipitation will increase in the 21st century over Bangladesh; the increasing rate was comparatively higher under the RCP8.5 scenario. The highest increase in rainfall is expected to happen over the drought-prone northern region. The general trends of drought frequency, duration, and intensity are likely to decrease in the 21st century over Bangladesh under both RCP scenarios, except for the maximum drought intensity during the beginning of the century, which is projected to increase over the country. The extreme and medium-term drought events did not show any significant changes in the future under both scenarios except for the medium-term droughts, which decreased by 55% compared to the base period during the 2070s under RCP8.5. However, extreme drought days will likely increase in most of the cropping seasons for the different future periods under both scenarios. The spatial distribution of changes in drought characteristics indicates that the drought-vulnerable areas are expected to shift from the northwestern region to the central and the southern region in the future under both scenarios due to the effects of climate change.

scholarly journals Future Changes in Precipitation and Drought Characteristics over Bangladesh under CMIP5 Climatological Projections

2019 ◽  
Author(s):  
Mohammad Kamruzzaman ◽  
Min-Won Jang ◽  
Jaepil Cho ◽  
Syewoon Hwang
Keyword(s):  
Climate Change ◽  
21St Century ◽  
General Circulation ◽  
General Circulation Models ◽  
Northern Region ◽  
Medium Term ◽  
Rcp Scenarios ◽  
Drought Characteristics ◽  
The Future ◽  
Northwestern Region

The impacts of climate change on precipitation and drought characteristics over Bangladesh were examined by using the daily precipitation outputs from 29 bias-corrected general circulation models (GCMs) under the representative concentration pathway (RCP) 4.5 and 8.5 scenarios. A precipitation-based drought estimator, namely, the Effective Drought Index (EDI), was applied to quantify the characteristics of drought events in terms of the severity and duration. The changes in drought characteristics were assessed for the beginning (2010–2039), middle (2040–2069), and end of this century (2070–2099) relative to the 1976–2005 baseline. The GCMs were limited in regard to forecasting the occurrence of future extreme droughts. Overall, the findings showed that the annual precipitation will increase in the 21st century over Bangladesh; the increasing rate was comparatively higher under the RCP8.5 scenario. The highest increase of rainfall is expected to happen over the drought-prone northern region. The general trends of drought frequency, duration, and intensity are likely to decrease in the 21st century over Bangladesh under both RCP scenarios, except for the maximum drought intensity during the beginning of the century, which is projected to increase over the country. The extreme and medium-term drought events did not show any significant changes in the future under both scenarios except for the medium-term droughts, which decreased by 55% compared to the base period during the 2070s under RCP8.5. However, extreme drought days will likely increase in most of the cropping seasons for the different future periods under both scenarios. The spatial distribution of changes in drought characteristics indicates that the drought-vulnerable areas are expected to shift from the northwestern region to the central and the southern region in the future under both scenarios due to the effects of climate change.

scholarly journals Risk analysis of climate change on coffee nematodes and leaf miner in Brazil

2008 ◽  
Vol 43 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Raquel Ghini ◽  
Emília Hamada ◽  
Mário José Pedro Júnior ◽  
José Antonio Marengo ◽  
Renata Ribeiro do Valle Gonçalves
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Management Practices ◽  
General Circulation Models ◽  
Climatic Conditions ◽  
Leaf Miner ◽  
Intergovernmental Panel ◽  
Distribution Maps ◽  
Distribution Centre ◽  
Disease Epidemics

The objective of this work was to assess the potential impact of climate change on the spatial distribution of coffee nematodes (races of Meloidogyne incognita) and leaf miner (Leucoptera coffeella), using a Geographic Information System. Assessment of the impacts of climate change on pest infestations and disease epidemics in crops is needed as a basis for revising management practices to minimize crop losses as climatic conditions shift. Future scenarios focused on the decades of the 2020's, 2050's, and 2080's (scenarios A2 and B2) were obtained from five General Circulation Models available on Data Distribution Centre from Intergovernmental Panel on Climate Change. Geographic distribution maps were prepared using models to predict the number of generations of the nematodes and leaf miner. Maps obtained in scenario A2 allowed prediction of an increased infestation of the nematode and of the pest, due to greater number of generations per month, than occurred under the climatological normal from 1961-1990. The number of generations also increased in the B2 scenario, but was lower than in the A2 scenario for both organisms.

