scholarly journals Assessment and Mitigation of Streamflow and Sediment Yield under Climate Change Conditions in Diyala River Basin, Iraq

Hydrology ◽  
2019 ◽  
Vol 6 (3) ◽  
pp. 63 ◽  
Author(s):  
Mahmoud S. Al-Khafaji ◽  
Rana D. Al-Chalabi
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Climate Models ◽  
Assessment Tool ◽  
Coefficient Of Determination ◽  
Base Period ◽  
Important Challenge ◽  
Diyala River ◽  
The Impact ◽  
Water Assessment

The impact of climate change on the streamflow and sediment yield in the Derbendkhan and Hemrin Watersheds is an important challenge facing the water resources of the Diyala River in Iraq. The Soil and Water Assessment Tool (SWAT) was used to project this impact on streamflow and sediment yield until year 2050 by applying five climate models for scenario A1B involving medium emissions. The models were calibrated and validated based on daily observed streamflow and sediment recorded for the periods from 1984 to 2013 and 1984 to 1985, respectively. The Nash–Sutcliffe efficiency and coefficient of determination values for the calibration (validation) were 0.61 (0.53) and 0.6 (0.62) for Derbendkhan and Hemrin, respectively. In addition, the average of the future predictions for the five climate models indicated that the streamflow (sediment yield) for the Derbendkhan and Hemrin Watersheds would decrease to 49% (43.7%) and 20% (30%), respectively, until 2050, compared with the observed flow of the base period from 1984 to 2013. The spatial analysis showed that 10.4% and 68% of the streamflow comes from Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively, while 10% and 60% of the sediment comes from the Iraqi parts of the Derbendkhan and Hemrin Watersheds, respectively. Deforestation of the northern part of the Hemrin Watershed is the best method to decrease the amount of sediment entering the Hemrin Reservoir.

Impact of Climate Change on the Spatiotemporal Distribution of Stream Flow and Sediment Yield of Darbandikhan Watershed, Iraq

2020 ◽  
Vol 38 (2A) ◽  
pp. 265-276
Author(s):  
Mahmoud S. Al- Khafaji ◽  
Rana D. Al- Chalabi
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Stream Flow ◽  
Assessment Tool ◽  
Coefficient Of Determination ◽  
Base Period ◽  
Time Step ◽  
Impact Of Climate Change ◽  
Global Circulation Models ◽  
The Impact

The impact of climate change on stream flow and sediment yield in Darbandikhan Watershed is an important challenge facing the water resources in Diyala River, Iraq. This impact was investigated using five Global Circulation Models (GCM) based climate change projection models from the A1B scenario of medium emission. The Soil and Water Assessment Tool (SWAT) was used to compute the temporal and spatial distribution of streamflow and sediment yield of the study area for the period 1984 to 2050. The daily-observed flow recorded in Darbandikhan Dam for the period from 1984 to 2013 was used as a base period for future projection. The initial results of SWAT were calibrated and validated using SUFI-2 of the SWAT-CUP program in daily time step considering the values of the Nash-Sutcliffe Efficiency (NSE) coefficient of determination (R2) as a Dual objective function. Results of NSE and R2 during the calibration (validation) periods were equal to 0.61 and 0.62(0.53 and 0.68), respectively. In addition, the average future prediction for the five climate models indicated that the average yearly flow and sediment yield in the watershed would decrease by about 49% and 44%, respectively, until the year 2050 compared with these of the base period from 1984 to 2013. Moreover, spatial analysis shows that 89.6 % and 90 % of stream flow and sediment come from the Iranian part of Darbandikhan watershed while the remaining small percent comes from Iraq, respectively. However, the middle and southern parts of Darbandikhan Watershed contribute by most of the stream...

Contribution of Climate Change and Landuse / Landcover Change on Variations of Hydrological Processes in The Water Towers of Yangtze River, China

2020 ◽  
Author(s):  
Naveed Ahmed ◽  
Genxu Wang ◽  
Sun Xiangyang ◽  
Ghulam Nabi ◽  
Fiaz Hussain ◽  
...  
Keyword(s):  
Climate Change ◽  
Yangtze River ◽  
Assessment Tool ◽  
Decision Criterion ◽  
Statistical Technique ◽  
Coefficient Of Determination ◽  
Landcover Change ◽  
Total Runoff ◽  
The Impact ◽  
Water Assessment

