Spatial Distribution and Anthropogenic Assessment of Heavy Metals in the Surface Sediments of Klang River

The study was conducted to quantify the concentration and distribution of metals (Cd, Zn, Ni, Cu, Pb, and Fe) in the surface sediments and to assess the status of metal contaminations in the Klang River, Malaysia. The concentrations of metals (μg∕g, Fe%, dry weight) were as follows: 0.57-2.19 μg∕g Cd; 31.89-272.33 μg∕g Zn; 5.96-24.47 μg∕g Ni; 10.57-52.87 μg∕g Cu; 24.23-64.11 μg∕g Pb and 1.56%-3.03% Fe. Sequential extraction technique (SET) showed that mean anthropogenic portions of metals were in the order of Zn (60.22%), Cu (56.01%), Cd (45.63%), Ni (42.08%), Pb (33.22%) and Fe (10.26%). The highest concentrations of metals ( p<0.05) were found in the stations located close to industrial parks and highly populated areas. The results of the present study showed that the effectiveness of total organic carbon (TOC) contents in controlling the distribution and enrichment of metals was a more important factor compared to grain size. The study also indicated that the control of metals pollution from direct influx of domestic wastes and insufficiently treated industrial wastes in the Klang River was an important and desirable way to minimize the detrimental effects of metals.     

Use of Cement Kiln Dust on the Engineering Modification of Soil Materials,Nile Delta,Egypt

Cement kiln dust (CKD) is the by-product generated from the manufacture of Portland cement. Disposal quantities of CKD in construction project are required to protect the environment. In the recent construction experience in the area of study at the last years showed that, ground and underground engineering on the soft soil are susceptible to various types of cracking in buildings and roads. The improvement of engineering properties of two disturbed soils by using CKD in different percentages (5, 10 and 20 %) was discussed in this paper. The results indicated that CKD additives increased the pH values and decreased the plasticity index in both types of soils under investigation. The maximum dry density (MDD) decreased and optimum moisture content (OMC) increased with increasing the percentage of CKD in soil A. In soil B the MDD and OMC decreased.     

A 3-tier tsunami vulnerability assessment technique for the north-west coast of Peninsular Malaysia

The 2004 tsunami that struck the Sumatra coast gave a warning sign to Malaysia that it is no longer regarded as safe from a future tsunami attack. Since the event, the Malaysian Government has formulated its plan of action by developing an integrated tsunami vulnerability assessment technique to determine the vulnerability levels of each sector along the 520-km-long coastline of the north-west coast of Peninsular Malaysia. The scope of assessment is focused on the vulnerability of the physical characteristics of the coastal area, and the vulnerability of the built environment in the area that includes building structures and infrastructures. The assessment was conducted in three distinct stages which stretched across from a macro-scale assessment to several local-scale and finally a micro-scale assessment. On a macro-scale assessment, Tsunami Impact Classification Maps were constructed based on the results of the tsunami propagation modelling of the various tsunami source scenarios. At this stage, highly impacted areas were selected for an assessment of the local hazards in the form of local flood maps based on the inundation modelling output. Tsunami heights and flood depths obtained from these maps were then used to produce the Tsunami Physical Vulnerability Index (PVI) maps. These maps recognize sectors within the selected areas that are highly vulnerable to a maximum tsunami run-up and flood event. The final stage is the development of the Structural Vulnerability Index (SVI) maps, which may qualitatively and quantitatively capture the physical and economic resources that are in the tsunami inundation zone during the worst-case scenario event. The results of the assessment in the form of GIS-based Tsunami-prone Vulnerability Index (PVI and SVI) maps are able to differentiate between the various levels of vulnerability, based on the tsunami height and inundation, the various levels of impact severity towards existing building structures, property and land use, and also indicate the resources and human settlements within the study area. Most importantly, the maps could help planners to establish a zoning scheme for potential coastline development based on its sensitivity to tsunami. As a result, some recommendations on evacuation routes and tsunami shelters in the potentially affected areas were also proposed to the Government as a tool for relief agencies to plan for safe evacuation.     

Piezometric levels as possible indicator of aquifer structure: analysis of the data from Maknassy basin aquifer system (Central Tunisia)

The knowledge of piezometric data is of vast interest in many applications, such as assessing groundwater flow direction and identifying recharge zone of the aquifer. In this paper, a methodology is presented as a complementary approach to characterize multilayered aquifer system structure and functioning using piezometric data and the cartography of the hydraulic charge difference. The methodology is presented to gradually discriminate the aquifer system levels and to evaluate the spatial distribution of hydraulic heads. The hydraulic charge difference mapping permits to track spatial evolution of the impermeable levels. The methodology has been applied over the Maknassy basin aquifer system, located in central Tunisia. The obtained results, showing the multilayered aquifer structure, are validated using hydrochemical approach and piezometric data not considered in the reasoning.     

