Geochemical and textural properties of carbonate and terrigenous sediments along the Jordanian coast of the Gulf of Aqaba

The physicochemical properties of 21 marine sediment samples were investigated, collected from five different localities along the Jordanian coast of the Gulf of Aqaba. According to the chemical parameters, sediments were categorized into three groups: carbonate (80% CaCO₃), composed mainly of materials of calcareous skeletal structures; terrigenous (<10% CaCO₃) depositional areas for land-derived materials from surrounding rocks and alluviums; and a admixture of the first two (19–37% CaCO₃). High significant linear correlations were found between organic carbon (OC) and total nitrogen (TN), indicating the occurrence of these components in a common phase (organic matter). Despite the co-occurrence of TP in organic matter, these two elements were negatively correlated, indicating anthropogenic sources of pollution such as phosphate exportation (hotel areas and clinker port sites) and industrial activities (industrial complex site). The study found that variations in texture properties and mud contents were due to differences in sediment sources, topography and their response during currents and waves. The finer, well-sorted sediments contain lower elemental concentrations of OC, calcium carbonate and TN (excluding TP) than coarser, poorly-sorted sediments.     

Evaluation of aquifers vulnerability to contamination in the Yarmouk River basin, Jordan, based on DRASTIC method

The existing different human activities and planned land uses put the groundwater resources in Jordan at considerable risk. There are evidences suggesting that the quality of groundwater supplies in north Jordan is under threat from a wide variety of point and non-point sources including agricultural, domestic, and industrial. Vulnerability maps are designed to show areas of greatest potential for groundwater contamination on the basis of hydrogeological conditions and human impacts. DRASTIC method incorporates the major geological and hydrogeological factors that affect and control groundwater movement: depth to groundwater (D), net recharge (R), lithology of the aquifer (A), soil texture (S), topography (T), lithology of vadose zone (I), and hydraulic conductivity (C). The main goal of this study is to produce vulnerability maps of groundwater resources in the Yarmouk River basin by applying the DRASTIC method to determine areas where groundwater protection or monitoring is critical. ArcGIS 9.2 was used to create the groundwater vulnerability maps by overlaying the available hydrogeological data. The resulting vulnerability maps were then integrated with lineament and land use maps as additional parameters in the DRASTIC model to assess more accurately the potential risk of groundwater to pollution. The general DRASTIC index indicates that the potential for polluting groundwater is low in the whole basin, whereas the resulting pesticide DRASTIC vulnerability map indicates that about 31% of the basin is classified as having moderate vulnerability, which may be attributed to agricultural activities in the area. Although high nitrate concentrations were found in areas of moderate vulnerability, DRASTIC method did not depict accurately the nitrate distribution in the area.     

Estimation of Longshore Sediment Transport Rate for a Typical Pocket Beach Along West Coast of India

Estimation of Longshore Sediment Transport Rate (LSTR) in the littoral zone is essential for managing and developing any coastal zone. Numerical models are powerful tool to understand and investigate various processes responsible for LSTR in a systematic manner since direct measurement of LSTR is a difficult task. A one dimensional LITDRIFT model was implemented along the Vengurla coast for estimation of LSTR and to analyze the sensitivity of each input parameters towards the computation of LSTR. Major input parameters required for the estimation of LSTR are nearshore wave climate, bathymetry, and sediment characteristics. The nearshore wave data at a depth of 15 m were collected using wave rider buoy in 2015 is used in the present study. Field observations were carried out to survey the regional bathymetry and sediment characteristics. Annual net LSTR along Vengurala coast is relatively less and varies from ?7778 to ?9015 m³ with an average of ?8511 m³. The net direction of LSTR is towards south and gross LSTR is 1.18 × 10⁵ m³/year. The LSTR reveals more sensitivity to coastline orientation and wave direction. A 1° changes in coastline angle and wave direction causes approximately 3000 m³/month difference in LSTR. Moreover, wave height, wave period, and bed roughness has an important role for controlling LSTR. The model results help to identify the role of each parameter contributing towards LSTR estimation and a similar model approach can be applied to other coasts for estimating LSTR in an accurate way.     