<p>The impact assessment of landuse / landcover change (LULCC) and climate change (CC) on the runoff in a highly elevated watershed has key importance in terms of sustainable water resources and ecological developments. In this research, statistical technique was deployed with the addition of Soil and Water Assessment Tool (SWAT) in the Water Towers of Yangtze River (WTYZ). The coefficient of determination (R<sup>2</sup>) and Nash-Sutcliffe Efficiency (NSE) were used as a decision criterion to ensure the performance of model simulations. The model performed satisfactory with monthly R<sup>2</sup> = 0.80 to 0.83 and NSE = 0.63 to 0.69 during calibration (1985 - 2000) and (2001 – 2016) periods. Major LULCC transformations were assessed from low grassland to medium grassland (2.017%) and wetlands (0.90%), bare land to medium grassland (0.23%) and glaciers to wetland (16.83%), high grassland to medium grassland (5.77%) during 1990s and 2005s. Impact of CC increased runoff by 97.97% and decreased evapotranspiration by -5.15% of total runoff and evapotranspiration respectively. It was also noteworthy that LULCC caused the increase in runoff and evapotranspiration by 2.02% and 105.15% relative to totals, respectively. Thus, the variations of runoff in the WTYZ are mainly impacted by landuse/landcover, while climate change have relatively least impacts.</p>

scholarly journals Evaluation of the Impact of Climate Change on Streamflow Using SWAT Model

2020 ◽  
Vol 13 ◽  
pp. 1-8
Author(s):  
Kingsley Nnaemeka Ogbu ◽  
Emeka L Ndulue ◽  
Isiguzo Edwin Ahaneku ◽  
Ikenna Joseph Ubah
Keyword(s):  
Climate Change ◽  
Stream Flow ◽  
Climate Models ◽  
Assessment Tool ◽  
Global Climate ◽  
Swat Model ◽  
Global Climate Models ◽  
Coefficient Of Determination ◽  
Water Resource System ◽  
The Impact

The Soil and Water Assessment Tool (SWAT) model was applied in this study to simulate stream-flow in the Oyun River Basin. The model was calibrated and validated using monthly stream-flow data for the basin. Model performance was satisfactory for calibration and validation with a coefficient of determination (R2) of 0.69 and 0.88, respectively. Climate change impact on Oyun River was assessed by driving the SWAT model with climate parameters obtained from two global climate models (HadGEM2-ES and BCC-CCSM1-1M) based on RCP 2.6 for 2050 – 2059 and 2080 – 2089 periods. With respect to a baseline period of 2000 – 2009, HadGEM2-ES predicted a 4.62% decrease in total stream-flow while the BCC-CSM1-1M predicted stream-flow increase by 6.18% for the 2050 – 2059 period. However, both HadGEM2-ES and BCC-CCSM1-1M predicted stream-flow to increase by 18.92% and 11.25% respectively for the 2080 period. The HadGEM2-ES model showed consistency in relating future rainfall predictions with future discharge trends for the periods under study. Model results show the need for adaptive measures to mitigate climate change impacts on the water resource system.

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.

scholarly journals Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

2013 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
General Circulation ◽  
Climate Models ◽  
Greenhouse Gas Emission ◽  
Circulation Model ◽  
Sediment Flux ◽  
Seasonal Temperature ◽  
Impact Of Climate Change ◽  
The Impact

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) are downscaled using a delta change approach. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Results indicate up to 3.0 °C shift in seasonal temperature and 27% (decrease) to 41% (increase) in seasonal precipitation. The largest increase in temperature is observed in the dry season while the largest change in precipitation is observed in the wet season. In general, temperature shows increasing trends but changes in precipitation are not unidirectional and vary depending on the greenhouse gas emission scenarios (GHGES), climate models, prediction period and season. The simulation results show that the changes in annual stream discharges are likely to range from a 17% decrease to 66% increase in the future, which will lead to predicted changes in annual sediment yield ranging from a 27% decrease to about 160% increase. Changes in intra-annual (monthly) discharge as well as sediment yield are even greater (−62 to 105% in discharge and −88 to 243% in sediment yield). A higher discharge and sediment flux are expected during the wet seasons, although the highest relative changes are observed during the dry months. The results indicate high uncertainties in the direction and magnitude of changes of discharge as well as sediment yields due to climate change. As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in both sediment management and climate change adaptation.

scholarly journals Impact of climate change on sediment yield in the Mekong River Basin: a case study of the Nam Ou Basin, Lao PDR

2012 ◽  
Vol 9 (3) ◽  
pp. 3339-3384
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
Assessment Tool ◽  
Negative Impact ◽  
Lao Pdr ◽  
Sediment Flux ◽  
Monthly Precipitation ◽  
Sediment Yields ◽  
Impact Of Climate Change ◽  
The Impact

