| 41. |
- Abbas, Nahla, et al.
(författare)
-
Impacts of Climate Change on Water Resources in Diyala River Basin, Iraq
- 2016
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Ingår i: Journal of Civil Engineering and Architecture. - New York : David Publishing Company. - 1934-7359 .- 1934-7367. ; 10:9, s. 1059-1074
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Tidskriftsartikel (refereegranskat)abstract
- Diyala River is the third largest tributary of the Tigris River running 445 km length and draining an area of 32,600 km2. The river is the major source of water supply for Diyala City for municipal, domestic, agriculture and other purposes. Diyala River Basin currently is suffering from water scarcity and contamination problems. Up-to-date studies have shown that blue and green waters of a basin have been demonstrating increasing variability contributing to more severe droughts and floods seemingly due to climate change. To obtain better understanding of the impacts of climate change on water resources in Diyala River Basin in near 2046~2064 and distant future 2080~2100, SWAT (soil and water assessment tool) was used. The model is first examined for its capability of capturing the basin characteristics, and then, projections from six GCMs (general circulation models) are incorporated to assess the impacts of climate change on water resources under three emission scenarios: A2, A1B and B1. The results showed deteriorating water resources regime into the future.
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| 42. |
- Abbas, Nahlah, et al.
(författare)
-
Impacts of Climate Change on Water Resources of Greater Zab and Lesser Zab Basins, Iraq, Using Soil and Water Assessment Tool Model
- 2017
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Ingår i: International Journal of Environmental, Chemical, Ecological, Geological and Geophysical Engineering. - : World Scientific and Engineering Academy and Society. - 2010-376X .- 2010-3778. ; 11:10, s. 823-829
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Tidskriftsartikel (refereegranskat)abstract
- The Greater Zab and Lesser Zab are the major tributaries of Tigris River contributing the largest flow volumes into the river. The impacts of climate change on water resources in these basins have not been well addressed. To gain a better understanding of the effects of climate change on water resources of the study area in near future (2049-2069) as well as in distant future (2080-2099), Soil and Water Assessment Tool (SWAT) was applied. The model was first calibrated for the period from 1979 to 2004 to test its suitability in describing the hydrological processes in the basins. The SWAT model showed a good performance in simulating streamflow. The calibrated model was then used to evaluate the impacts of climate change on water resources. Six general circulation models (GCMs) from phase five of the Coupled Model Intercomparison Project (CMIP5) under three Representative Concentration Pathways (RCPs) RCP 2.6, RCP 4.5, and RCP 8.5 for periods of 2049-2069 and 2080-2099 were used to project the climate change impacts on these basins. The results demonstrated a significant decline in water resources availability in the future.
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| 43. |
- Abbas, Nahla, et al.
(författare)
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Model-Based Assessment of Climate Change Impact on Isaac River Catchment, Queensland
- 2016
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Ingår i: Engineering. - : Scientific Research Publishing, Inc.. - 1947-3931 .- 1947-394X. ; 8:7, s. 460-470
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Tidskriftsartikel (refereegranskat)abstract
- Isaac River catchment, which is located within Fitzroy basin in Central Queensland, Australia is mostly a semi-arid region, sparsely populated, but rife with economic activities such as mining, grazing, cropping and production forestry. Hydro-meteorological data over the past several decades reveal that the catchment is experiencing increasing variability in precipitation and streamflow contributing to more severe droughts and floods supposedly due to climate change. The exposure of the economic activities in the catchment to the vagaries of nature and the possible impacts of climate change on the stream flow regime are to be analyzed. For the purpose, SWAT model was adopted to capture the dynamics of the catchment. During calibration of the model 12parameters were found to be significant which yielded a R2 value of 0.73 for calibration and 0.66 for validation. In the next stage, six GCMs from CMIP3 namely, CGCM3.1/T47, CNRM-CM3, GFDLCM2.1, IPSLCM4, MIROC3.2 (medres) and MRI CGCM2.3.2 were selected for climate change projections in the Fitzroy basin under a very high emissions scenario (A2), a medium emissions scenario(A1B) and a low emissions scenario (B1) for two future periods (2046-2064) and (2080-2100). All GCMs showed consistent increases in temperature, and as expected, highest rate for A2 and lowest rate for B1. Precipitation predictions were mixed-reductions in A2 and increases in A1B and B1, and more variations in distant future compared to near future. When the projected temperaturesand precipitation were inputted into the SWAT model, and the model outputs were compared with the baseline period (1980-2010), the picture that emerged depicted worsening water resources variability.
