scholarly journals Evaluating watershed hydrological responses to climate changes at Hangar Watershed, Ethiopia

2021 ◽  
Author(s):  
Abdata Wakjira Galata ◽  
Kiyya Tesfa Tullu ◽  
Abebe Chala Guder
Keyword(s):  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Annual Runoff ◽  
Annual Precipitation ◽  
Watershed Hydrology ◽  
Rcp Scenarios ◽  
Average Annual Runoff ◽  
The Future ◽  
Average Annual Precipitation

Abstract The aim of this study is to model the responses of Hangar Watershed hydrology to future climate changes under two representative concentration pathway (RCP) scenarios. Future changes in precipitation and temperature were produced using the output of dynamically downscaled data of a regional climate model (RCM) 0.44° resolution under RCP 4.5 and 8.5 scenarios for 2025–2055 and 2056–2086. The future projection of the RCM model of precipitation and temperatures showed an increasing trend relative to the base period (1987–2017). At 2025–2055 average annual precipitation increments of +15.7 and +19.8% were expected for RCP 4.5 and RCP 8.5, respectively. For 2056–2086 of RCP 4.5 and 8.5, a similar trend was also shown as average annual precipitation may increase by +20.1 and +23.4%, respectively. The changes of climate parameters were used as input into the SWAT hydrological model to simulate the future runoff at Hangar Watershed. The increment in precipitation projection resulted in a positive magnitude impact on average runoff flow. The average annual change in runoff at 2025–2055 of both RCP 4.5 and 8.5 may increase by +24.5 and +23.6%, respectively. In 2056–2086, a change in average annual runoff of +73.2 and +73.2% for RCP 4.5 and 8.5 may be expected, respectively.

Future Extreme Climates Projection over Huang-Huai-Hai Region of China

2014 ◽  
Vol 955-959 ◽  
pp. 3887-3892 ◽  
Author(s):  
Huang He Gu ◽  
Zhong Bo Yu ◽  
Ji Gan Wang
Keyword(s):  
Climate Changes ◽  
Climate Model ◽  
Regional Climate ◽  
Surface Air Temperature ◽  
Daily Rainfall ◽  
Heavy Rain ◽  
Near Surface ◽  
Temperature And Precipitation ◽  
Huai River ◽  
The Future

This study projects the future extreme climate changes over Huang-Huai-Hai (3H) region in China using a regional climate model (RegCM4). The RegCM4 performs well in “current” climate (1970-1999) simulations by compared with the available surface station data, focusing on near-surface air temperature and precipitation. Future climate changes are evaluated based on experiments driven by European-Hamburg general climate model (ECHAM5) in A1B future scenario (2070-2099). The results show that the annual temperature increase about 3.4 °C-4.2 °C and the annual precipitation increase about 5-15% in most of 3H region at the end of 21st century. The model predicts a generally less frost days, longer growing season, more hot days, no obvious change in heat wave duration index, larger maximum five-day rainfall, more heavy rain days, and larger daily rainfall intensity. The results indicate a higher risk of floods in the future warmer climate. In addition, the consecutive dry days in Huai River Basin will increase, indicating more serve drought and floods conditions in this region.

scholarly journals Assess the impacts of climate change on the patterns of rainfall, temperature, and streamflow in the Abelti Watershed of Southwestern Ethiopia

2021 ◽  
Author(s):  
BEYENE AKIRSO ALEHU ◽  
Seble Gizachew Bitana
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
Management Strategies ◽  
Maximum Temperature ◽  
Rcp Scenarios ◽  
Hydrologic Modelling ◽  
Sustainable Resources ◽  
The Future ◽  
The Impact

