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621.
Wind-induced hydrodynamic changes impact on sediment resuspension for large,shallow Lake Taihu,China
Abdul Jalil Yiping Li Ke Zhang Xiaomeng Gao Wencai Wang Hafiz Osama Sarwar Khan Baozhu Pan Salar Ali Kumud Acharya 《国际泥沙研究》2019,34(3):205-215
The internal sediment release is a key factor controlling eutrophication processes in large,shallow lakes.Sediment resuspension is associated with the wave and current induced shear stress in large,shallow lakes.The current study investigated the wind field impacts on sediment resuspension from the bottom at Meiliang Bay of large,shallow Lake Taihu.The impacts of the wind field on the wave,current,and wave-current combined shear stresses were calculated.The critical wind speed range was 4–6 m/s after which wave and current shear stress started to increase abruptly,and onshore wind directions were found to be mainly responsible for greater shear stress at the bottom of Lake Taihu.A second order polynomial fitting correlation was found between wave(R^2 0.4756)and current(R^2 0.4466)shear stresses with wind speed.Wave shear stress accounted for 92.5% of the total shear stress at Meiliang Bay.The critical wave shear stress and critical total shear stress were 0.13 N/m^2 for sediment resuspension whereas the current shear stress was 0.019 N/m^2 after which suspended sediment concentrations(SSC)increased abruptly.A second order polynomial fitting correlation was found between wave(R^2 0.739),current(R^2 0.6264),and total shear stress(R^2 0.7394)with SSC concentrations at Meiliang Bay of Lake Taihu.The sediment resuspension rate was 120 to 738 g/m^2/d during 4–6 m/s onshore winds while offshore winds contributed ≥ 200 g/m^2/d.The study results reveal the driving mechanism for understanding the role of the wind field in sediment resuspension while considering wind speed and direction as control parameters to define wave and current shear stresses. 相似文献
622.
Integration of geoelectric and hydrochemical approaches for delineation of groundwater potential zones in alluvial aquifer 下载免费PDF全文
Qaisar Mehmood Muhammad Arshad Muhammad Rizwan Shanawar Hamid Waqas Mehmood Muhammad Ansir Muneer Muhammad Irfan Lubna Anjum 《地下水科学与工程》2020,8(4):366-380
Geoelectric and hydrochemical approaches are employed to delineate the ground-water potential zones in District Okara, a part of Bari Doab, Punjab, Pakistan. Sixty-seven VES surveys are conducted with the Electrical Resistivity Meter. The resultant resistivity verses depth model for each site is estimated using computer-based software IX1D. Aquifer thickness maps and interpreted resistivity maps were generated from interpreted VES results. Dar-Zarrouk parameters, transverse resistance (TR), longitudinal conductance (SL) and anisotropy (λ) were also calculated from resistivity data to delineate the potential zones of aquifer. 70% of SL value is ≤3S, 30% of SL value is > 3S. According to SL and TR values, the whole area is divided into three potential zones, high, medium and low potential zones. The spatial distribution maps show that north, south and central parts of study area are marked as good potential aquifer zones. Longitudinal conductance values are further utilized to determine aquifer protective capacity of area. The whole area is characterized by moderate to good and up to some extent very good aquifer protective area on the basis of SL values. The groundwater samples from sixty-seven installed tube wells are collected for hydro-chemical analysis. The electrical conductivity values are determined. Correlation is then developed between the EC (μS/cm) of groundwater samples vs. interpreted aquifer resistivity showing R2 value 0.90. 相似文献
623.
Saleh Yousefi Hamid Reza Moradi Saskia Keesstra Hamid Reza Pourghasemi Oldrich Navratil Janet Hooke 《国际地球制图》2019,34(3):276-292
In the present study, we investigate the effects of urbanization growth on river morphology in the downstream part of Talar River, east of Mazandaran Province, Iran. Morphological and morphometric parameters in 10 equal sub-reaches were defined along a 11.5 km reach of the Talar River after land cover maps were produced for 1955, 1968, 1994, 2005 and 2013. Land cover types changed extremely during the study period. Residential lands were found to have increased in area by about 1631%, while forest land and riparian vegetation decreased in by approximately 99.9 and 96.2%, respectively. The results of morphometric and morphological factors showed that average channel width (W) for all 11.5 km of the study river decreased by 84% during the study period, while the flow length increased by about 2.14%. 相似文献
624.
Roshanravan Bijan Aghajani Hamid Yousefi Mahyar Kreuzer Oliver 《Natural Resources Research》2019,28(2):309-325
Natural Resources Research - Classification of spatial exploration data for exploration targeting using neuro-fuzzy models means that the many spatial values have to be simplified and assigned to a... 相似文献
625.
Roshanravan Bijan Aghajani Hamid Yousefi Mahyar Kreuzer Oliver 《Natural Resources Research》2019,28(3):1089-1105
Natural Resources Research - In this paper an improved prediction-area plot has been developed. This type of plot includes performance measures similar to other existing methods (receiver operating... 相似文献
626.
Muhammad MURTAZA Abdul Hadi Abd RAHMAN Joerg MUTTERLOSE Najiatun NAJLA Mazshurraiezal Bin NASIR 《《地质学报》英文版》2021,95(2):333-341
Discovery of the remains of belemnites referred to the Hibolithes sp. from the Jurassic–Cretaceous Pedawan Formation in Sarawak, on the island of Borneo(Malaysia) comprises four fragments of belemnite rostra. The specimens are characterized by multiple fractures and vein filling. Two fragments measuring about 130 mm are relatively intact, with only part of the alveolar region missing; a third piece represents the middle part of a rostrum, and the fourth specimen is too fragmentary to be assigned to any specific part of the rostrum. Based on specimen characteristics, a Tithonian–Hauterivian age is plausible. The sedimentary succession that yielded the belemnite material comprises thick shale that reflects the Te division of Bouma sequence. The occurrence of a Hibolithes taxon in the uppermost Jurassic to lowermost Cretaceous Pedawan Formation sediments in Borneo reflects a near to global palaeobiogeographic distribution of this genus. 相似文献
627.
Al-Qadami Ebrahim Hamid Hussein Mustaffa Zahiraniza Shah Syed Muzzamil Hussain Matínez-Gomariz Eduardo Yusof Khamaruzaman Wan 《Natural Hazards》2022,110(1):325-348
Natural Hazards - Vehicles can be easily swept away by floodwaters once the flow velocity and depth reach certain critical limits, with probabilities toward fatality reported to be nearly 50%.... 相似文献