A solid waste disposal site selection procedure based on groundwater vulnerability mapping

In this study, a new, GIS-based solid waste site selection tool (DUPIT) is introduced to obtain a systematic and unbiased methodology during the evaluation phases of alternative solid waste disposal areas with regards to vulnerability to groundwater pollution. The proposed tool is an index technique based on the linear combination of five different hydrogeological parameters including Depth to groundwater table, Upper layer lithology, Permeability of the unsaturated zone, Impermeable layer thickness and Topographic slope. Five different categories are developed to classify each alternative based on the suitability of the site for a solid waste disposal area. As a result, each site is ranked according to the contamination risks for groundwater resources. The proposed technique is applied to the District of Torbali near Izmir, Turkey to determine the most appropriate solid waste disposal site location. The Torbali application is implemented by using a GIS database developed for the area. Based on the results of this application, the best alternative solid waste disposal site for Torbali is selected to be located in the northern portions of the city where the groundwater table is deep, the permeability is low and the topographic slope is mild.     

Forecasting shield pressures at a longwall face using artificial neural networks

Leg pressure data from all shields of a longwall face are monitored and recorded in the surface computer. An algorithm is developed to detect peak pressures or periodic roof weightings from these pressure data. The intensities and locations of periodic roof weighting are further analyzed using artificial neural network for forecasting of forthcoming shield pressures. The network was trained using data 153 m (500 ft) of face advance. Shield pressures are forecasted for the successive nine mining cycles or approximately 9 m of face advancement. The results obtained validate the efficacy of the developed model.     

Environmental geological assessment of a solid waste disposal site: a case study in Sivas, Turkey

The selection of the disposal site is probably the most important step in the development of solid waste management. In site selection, geology plays a determining role. This study evaluates the characteristics of the environment on the basis of the geological, hydrogeological and geo-engineering properties of the solid waste site of the Sivas city, Turkey. The area is underlain by the Oligocene-Miocene rocks which have limited aquifer properties. Thin Quaternary alluvium and soil cover overlie the Oligo-Miocene rocks, which are represented as well graded sand and inorganic silt of low plasticity. The Quaternary alluvium and soil cover are classified as inorganic clays having a low plasticity and the permeability varies from 1.2×10⁻⁶ to 3.11×10⁻⁶ m/s. These values are much higher than 1×10⁻⁸ m/s, which is accepted for waste disposal standards. Seepage waters have a potential to pollute the ground water and the Kızılırmak River, which is 500 m to the southwest of the waste disposal area and because the disposal site is close to the river, the potential for flash flooding poses a high pollution risk. The waste disposal area must be covered by clay layers or an impervious artificial membrane. In addition, seepage must be controlled and removed from the site.     

西昆仑成矿带成矿特征及勘查远景

西昆仑位于我国西北边陲,塔里木盆地西南山区,面积约180000km2,受自然条件制约,一直是我国地质工作程度最低的地区之一。随着国土资源大调查项目的实施和投入力度的加大,一系列基础地质调查成果和找矿新发现,初步显露出该区找矿潜力。在分析成矿地质背景、研究成矿地质特征、总结成矿地质规律的基础上,结合元素富集特点和找矿新发现,探讨了成矿远景,提出了地质找矿主要目标。考虑自然地理因素,优选8个靶区,作为近期找矿地质工作部署的依据。     

Probability of correct selection from lognormal and convective diffusion models based on the likelihood ratio

The objective of the paper is to show that the use of a discrimination procedure for selecting a flood frequency model without the knowledge of its performance for the considered underlying distributions may lead to erroneous conclusions. The problem considered is one of choosing between lognormal (LN) and convective diffusion (CD) distributions for a given random sample of flood observations. The probability density functions of these distributions are similarly shaped in the range of the main probability mass and the discrepancies grow with the increase in the value of the coefficient of variation (C _V ). This problem was addressed using the likelihood ratio (LR) procedure. Simulation experiments were performed to determine the probability of correct selection (PCS) for the LR method. Pseudo-random samples were generated for several combinations of sample sizes and the coefficient of variation values from each of the two distributions. Surprisingly, the PCS of the LN model was twice smaller than that of the CD model, rarely exceeding 50%. The results obtained from simulation were analyzed and compared both with those obtained using real data and with the results obtained from another selection procedure known as the QK method. The results from the QK are just the opposite to that of the LR procedure.     

运用禁忌搜索算法进行高光谱影像降维的研究

本文在分析了传统降维方法所面临问题的基础上，将禁忌搜索算法引入到高光谱影像的特征选择研究，指出由于禁忌搜索算法所具有的良好全局寻优能力，因而在该类影像的降维研究中有着广阔的应用前景。针对高维光谱数据的特点，讲述了算法运行过程中需注意的若干关键问题。实验表明，将禁忌搜索算法获取的波段进行高光谱影像分类，在求解的时间上和分类结果的精度都可达到令人满意的效果。     

浅谈盆地热历史及烃源岩热演化研究在中国油气资源战略选区调查评价中的意义

目前国家开展了全国油气资源战略选区调查与评价专项10个项目，包括陆上新区，海域，老油气区的新领域、新层系、新类型，长期久攻不克的地区、盆地和地表、地形条件复杂的地区。这些地区总体来讲油气工作程度较低。在油气调查评价中，特别是初期．烃源岩的评价是第一位的，而烃源岩热演化研究是烃源岩评价的重要内容之一。同时盆地内烃源岩热演化史的差异对盆地内的油气分布具有重要影响；热历史又从另一个侧面反映了盆地的成因及发展过程，对于指导油气勘探具有重要意义。     

丘陵山区农村宅基地选址地质灾害防范工作方法研究

目前对于农村分散宅基地的地质灾害防范问题尚未形成一套便于有效操作的管理办法,尤其是对于地处丘陵山区的地区而言,由于易发区覆盖面广,地质灾害点密度大,因而涉及的问题更多。文章主要针对丘陵、山区的农村宅基地选址、审批过程中的地质灾害防范工作做出评述,同时对评价管理的工作程序进行探讨。针对在易发区内相对合理用地的地质灾害防范问题,对丘陵、山区农村宅基地审批过程中涉及的易发区地质灾害防范及危险性评估(价)的工作,应结合面临的形势、当地具体条件及工作的可操作性做相应的调整。通过60个点(地块)的普遍样本及30个点的典型样本的调查及归纳,通过对各种类型宅基地有可能出现的不良地质现象应对措施的制定,笔者认为可通过7种途径进行丘陵、山区农村宅基地选址的地质灾害防范工作。     

Gendered production spaces and crop varietal selection: Case study in Yucatán, Mexico

This paper examines the influence of gender relations and gendered domains on maize and squash varietal selection in a village in Yucatán State, southeast Mexico. Results of the exploratory study indicate that the traditional production spaces of homegardens and agricultural fields are complementary gendered domains of varietal maintenance for both crops although with different cropping patterns, while a 'new' space, of land allocated to some families for future residential construction ( terreno ) is in the meantime a jointly worked agricultural domain. Women's labour, knowledge and preferences predominate in post-harvest processes. Fieldwork revealed that neither men nor women are independent decision-makers, planning what to grow, where and in what amounts, but that in most aspects of farming the interests of both are accommodated within the household's production spaces.     

隧道线路方案选择原则

针对目前铁路建设中隧道向密度更高、长度更长、断面更大的三个发展趋势,简述了地形条件和地质条件等因素对隧道线形、隧道位置方案选择原则的影响。本文对指导隧道线路方案设计具有重要作用。