Acta Geotechnica - It is a problematic task to perform petro-physical property prediction of carbonate reservoir rocks in most cases, specifically for permeability prediction since a carbonate rock... 相似文献
This paper focuses on characterizing the current status of physical and chemical characteristics of King Talal Dam (KTD) sediments. The quality of sediments was investigated based on several international sediment quality guidelines. The volume of sediment and sedimentation rate in (KTD) was also estimated. Five types of granulometric textural facies were observed for the sediments of KTD reservoir bed, with an average grain size distribution of gravel (1.38%), sand (32.38%), silt (32.35%) and clay (32.38%). The fraction of <63 micron showed that the total mean size was 8.0 micron. Other sediment parameters in KTD were 7.0% for total organic matter (TOM), 7.3 for pH, 35.9% for CaCO3 and 100.5 meq/100 g for cation exchange capacity, with dominant mineralogical constituents of quartz, calcite, dolomite, clay minerals and minor feldspar. The total concentrations of F, Cl, NO2, NO3, PO4 and SO4 in sediment samples were lower inward for KTD. The vast majority of trace metals in sediments were generally within the standard limits recommended for soils. TOM and grain size of sediment are major factors governing the trace metal concentrations. The calculated geoaccumulation index (Igeo) and enrichment factor of metals in bottom sediments showed that the metals were in the following order: Cd > Pb > Zn > Co > Cr > Ni > Fe > Cu > Sr > Mn and Cd > Zn > Pb > Co > Cr > Ni > Cu > Sr > Mn, respectively. Based on the sonic survey of KTD reservoir, the annual sedimentation rate was about 0.4061 MCM/year, in which about 18.66% of the reservoir initial storage capacity was lost to sediments and a projected lifespan of about 198 years. 相似文献
Losses due to natural disasters induce rural–urban migration throughout the world. It is also a major driver of population influx in Dhaka city, the capital of one of the most disaster-affected countries in the world, Bangladesh. While the relationship between natural disasters and migration is evident, the magnitude of household-level losses inducing rural–urban migration has not been widely discussed. This paper approaches this issue based on an empirical study. Using appropriate sampling procedure, a total of 407 households in Dhaka statistical metropolitan area were interviewed. This research finds out that 18.43% of rural–urban migrants in Dhaka city are disaster induced. A sharp drop in income immediately after the disaster is the predominant reason behind their migration. The river bank erosion-affected migrants encountered as high as 89% drop in income, whereas the flood-affected migrants experienced 70% drop. This article identifies five post-disaster components that ultimately determine migration. To conclude, the paper offers several approaches to minimize mass rural out-migration.
This study investigated the status and distribution patterns of selected heavy metals in roadside soils along Irbid-North Shooneh Highway, Jordan. This highway has experienced a growing number of vehicles that are likely to influence the levels of heavy metals in the surrounding agricultural lands. The average concentrations of Cr, Co, Cd, Cu, Pb, Zn, and Ni were 16.0, 36.0, 11.0, 4.0, 79.0, 122.0, and 60.0 mg/kg, respectively. Cd, Pb, and Co showed average levels that are higher than the average world soil background values. Elevated levels of heavy metals were measured in surface soil layer which decreased with depth, and with distance from the roadway. The contamination factor (CF), pollution load index (PLI), single ecological risk (Ei), potential ecological risk index (PERI), and geo-accumulation index (Igeo) generally indicated that the roadside soils are contaminated with Cd, Pb, and Ni. Heavy metals in soils are of geogenic and anthropogenic origins. Weathering of parent rocks in Wadi Al-Arab catchment is the primary natural source, whereas agrochemicals, vehicle exhausts, degradation of surface wear and paint of vehicles, vehicle wear debris of tire, and brake lining are the main anthropogenic sources of heavy metals. 相似文献
This work intends to monitor and assess the current water quality conditions at King Talal Dam (KTD), Jordan, based on vertical profiles and longitudinal surveys. While the surface distribution of water quality parameters in KTD varied spatially, their variations showed no distinct trends. Lateral and horizontal variations in water quality in KTD are probably linked with photosynthesis, sampling period, closeness to Zarqa River and Wadi Rmemeen, and water depths, among other factors. The vast majority of water quality parameters in KTD dammed reservoir showed vertical profiles that either decrease slightly with increasing depth from the surface (temperature and dissolved oxygen) or remain relatively unchanged (major ions, trace elements). These results suggest that water has probably been vertically mixed. Data also demonstrated rock weathering as a dominant process governing the water chemistry of KTD reservoir water. Based on chlorophyll- a classification of Forsberg and Ryding [19], KTD reservoir is in a mesotrophic-eutrophic condition. Evaluation of water quality for irrigation use revealed that KTD reservoir water is suitable for irrigation purposes, except for Na% and total hardness. 相似文献
In this paper an arbitrary Lagrangian–Eulerian (ALE) method to solve dynamic problems involving large deformation is presented. This ALE method is based upon the operator-split technique in which the material displacements and mesh displacements are uncoupled. A brief history of the ALE method is first presented and then special issues such as time-stepping, mesh refinement, energy absorbing boundaries, dynamic equilibrium checks and remapping of state variables are explained. The ALE method and the updated-lagrangian (UL) method are then used to analyse some geotechnical problems to examine the significance of inertia effects, large deformation and contact mechanics. The results show the efficiency of the ALE method for solving dynamic geotechnical problems involving large deformation. 相似文献