人类活动、自然灾害和活动构造研究

人类活动是生物圈中最重要的活动之一.半个世纪以来,人类活动的重要特征就是人口的城市化.地球的岩石圈、水圈、气圈不断变化,其中许多剧烈的变化,表现为自然灾害,严重影响生态环境,对人类形成威胁.随着经济发展和人口的城市化,这种人类活动和生态环境的相互作用越来越紧密,自然灾害越来越严重.本文利用GDP作为人类活动的度量,定量地分析了人类活动和自然灾害的关系.另外强调,活动构造作为第四纪地质学研究的一部分,是了解环境演变和灾害发生机理的地学基础,将成为十分活跃的新研究领域.

HUMAN ACTIVITY, NATURAL DISASTERS AND ACTIVE TECTONICS

Urbanization is a worldwide trend. According to UN figures, the rate of urbanization throughout the world is continuously rising. In 1950 near 30% of the world population (2.5 billion) lived in cities. It is now about 50% (6 billion), and will increase to over 60% (8.3 billion) by the year 2025. At the same time, the number of cities with over million inhabitants increased from 83 in 1950 to 325 today, almost fourfold increase. This trend is especially pronounced in the countries of the Third World, where the number of cities over one million inhabitants has increases sixfold. City people are more dependent on the infrastructure, i.e. the supply of water, electricity, gas, heating, telecommunications and transport connections than the more self-reliant rural population, which is more accustomed to helping one another in emergencies. Numerous natural catastrophes of recent years have shown quite emphatically how vulnerable the infrastructures of major cities are to minor breakdowns and how acute shortages in supply can develop within a short time. Our statistics showed that there is an empirical relation between the economic loss caused by natural hazards (in US$) and the social wealth expressed by GDP(Gross Domestic Product in US$) is: Loss caused by natural hazards = a + b × GDP + c × GDP2 Where a, b, and c are constants: a = 4 × 1013(US$) b = - 5000 c = 2.5 × 10 -7(US$-1) The losses increase remarkably when population concentrates in urban area and when social wealth increases. For mitigating the natural hazards, scientists encounter many challenges. One of them is the active tectonics research. Seismic events at the Latur and Jabalpur (India), New Madrid (United States), and many other earthquakes suggest that the stable continental regions are much more vulnerable to earthquakes than was once thought. The integrated study of active tectonics (including active faults and hidden faults) for understanding their seismic potential is a new topic of continental dynamics. Active tectonics should be integrative, innovative and should be focused on tectonically active regions for understanding the processes responsible for shaping the Earth's continental crust using new technologies. In particular, the study areas should be an actively deforming region or subregion of the Earth's continental crust, where dynamic properties can be observed or measured. These areas commonly have the following attributes: Topographic, stress and fluid profiles or distributions interaced with active deformation; heat flow and geothermal gradients that accompanied fluid and mineral chemical reactions; seismic and aseismic slip related to the present tectonism; and strain and metamorphism were not overprinted by younger deformation.