摘要:

AbstractRepeated samples from the top 5cm of sediment in a homogeneous network of 100 sampling stations in the Barth bodden (mean depth—1.8 m) are analysed for dry weight, organic matter (loss on ignition), grain size distribution, total phosphorus and iron which is soluble in hydrochloric acid. The distribution of mineral and mud sediments (organic matter>5%) follows the bottom topography: trays, closed basins and channels show the respective muddy concentrations; spits, ground waves and windexposed uplifts from depressions are mostly mineralic. The water depth has only a subordinate effect on distribution. After unquiet meteorological and hydrographic situations mainly the fine‐grained material is redistributed. As comparative investigations over four years show, due to this the distribution pattern is not changed fundamentally, so that the distribution of mainly mineralic, muddy and intermediate transition ranges can be mapped, unless this would be done according to surveys under extreme hydrographic and meteorological conditions. The individual parameters of the sediment quality show significant correlations between each ot

ISSN:0323-4320    

DOI:10.1002/aheh.19840120112

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe filter‐technical equipment of seven water works in a tropical region of India is described. The structure of the filter sand layer, the grain size distribution and the degree of uniformity are compared by means of tables. The uniformity coefficient of a good filter sand is smaller than 1.7. Besides physical properties, also the surface properties of the filter sand grains are of interest. Different analytical methods for determining the incrustation are described. The amount of the filter grain load also depends on age, i.e. on the service life of the filter sand. The efficiency of a filter plant is determined also by the regeneration process, i.e. by back‐wash. This includes the methods of scouring with water only and the back‐washing with wate

ISSN:0323-4320    

DOI:10.1002/aheh.19840120113

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

摘要:

AbstractThe wetland of 56 ha is situated at a height of 1565 m in the valley of the Jehlum river. Among macrophytes prevailTypha,Phragmites, ScirpusandSparganium, and they are investigated at eight stations in the annual cycle. The mineral composition of the aboveground and belowground biomass and of the sediment was determined. The mean total biomass shows considerable variations, but also a pronounced annual variation with the summer maximum of 1445 g/m2above‐ground and 1550 g/m2below‐ground. The mineral constituents show clearly decreasing concentrations during the season of vegetation as far as potassium, calcium, magnesium and nitrogen are concerned, the nutrient contents lying between 0.041 and 1.9% P or 0.57 and 1.65 % N. In a regression analysis the biomasses show significant multiple regressions to concentrations of chloride‐ions, nitrogen and partly TPP and oxygen in the water and sed

ISSN:0323-4320    

DOI:10.1002/aheh.19840120114

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120115

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120116

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120117

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120118

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY

ISSN:0323-4320    

DOI:10.1002/aheh.19840120101

出版商:WILEY‐VCH Verlag GmbH    

年代:1984

数据来源: WILEY