Abstract Changes in rainfall, temperature and streamflow (stf) will be one of the most critical factors determining the overall impact of climate change (CC). Thus, in this study we evaluated rainfall(rf), temperature, and stf pattern under changing climate in the Abelti-Watershed (a sub-watershed of upper Omo Gibe basin), Ethiopia. The Representative Concentration Pathway (RCP) scenarios of Hadley Global Environment Model 2-Earth System (HadGEM2-ES) under Coordinated Regional Climate Downscaling Experiment (CORDEX)-Africa database selected for the near (2011-2040), med (2041-2070), and end (2071-2100) periods. Hydrologic Engineering Centers-Hydrologic Modelling System (HEC-HMS) model applied for stf projection. XL-STAT conducts average annual and seasonal rf, minimum and maximum temperature (tmin&tmax), and stf trend tests. Mean seasonal and annual rf and stf variation evaluation taken using the coefficient of variation (CV). Finally, the impact of CC analysis is taken based on the baseline period. The results revealed that the climate model projection is successful for given weather stations. HEC-HMS model showed a satisfactory performance during calibration (R2=0.82) and validation (R2=0.78). The MK trend of tmin&tmax show significantly increasing; whereas rf and stf show insignificantly decreasing except under RCP8.5. The rf and stf CV analysis indicated less, moderate, and high in the study area. And the future long year average annual rf increased by -3.6%, -1.9% and -7.7%; temperature +1.15%, +2.2% and +4.2%; and stf -2.9%, -0.05% and -8.5% under RCP2.6, RCP4.5 and RCP8.5 respectively. Thus, the decrement in rf and the increment in temperature lead to more evapotranspiration and affect the stf negatively. In conclusion, stf in the Abelti-watershed could significantly decline with adverse consequences for water supplies, agriculture, and ecosystem health for the future. Therefore, this study may contribute to the planning and implementation of sustainable resources development and management strategies and help to mitigate the consequences of CC.

scholarly journals Evaluation of the Impacts of Climate Change on Runoff in Dadu River Basin Based on CORDEX Regional Climate Model

2021 ◽  
Author(s):  
Zhangrong Pan ◽  
Wei Li ◽  
Junhong Guo ◽  
Zhuo Chen ◽  
Hui Qin
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
River Basin ◽  
Climate Model ◽  
Swat Model ◽  
Regional Climate ◽  
Annual Runoff ◽  
Runoff Changes ◽  
The Future ◽  
Dadu River

Owing to the rich water resources, the Dadu River basin is an important hydroelectric resources development area in Sichuan Province over China. The climate change will have a great impact on the runoff change in the Dadu River Basin. The prediction of the future runoff in the Dadu River Basin can effectively improve the utilization rate of water resources, and provide a reference for hydropower dispatching. At first, to reduce the uncertainties from climate model, this paper used Stepwise Clustering Analysis to calibrate and validate the CORDEX regional climate model ensemble data from 1970 to 2005 and projected the climate change trend of Dadu River basin from 2035 to 2065. Then the Dadu River watershed scales of SWAT model was established, using the SWAT-CUP for calibration and verification. Finally, the corrected future climate data are used to drive the SWAT model to realize the future runoff forecast in the Dadu River Basin. The results show that under the scenario of RCP4.5 and RCP8.5, the variation range of rainfall is small, and the maximum and minimum temperatures show an overall increasing trend. The maximum (minimum) temperature will increase about 0.6℃ (1.0℃) under the scenarios of RCP4.5 and 0.9℃ (1.4℃) under the scenario of RCP8.5. Compared with the baseline period, the future (2035-2065) annual runoff under RCP4.5 and RCP8.5 scenarios will increase by about 8.6% and 8.2%, respectively. Under the future climate change, the inter-annual runoff in the Dadu River Basin will change greatly, and the trend of runoff fluctuation is not consistent before and after 2050. Before 2050, runoff changes are small, however, after 2050, runoff changes under the two scenarios will increase by about 12%. On the one hand, this trend may be due to the impact of iceberg melting on runoff caused by temperature changes around 2050, on the other hand, it may be due to the combined effect of local plant evapotranspiration and ecological regulation.

scholarly journals A Statistical–Distributed Model of Average Annual Runoff for Water Resources Assessment in DPR Korea

Water ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 965 ◽  
Author(s):  
Tongho Ri ◽  
Jiping Jiang ◽  
Bellie Sivakumar ◽  
Tianrui Pang
Keyword(s):  
Water Resources ◽  
Air Temperature ◽  
Empirical Relationship ◽  
Annual Runoff ◽  
Annual Precipitation ◽  
Distributed Model ◽  
Runoff Formation ◽  
Proposed Model ◽  
Average Annual Runoff ◽  
Average Annual Precipitation

