合流域と流域環境の保全に関する基礎的研究
1978 年 42 巻 1 号 p. 18-28
詳細
1978 年 42 巻 1 号 p. 18-28
The purpose of this study is to clalify the relation between the physical feature in the area around stream junction (A. S. J.) and the human impact to the physical environment of a basin. Secondly the biotic indicator and it's possibility for seizing the condition of the environment in a basin were analyzed. The scientific backgrounds for the conservation planning of a basin were obtained.
Especially, we put stresses on the following aspects.
The survey of bird-fauna in A. S. J. of River Tama and River Asakawa.
The relation between the envionmental conditions in a basin and environmental quality in A. S. J. was analyzed with the following indicators.
Environmental condition
the degree of relief, the degree of green covered space, land-use
Environmental quality
the quality of water, the quality of vegeation on a river-bank
In the same way in the basin of River Asakawa, was the relation analyzed with the following indicators.
Environmental condition
the occupancy rate of land-use type, altered-land against the total area
Environmental quality clearness of water, productivity of filiform bacilli (which is called MIZUWATA) number of species of ground beetles
We could reach at the following results during the analysis of the first reserch.
Each species of birds segrigates in habitation individually. This segrigation shows that the natural environment has complicated and various diversity in its quality.
The second analysis brought the follwing result.
The quantity of the plants that suit nitrogenious soil is concerned with the occupancy rate of urban land-use.
The third analysis brought the following result.
The clearness of water, the productivity of filiform bacilli and the number of species of ground-beetles are concerned with the occupancy rate of urban land-use and the rate of area of altered land.
Therefore, we should take the condition of the environment in A. S, J. into consideration with the impacts caused by rapid development in a basin for the conservation of the natural environment.
