scholarly journals Trends of climate change at the mid-low Nazas-Aguanaval inland basin based on a geographical approach

2021 ◽  
Vol 8 (3) ◽  
Author(s):  
Omag Cano Villegas ◽  
Gisela Muro-Pérez ◽  
Enrique Jurado ◽  
Joel Flores ◽  
José Gamaliel Castañeda-Gaytan ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Chihuahuan Desert ◽  
Swat Model ◽  
Regional Climate ◽  
Management Strategies ◽  
Monthly Precipitation ◽  
Sampling Point ◽  
Regional Patterns ◽  
Mean Values

An integrative geographical climatology is presented to objectively identify regional patterns of climate variability within the mid-low Nazas-Aguanaval basin within the States of Durango and Coahuila in Central Northern Mexico, using decadal mean values for maximum and minimum temperature, as well as monthly precipitation during the seven periods from 1951-2020. The historical data was acquired from 26 field meteorological stations and 44 grid points from the SWAT model. Furthermore, the data was categorized by means of geographical features of altitude, longitude and latitude in three groups each. A combination of meteorological vulnerability from all the categories for each sampling point was then estimated for each locality. From the overall analysis, western sites resulted as the most vulnerable to climatic changes, while eastern and central (latitude) displayed the lowest variability occurrence. By means of downscaling the meteorological variation, it is possible to improve the understanding of mechanisms relying on regional climate variability and climate change. This evaluation can be further incorporated to management strategies for different stakeholders in arid and semi-arid lands, particularly within the Chihuahuan Desert.

Classification of Regional Climate Variability in the State of California

2009 ◽  
Vol 48 (8) ◽  
pp. 1527-1541 ◽  
Author(s):  
John T. Abatzoglou ◽  
Kelly T. Redmond ◽  
Laura M. Edwards
Keyword(s):  
Climate Variability ◽  
Large Scale ◽  
Regional Climate ◽  
Principal Component ◽  
The State ◽  
Monthly Precipitation ◽  
Regional Patterns ◽  
Novel Approach ◽  
Circulation Patterns

Abstract A novel approach is presented to objectively identify regional patterns of climate variability within the state of California using principal component analysis on monthly precipitation and temperature data from a network of 195 climate stations statewide and an ancillary gridded database. The confluence of large-scale circulation patterns and the complex geography of the state result in 11 regional modes of climate variability within the state. A comparison between the station and gridded analyses reveals that finescale spatial resolution is needed to adequately capture regional modes in complex orographic and coastal settings. Objectively identified regions can be employed not only in tracking regional climate signatures, but also in improving the understanding of mechanisms behind regional climate variability and climate change. The analysis has been incorporated into an operational tool called the California Climate Tracker.

scholarly journals Comparative analyses of hydrological responses of two adjacent watersheds to climate variability and change scenarios using SWAT model

2017 ◽  
Author(s):  
Sangchul Lee ◽  
In-Young Yeo ◽  
Ali M. Sadeghi ◽  
Gregory W. McCarty ◽  
Wells D. Hively ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Stream Flow ◽  
Climate Change Scenario ◽  
Swat Model ◽  
Co2 Concentration ◽  
Change Scenario ◽  
Baseline Scenario ◽  
Climate Variability And Change ◽  
Precipitation Increase

Abstract. Water quality problems in the Chesapeake Bay Watershed (CBW) are expected to exacerbate under climate variability and change. However, climate impacts on agricultural lands and resultant nutrient loads into surface water resources are largely unknown. This study evaluates the impacts of climate variability and change on two adjacent watersheds in the Coastal Plain of the CBW, using Soil and Water Assessment Tool (SWAT) model. We prepared six climate sensitive scenarios to assess the individual effects of variations in CO2 concentration (590 and 850 ppm), precipitation increase (11 and 21 %) and temperature increase (2.9 and 5.0 °C), and considered the predicted climate change scenario using five general circulation models (GCMs) under the Special Report on Emissions Scenarios (SRES) A2 scenario. Using SWAT model simulations from 2001 to 2014, as a baseline scenario, the predicted water and nitrate budgets under climate variability and change scenarios were analyzed at multiple temporal scales. Compared to the baseline scenario, precipitation increase of 21 % and elevated CO2 concentration of 850 ppm significantly increased stream flow and nitrate loads by 50 % and 52 %, respectively, while, temperature increase of 5.0 °C reduced stream flow and nitrate loads by 12 % and 13 %, respectively. Under the climate change scenario, annual stream flow and nitrate loads showed an average increase of nearly 40 %, relative to the baseline scenario. Differences in hydrological responses observed from the two watersheds were primarily attributed to contrasting land use and soil characteristics. The watershed with larger percent croplands indicated increased nitrate yield of 0.52 kg N ha−1 compared to the one with less percent croplands under the climate change scenario, due to increased export of nitrate derived from fertilizer. The watershed dominated by poorly-drained soils showed a lower increase in nitrate yield than one dominated by well-drained soils, due to a high potential of nitrate loss in surface runoff and enhanced denitrification. To mitigate increased nitrate loads potentially caused by climate change, the enhanced implementation of conservation practices would be necessary for this region in the future. These findings assist watershed managers and regulators as they seek to establish effective adaptation strategies to mitigate water quality degradation in this region.