Water resource management is critical for the economic development of the Democratic People’s Republic of Korea (DPRK), where runoff plays a central role. However, long and continuous runoff data at required spatial and temporal scales are generally not available in many regions in DPRK, the same as in many countries around the world. A common practice to fill the gaps is to use some kind of interpolation or data-infilling methods. In this study, the gaps in annual runoff data were filled using a distributed runoff map. A novel statistical–distributed model of average annual runoff was derived from 50 years’ observation on 200 meteorological observation stations in DPRK, considering the influence of climatic factors. Using principal component analysis, correlation analysis and residual error analysis, average annual precipitation, average annual precipitation intensity, average annual air temperature, and hot seasonal air temperature were selected as major factors affecting average annual runoff formation. Based on the water balance equation and assumptions, the empirical relationship for runoff depth and impact factors was established and calibrated. The proposed empirical model was successfully verified by 93 gauged stations. The cartography of the average annual runoff map was automatically implemented in ArcGIS. A case study on the Tumen River Basin illustrated the applicability of the proposed model. This model has been widely used for the development and management of water resources by water-related institutes and design agencies in DPRK. The limitation of the proposed model and future works are also discussed, especially the impacts of climate changes and topology changes and the combination with the physical process of runoff formation.

The effect of climate change on urban drainage: an evaluation based on regional climate model simulations

2006 ◽  
Vol 54 (6-7) ◽  
pp. 9-15 ◽  
Author(s):  
M. Grum ◽  
A.T. Jørgensen ◽  
R.M. Johansen ◽  
J.J. Linde
Keyword(s):  
Climate Change ◽  
Extreme Precipitation ◽  
Climate Model ◽  
Regional Climate ◽  
Rain Gauge ◽  
Urban Drainage ◽  
Extreme Precipitation Events ◽  
Rainfall Extremes ◽  
The Future ◽  
Precipitation Events

That we are in a period of extraordinary rates of climate change is today evident. These climate changes are likely to impact local weather conditions with direct impacts on precipitation patterns and urban drainage. In recent years several studies have focused on revealing the nature, extent and consequences of climate change on urban drainage and urban runoff pollution issues. This study uses predictions from a regional climate model to look at the effects of climate change on extreme precipitation events. Results are presented in terms of point rainfall extremes. The analysis involves three steps: Firstly, hourly rainfall intensities from 16 point rain gauges are averaged to create a rain gauge equivalent intensity for a 25 × 25 km square corresponding to one grid cell in the climate model. Secondly, the differences between present and future in the climate model is used to project the hourly extreme statistics of the rain gauge surface into the future. Thirdly, the future extremes of the square surface area are downscaled to give point rainfall extremes of the future. The results and conclusions rely heavily on the regional model's suitability in describing extremes at time-scales relevant to urban drainage. However, in spite of these uncertainties, and others raised in the discussion, the tendency is clear: extreme precipitation events effecting urban drainage and causing flooding will become more frequent as a result of climate change.

The influence of global climate changes on Western Siberia climate in the first half of XXI century

2018 ◽  
Author(s):  
А.А. Лагутин ◽  
Н.В. Волков ◽  
Е.Ю. Мордвин
Keyword(s):  
Radiative Forcing ◽  
Climate Changes ◽  
Western Siberia ◽  
Climate Model ◽  
Global Climate ◽  
Regional Climate ◽  
First Century ◽  
Global Climate Changes ◽  
Rcp 8.5

Представлены результаты исследований влияния глобальных климатических изменений системы Земля на климат Западной Сибири. Для установления зон региона, в которых к середине XXI в. прогнозируются изменения, использовались модельные данные региональной климатической модели RegCM4 и принятые в этом классе задач стандартизованные евклидовы расстояния между характеристиками климата для двух состояний климатической системы — современного и будущего. Установлены зоны Западной Сибири, в которых в рамках сценариев RCP 4.5 и RCP 8.5 возможной эволюции глобальной системы к 2050 г. прогнозируются изменения климата. Purpose. An analysis of the influence of a global climate changes on the climate of Western Siberia, determination of zones of the region where changes are expected in the middle of the twenty-first century. Methodology. Results obtained using the model data of the regional climate model RegCM4 and the standardized Euclidean distances between climate characteristics. Findings, originality. Simulations of the climate characteristics for the two states of the climate system — contemporary and future — have been carried out. The zones of Western Siberia region, in which climate change is expected in the framework of RCP 4.5 and RCP 8.5 radiative forcing scenarios by the 2050, have been determined.

scholarly journals Impacts of 1.5 and 2.0 °C Global Warming on Water Balance Components over Senegal in West Africa

