An evaluation of the undiscovered mineral resources of India based on the concept of unit regional value     

M. V. B. Raju  G. B. Misra 《Mathematical Geology》1991,23(6):841-852

Unit regional value (URV) and unit regional weight (URW) are relatively new concepts which are used to measure the intensity of the development of the mineral resources of any particular region. URV and URW of the mineral resources of India have been evaluated by sector, by commodity, as well as by state. The results are compared with values for the U.S.A. established by earlier workers and which can be taken as a standard for comparison with the mineral resources of other regions. URV of India, evaluated through the years 1898–1985, shows that the total mineral resources produced stands at $24.4 billion U.S. (deflated to 1967 value). Log URV of India lies below one standard deviation of the value for the states of the U.S. Like the U.S. India's major contribution to its URV is from fuels, but it is much less compared to that of the U.S. Next to fuels, metals, nonmetals, construction materials, and precious materials follow in that order. Except for two states, viz. Bihar and West Bengal, all other states are just below two standard deviations of the states of the U.S. The state of J&K is even much lower than the two standard deviations mark. It is concluded that India has a high potential for undiscovered mineral resources. However, this will require a large investment in exploration, on the order of Rs. 7760 crores, in the next few years.  相似文献   

Analysis of Rayleigh waves in saturated porous elastic media by finite element method     

H. Hirai 《Soil Dynamics and Earthquake Engineering》1992,11(6)

A numerical procedure for the analysis of Rayleigh waves in saturated porous elastic media is proposed by use of the finite element method. The layer stiffness matrix, the layer mass matrix and the layer damping matrix in a layered system are presented for the discretized form of the solid-fluid equilibrium equation proposed by Biot. In order to consider the influence of the permeability coefficient on the behavior of Rayleigh waves, attention is focused on the following states: ‘drained’ state, ‘undrained’ state and the states between two extremes of ‘drained’ and ‘undrained’ states. It is found from computed results that the permeability coefficient exerts a significant effect on dispersion curves and displacement distributions of Rayleigh waves in saturated porous media.  相似文献   

利用CDSN资料研究中强地震的差异：—CDSN应用系列论文三     

傅昌洪 《地震地磁观测与研究》1992,13(3):31-39

本文利用中国数字地震台网(CDSN)短周期垂直向的直达 P 波数字资料,通过频谱分析的方法,测定了3个5级左右的中强地震及其随后小地震的应力降和介质 Q 值。初步研究了不同类型的中强地震在这方面的差异。并指出,中强地震的应力降低,与随后发生的小地震的平均应力降比值也小时,有可能在震中附近还会发生更大的地震。相反,中强地震的应力降高,与小地震的平均应力降的比值大时,随后发生更大地震的可能性就小。同时还指出,中强地震发生前,往往介质 Q 值部较低。这在中强地震发生后,对及时估计地震趋势有一定的实用价值.  相似文献   

灾害防御工程的经济效益评价原理及方法——以水坝震害防御工程为例     

罗云  田家华  龙昱 《地球科学》1992,(5)

根据价值工程理论和成本-效益理论,在作者提出的防灾工程功能函数、成本函数、价值函数、效益函数等灾害经济学基本函数及数学模型的基础上,结合地质灾害防御工程实例,探讨了防灾工程经济效益的评价原理及方法。  相似文献   

重磁联合广义反演磁、密度界面     

Wang Xichen 《吉林大学学报(地球科学版)》1990,(1)

本文利用广义线性反演技术,讨论了综合重磁两种地球物理资料集,联合反演磁、密度界面的方法及效果,所做的模型实验证明了重磁联合反演方法在削减解的非唯一性,提高解的可信度方面,是一种有前途的综合反演方法。  相似文献   

时间域航空电磁数据的反演   总被引：3，自引：0，他引：3  

黄皓平  王维中 《地球物理学报》1990,33(1):87-97

本文用广义逆矩阵理论讨论了时间域航空电磁数据的反演方法.以水平二层大地和球体模型为例进行了计算,结果表明这种方法对时间域电磁数据的反演是行之有效的.对于理论数据,一般仅需迭代数次即可稳定地收敛到真值.通过奇异值分析,可以确定一个模型中的相对重要参数和无关紧要参数;对于求解某一特定参数,可确定哪些数据起决定性的作用.由奇异值分解而得出的信息密度矩阵、模型分辨矩阵,分别给出了模型响应拟合数据和模型参数分辨率的度量.这些信息对于时间域航空电磁系统的设计、野外测量和资料解释都具有重要的参考价值.最后给出了实例.  相似文献   