scholarly journals Assessment of Local Climate Change: Historical Trends and RCM Multi-Model Projections Over the Salento Area (Italy)

Water ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 978 ◽  
Author(s):  
Marco D’Oria ◽  
Maria Tanda ◽  
Valeria Todaro
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Climate Model ◽  
Heat Waves ◽  
Regional Climate ◽  
Warm Season ◽  
Annual Rainfall ◽  
Maximum Temperature ◽  
Monthly Precipitation ◽  
Local Climate

This study provides an up-to-date analysis of climate change over the Salento area (southeast Italy) using both historical data and multi-model projections of Regional Climate Models (RCMs). The accumulated anomalies of monthly precipitation and temperature records were analyzed and the trends in the climate variables were identified and quantified for two historical periods. The precipitation trends are in almost all cases not significant while the temperature shows statistically significant increasing tendencies especially in summer. A clear changing point around the 80s and at the end of the 90s was identified by the accumulated anomalies of the minimum and maximum temperature, respectively. The gradual increase of the temperature over the area is confirmed by the climate model projections, at short—(2016–2035), medium—(2046–2065) and long-term (2081–2100), provided by an ensemble of 13 RCMs, under two Representative Concentration Pathways (RCP4.5 and RCP8.5). All the models agree that the mean temperature will rise over this century, with the highest increases in the warm season. The total annual rainfall is not expected to significantly vary in the future although systematic changes are present in some months: a decrease in April and July and an increase in November. The daily temperature projections of the RCMs were used to identify potential variations in the characteristics of the heat waves; an increase of their frequency is expected over this century.

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 Anthropogenic climate change versus internal climate variability: Impacts on Alpine snow cover

2020 ◽  
Author(s):  
Fabian Willibald ◽  
Sven Kotlarski ◽  
Adrienne Grêt-Regamey ◽  
Ralf Ludwig
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Snow Cover ◽  
Climate Model ◽  
Regional Climate ◽  
Anthropogenic Climate Change ◽  
Swiss Alps ◽  
Internal Climate Variability ◽  
Annual Variability ◽  
The Future

Abstract. Snow is a sensitive component of the climate system. In many parts of the world, water, stored as snow, is a vital resource for agriculture, tourism and the energy sector. As uncertainties in climate change assessments are still relatively large, it is important to investigate the interdependencies between internal climate variability and anthropogenic climate change and their impacts on snow cover. We use regional climate model data from a new single model large ensemble with 50 members (ClimEX LE) as driver for the physically based snow model SNOWPACK at eight locations across the Swiss Alps. We estimate the contribution of internal climate variability to uncertainties in future snow trends by applying a Mann-Kendall test for consecutive future periods of different lengths (between 30 and 100 years) until the end of the 21st century. Under RCP8.5, we find probabilities between 15 % and 50 % that there will be no significantly negative trend in future mean snow depths over a period of 50 years. While it is important to understand the contribution of internal climate variability to uncertainties in future snow trends, it is likely that the variability of snow depth itself changes with anthropogenic forcing. We find that relative to the mean, inter-annual variability of snow increases in the future. A decrease of future mean snow depths, superimposed by increases in inter-annual variability will exacerbate the already existing uncertainties that snow-dependent economies will have to face in the future.

scholarly journals Making rainfed crops adapted to potential climate change impacts: Modeling sustainable options

2020 ◽  
Vol 183 ◽  
pp. 03002
Author(s):  
Youssef Brouziyne ◽  
Abdelghani Chehbouni ◽  
Aziz Abouabdillah ◽  
Jamal Hallam ◽  
Fouad Moudden ◽  
...  
Keyword(s):  
Climate Change ◽  
Food Security ◽  
Sustainable Management ◽  
Swat Model ◽  
Management Strategies ◽  
Climate Change Impacts ◽  
Future Climate ◽  
Future Climate Change ◽  
Climate Projections ◽  
Climate Change Scenarios

Rainfed agriculture is becoming increasingly vulnerable to climate change. This situation is expected to worsen under most future climate projections, which might increase the risks linked to food security and economies which depend on it. Providing insights about the potential responses of rainfed crops to climate change will helps on designing future adaptation strategies. In this study, large amount of data and the agro-hydrological model SWAT have been used to investigate future climate change impacts on rainfed wheat and sunflower crops in a semiarid watershed in Morocco (R’dom watershed). Downscaled CORDEX climate projections were used in generating future plants growth simulation for R’dom watershed in the 2031 to 2050 horizon under two Representative Concentration Pathways (RCPs): 4.5 and 8.5. The main results of climate change scenarios highlighted that R’dom watershed will undergo significant decrease in water resources availability with more impact under the scenario RCP 8.5. Water productivities of both studied crops could be lower by up to -21% in comparison with baseline situation. Different sustainable management strategies have been simulated using SWAT model under climate change context. The adopted approach succeeded in building up sustainable management strategies toward secured food security in the future.

