Dryland Salinity on the Dundas Tableland: A historical appraisal

The groundwater recharge-discharge model, or hydro-equilibrium model, has driven Victorian dryland salinity research for the last 30 years. This paper challenges its application to the Dundas Tableland, south-western Victoria, on historical grounds. In exposing the weak historical foundation of the model for one geographical area so well represented in mainstream investigations, the critique is designed to question the validity of applying the model to other parts of Australia without corresponding historical research. More generally, it is hoped that this contribution from another discipline gives a respectful but significant nudge to the hegemony of physical science in defining and finding solutions for environmental problems.     

Historic fluvial development of the Alpine-foreland Tagliamento River, Italy, and consequences for floodplain management

The fluvial geomorphological development of the Tagliamento River and its flooding history is analysed using historical documents and maps, remote-sensed data and hydrological information. The river has been building a complex alluvial fan starting from the middle part of its alluvial course in the Venetia–Friuli alluvial plain. The riverbed is aggrading over its entire braided length. The transition from braiding to meandering near Madrisio has shifted downstream where the river width determined by the dikes becomes narrower, causing major problems. The flood hazard concentrates at those places and zones where flooding occurred during historical times. Prior to the agrarian and industrial revolution, land use was adjusted to the flooding regime of the river. Subsequent land-use pressure led to a confinement of the river by dikes to such an extent that the flood risk in the floodplain downstream of Madrisio has increased consistently, and represents nowadays a major territorial planning issue. The planned retention basins upstream of the middle Tagliamento will alleviate the problem, but not solve it in the medium and long term. Therefore, fluvial corridors in the lower-middle parts (from Pinzano to the sea) have been identified on the basis of the flooding history in relation to fluvial development during historical times. The result should be used for hydraulic simulation studies and land-use planning.     

广东古代历史人文资源的旅游开发

广东是古代历史人文资源精彩的省份,历史上众多入粤和本土历史名人,留下了大量活动遗迹和文化遗产,而历史文化名城是这些资源的富集地,可惜大部分已经湮没.对此应予认真恢复建设,其方向是发展文化旅游,以弥补我省稀缺的内容,并形成新的系列旅游品牌.这是对历史资源社会功能的最大发挥,也是最有效的保护,并可以得到较好的经济收益.为此所有地级市和历史文化名城均应对其作保护利用规划,使历史人文资源得到完整系统的整合,并作科学合理的开发建设,一定会取得满意的社会经济效益.     

Scattering of surface waves modelled by the integral equation method

The integral equation method is used to model the propagation of surface waves in 3-D structures. The wavefield is represented by the Fredholm integral equation, and the scattered surface waves are calculated by solving the integral equation numerically. The integration of the Green's function elements is given analytically by treating the singularity of the Hankel function at   R = 0  , based on the proper expression of the Green's function and the addition theorem of the Hankel function. No far-field and Born approximation is made. We investigate the scattering of surface waves propagating in layered reference models imbedding a heterogeneity with different density, as well as Lamé constant contrasts, both in frequency and time domains, for incident plane waves and point sources.     

前兆台网历史数据迁移与整合

长期以来,前兆数据的多系统、多格式、多流程给数据管理和应用带来了很大的复杂性.为此,全国实施了前兆历史数据迁移,将“九五”、模拟和人工观测历史数据迁移到“十五”数据库系统中,并解决了迁移中的代码对应、数据量纲或单位转换、数据衔接、错误纠正、数据库结构差异、数据同步等问题,整合了前兆数据系统,为数据应用带来极大便利,切实提升了前兆数据管理和共享服务能力.本文详细介绍了前兆历史数据迁移的内容、工作流程和工具软件、迁移中的技术难点、取得的成果,以及存在的问题等.     

环渤海虚拟地震台网建设

介绍环渤海虚拟地震台网的建设意图和内容,以及该台网建成后发挥的重要作用.环渤海虚拟地震台网的建设,可提高环渤海地区的地震监测能力,为研究海洋地震提供基础资料,以满足防震减灾事业的需要.