Stability of the triangular libration points of the circular restricted problem in the presence of resonances     

A.P. Thakur  R.B. Singh 《Celestial Mechanics and Dynamical Astronomy》1996,66(2):191-202

The stability of triangular libration points, when the bigger primary is a source of radiation and the smaller primary is an oblate spheroid. has been investigated in the resonance cases ₁ = 2₂ and ₁ = 3₂. The motion is unstable for all the values of parameters q and A when ₁ = 2₂ and the motion is unstable and stable depending upon the values of the parameters q and A when ₁ = 3₂. Here q is the radiation parameter and A is the oblateness parameter.  相似文献   

The provenance and evolution of comets     

M. E. Bailey 《Earth, Moon, and Planets》1995,71(3):57-68

The process of comet formation through the hierarchical aggregation of originally submicron-sized interstellar grains to form micron-sized particles and then larger bodies in the protoplanetary disc, culminating in the formation of planetesimals in the disc extending from Jupiter to beyond Neptune, is briefly reviewed. The planetesimal theory for the origin of comets implies the existence of distinct cometary reservoirs, with implications for the immediate provenance of observed comets (both long-period and short-period) and their evolution as a result of planetary perturbations and physical decay, for example splitting and sublimation. The principal mode of cometary decay and collisional interaction with the terrestrial planets is through the formation and evolution of streams of cometary debris and hitherto undiscovered families of cometary asteroids. Recent dynamical results, in particular the sungrazing and sun-colliding end-state for short-period comet and asteroid orbits, are briefly discussed.  相似文献   

山地区域土地生态红线划定方法与实证研究——以重庆市涪陵区义和镇为例   总被引：4，自引：1，他引：3  

丁雨賝  冯长春  王利伟 《地理科学进展》2016,35(7):851-859

无序和不合理的土地利用是引发生态问题的重要因素。合理划定土地生态红线,可协调土地利用和生态环境的关系,促进土地资源的合理配置,保障区域生态安全。山地区域地势起伏较大,水系密布,土地利用破碎化,作为重要的水土保持和水源涵养区域,是进行生态恢复和重建的关键地区。本文以山地区域村镇为例,运用GIS平台,基于生态敏感性和生态服务价值,对土地生态进行综合评价,据此划定刚性和弹性的土地生态红线。生态敏感性评价的指标包括坡度、植被覆盖度、水体、土壤类型和降水侵蚀力等5个指标;生态服务价值评价的指标包括食物生产、原料生产、气体调节、气候调节、水文调节、土壤保持、维持养分循环、生物多样性和美学景观9个指标。义和镇的刚性生态红线内所包含的刚性生态保护区面积为43.90 km²,占义和镇总面积的44.34%。弹性生态红线包含的弹性生态保护区面积为29.18 km²,占义和镇总面积的29.47%。义和镇的生态红线范围主要包含东北部山地区域和南部水系丰富地区,该区域的生态敏感性较高,同时也有较高的生态服务价值,因此生态红线的划定对于生态修复和生态保护具有指引作用,为生态系统健康发展提供基础保障,并可为构建生态文明安全格局提供科学支持。  相似文献   

基于LUCC的张家界市生态补偿研究     

申海建  陈啸珏 《国土资源导刊(湖南)》2016,(4):38-44

本文基于张家界市土地利用/土地覆盖变化,通过改进的生态系统服务价值与生态足迹的方法,测算了研究区域的生态补偿额度。研究表明:(1)从2001~2013年张家界市各县(区)生态系统服务价值变化率来看,永定区呈下降态势;增幅最大的是武陵源区,其次是桑植县,慈利县增幅最小。(2)2013年张家界市的人均生态足迹为1.3625 hm~2,而实际生态承载力为0.9556 hm~2,人均可利用生态承载力为0.8409 hm~2,则人均生态赤字为-0.5215 hm~2。(3)计算出了张家界市各县(区)的生态补偿标准,其中慈利县需要支付的生态补偿量最高,为18.61亿元;其次是永定区,为10.49亿元;再次是武陵源区,为582.12万元;最小的是桑植县,为359.70万元。评价结果将促进张家界市生态环境保护和经济社会的可持续发展。  相似文献