An Improved Daily Weather Generator for the Assessment of Regional Climate Change Impacts

2021 ◽  
Author(s):  
Mohammad Reza Khazaei ◽  
Mehraveh Hasirchian ◽  
Bagher Zahabiyoun
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Regional Climate ◽  
Low Frequency ◽  
Climate Change Impacts ◽  
Regional Climate Change ◽  
General Circulation Models ◽  
Weather Generator ◽  
Weather Data ◽  
Monthly Precipitation

Abstract Weather Generators (WGs) are one of the major downscaling tools for assessing regional climate change impacts. However, some deficiencies in the performance of WGs have limited their usage. This paper presents a method for correcting the low-frequency variability (LFV) of precipitation in the Improved Weather Generator (IWG) model. The method is based on bias correction in the monthly precipitation distribution of the generated daily series. The performance of the modified model was tested directly by comparing the statistics of generated and observed weather data for 14 stations, and also indirectly by comparing the characteristics of simulated stream-flows of a basin from the simulations run based on generated and observed weather data. The results showed that the method not only corrected the LFV of precipitation but also improved the reproduction of many other statistics. The provided IWG2 model can serve as a useful tool for the downscaling of General Circulation Models (GCMs) scenarios to assess regional climate change impacts, especially hydrological effects.

Relative Importance of Internal Climate Variability versus Anthropogenic Climate Change in Global Climate Change

2021 ◽  
Vol 34 (2) ◽  
pp. 465-478
Author(s):  
Jie Chen ◽  
Xiangquan Li ◽  
Jean-Luc Martel ◽  
François P. Brissette ◽  
Xunchang J. Zhang ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Global Climate ◽  
Regional Climate ◽  
Baseline Period ◽  
Anthropogenic Climate Change ◽  
Boreal Summer ◽  
Boreal Winter ◽  
Internal Climate Variability ◽  
Equatorial Band

AbstractTo better understand the role of internal climate variability (ICV) in climate change impact studies, this study quantifies the importance of ICV [defined as the intermember variability of a single model initial-condition large ensemble (SMILE)] in relation to the anthropogenic climate change (ACC; defined as multimodel ensemble mean) in global and regional climate change using a criterion of time of emergence (ToE). The uncertainty of the estimated ToE is specifically investigated by using three SMILEs to estimate the ICV. The results show that using 1921–40 as a baseline period, the annual mean precipitation ACC is expected to emerge within this century over extratropical regions as well as along the equatorial band. However, ToEs are unlikely to occur, even by the end of this century, over intratropical regions outside of the equatorial band. In contrast, annual mean temperature ACC has already emerged from the temperature ICV for most of the globe. Similar spatial patterns are observed at the seasonal scale, while a weaker ACC for boreal summer (June–August) precipitation and additional ICV for boreal winter (December–February) temperature translate to later ToEs for some regions. In addition, the uncertainty of ToE related to the choice of a SMILE is mostly less than 20 years for annual mean precipitation and temperature. However, it can be as large as 90 years for annual mean precipitation over some regions. Overall, results indicate that the choice of a SMILE is a significant source of uncertainty in the estimation of ToE and results based on only one SMILE should be interpreted with caution.

scholarly journals Evaluation of the Impacts of Climate Change on Sediment Yield from the Logiya Watershed, Lower Awash Basin, Ethiopia

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 81
Author(s):  
Nura Boru Jilo ◽  
Bogale Gebremariam ◽  
Arus Edo Harka ◽  
Gezahegn Weldu Woldemariam ◽  
Fiseha Behulu
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Swat Model ◽  
Regional Climate ◽  
Model Performance ◽  
Coefficient Of Determination ◽  
Rcp Scenarios ◽  
Time Frames ◽  
Impacts Of Climate Change

It is anticipated that climate change will impact sediment yield in watersheds. The purpose of this study was to investigate the impacts of climate change on sediment yield from the Logiya watershed in the lower Awash Basin, Ethiopia. Here, we used the coordinated regional climate downscaling experiment (CORDEX)-Africa data outputs of Hadley Global Environment Model 2-Earth System (HadGEM2-ES) under representative concentration pathway (RCP) scenarios (RCP4.5 and RCP8.5). Future scenarios of climate change were analyzed in two-time frames: 2020–2049 (2030s) and 2050–2079 (2060s). Both time frames were analyzed using both RCP scenarios from the baseline period (1971–2000). A Soil and Water Assessment Tool (SWAT) model was constructed to simulate the hydrological and the sedimentological responses to climate change. The model performance was calibrated and validated using the coefficient of determination (R2), Nash–Sutcliffe efficiency (NSE), and percent bias (PBIAS). The results of the calibration and the validation of the sediment yield R2, NSE, and PBIAS were 0.83, 0.79, and −23.4 and 0.85, 0.76, and −25.0, respectively. The results of downscaled precipitation, temperature, and estimated evapotranspiration increased in both emission scenarios. These climate variable increments were expected to result in intensifications in the mean annual sediment yield of 4.42% and 8.08% for RCP4.5 and 7.19% and 10.79% for RCP8.5 by the 2030s and the 2060s, respectively.

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