Light hydrocarbons geochemistry of surface sediments from Pranhita-Godavari Basin,Andhra Pradesh

A geochemical study of surface sediments from Pranhita-Godavari Basin, Andhra Pradesh, India was carried out using light hydrocarbon compounds to assess the hydrocarbon potential of the basin. Suite of 80 soil samples were collected from the depth of 2.5 m and analyzed for adsorbed light gaseous hydrocarbons namely methane (CH₄), ethane (C₂H₆) and propane (C₃H₈) in Gas chromatograph. Compound specific Carbon isotope ratios for CH₄ and C₂H₆ were also determined using GC-C IRMS (Gas Chromatograph Combustion Isotope Mass Spectrometer). The presence of moderate to low concentrations of methane (C_CH4 C_{CH_4 } : 1 to 138 ppb), ethane (H₄{H_4 }: 1 to 35 ppb) and propane (C_{C3 H8} C_{C_3 H_8 } : 1 to 20 ppb) was measured in the soil samples. Carbon isotopic composition of d¹³ C_CH4 \delta ^{13} C_{CH_4 } ranges between −27.9 to −47.1 ‰ and d¹³ C_{C2 H6} \delta ^{13} C_{C_2 H_6 } ranged between −36.9 to −37.2 ‰ (V-PDB) indicating that these gases are of thermogenic origin. Study of soil samples suggests the area has good potential for hydrocarbon.     

Guidelines for EIA of fish and shrimp hatcheries in a semi-enclosed water body

Natural fisheries in most parts of the world are under pressure due to heavy fishing activities and pollution threats. The establishment of fish and shrimp hatcheries using native species provides an opportunity for replenishment of fish and shrimp stocks in an environmentally responsible manner. This paper provides guidelines for conducting an EIA of fish and shrimp hatcheries in a semi-enclosed water body, such as the Arabian Gulf and Red Sea. The purpose of the guidelines is to outline issues that may be relevant to the design and construction of hatcheries and to identify important factors for consideration in an EIA study. Effective consultations and technical discussions during the design stage with project proponent and relevant government agencies are recommended. Early evaluation of alternative sites and consideration of environmental factors in ascertaining the suitability of intended project site can help minimize potential impacts. Aspects to be considered in depth include impacts on water quality, sediment and habitat loss. The paper also provides suggested mitigation measures for minimizing potential impacts along with key elements to be considered in the development of an adequate Environmental Management and Monitoring Plan.     

Utilization of supervised classification in structural and lithological mapping of Wadi Al-Marwah Area,NW Arabian Shield,Saudi Arabia

Wadi Al-Marwah area is located in the northwestern part of the Arabian Shield, Saudi Arabia. It is mainly covered by Precambrian igneous and sedimentary rock units. This area was not subjected to previous detailed lithological or structural mapping. This study aims to apply supervised classification technique of remotely sensed digital satellite data of Landsat 7 for detailed lithological and structural mapping of the area. The fusion between multispectral Enhanced Thematic Mapper (ETM)+ data and high-resolution panchromatic ETM+ band-8 produced a color composite fused image for the study area, scale 1:50,000. The structural lineaments of the study area were extracted and interpreted from the digital imageries data. Little discrepancies or improvements were detected when combining the supervised classification results with the Landsat ratios or principal component analysis. These highlighted the benefits of multispectral classification, especially in terms of lithologic discrimination. The overall results of image processing techniques, applied in this work, were excellent and succeeded in the performance of a more detailed and accurate lithological and structural maps (scale 1:50,000) than the previous published maps for the investigated area.     

