关于侵采国营矿山资源问题的探讨

以具体事例说明了国营矿山资源被侵采现象的严重性及其危害性。通过分析乱采滥挖屡禁不止的原因，找出了维护国营矿山主体地位。

侵采国营矿山资源问题的探讨

我国现有各类国营矿山企业,对我国社会主义经济建设发挥着至关重要的工业原料的保障作用。《矿产资源法》对国营矿山的法律地位作了十分明确的原则性规定:“国营矿山是开采矿产资源的主体,国家保障国营矿山企业的巩固和发展。”但多年来地方群众采矿势力不断地侵袭国营矿山资源,造成严重的干扰和破坏。此现象不仅屡禁不止而且是愈演愈烈。为何有法不能治理,如何维护国营矿山的主体地位,使其正常生产,已引起社会的关注。积极寻求有效的对策,切实加强矿产资源的保护是一个急需探讨的课题。

Mechanism of Mining-induced Slope Movement for Gullies Overlaying Shallow Coal Seams

This paper provides an improved understanding of the movement mechanisms of both bed-rock gully and sandy soil gully when underground mining occurs underneath,followed by systematic analysis of the contributing factors such as mining advance direction,gully slope angle,gully erosion coefficient and mining height.This paper presents the results from monitoring,theoretical analyses and up to date modeling based on the geological features in the gully affected area,and the implications of these results to the success of roof support trial.It was observed that when mining occurred towards the gully,sliding of slope block along the fracture surface occurred,which resulted in unstable roof condition;when mining progressed away from the gully,polygon blocks developed in the gully slope and rotated in reversed direction forming hinged structure;within the bed-rock slope,the hinged structure was unstable due to shear failure of the polygon block;however,within the sandy soil slope,the structure was relatively stable due to the gradual rotating and subsiding of the polygon block.The increase of the value of slope angle and mining height lead to a faster and more intensive fracture development within the gully slope,which had a pronounced effect on gully slope stability and underground pressure.Various remediation approaches are hence proposed in this paper including introducing more powerful support and reasonable mining height,setting up working face along or away from gullies,using room and pillar,strip mining and backfill instead of longwall mining.

Quantitative evaluation of soil erosion of land subsided by coal mining using RUSLE

Based on a RUSLE model, we identified the key factors of the impact on soil erosion induced by coal min- ing subsidence. We designed a method for predicting/.S factors of a mining subsidence basin, using ana- lytical GIS spatial technology. Using the Huainan mining area as an example, we calculated the modulus of erosion, its volume and classified the grade of soil erosion for both the original area and the subsidence basin. The results show that the maximum modulus of erosion and the volume of erosion of the subsi- dence basin without water logging would increase by 78% and 23% respectively compared with the ori- ginal situation. The edge of the subsidence basin, where the land subsidence was uneven, is subject to the greatest acceleration in soil erosion. In the situation of water logging after subsidence, the maximum modulus of erosion would decrease if the accumulated slope length were reduced. This maximum mod- ulus around the water logged area within the subsidence basin is equal to that without water logging, while the total volume of erosion decreases. Therefore, mining subsidence aggravates soil erosion espe- cially at the edge of basins where water and soil conservation measures should be taken.

Algorithm of Intrusion Detection Based on Data Mining and Its Implementation

Intrusion detection is regarded as classification in data mining field. However instead of directly mining the classification rules, class association rules, which are then used to construct a classifier, are mined from audit logs. Some attributes in audit logs are important for detecting intrusion but their values are distributed skewedly. A relative support concept is proposed to deal with such situation. To mine class association rules effectively, an algorithms based on FP-tree is exploited. Experiment result proves that this method has better performance.