scholarly journals Hydrologic Model Evaluation and Assessment of Projected Climate Change Impacts Using Bias-Corrected Stream Flows

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2312
Author(s):  
Joseph A. Daraio
Keyword(s):  
Climate Change ◽  
Bias Correction ◽  
Stream Flow ◽  
General Circulation ◽  
Model Performance ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Historical Period ◽  
Hydrologic Models ◽  
Stream Flows

Hydrologic models driven by downscaled meteorologic data from general circulation models (GCM) should be evaluated using long-term simulations over a historical period. However, simulations driven by GCM data cannot be directly evaluated using observed flows, and the confidence in the results can be relatively low. The objectives of this paper were to bias correct simulated stream flows from calibrated hydrologic models for two basins in New Jersey, USA, and evaluate model performance in comparison to uncorrected simulations. Then, we used stream flow bias correction and flow duration curves (FDCs) to evaluate and assess simulations driven by statistically downscaled GCMs for the historical period and the future time slices 2041–2070 and 2071–2099. Bias correction of stream flow from simulations increased confidence in the performance of two previously calibrated hydrologic models. Results indicated there was no difference in projected FDCs for uncorrected and bias-corrected flows in one basin, while this was not the case in the second basin. This result provided greater confidence in projected stream flow changes in the former basin and implied more uncertainty in projected stream flows in the latter. Applications in water resources can use the methods described to evaluate the performance of GCM-driven simulations and assess the potential impacts of climate change with an appropriate level of confidence in the model results.

scholarly journals Climate change scenarios and its impact on water resources of Langtang Khola Basin, Nepal

2014 ◽  
Vol 364 ◽  
pp. 9-13
Author(s):  
T. Raj Adhikari ◽  
L. Prasad Devkota ◽  
A. Bhakta Shrestha
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Local Level ◽  
General Circulation Models ◽  
Temperature Data ◽  
Future Climate ◽  
Optimization Approach ◽  
Climate Change Scenarios ◽  
The Future ◽  
Precipitation And Temperature

Abstract. General Circulation Models (GCMs) successfully simulate future climate variability and climate change on a global scale; however, poor spatial resolution constrains their application for impact studies at a regional or a local level. The dynamically downscaled precipitation and temperature data were used for the future climate scenarios prediction for the period 2000–2050s, under the Special Report on Emissions Scenarios (SRES) A2 and A1B scenarios. In addition, rating equation was developed from measured discharge and gauge (stage) height data. The generated precipitation and temperature data from downscale and rating equation was used to run the HBV-Light 3.0 conceptual rainfall–runoff model for the calibration and validation of the model, gauge height was taken in the reference period (1988–2009). In the HBV-Light 3.0, a GAP optimization approach was used to calibrate the observed streamflow. From the precipitation scenarios with SRES A2 and A1B emissions at Kyanging, an increase of precipitation during summer and spring and a decrease during winter and autumn seasons was shown. The model projected annual precipitation for the 2050s of both the A2 and A1B scenarios are 716.4 mm and 703.6 mm, respectively. Such precipitation projections indicate the future increase of precipitation in all seasons except the summer. By the end of the 2050s simulation projects an increase maximum (minimum) discharge of 37.8 m3/s (13.9 m3/s) for A1B scenario and 36.2 m3/s (14.3 m3/s) for A2 scenario. A maximum projected discharge will increase for all seasons except for spring, whereas the minimum will decrease in summer.

scholarly journals Climate Change and the Future Heat Stress Challenges among Smallholder Farmers in East Africa

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 753
Author(s):  
Genesis Tambang Yengoh ◽  
Jonas Ardö
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Smallholder Farmers ◽  
General Circulation Models ◽  
Sub Saharan Africa ◽  
Critical Element ◽  
Critical Periods ◽  
The Future ◽  
Sub Saharan ◽  
The Impact

