Proceedings of the General Meeting of the Association of Japanese Geographers

Show abstractHide abstract

The Namib Desert is located along the western coast of Namibia and is affected by the cold Benguela Current. Although forests are distributed along the ephemeral river, the Kuiseb River in the Namib Desert, many trees are almost dead in certain areas (Mizuno, 2005; Mizuno & Yamagata, 2005). The aim of this research was to clarify the relationship between recent environmental changes and such tree deaths.
Roots of a seedling of Acacia erioloba germinated by rainfall from January 2006 were examined in November 2007 in this study. The Acacia erioloba has grown to a height of 10cm and its root to over 230cm within the two years period from January 2006 onwards to November 2007. Acacia erioloba extends deeply its main roots to the moist fine grained soil layer (sandy silt) and absorbs the water through lateral roots there, in the stage of sapling (seedling). When it reaches the stage at which water supply from the moist fine grained soil layer is not enough for the large body, the tree extends innumerable lateral roots within the 50cm depth lightly from the land surface, and they absorb water brought by fog and so on to the shallow ground. The Acacia erioloba dies when the lateral roots become unable to absorb water near the land surface due to the heavy deposit as a result of the recent decrease of floods. Until the middle of the 1970s, each flood washed away successively the sand deposited by the previous flood, and the trees died only rarely. Recently, particularly from 1980 to 1985, the number of flood days dramatically decreased, many trees died. The most persuasive causation is sand deposition and a drop in the water table caused by the decrease in flooding.

Fullsize Image

View full abstract

The purpose of this study is to crafty the areal pattern of urban renewal in terms of both the changes in spatial structure through the urban policy and the conversion of social space of a central commercial district through a case of a large Polish city: Poznan where the urban renewal projects have been implemented and commercial facilities have increased in number after the Revolution of 1989. The result of analysis shows that the urban area of Poznan has largely changed in social-economic aspects. Those changes are caused by both public projects: urban renewal projects and renewal activities for the commercial facilities based on the direct and indirect investment from Polish and foreign company. Especially, the conversion of commercial facilities in this area for offering new merchandise optimized to customer needs leads to a large-scale change in landscape in a central commercial district called Potwiejska Street. In the central commercial districts, the young families preferring to live in an urban central area and enjoying accessibility to urban facilities increased in number and they continually renovate and repair their residential units. Meanwhile, although the city authority has programs of over 130 urban renewal projects, only two projects have been carried out as pilot project since 2006. In the scheme of Srodka pilot project, the city authority redeveloped several urban infrastructures such as schools and roads, many of which largely financially depended on EU Structural Fund. It has not yet carried out enough number of public interventions because of lack of financial, social and legal institutions to promote urban renewal.

View full abstract

Register with J-STAGE for free!