Causes of Land Loss in Tuvalu,a Small Island Nation in the Pacific

Studies on land loss in Tuvalu reveal the following findings. Although both sea level rise and coastal erosion can cause land loss in the tropic Pacific oceanic islands, their mechanisms are different. When sea level rises, the low elevation coastal zone submerges and the erosion datum plane rises, the beach process progresses normally as always, resulting in no beach sediment coarsening. When the sea level is stable, coastal erosion removes finer sediment from reef flat, beach and land, resulting in beach sediment coarsening. The human-induced coastal erosion in the tropic Pacific oceanic islands has the following features. 1) Erosion occurs or intensifies immediately after inappropriate human activities. 2) It occurs near the places having human activities and places related to the above places in sediment supply. 3) It often occurs on original prograding or stable coasts (on lagoon coasts for atolls) because there are more coastal engineering projects and other human activities on such coasts. 4) It is chronic, covering a long period of time. The coastal geological events in Tuvalu islands do not accord with the features resulted from sea level rise but do accord with the features resulted from coastal erosion, particularly from human-induced erosion. The land loss in Tuvalu is mainly caused by inappropriate human activities including coastal engineering and aggregate mining, and partly caused by cyclones. Moreover, all recent measurements (satellite altimetry,thermosteric sea level data and tide observations) so far have not been able to verify any sea level rise around Tuvalu islands.

Channel Response to Gravel Mining Activities in Mountain Rivers

s: The removal of bed material from active river channels usually affects the bed profile of the streambed, causing progressive degradation upstream and downstream of the extraction site. These effects can extend for kilometers affecting hydraulic structures located in the vicinity of the river reach. In this paper, the geomorphic effects of gravel mining are reviewed and summarized. Some cases in Venezuelan streams are presented to illustrate the problem. To describe the processes of erosion and sedimentation in a gravel extraction pit, a recent developed mathematical model for the simulation of flow and sediment transport in gravel-cobble bed streams is applied to a hypothetical case of gravel mining in a river channel. A simple rectangular dredge pit is imposed as initial condition in the channel bed, and changes in bed elevations and grain size distribution of bed material are calculated by using the numerical model. The process of deposition within the pit, and the downstream and upstream migration of the erosion wave are well simulated by the model and closely resemble the phenomena observed in laboratory experiments. The response of the friction coefficient to the changes in flow and bed elevations shows the importance in modeling adequately flow resistance and sediment transport in gravel-cobble bed streams.

Shifts in the Cervo Stream near Vercelli （16th-17th Century）

In the 16th-17th century, the Cervo stream flowed N-S, following the northern and eastern margins of the city of Vercelli, in northwest Italy. For centuries, the stream served as a waterway, as a gravel quarry, and for fishing. Besides being an important resource, the Cervo stream was also a constant threat to the integrity of the urban centre of VerceUi： Erosion was very high along the right bank and continuously damaged the city walls, as well as the eastern settlements between the city and the stream （＂Borghetto＂）. In the 16th-17th century, according to records of the Vercelli municipality, there is often reference to the ＂damage＂ to the city walls or to the city itself caused by stream flooding and erosion. There is also reference to the numerous attempts made to shift the course of the stream eastward, away from the city.

Soil Depletion

Soils are under threat around the world. Erosion, pollution, salinization and acidification degrade soils irreversibly. Evidently, the rate of soil degradation greatly exceeds the rate of soil formation. In some countries, soil lost is almost 100 times faster than the rate of its formation. Therefore, soil needs to be considered as a nonrenewable resource. Incessant construction activities along with unsustainable mining operations and energy-related undertakings in recent years have accelerated the degradation of soil in Turkey. Highway travellers can witness the mindless plunder all over the land. As one travels smoothly on newly constructed highways, looming along the roads are piles of leftover destruction： heaps of broken asphalt from previous roads; newly excavated topsoil dumped into adjacent streams; eroded hillsides. In the age of global climate change, these so-called development efforts sound incomprehensible since such anthropogenic activities exacerbate the change. Clearly, climate change increases the erosion rates and reduces the soil quality. This fact alone requires each country to adopt and implement sound conservation practices to protect their soils, and hence, social stability and security. The most effective way to conserve soil is to establish and maintain ground cover vegetation. Avoiding unnecessary soil sealing also conserves soil.