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| 44. |
- Abbas, Nahlah, et al.
(författare)
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Recent Trends and Long-Range Forecasts of Water Resources of Northeast Iraq and Climate Change Adaptation Measures
- 2018
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Ingår i: Water. - Switzerland : MDPI. - 2073-4441. ; 10:11, s. 1-19
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Tidskriftsartikel (refereegranskat)abstract
- Iraq has been experiencing water resources scarcity, and is vulnerable to climate change. Analysis of historical data revealed that the region is experiencing climate change to a degree higher than generally reported elsewhere. The relationship between climate change and its effect on water resources of a region has been sparsely addressed in published literature. To fill that gap this research work first investigates if there has been a significant change in climate in the region, which has been found to be true. In the next stage, the research projects future climatic scenarios of the region based on six oft-used General CirculationModel (GCM) ensembles, namely CCSM4, CSIRO-Mk3.6.0, GFDL-ESM2M, MEROC5, HadGEM2-ES, and IPSL-CM5A-LR. The relationship between climate change and its impact on water resources is explored through the application of the popular, widely used SWAT model. The model depicts the availability of water resources, classified separately as blue and green waters, for near and distant futures for the region. Some of the findings are foreboding and warrants urgent attention of planners and decision makers. According to model outputs, the region may experience precipitation reduction of about 12.6% and 21% in near (2049–2069) and distant (2080–2099) futures, respectively under RCP8.5. Those figures under RCP4.5 are 15% and 23.4%, respectively and under RCP2.6 are 12.2% and 18.4%, respectively. As a consequence, the blue water may experience decreases of about 22.6% and 40% under RCP8.5, 25.8% and 46% under RCP4.5, and 34.4% and 31% under RCP2.6 during the periods 2049–2069 and 2080–2099, respectively. Green water, by contrast, may reduce by about 10.6% and 19.6% under RCP8.5, by about 14.8% and 19.4% under RCP4.5, and by about 15.8% and 14.2% under RCP2.6 during the periods 2049–2069 and 2080–2099, respectively. The research further investigates how the population are adapting to already changed climates and how they are expected to cope in the future when the shift in climate is expected to be much greater.
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| 45. |
- Abbas, Nahla, et al.
(författare)
-
The Impacts of Climate Change on Fitzroy River Basin, Queensland, Australia
- 2017
-
Ingår i: Journal of Civil Engineering and Architecture. - USA : David Publishing Company. - 1934-7359 .- 1934-7367. ; 11:1, s. 38-47
-
Tidskriftsartikel (refereegranskat)abstract
- An analysis of historical data of Fitzroy River, which lies in the east coast of Australia, reveals that there is an increasing trend in extreme floods and droughts apparently attributable to increased variability of blue and green waters which could be due to climate change. In order to get a better understanding of the impacts of climate change on the water resources of the study area for near future as well as distant future, SWAT (soil and water assessment tool) model was applied. The model is first tested for its suitability in capturing the basin characteristics with available data, and then, forecasts from six GCMs (general circulation model) with about half-a-century lead time to 2046~2064 and about one-century lead time to 2080~2100 are incorporated to evaluate the impacts of climate change under three marker emission scenarios: A2, A1B and B1. The results showed worsening water resources regime into the future.
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| 46. |
- Abbas, Nahlah, et al.
(författare)
-
The Impacts of Sea Level Rise on Basrah City,Iraq : The Impacts of Sea Level Rise on Basrah City,Iraq
- 2020
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Ingår i: Open Journal of Geology. - USA : Scientific Research Publishing. - 2161-7570 .- 2161-7589. ; 10:12, s. 1189-1197
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Tidskriftsartikel (refereegranskat)abstract
- Sea Level Rise (SLR) above the Mean Sea Level (MSL) is more likely to cause a significant risk to the coastal regions. This research explores the potential impact of sea level rise, due to climate change, on coastal areas. It examines the impact of sea level rise on Basrah city and adjacent cities in Iraq. A digital elevation model (DEM) was used to create a model of Potentially Inundated Areas, manipulated and processed in Geographical Information System version 10.7 (ArcGIS 10.7). Through this model, the impact of sea level rise was assessed on the surface area. After the susceptible areas were delineated, it was estimated that at worst case scenario of 5 m sea level rise will impact Basrah city by losing 38 percent of its total surface area.
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| 47. |
- Abbas, Nahla, et al.