Atmosphere ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 712
Author(s):  
Mamadou Lamine Mbaye ◽  
Mouhamadou Bamba Sylla ◽  
Moustapha Tall
Keyword(s):  
Global Warming ◽  
West Africa ◽  
Water Deficit ◽  
Climate Model ◽  
Regional Climate ◽  
Climate Change Impacts ◽  
Water Balance Components ◽  
Global Mean Temperature ◽  
The Future ◽  
Annual Water

This study assesses the changes in precipitation (P) and in evapotranspiration (ET) under 1.5 °C and 2.0 °C global warming levels (GWLs) over Senegal in West Africa. A set of twenty Regional Climate Model (RCM) simulations within the Coordinated Regional Downscaling Experiment (CORDEX) following the Representative Concentration Pathways (RCP) 4.5 emission scenario is used. Annual and seasonal changes are computed between climate simulations under 1.5 °C and 2.0 °C warming, with respect to 0.5 °C warming, compared to pre-industrial levels. The results show that annual precipitation is likely to decrease under both magnitudes of warming; this decrease is also found during the main rainy season (July, August, September) only and is more pronounced under 2 °C warming. All reference evapotranspiration calculations, from Penman, Hamon, and Hargreaves formulations, show an increase in the future under the two GWLs, except annual Penman evapotranspiration under the 1.5 °C warming scenario. Furthermore, seasonal and annual water balances (P-ET) generally exhibit a water deficit. This water deficit (up to 180 mm) is more substantial with Penman and Hamon under 2 °C. In addition, analyses of changes in extreme precipitation reveal an increase in dry spells and a decrease in the number of wet days. However, Senegal may face a slight increase in very wet days (95th percentile), extremely wet days (99th), and rainfall intensity in the coming decades. Therefore, in the future, Senegal may experience a decline in precipitation, an increase of evapotranspiration, and a slight increase in heavy rainfall. Such changes could have serious consequences (e.g., drought, flood, etc.) for socioeconomic activities. Thus, strong governmental politics are needed to restrict the global mean temperature to avoid irreversible negative climate change impacts over the country. The findings of this study have contributed to a better understanding of local patterns of the Senegal hydroclimate under the two considered global warming scenarios.

scholarly journals Regionalization of Climate Change Simulations over the Eastern Mediterranean

2009 ◽  
Vol 22 (8) ◽  
pp. 1944-1961 ◽  
Author(s):  
Bariş Önol ◽  
Fredrick H. M. Semazzi
Keyword(s):  
Climate Change ◽  
Regional Climate Model ◽  
Temperature Increase ◽  
Climate Model ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Future Climate ◽  
Climate Change Projections ◽  
Model Simulations ◽  
The Future

Abstract In this study, the potential role of global warming in modulating the future climate over the eastern Mediterranean (EM) region has been investigated. The primary vehicle of this investigation is the Abdus Salam International Centre for Theoretical Physics Regional Climate Model version 3 (ICTP-RegCM3), which was used to downscale the present and future climate scenario simulations generated by the NASA’s finite-volume GCM (fvGCM). The present-day (1961–90; RF) simulations and the future climate change projections (2071–2100; A2) are based on the Intergovernmental Panel on Climate Change (IPCC) greenhouse gas (GHG) emissions. During the Northern Hemispheric winter season, the general increase in precipitation over the northern sector of the EM region is present both in the fvGCM and RegCM3 model simulations. The regional model simulations reveal a significant increase (10%–50%) in winter precipitation over the Carpathian Mountains and along the east coast of the Black Sea, over the Kackar Mountains, and over the Caucasus Mountains. The large decrease in precipitation over the southeastern Turkey region that recharges the Euphrates and Tigris River basins could become a major source of concern for the countries downstream of this region. The model results also indicate that the autumn rains, which are primarily confined over Turkey for the current climate, will expand into Syria and Iraq in the future, which is consistent with the corresponding changes in the circulation pattern. The climate change over EM tends to manifest itself in terms of the modulation of North Atlantic Oscillation. During summer, temperature increase is as large as 7°C over the Balkan countries while changes for the rest of the region are in the range of 3°–4°C. Overall the temperature increase in summer is much greater than the corresponding changes during winter. Presentation of the climate change projections in terms of individual country averages is highly advantageous for the practical interpretation of the results. The consistence of the country averages for the RF RegCM3 projections with the corresponding averaged station data is compelling evidence of the added value of regional climate model downscaling.

