GIS-based analytic hierarchy process as a multicriteria decision analysis instrument: a review

Information and communication technology, which has been incorporated and provided in the Geographic Information System (GIS), is valuable and effective geospatial information for the decision makers in improving their decisions in planning and development. The integration of this GIS using the multicriteria decision analysis approach provides an environment to the decision makers in citing areas using land suitability analysis procedures. This review paper particularly examines the GIS-based analytic hierarchy process as a multicriteria analysis/evaluation technique in land suitability analysis by means of literature reviews and surveys.     

An international comparison of governmental disclosure of hydrocarbon spills from offshore oil and gas installations

The cumulative effect of accidental spills from oil and gas extraction in the marine environment can have significant impacts on marine wildlife. Oil and gas operators are typically required to report spill data as part of a regulatory process. We conducted a survey of the public disclosure of hydrocarbon spill data for four countries, Australia, Canada, United Kingdom and United States. There was significant variation in the spill data statistics that were publicly reported by the regulators. No country provided full disclosure of spill data or follow-up actions taken by the regulator on their website. The lack of disclosure of spill data is of concern because the scale of environmental effects is more difficult to assess, insufficient information is available to assess the accuracy of predictions made in the environmental assessment process, and without consistency of spill reporting there is no method to compare regional differences of spill rates.     

稳定盐膏层井眼的不饱和有机盐水钻井液新技术

从力学和物理学角度分析,人们一般采用油基钻井液、饱和盐水钻井液或欠饱和盐水钻井液钻盐膏层,但油基钻井液因为自身缺陷无法大规模使用,而且井下经常出现事故或复杂情况。在成本可接受的情况下,采用适当密度的不饱和有机盐钻井液,可使钻井液在满足地层盐岩适当溶解的同时又具有较强的抑制性,从而达到盐膏层井眼稳定的目的。在室内进行了以密度为1.30 g/cm3和1.36 g/cm3有机盐水溶液为基液配制而成的两套钻井液常规性能、抗污染性能和盐溶量实验,认为两套钻井液都能够满足盐膏层的钻井需要,且在Y5-2井也进行了现场试验,表明与同构造上的其它完成井相比,无事故或复杂情况,综合成本低。     

Effect of shipping activity on warming trends in the Canadian Arctic

This paper presents a detailed account of the effect of shipping activity on the increasing trends of air temperatures in the Canadian Arctic region for the period of 1980–2018. Increasing trend of temperature has gained significant attention with respect to shipping activities and sea ice area in the Canadian Arctic. Temperature, sea ice area and shipping traffic datasets were investigated, and simple linear regression analyses were conducted to predict the rate of change(per decade) of the average temperature, considering winter(January) and summer(July) seasons. The results indicate that temperature generally increased over the studied region. Significant warming trend was observed during July, with an increase of up to 1℃, for the Canadian Arctic region. Such increasing trend of temperature was observed during July from the lower to higher latitudes. The increase in temperature during July is speculated to increase the melting of ice. Results also show a decline in sea ice area has a significant positive effect on the shipping traffic, and the numbers of marine vessel continue to increase in the region. The increase in temperature causes the breaking of sea ice due to shipping activities over northern Arctic Canada.     

Retention studies of chromium (VI) from aqueous solution on the surface of a novel carbonaceous material

In the present study, the retention capacity of carbonaceous material obtained from the diesel engine exhaust mufflers for Cr(VI) removal has been investigated. The physicochemical properties such as density, pH of aqueous slurry, pH at point of zero charge, ash content, moisture content, volatile matter, surface area, scanning electron microscopy and electron dispersive spectroscopy of the carbonaceous material were determined. The capacity of adsorbent for removal of Cr(VI) from aqueous solution was observed under different experimental condition like contact time, initial concentration of metal ions, pH and temperatures on the adsorption capacity of the adsorbent. Maximum adsorption of Cr(VI) ions was found at low pH. The adsorption process was found to follow second-order kinetics. The rate constant was evaluated at different temperatures along with other thermodynamic parameters like activation energy, Gibbs free energy change, enthalpy change and entropy change. Both Langmuir and Freundlich isotherms were used to describe the adsorption equilibrium of carbonaceous material at different temperatures. Langmuir isotherm shows better fit than Freundlich isotherm at given conditions. The result shows that low-cost carbonaceous material from diesel engine exhaust mufflers can be efficiently used for wastewater treatment containing Cr(VI) ions.     

Petrology and geochemistry of Jura granite and granite gneiss in the Neelum Valley,Lesser Himalayas (Kashmir,Pakistan)

Late Proterozoic rocks of Tanol Formation in the Lesser Himalayas of Neelum Valley area are largely green schist to amphibolite facies rocks intruded by early Cambrian Jura granite gneiss and Jura granite representing Pan-African orogeny event in the area. These rocks are further intruded by pegmatites of acidic composition, aplites, and dolerite dykes. Based on field observations, texture, and petrographic character, three different categories of granite gneiss (i.e., highly porphyritic, coarse-grained two micas granite gneiss, medium-grained two micas granite gneiss, and leucocratic tourmaline-bearing muscovite granite gneiss), and granites (i.e., highly porphyritic coarse-grained two micas granite, medium-grained two micas granite, and leucocratic tourmaline-bearing coarse-grained muscovite granite) were classified. Thin section studies show that granite gneiss and granite are formed due to fractional crystallization, as revealed by zoning in plagioclase. The Al saturation index indicates that granite gneiss and granite are strongly peraluminous and S-type. Geochemical analysis shows that all granite gneisses are magnesian except one which is ferroan whereas all granites are ferroan except one which is magnesian. The CaO/Na₂O ratio (>0.3) indicates that granitic melt of Jura granite gneiss and granite is pelite-psammite derived peraluminous granitic melt formed due to partial melting of Tanol Formation. The rare earth element (REE) patterns of the Jura granite and Jura granite gneiss indicate that granitic magma of Jura granite and Jura granite gneiss is formed due to partial melting of rocks that are similar in composition to that of upper continental crust.     

江西兴国县偏酸性地下水研究现状

兴国县浅层地下水为各城镇和农村的主要饮用水源,浅层地下水中酸性地下水(p H6.5)分布范围占全区面积的1/2,区域地下水酸化现象较为明显,已成为该地区安全用水问题之一。中国地质调查局根据原国土资源部的统一部署,于2017年启动了兴国水文地质调查工作。基于768组地下水现场水质测试和80组相关水化学分析资料,本文研究了兴国县偏酸性地下水的分布特征及其影响因素。结果发现:pH6.5的偏酸性地下水分布普遍,主要分布于花岗岩类裂隙水中,地下水pH值受当地酸雨影响明显,与酸性土壤分布吻合,与含水介质类型密切相关,随地下水位埋深的增加,pH值增大。本研究对正确认识偏酸性地下水分布特征与影响因素,促进城镇农村居民安全用水,为预防地下水酸化污染具有重要意义。