Short-term geomorphological evolution of the Poggio Baldi landslide upper scarp via 3D change detection

On 19 March 2010, a 4 million m³ landslide occurred at Poggio Baldi, a small village in the Santa Sofia municipality, central Apennines (Forlì-Cesena, Italy). The landslide caused severe damages to some homes and obstructed both the SS310 national road and the Bidente river. The Poggio Baldi landslide arose in the “Marnoso-Arenacea Romagnola” formation composed of a pelitic-arenaceous turbiditic sequence. The landslide was classified as a rotational landslide, evolving into a partially confined flow-like landslide and causing the reactivation of the deposit of a previous landslide that took place in 1914. This paper reports a study of the phenomena currently occurring on the 100-m high main scarp of this landslide complex. The aim of the study was to assess ground changes that occurred on the upper scarp from 2015 to 2018 and to infer a preliminary evolutionary model capable of supporting short-term landslide scenarios. For this purpose, multi-station terrestrial laser scanner surveys were performed in 2015, 2016, 2017, and 2018. Additionally, an unmanned aerial vehicle three-dimensional photogrammetric survey was carried out in 2016. Analyses of the three-dimensional digital models of the main scarp made it possible to carry out several exhaustive multi-temporal investigations and to derive a detailed three-dimensional change detection scheme for it. The results showed an active geomorphological evolution of the rock scarp area due to frequent rockfalls and topples (of the order of a few m³), with significant local volume changes (a few thousand m³/year) and with potential implications for the long-term evolution of the entire slope.

     

Submarine and coastal karstic groundwater discharges along the southwestern Mediterranean coast of Turkey

A 120 km-long part of the southwestern coast of Turkey, with well-developed karst terrain in contact with the sea, has been investigated by systematic diving surveys to determine the submarine groundwater discharges (SGDs). The physical, chemical and isotopic data have been used to determine the rate of the fresh groundwater end member (FEM) and its temporal dynamics. About 150 SGDs have been detected by diving surveys employed mostly up to a depth of 30 m below sea level (bsl). Among those, 15 SGDs are in the form of coastal or submarine caves with entrances ranging between sea surface and 40 m bsl. The FEM contribution in SGDs ranges from a few percent to more than 80%. Stable isotope data suggest a range of mean recharge area elevations extending from the coast to more than 1,000 m inland. In many of the SGDs, the FEMs are characterized by tritium-based residence times ranging from recent to several decades. Hypothetical geochemical calculations of mixing between freshwater and seawater end members reveal that more than 45% of freshwater contribution is required for karst development in the SGDs. Models suggest a threshold pH of 7.6 or lower for the carbonate rock dissolution.     

An application of fuzzy fault tree analysis for spread mooring systems

In this paper, a fuzzy fault tree analysis methodology for spread mooring systems is presented. The methodology combines the effects of operational failures and human errors under fuzzy environment for the spread mooring configurations. In conventional fault tree analysis (FTA), which is an established technique in hazard identification, the ambiguous and imprecise events such as human errors cannot be handled efficiently. In addition to this, the tolerances of the probability values of hazards are not taken into account. Moreover, it is difficult to have an exact estimation of the failure rates of the system components or the probability of the occurrence of undesired events due to the lack of sufficient data. To overcome these disadvantages, a fault tree analysis based on the fuzzy set theory is proposed and applied to the spread mooring system alternatives. Furthermore, sensitivity analysis is carried out based on the fuzzy weighted index (FWI) in order to measure the impact of each basic event on the top event. The results show that the fuzzy fault tree risk analysis method (FFTA) is more flexible and adaptive than conventional fault tree analysis for fault diagnosis and hazard estimation of spread mooring systems.     

Effects of additional HONO sources on visibility over the North China Plain

The objective of the present study was to better understand the impacts of the additional sources of nitrous acid （HONO） on visibility, which is an aspect not considered in current air quality models. Simulations of HONO contributions to visibility over the North China Plain （NCP） during August 2007 using the fully coupled Weather Research and Forecasting/Chemistry （WRF/Chem） model were performed, including three additional HONO sources： （1） the reaction of photo-excited nitrogen dioxide （NO~） with water vapor; （2） the NO2 heterogeneous reaction on aerosol surfaces; and （3） HONO emissions. The model generally reproduced the spatial patterns and diurnal variations of visibility over the NCP well. When the additional HONO sources were included in the simulations, the visibility was occasionally decreased by 20%-30% （3-4 km） in local urban areas of the NCP. Monthly-mean concentrations of NO3, NH＋, SO]- and PM2.5 were increased by 20%-52% （3-11μg m-3）, 10%-38%, 6%-10%, and 6%-11% （9-17 μg m-3）, respectively; and in urban areas, monthly-mean accumulation- mode number concentrations （AMNC） and surface concentrations of aerosols were enhanced by 15%-20% and 10%-20%, respectively. Overall, the results suggest that increases in concentrations of PM2.5, its hydrophilic components, and AMNC, are key factors for visibility degradation. A proposed conceptual model for the impacts of additional HONO sources on visibility also suggests that visibility estimation should consider the heterogeneous reaction on aerosol surfaces and the enhanced atmospheric oxidation capacity due to additional HONO sources, especially in areas with high mass concentrations of NOx and aerosols.     

Water Problems in Gaza Strip,Palestine

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