Decomposition of Future Moisture Flux Changes over the Tibetan Plateau Projected by Global and Regional Climate Models

2019 ◽  
Vol 32 (20) ◽  
pp. 7037-7053
Author(s):  
Hongwen Zhang ◽  
Yanhong Gao ◽  
Jianwei Xu ◽  
Yu Xu ◽  
Yingsha Jiang
Keyword(s):  
Tibetan Plateau ◽  
Climate Model ◽  
Dynamical Downscaling ◽  
Regional Climate ◽  
Moisture Flux ◽  
Historical Period ◽  
The Tibetan Plateau ◽  
Dynamic Component ◽  
Coarse Resolution ◽  
The Future

Abstract To meet the requirement of high-resolution datasets for many applications, a dynamical downscaling approach using a regional climate model (the WRF Model) driven by a global climate model (CCSM4) has been adopted. This study focuses on projections of future moisture flux changes over the Tibetan Plateau (TP). First, the downscaling results for the historical period (1980–2005) are evaluated for precipitation P, evaporation E, and precipitation minus evaporation P − E against Global Land Data Assimilation System (GLDAS) data. The mechanism of P − E changes is analyzed by decomposition into dynamic, thermodynamic, and transient eddy components. Whether the historical period changes and mechanisms continue into the future (2010–2100) is investigated using the WRF and CCSM model projections under the RCP4.5 and RCP8.5 scenarios. Compared with coarse-resolution forcing, downscaling was found to better reproduce the historical spatial patterns and seasonal mean of annual average P, E, and P − E over the TP. WRF projects a diverse spatial variation of P − E changes, with an increase in the northern TP and a decrease in the southern TP, compared with the uniform increase in CCSM. The dynamic component dominates P − E changes for the historical period in both the CCSM and WRF projections. In the future, however, the thermodynamic component in CCSM dominates P − E changes under RCP4.5 and RCP8.5 from the near-term (2010–39) to the long-term (2070–99) future. Unlike the CCSM projections, the WRF projections reproduce the mechanism seen in the historical period—that is, the dynamic component dominates P − E changes. Furthermore, future P − E changes in the dynamical downscaling are less sensitive to warming than its coarse-resolution forcing.

scholarly journals Projected Changes of Precipitation IDF Curves for Short Duration under Climate Change in Central Vietnam

Hydrology ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 33 ◽  
Author(s):  
Nguyen Tien Thanh ◽  
Luca Dutto Aldo Remo
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Southern Oscillation ◽  
Regional Climate ◽  
Extreme Weather Events ◽  
Climate Data ◽  
Rcp Scenarios ◽  
Central Vietnam ◽  
Idf Curves ◽  
Projected Changes

In future years, extreme weather events are expected to frequently increase due to climate change, especially in the combination of climate change and events of El Niño–Southern Oscillation. This pays special attention to the construction of intensity–duration–frequency (IDF) curves at a tempo-spatial scale of sub-daily and sub-grid under a context of climate change. The reason for this is that IDF curves represent essential means to study effects on the performance of drainage systems, damps, dikes and reservoirs. Therefore, the objective of this study is to present an approach to construct future IDF curves with high temporo-spatial resolutions under climate change in central Vietnam, using the case of VuGia-ThuBon. The climate data of historical and future from a regional climate model RegCM4 forced by three global models MPI-ESM-MR, IPSL-CM5A-LR and ICHEC-EC-EARTH are used to re-grid the resolution of 10 km × 10 km grid spacing from 25 km × 25 km on the base of bilinear interpolation. A bias correction method is then applied to the finest resolution of a hydrostatic climate model for an ensemble of simulations. Furthermore, the IDF curves for short durations of precipitation are constructed for the historical climate and future climates under two representative concentration pathway (RCP) scenarios, RCP4.5 and RCP8.5, based on terms of correlation factors. The major findings show that the projected precipitation changes are expected to significantly increase by about 10 to 30% under the scenarios of RCP4.5 and RCP8.5. The projected changes of a maximum of 1-, 2-, and 3-days precipitation are expected to increase by about 30–300 mm/day. More importantly, for all return periods (i.e., 10, 20, 50, 100, and 200 years), IDF curves completely constructed for short durations of precipitation at sub-daily show an increase in intensities for the RCP4.5 and RCP8.5 scenarios.

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