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou Basin located in Northern Laos. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Future precipitation and temperature series are constructed through a delta change approach. As per the results, in general, temperature as well as precipitation show increasing trends in both scenarios, A2 and B2. However, monthly precipitation shows both increasing and decreasing trends. The simulation results exhibit that the wet and dry seasonal and annual stream discharges are likely to increase (by up to 15, 17 and 14% under scenario A2; and 11, 5 and 10% under scenario B2 respectively) in the future, which will lead to increased wet and dry seasonal and annual sediment yields (by up to 39, 28 and 36% under scenario A2; and 23, 12 and 22% under scenario B2 respectively). A higher discharge and more sediment flux are expected during the wet seasons, although the changes, percentage-wise, are observed to be higher during the dry months. In conclusion, the sediment yield from the Nam Ou Basin is likely to increase with climate change, which strongly suggests the need for basin-wide sediment management strategies in order to reduce the negative impact of this change.

scholarly journals Assessment of climate change impact on hydrology of a transboundary river of Bhutan and India

2021 ◽  
Author(s):  
Phub Zam ◽  
Sangam Shrestha ◽  
Aakanchya Budhathoki
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Assessment Tool ◽  
Regional Climate ◽  
Flow Simulation ◽  
Water Security ◽  
Regional Climate Models ◽  
Transboundary River ◽  
Rcp 8.5 ◽  
The Impact

Abstract Assessing the impacts of climate change on a transboundary river plays an important role in sustaining water security within as well as beyond the national boundaries. At times, the unilateral decision taken by one country can increase the risk of negative effect on the riparian countries and if the impact is felt strongly by the other country, it can lead to international tension between them. This study examines the impact of climate change on hydrology between a shared river which is Wangchu river in Bhutan and Raidak river in India. The river is mainly used to produce hydropower in the two largest hydropower plants on which the majority of Bhutan's economic development depends and is mainly used for agriculture in India. The Soil and Water Assessment Tool (SWAT) was used for future flow simulation. Future climate was projected for near future (NF) from 2025–2050 and far future (FF) from 2074–2099 using an ensemble of three regional climate models (ACCESS, CNRM-CM5 and MPI-ESM-LR) for two RCPs (Representative Concentration Pathways), RCP 4.5 and RCP 8.5 scenario. The ensemble results indicated that, in future, the study area would become warmer with temperature increase of 1.5 °C under RCP 4.5 and 3.6 °C under RCP 8.5. However, as per RCP 4.5 and RCP 8.5, rainfall over the study area is projected to decrease by 1.90% and 1.38% respectively. As a consequence of the projected decrease in rainfall, the flow in river is projected to decrease by 5.77% under RCP 4.5 and 4.73% under RCP 8.5. Overall, the results indicated that the degree of hydrological change is expected to be higher, particularly for low flows in both Wangchu and Raidak River. Since transboundary water is a shared for economic growth, climate change adaptation and opportunities should also be considered by both the nations for better water management.

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.

scholarly journals Alteration of the Ecohydrological Status of the Intermittent Flow Rivers and Ephemeral Streams due to the Climate Change Impact (Case Study: Tsiknias River)

Hydrology ◽  
2021 ◽  
Vol 8 (1) ◽  
pp. 43
Author(s):  
Soumaya Nabih ◽  
Ourania Tzoraki ◽  
Prodromos Zanis ◽  
Thanos Tsikerdekis ◽  
Dimitris Akritidis ◽  
...  
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Assessment Tool ◽  
Land Use Changes ◽  
Anthropogenic Factors ◽  
Intermittent Flow ◽  
Climate Change Scenarios ◽  
Ephemeral Streams ◽  
Extreme Flood ◽  
The Impact

Climate change projections predict the increase of no-rain periods and storm intensity resulting in high hydrologic alteration of the Mediterranean rivers. Intermittent flow Rivers and Ephemeral Streams (IRES) are particularly vulnerable to spatiotemporal variation of climate variables, land use changes and other anthropogenic factors. In this work, the impact of climate change on the aquatic state of IRES is assessed by the combination of the hydrological model Soil and Water Assessment Tool (SWAT) and the Temporary Rivers Ecological and Hydrological Status (TREHS) tool under two different Representative Concentration Pathways (RCP 4.5 and RCP 8.5) using CORDEX model simulations. A significant decrease of 20–40% of the annual flow of the examined river (Tsiknias River, Greece) is predicted during the next 100 years with an increase in the frequency of extreme flood events as captured with almost all Regional Climate Models (RCMs) simulations. The occurrence patterns of hyporheic and edaphic aquatic states show a temporal extension of these states through the whole year due to the elongation of the dry period. A shift to the Intermittent-Pools regime type shows dominance according to numerous climate change scenarios, harming, as a consequence, both the ecological system and the social-economic one.

Sign in / Sign up

Export Citation Format

Share Document