Impacts of climate change on soil moisture and evapotranspiration in reconstructed watersheds in northern Alberta,Canada     

Nader Keshta  Amin Elshorbagy  Sean Carey 《水文研究》2012,26(9):1321-1331

This study aims at developing a generalized understanding of the sensitivity of soil moisture patterns in reconstructed watersheds, in northern Alberta, to changes in the projected precipitation in the twenty‐first century. The GSDW model is applied to three watersheds using climate scenarios generated using daily precipitation and air temperature output from a global climate model (CGCM3), under A2 and B1 emission scenarios, to simulate the corresponding soil moisture. CGCM3 results indicate an increase in the mean annual temperature for Fort McMurray, Alberta of 3·3 (A2) and 2·4 °C (B1), and an increase in the predicted annual precipitation of 34% (A2) and 8·6% with A2 and B1 emission scenarios, respectively. The GSDW model is used, along with onsite historical data, to downscale A2 and B1 emission scenarios and to evaluate the future hydrological performance of the designated watersheds with respect to soil moisture deficit and actual evapotranspiration using a probabilistic framework. The forecasted maximum soil moisture deficit values based on A2 and B1 emission scenarios are expected to decrease compared to those based on the current, largely because of the expected increase in precipitation rates, associated with an expected increase in evapotranspiration. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Improving WRF-Hydro runoff simulations of heavy floods through the sea surface temperature fields with higher spatio-temporal resolution     

Berina Mina Kilicarslan  Ismail Yucel  Heves Pilatin  Eren Duzenli  Mustafa Tugrul Yilmaz 《水文研究》2021,35(9):e14338

This study investigates the impact of the spatio-temporal accuracy of four different sea surface temperature (SST) datasets on the accuracy of the Weather Research and Forecasting (WRF)-Hydro system to simulate hydrological response during two catastrophic flood events over the Eastern Black Sea (EBS) and the Mediterranean (MED) regions of Turkey. Three time-variant and high spatial resolution external SST products (GHRSST, Medspiration and NCEP-SST) and one coarse-resolution and time-invariant SST product (ERA5- and GFS-SST for EBS and MED regions, respectively) already embedded in the initial and the boundary conditions datasets of WRF model are used in deriving near-surface atmospheric variables through WRF. After the proper event-based calibration is performed to the WRF-Hydro system using hourly and daily streamflow data in both regions, uncoupled model simulations for independent SST events are conducted to assess the impact of SST-triggered precipitation on simulated extreme runoff. Some localized and temporal differences in the occurrence of the flood events with respect to observations depending on the SST representation are noticeable. SST products represented with higher cross-correlations (GHRSST and Medspiration) revealed significant improvement in flood hydrographs for both regions. The GHRSST dataset shows a substantial improvement in NSE (~70%), RMSE reduction up to 20%, and an increase in correlation from 0.3 to 0.8 with respect to the invariable SST (ERA5) in simulated runoffs over the EBS region. The use of both GHRSST and Medspiration SST data characterized with high spatio-temporal correlation resulted in runoff simulations exactly matching the observed runoff peak of 300 m³/s by reducing the overestimation seen in invariable SST (GFS) in the MED region. Improved precipitation simulation skills of the WRF model with the detailed SST representation show that the hydrographs of GHRSST and Medspiration simulations show better performance compared to the simulated hydrographs by observed precipitation.  相似文献   

Modeling Fate and Transport of Volatile Organic Compounds (VOCs) Inside Sewer Systems     

Mohammadyousef Roghani Ph.D.  Ying Li Ph.D.  Nader Rezaei Ph.D.  Ariel Robinson  Elham Shirazi Ph.D.  Kelly G. Pennell Ph.D. 《Ground Water Monitoring & Remediation》2021,41(2):112-121

Hazardous waste site investigations have shown that volatile organic compounds (VOCs) can be transported via sewer pipes and migrate into indoor spaces. Despite field data confirming the presence of this exposure pathway, there is lack of context-based numerical models that provide guidance to characterize and predict VOCs concentration in sewer gas at vapor intrusion sites. Particularly, this poses a challenge when assessing and mitigating risks associated with these exposure pathways. Therefore, a numerical model has been developed to simulate the concentration of VOCs in sewer gas in different stages throughout the sewer lines. The developed model considers various input parameters, including temperature, sewer liquid depth, groundwater depth, and sewer construction characteristics to incorporate local and operational conditions. The model's output is verified using field data from a sewer system constructed near a Superfund site. Moreover, a sensitivity analysis was conducted to evaluate the model's response to variation of the external input parameters. To the best of our knowledge, this study is the first attempt to model VOCs concentration in sewer gas, particularly to address vapor intrusion. The developed model can be used as a numerical tool to support the development of sewer assessment guidelines, risk assessment studies, and mitigation strategies.  相似文献   

Natural Pozzolan-based geopolymers for sustainable construction     

Nader Ghafoori  Meysam Najimi  Brittany Radke 《Environmental Earth Sciences》2016,75(14):1110

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Ionic liquid as a medium to remove iron and other metal ions: a case study of the North Kelantan Aquifer,Malaysia   总被引：1，自引：1，他引：0  

