摘要:

AbstractSamples were collected year‐round over a one‐year period at sites located downstream from a hypolimnetic‐release reservoir on the Blue River, Colorado, to examine macroinvertebrate responses along a complex environmental gradient induced by river regulation. Six sampling sites were established in riffles downstream of the dam using approximately a geometric progression starting at 0.25 km. Ordination techniques were used to elucidate macroinvertebrate distributional patterns along the complex environmental gradient. The detrended correspondence analysis (DCA) showed a sequential faunal gradient with the most rapid change occurring within the first 2.0 km below the impoundment. Detrended canonical correspondence analysis (DCCA) was used to relate faunal distributions to downstream changes in environmental variables. Downstream decreases in periphyton standing crop and minimum temperatures, and downstream increases in food resources and maximum temperatures, were identified as the major variables structuring faunal assemblages. The combined use of different gradient analysis techniques proved useful for identifying distinct macroinvertebrate distributional patterns and the environmental variables that may be responsible for these pat

ISSN:0886-9375    

DOI:10.1002/rrr.3450050502

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe exchange processes between the Rhine river and the alluvial aquifer were analysed in the upper part of the rift valley (upstream of Strasbourg). Hydraulic works, and the consequent suppression of flooding, along the Alsace Rhine floodplain greatly modified these processes. The transfer of persistent toxic micropollutants (organochlorine compounds, mercury), and non‐persistent pollutants (organophosphorous compounds: Sandoz spill) from the Rhine to the groundwater‐fed streams was exhibited by pollutant bioaccumulation in fish (particularly in the eel) and eutrophication of these streams near the canalized river.Comparison of the hydrological functioning of the two main river floodplains (the Rhine and its tributary, the Ill in the Alsace Rhine plain) shows two completely different exchange processes: in the case of the canalized Rhine, the groundwater is affected by direct transfer of pollutants through the channel bed. In the other case, that of the river Ill, where the floodplain is still widely flooded each year, the self‐purification of the floodwaters transferred to the groundwater is very effective: the soil‐root system of alluvial forest and meadow apparently having a high purification c

ISSN:0886-9375    

DOI:10.1002/rrr.3450050503

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractUntil recently, entitlements to water in Australia have been tied to a specific area of land. Several State water management agencies have now adopted more flexible arrangements for the transfer of water rights between users on regulated streams. The case for freer transfers is linked to the perceived need for greater efficiency in water use. Transferability also has potential in facilitating the movement of water between different sectors of the water industry and in achieving more rational and environmentally acceptable use of resources. Justification for breaking the nexus between water rights and land needs to be assessed against a number of physical, social, economic, and environmental issues some of which have only become apparent with accelerated resource development, and expansion and concentration of Australia's urban‐industrial base. These trends are reflected in competing claims on water resources to supply the increasing demand from city‐based populations; to maintain the viability of industrial systems; to sustain more intensive high technology forms of irrigation agriculture; and to satisfy the water needs of often remote mining and tourist developments. No longer can such claims easily be met by harnessing further water resources. Transfers of water rights, on a much larger scale, within and between water‐using regions and sectors, and across State borders, are likely to be an important element in Australia's water industry in coming de

ISSN:0886-9375    

DOI:10.1002/rrr.3450050504

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractOff‐river storages accept water from their adjacent stream, often when streamflow is high, and may return water to the stream when streamflow is low. In addition, off‐river storages usually have a water catchment of their own, independent of the main stream, which may contribute a significant proportion of inflow to the storage in total or on some occasions. Off‐river storages have many uses including water supply and flood mitigation, and can also be a significant resource in their own right.In the same manner that off‐river storages receive, hold, and subsequently discharge water flow, so contaminants contained in the water column may be received, held, and released. However, the timescale of contaminant retention and release may be quite different from that applying to water flows. Also physical, chemical and biological processes in the storage may alter the nature of the contaminants, such that released materials have different environmental implications from those input. This paper presents a discussion of the role of off‐river storages in contaminant movement and distribution in a river reach, and a framework for assessing the influence of these storages on the riverine environment. Case‐study data from the Fly River catchment in Papua New Guinea is then examined in thi

ISSN:0886-9375    

DOI:10.1002/rrr.3450050505

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe non‐persistent herbicides glyphosate and 2,4‐D amine were applied to riparian stands of R. japonica on the banks of the River Cynon, South Wales at doses of 2154 g and 2790 g active ingredient (a.i.) ha−1respectively. Glyphosate being tested with one or two applications per season, 2,4‐D amine with two only. Two weeks after spraying, the biomass and leaf area ratio of shoots in all treated plots was depressed but was significantly (P<0–01) lower in the 2,4‐D amine plots. Ten weeks after treatment shoots had begun to recover but the biomass was still<40 per cent of the control areas. Rapid (six weeks after treatment) recovery of Leaf Area Ratio was also observed. Second applications of glyphosate and 2,4‐D amine to the respective plots resulted in shoot death after four weeks. Management recommendations are made for the control of R. japonica on riverbanks based on the resu

ISSN:0886-9375    

DOI:10.1002/rrr.3450050506

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450050507

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450050508

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450050509

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450050510

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY

ISSN:0886-9375    

DOI:10.1002/rrr.3450050501

出版商:John Wiley&Sons, Ltd    

年代:1990

数据来源: WILEY