(författare)
-
Water resources problems of Iraq: Climate change adaptation and mitigation
- 2018
-
Ingår i: Journal of Environmental Hydrology. - : International Association for Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 26
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Tidskriftsartikel (refereegranskat)abstract
- Iraq is suffering from water scarcity, and future predictions indicate that it could get worse due to changing climate. Arguably, climate change is one of the greatest challenges onfronting this region it could have significant adverse effects on water resources and hence the environment and economy, particularly in the agricultural sector. This study considers possible adaptation and mitigation measures that could be undertaken in response to climate change. To overcome this problem,adaptation measures at farm and government level were conferred. Farm-level adaptation comprises adopting crop modification, soil conservation, irrigation, changing crop calendar and planting of trees. The government role is to ensure success of these adaptation measures. The government should get involved and support the farmers financially and technologically.
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| 48. |
- Abbas, Syed Adeel, et al.
(författare)
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Spinel-type Na2MoO4 and Na2WO4 as promising optoelectronic materials : First-principle DFT calculations
- 2020
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Ingår i: Chemical Physics. - : Elsevier. - 0301-0104 .- 1873-4421. ; 538
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Tidskriftsartikel (refereegranskat)abstract
- The mechanical, thermodynamic, electronic, and optical properties of Na2MoO4 (NMO) and Na2WO4 (NWO) spinels are elaborated by density functional theory (DFT) based full potential augmented plane wave method (FP-LAPW + lo). Our optimized lattice constants for the studied spinels are in good agreement with that obtained experimentally. The enthalpy of formation ensures the thermodynamic stability of NMO and NWO in the cubic phase. The Born mechanical stability criteria guarantees their mechanical stability, while Poisson ratio (ν) and Pugh's ratio (B/G) infer their brittle behavior. The Debye temperature (θD) is significant for NMO than NWO. The wide bandgap of 3.5 eV for NMO and 4.4 eV for NWO show the maximum absorption in the ultraviolet region that increases their importance for optoelectronic applications. The optical properties are explained in term of dielectric constant, refractive index, absorption of light, reflection, and optical loss factor.
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| 49. |
- Abbas, Zainab Dekan, et al.
(författare)
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Locating Dam Sites For Water Harvesting : Case Study Of Najaf Province, Iraq
- 2019
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Ingår i: Journal of Environmental Hydrology. - Canada : The International Association of Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 27, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The Middle East is considered as an arid area. Iraq was an exception due to the presence of the Tigris and Euphrates Rivers. After 1970, the flow of these rivers started to decrease due to climate change and building of dams in the upper parts of the catchments of the rivers. Now, Iraq is experiencing water shortage problems. Rain water harvesting will definitely minimize the effect of water shortage problems. In this research an arid area was selected (al Najaf) to find out the best sites for water harvesting using GIS techniques. The good agreement between the results from a simple GIS model and observations in cases such as al Najaf Sea is indicating a promising future for GIS application in hydrological modeling. The present study proposed a function formula of estimating suitable dam site using existing geographic information map such as the digital elevation maps. It is expected that it will save time, cost and work force. Finally, through the contour map of the study area, the lowest three elevation values at the governorate level were observed (20, 40, 60m). Based on these values, three possibilities were suggested to select the dam sites.
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| 50. |
- Abbu, Muthanna, et al.
(författare)
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The mechanical properties of lightweight (volcanic pumice) concrete containing fibers with exposure to high temperatures
- 2023
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Ingår i: Journal of the Mechanical Behavior of Materials. - : Walter de Gruyter. - 2191-0243. ; 32:1
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Tidskriftsartikel (refereegranskat)abstract
- Fires are considered one of the main risks leading to building collapse. Lightweight concrete comprises a variety of components, each of which has a distinct behavior under the effect of temperature change. A total of sixteen concrete mixtures were investigated in this paper. A reference mix of concrete comprising simply ordinary Portland cement and ten mixes having varying percentages of fine and coarse lightweight aggregates (pumice), which were replaced gravel and sand by fine pumice and coarse aggregates pumice by 20%, 40%, 60%, 80%, and 100%, respectively. In addition, the study focused on the effects of adding fibers to lightweight aggregate concrete mixtures. Polypropylene fibers, carbon fibers, and steel fibers were employed as fiber additions. The binary mixture had higher density than the remaining mixtures containing one substitute. The behavior of six concrete mixes in addition to the reference mix of ordinary concrete after exposure to temperatures 100, 250, 350 and 450 °C for two hours and then cooled in two ways (water and air) as well as examined directly and the results showed that the concrete mixes containing fiber better behavior compared to other mixtures, especially at high temperature. If left to cool in the air, the lightweight concrete containing Volcanic Pumice can recover its compression strength after being exposed to high temperatures.
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