Heavy metals signature of human activities recorded in coral skeletons along the Jordanian coast of the Gulf of Aqaba, Red Sea

The concentrations of six heavy metals were studied in five living coral species and their fossil counterparts collected along the Jordanian Coast of the Gulf of Aqaba. The study aimed at investigating the validity of using coral skeletons as bioindicators for environmental pollution by heavy metals in the Gulf of Aqaba, Red Sea. The skeletal samples of the collected corals were acid digested and analyzed for Cd, Cu, Fe, Mn, Pb, and Zn content using flame atomic absorption spectrophotometer. The results obtained have shown that higher concentrations of heavy metals were found in coral skeletons from areas hosting intense developments and human activities. The massive Porites sp. coral tended to accumulate the highest metal concentrations among the other species (except for Mn). This was due to interspecific differences or selectivity of heavy metals between different coral species. It was noteworthy that fossil coral species recorded higher average metal concentrations than their living counterparts; this was attributed to surface contamination due to prolonged burial of the fossil corals in sediment over the years. The study concluded that corals (specially the massive Porites species) are vulnerable to the accumulation of high concentrations of heavy metals in their skeletons and therefore can serve as proxies to monitor environmental pollution.     

Assessment of groundwater quality and its suitability for drinking and agricultural uses in arid environment

Groundwater quality in Ma’an area was evaluated for its suitability for drinking and agricultural uses by determining the main physical and chemical properties during a 1 year survey study (August 2009 to August 2010). Several samples were collected from ten different wells and analysed for temperature, pH, conductivity, total dissolved solids, total hardness, major cations (Ca²⁺, Mg²⁺, Na⁺ and K⁺), major anions (HCO₃ ^?, Cl^?, NO₃ ^?, SO₄ ^2?, F^? and Br^?) and trace metals (Fe²⁺, Al³⁺, Mn²⁺, Cu²⁺, Zn²⁺, Pb²⁺ and Cd²⁺). The general chemistry of water samples was typically of alkaline earth waters with prevailing bicarbonate chloride. The results showed great variations among the analyzed samples with respect to their physical and chemical parameters. However, most values were below the maximum permissible levels recommended by Jordanian and WHO drinking water standards. The quality assessment shows that in general, the GW in the study area is not entirely fit for direct drinking with respect to EC, and Pb²⁺. According to the residual sodium carbonate and sodium adsorption ratio, the water in the studied wells can be used for irrigational purposes.     

Response of infaunal macrobenthos to the sediment granulometry in a tropical continental margin–southwest coast of India

Surficial sediment samples, collected from the continental margin of the southwest coast of India in July 2004, were examined for the grain size and soft-bottom macrobenthic fauna, to understand the sediment granulometry and its effect on the faunal distribution. Samples were collected using Smith-McIntyre Grab, from 20 to 200 m depth range, consisting of mid-shelf, outer shelf and slope. Fine-grained sediment located in the mid shelf and supported low faunal abundance. Polychaetes constituted the bulk of the fauna. Feeding guild changed with depth and sediment granulometry. Coexistence of deposit feeders and carnivores in outer shelf and deposit feeders and filter feeders in the slope region indicated the effective utilization of different food resources. In general, richness and diversity were high in the southern region. Depth wise, the diversity and abundance were relatively high in the 50–75 m depth range. Correlation and BIO-ENV analysis showed that combination of different factors such as sediment texture, sediment sorting and depth were found to influence the distribution of macrobenthos. Hence, spatial variations observed in benthic community were presumably linked to the variations in sediment granulometry and the energy level conditions prevailing in the area.     

Participatory forestry as a strategy for reforestation in Bangladesh

Deforestation has been a serious ecological problem in Bangladesh for the past four decades. Illegal logging, demand for fuelwood and farmland encroachment are the principal causes of dwindling biomass resource. About 17.8% of the total area of the country are under forest cover (BBS 1993), but less than half of that area are under real tree formations. It is estimated that Bangladesh loses its forest lands by about 3.3% every year (World Bank 1994). This paper attempts to present a review of a newer strategy to meet this challenge; a strategy, not merely of halting deforestation, but of reforestation on a national scale and through people's participation in the process.In response to the crisis in the forestry sector, traditional government forest management programs have been replaced by participatory forestry in recent years as the principal strategy for reforestation. This change in strategy has two goals (1) encourage new plantations, and (2) generate income and create jobs for the rural poor. Participatory forestry is a benefit sharing scheme in which the landless and the marginal farmers are employed in tree plantation work.