摘要:

ABSTRACTA geological survey was made at Tarfala drainage basin in 1988. The objective was to generate a reliable geological background of this arctic area with very low anthropogenic charges for further investigations into the processes of chemical weathering and evolution of chemical composition of: surface and ground water. Field and laboratory work produced some results on the weathering of the rockcrust. Release of Ca and Al has been recorded at different depths from rock surface.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880306

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTThe intention of this study was to analyse the changes in the pattern of certain landscape elements, land use types and small biotopes (linear structures), and to determine how these changes have influenced the occurrence of grassland plant species. This was accomplished by combining retrospective studies of aerial photographs from 1947, 1965 and 1984 with field data over plant species. The results showed that the total changes in land use types, which have affected 27% of the area, reduced the distribution of grassland areas by 61%. Altogether, the linear structures decreased in line length by 28%. The most affected class, field verges, was reduced by almost 60%. The effects on the natural grassland flora are briefly discussed in this article.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880307

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor

摘要:

ABSTRACTA study on soil erosion and land use was carried out in a small watershed in Okhaldunga, eastern Nepal. The land was surveyed in order to determine whether there was risk for severe erosion or not. Farmers were interviewed and a soil erosion risk map was made.

ISSN:0435-3676    

DOI:10.1080/04353676.1990.11880308

出版商:Taylor&Francis    

年代:1990

数据来源: Taylor