Agricultural production in sub-Saharan Africa remains dependent on high inputs of human labor, a situation associated with direct exposure to daylight heat during critical periods of the agricultural calendar. We ask the question: how is the Wet-Bulb Globe Temperature (WBGT) going to be distributed in the future, and how will this affect the ability of smallholder farmers to perform agricultural activities? Data from general circulation models are used to estimate the distribution of WBGT in 2000, 2050 and 2100, and for high activity periods in the agricultural calendar. The distribution of WBGT is divided into recommended maximum WBGT exposure levels (°C) at different work intensities, and rest/work ratios for an average acclimatized worker wearing light clothing (ISO, 18). High WBGTs are observed during the two periods of the East African. In February to March, eastern and coastal regions of Kenya and Tanzania witness high WBGT values—some necessitating up to 75% rest/hour work intensities in 2050 and 2100. In August to September, eastern and northern Kenya and north and central Uganda are vulnerable to high WBGT values. Designing policies to address this key challenge is a critical element in adaptation methods to address the impact of climate change.

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

2018 ◽  
Author(s):  
Seungwoo Chang ◽  
Wendy Graham ◽  
Jeffrey Geurink ◽  
Nisai Wanakule ◽  
Tirusew Asefa
Keyword(s):  
Climate Change ◽  
Water Use ◽  
Groundwater Level ◽  
General Circulation ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Tampa Bay ◽  
Future Climate ◽  
Future Climate Change ◽  
Groundwater Levels

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 and compliance with water resource regulations is more recent. It is important to predict potential impacts of future climate change on streamflows and groundwater levels to reduce risks and increase resilience in water resources management and planning. This study evaluated future streamflows and groundwater levels in the Tampa Bay region in west-central Florida using an ensemble of different GCMs, reference evapotranspiration (ET0) methods, and water use scenarios to drive an integrated hydrologic model (IHM). 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, to drive the IHM for eight different human water use scenarios. Results showed that changes in projected streamflow were most sensitive to GCM selection, however, projections of groundwater level change were sensitive to both GCM and water use scenario. Projected changes in streamflow and groundwater level were relatively insensitive to the ET0 methods evaluated in this study. Six of eight GCMs projected a decrease in streamflow and groundwater level in the future regardless of water use scenario or ET method. These results indicate a high probability of a reduction in future water supply in the Tampa Bay region if environmental regulations intended to protect current aquatic ecosystems do not adapt to the changing climate.

scholarly journals Isolating the impacts of land use and climate change on streamflow

2015 ◽  
Vol 12 (2) ◽  
pp. 2201-2242 ◽  
Author(s):  
I. Chawla ◽  
P. P. Mujumdar
Keyword(s):  
Climate Change ◽  
Land Use ◽  
River Basin ◽  
General Circulation ◽  
General Circulation Models ◽  
Hydrologic Model ◽  
Combined Effect ◽  
Infiltration Capacity ◽  
Ganga Basin

Abstract. Streamflow regime is sensitive to changes in land use and climate in a river basin. Quantifying the isolated and integrated impacts of land use and climate change on streamflow is challenging as well as crucial to optimally manage water resources in the river basin. This paper presents a simple hydrologic modelling based approach to segregate the impacts of land use and climate change on streamflow of a river basin. The upper Ganga basin in India is selected as the case study to carry out the analysis. Streamflow in the river basin is modelled using a calibrated variable infiltration capacity hydrologic model. The approach involves development of three scenarios to understand the influence of land use and climate on streamflow. The first scenario assesses the sensitivity of streamflow to land use changes under invariant climate. The second scenario determines the change in streamflow due to change in climate assuming constant land use. The third scenario estimates the combined effect of changing land use and climate over streamflow of the basin. Based on the results obtained from the three scenarios, quantification of isolated impacts of land use and climate change on streamflow is addressed. Future projections of climate are obtained from dynamically downscaled simulations of six general circulation models (GCMs) available from the Coordinated Regional Downscaling Experiment (CORDEX) project. Uncertainties associated with the GCMs and emission scenarios are quantified in the analysis. Results for the case study indicate that streamflow is highly sensitive to change in urban area and moderately sensitive to change in crop land area. However, variations in streamflow generally reproduce the variations in precipitation. Combined effect of land use and climate on streamflow is observed to be more pronounced compared to their individual impacts in the basin. It is observed from the isolated effects of land use and climate change that climate has a more dominant impact on streamflow in the region. The approach proposed in this paper is applicable to any river basin to isolate the impacts of land use change and climate change on the streamflow.

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