Nur Hayati Hussin  Ismail Yusoff  Yatimah Alias  Sharifah Mohamad  Nurul Yani Rahim  Muhammad Aqeel Ashraf 《Environmental Earth Sciences》2014,71(5):2105-2113

An alternative iron removal treatment method using liquid-liquid extraction with the room-temperature ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, as a solvent medium was studied. The chelating agent 1,10-phenanthroline was used as the extractant. The extraction of Fe(III) and Fe(II) was influenced significantly by the pH of the aqueous phase. The successful removal of iron was achieved; more than 95 % of the initial iron concentration was removed from the groundwater samples. However, detailed research is needed before the ionic liquid method can replace the conventional groundwater treatment protocol because the recovery rate was very low upon reuse (approximately 25–60 %). This low recovery was due to the ion exchange process; the appearance of anions from ionic liquids was also detected in groundwater samples.  相似文献   

Knickpoints along the upper Indus River,Pakistan: an exploratory survey of geomorphic processes     

Muhammad F. Ahmed  J. David Rogers  Elamin H. Ismail 《Swiss Journal of Geoscience》2018,111(1-2):191-204

This article summarizes an exploratory study carried out to investigate the significance of various geomorphic features on the formation of observed knickpoints along the upper Indus River in northern Pakistan. These features include bedrock lithology, active faults, sediment flux from tributary channels, and landslide dams which have blocked the main channel. The knickpoints and their related geomorphic parameters (channel profile, concavity, drainage area and normalized steepness index, etc.) were extracted from Advanced Spaceborne Thermal Emission and Reflection (ASTER) Global Digital Elevation Models (GDEMs) with 30 m resolution using ArcGIS, River Tools, and Matlab software. A total of 251 major and minor knickpoints were extracted from the longitudinal profile along a ~ 750 km reach upstream of Tarbela Reservoir. The identified knickpoints and their respective normalized steepness index (k_sn values) were compared with bedrock lithology, mapped faults, regional landslide/rockslide inventory, and the locations of historic landslide dams. The analyses revealed that the knickpoints do not correlate with the bedrock lithology except where major unit boundaries coexist with mapped faults, especially in reaches criss-crossed by active thrust faults in the Nanga Parbat Haramosh (NPHM) region. Neither did the river’s major confluences exhibit any notable knickpoints, but the correlations between knickpoints, mapped landslides, and historic rockslide avalanche dams accounted for approximately 75% of the observed knickpoints, a surprising finding. These observations suggest that more detailed studies aided by high resolution data should be undertaken to further explore the characteristics of knickpoints triggered by tectonic uplift, local fault offset, bedrock erodibility, and landslide/rockslide dams.  相似文献   

Probabilistic frequency ratio model for groundwater potential mapping in Al Jaww plain,UAE     

Elmahdy  Samy Ismail  Mohamed  Mohamed Mostafa 《Arabian Journal of Geosciences》2015,8(4):2405-2416

Arabian Journal of Geosciences - The United Arab Emirates, as a part of the Arabian Peninsula, is among the driest countries on earth. This study aims to map and explore new groundwater reservoirs...  相似文献   

Groundwater beneath the urban area of Khan Younis City,southern Gaza Strip (Palestine): hydrochemistry and water quality     

Jabal  Mohd S. Abu  Abustan  Ismail  Rozaimy  Mohd Remy  El Najar  Hussam 《Arabian Journal of Geosciences》2015,8(4):2203-2215

Arabian Journal of Geosciences - This paper presents the results of a groundwater hydrochemical assessment in the urban area of Khan Younis City in the southern Gaza Strip by measuring its...  相似文献   

Spatial and temporal variability of ozone and nitrogen dioxide over a major urban estuarine ecosystem     

Maria Tzortziou  Jay R. Herman  Alexander Cede  Christopher P. Loughner  Nader Abuhassan  Sheenali Naik 《Journal of Atmospheric Chemistry》2015,72(3-4):287-309

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A classification of polar cap auroral arcs     

S. Ismail  C.-I. Meng 《Planetary and Space Science》1982,30(4):319-330

Global auroral imagery obtained by DMSP satellites during the years 1972–1979 over both the northern and southern high latitude polar regions were examined to study the morphology of the discrete arcs known as polar cap arcs. Based upon their morphology, the polar cap arcs can be generally classified into three types viz. (1) the distinctly sun-aligned polar cap arcs—Type 1 arcs, (2) the morning/evening polar cap arcs expanded from the auroral oval—Type 2 arcs and (3) the hook shaped arcs connecting the polar cap arc with the oval arc (including the hitherto unreported oppositely oriented hook shaped arcs)—Type 3 arcs. Concurrent auroral electrojet indices (AE) and interplanetary magnetic field (IMF) data were used to study the occurrence of the polar cap arcs. It was found that Type 1 arcs were observed mostly during low geomagnetic activity conditions, bright Type 2 arcs during the recovery phase of the substorms and Type 3 arcs do not occur during the recovery phase of the substorm. Over both hemispheres, the polar cap arcs were observed mostly during northward IMF. Furthermore, Type 1 arcs were obeserved over the northern polar cap during mostly negative B_x periods and over the southern polar cap during mostly positive B_x periods. The latter observation suggests that these types of arcs may be non-conjugate.  相似文献