Investigation of deposits for traditional extraction activities (metals and coal) has generally been based on determining grade, or content, of the required material. In order to apply the grade concept to an ornamental rock such as slate, it is first necessary to define the variables that determine both the geotechnical recovery rate for the rock mass — which conditions the size of the extracted blocks – and the aesthetic features of the slate — which define the quality of the slabs as potential roofing material.
For this research, geotechnical and aesthetic data for a slate deposit were collected from 16 continuous core borehole samples. A fuzzy expert system was then developed using this data, defining the rock mass recovery rate and slab quality in accordance with the criteria of a slate expert, producing as a final output a zonation of the deposit in terms of top quality slate, medium quality slate or waste.
A mathematical model based on fuzzy logic was chosen due to the fact that the boundaries between different quality groups in a deposit are not clearly distinguished. Moreover, quality also depends on a company's infrastructures for transformation of the blocks, and also on its commercial strategies. 相似文献
The future availability and sustainability of fresh groundwater resources in the South West district of the national capital territory (NCT) Delhi, India, have been projected. Due to a rapid decline in groundwater level and quality, the district has been required by the Government of India to regulate development of groundwater resources. Shallow groundwater is mostly saline and water resources in the area are limited. The methodology applied here involves microzonation of the district in terms of thickness of fresh groundwater and then quantification of present and future availability of freshwater in different freshwater zones, including tentative timescales. The calculation method has been aided by data on historic trends in water level at representative groundwater monitoring stations, located either in fresh groundwater zones or near to them. It is estimated that the presently available 481 million m3 of resources will be reduced to 374 million m3 by year 2007 and to 303 million m3 by the year 2012, and by the year 2022 the district will have only 176 million m3 of available fresh groundwater resources. 相似文献
A decision support system (DSS) has been developed to assist expert and non-expert users in the evaluation and selection of
eco-engineering strategies for slope protection. This DSS combines a qualitative hazard assessment of erosion and mass movements
with a detailed catalogue of eco-engineering strategies for slope protection of which the suitability is evaluated in relation
to the data entered. The slope decision support system (SDSS) is a knowledge based DSS in which knowledge is stored in frames
containing rules that can evaluate the available information for a project, stored as project specific information (PSI) in
a data file. The advantages of such a system are that it accepts incomplete information and that the qualitative nature of
the information does not instil the user with a sense of unjustified exactitude. By its multidisciplinary and progressive
nature, the DSS will be of value during the initial stages of an eco-engineering project when data collection and the potential
of different eco-engineering strategies are considered. The accent of the output of the DSS is on the application of eco-engineering
strategies for slope protection as an environmentally-friendly solution aiding sustainable development. For its acceptance
within the engineering community, the DSS needs to prove its predictive capacity. Therefore, its performance has been benchmarked
against successful and unsuccessful cases of slope stabilisation using eco-engineering. The target audience and the areas
of application of this DSS are reviewed and the strategies for further development in this area suggested. 相似文献
An increasing number of palaeo-climatic records have been reported to identify the Holocene climate history in the arid Xinjiang region of northwest China. However, few studies have fully considered the internal linkages within the regional climate system, which may limit our understanding of the forcing mechanisms of Holocene climate change in this region. Here, we systematically consider three major issues of the moisture/precipitation, temperature and near-surface wind relevant to the Holocene climate history of Xinjiang. First, despite there still has debated for the Holocene moisture evolution in this region, more climatic reconstructions from lake sediments, loess, sand-dunes and peats support a long-term regional wetting trend. Second, temperature records from ice cores, peats and stalagmites demonstrate a long-term winter warming trend during the Holocene in middle- to high-latitudes of Asia. Third, recent studies of aeolian sedimentary sequences reveal that the near-surface winds in winter gradually weakened during the Holocene, whereas the winter mid-latitude Westerlies strengthened in the Tienshan Mountains. Based on this evidence, in the arid Xinjiang region we propose an early to middle Holocene relatively cold and dry interval, with strong near-surface winds; and a warmer, wetter interval with weaker near-surface winds in the middle to late Holocene during winter. Additionally, we develop a conceptual model to explain the pattern of Holocene climate changes in this region. From the early to the late Holocene, the increasing atmospheric CO2 content and winter insolation, and the shrinking of high-latitude continental ice-sheets, resulted in increasing winter temperatures in middle to high latitudes in the Northern Hemisphere. Subsequently, the increased winter temperature strengthened the winter mid-latitude Westerlies and weakened the Siberian high-pressure system, which caused an increase in winter precipitation and a decrease in near-surface wind strength. This scenario is strongly supported by evidence from geological records, climate simulation results, and modern reanalysis data. Our hypothesis highlights the important contribution of winter temperature in driving the Holocene climatic evolution of the arid Xinjiang region, and it implies that the socio-economic development and water resources security of this region will face serious challenges presented by the increasing winter temperature in the future. 相似文献