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1.
Hydrobiological studies on the Tugela river system 总被引:6,自引:6,他引:0
Summary A chemical and biological survey of the Tugela river, Natal is described. Some relationships between physical and chemical conditions in the river and the geology and climate of the basin are indicated. The flora and fauna of the main river is described, and the zonation of species in the river, and seasonal variations in the communities at various stations in the zones are delineated.Some relationships between the physical and chemical conditions in the basin, and the distribution and seasonal variations of the biological communities are indicated. Comparisons are made with other rivers. It is concluded that the Tugela river as a type in Southern Africa, falls intermediate between temperate and sub-tropical conditions. 相似文献
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We have developed a personal-computer-based water quality analysis system for river basins. The system estimates potential N outflow by model and calculates actual N outflow from monitoring data. For the former it uses the potential load factor method to estimate annual nitrogen load from various sources and runoff potential from each area of land in a basin. For the latter it analyzes water quality monitoring data in relation to meteorological data. We used the system to analyze N outflow in basins around Lake Kasumigaura and the Yahagi River in central Honshu, Japan. The land around Lake Kasumigaura is rather flat, and about 25% is periodically flooded for rice and lotus cultivation. The land around the Yahagi River is mountainous, and much less land is flooded. In the Yahagi River basin the actual N outflow agreed closely with the potential. However, the actual N outflow in the basin around Lake Kasumigaura was much less than the potential, suggesting that a large part of the N load is denitrified in 相似文献
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We have developed a personal-computer-based water quality analysis system for river basins. The system estimates potential N outflow by model and calculates actual N outflow from monitoring data. For the former it uses the potential load factor method to estimate annual nitrogen load from various sources and runoff potential from each area of land in a basin. For the latter it analyzes water quality monitoring data in relation to meteorological data. We used the system to analyze N outflow in basins around Lake Kasumigaura and the Yahagi River in central Honshu, Japan. The land around Lake Kasumigaura is rather flat, and about 25% is periodically flooded for rice and lotus cultivation. The land around the Yahagi River is mountainous, and much less land is flooded. In the Yahagi River basin the actual N outflow agreed closely with the potential. However, the actual N outflow in the basin around Lake Kasumigaura was much less than the potential, suggesting that a large part of the N load is denitrified in flooded soils. This further indicates that a sequence of different land uses including flooded rice fields is an important factor determining N outflow in basins in Japan. On the basis of the above analyses, we incorporated a denitrification model into the system that enables us to estimate N balance in a designated basin;this system may be helpful in the formulation of scenarios of land use andsoil management for improving water quality. 相似文献
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We have developed a personal-computer-based water quality analysis system for river basins. The system estimates potential N outflow by model and calculates actual N outflow from monitoring data. For the former it uses the potential load factor method to estimate annual nitrogen load from various sources and runoff potential from each area of land in a basin. For the latter it analyzes water quality monitoring data in relation to meteorological data. We used the system to analyze N outflow in basins around Lake Kasumigaura and the Yahagi River in central Honshu, Japan. The land around Lake Kasumigaura is rather flat, and about 25% is periodically flooded for rice and lotus cultivation. The land around the Yahagi River is mountainous, and much less land is flooded. In the Yahagi River basin the actual N outflow agreed closely with the potential. However, the actual N outflow in the basin around Lake Kasumigaura was much less than the potential, suggesting that a large part of the N load is denitrified in flooded soils. This further indicates that a sequence of different land uses including flooded rice fields is an important factor determining N outflow in basins in Japan. On the basis of the above analyses, we incorporated a denitrification model into the system that enables us to estimate N balance in a designated basin; this system may be helpful in the formulation of scenarios of land use and soil management for improving water quality. 相似文献
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Hydrobiological studies on the Tugela River system 总被引:4,自引:4,他引:0
W. D. Oliff 《Hydrobiologia》1963,21(3-4):355-379
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W. D. Oliff 《Hydrobiologia》1960,16(2):137-196
Summary A survey of pollution in the Bushmans river, and a tributary, the Little Bushmans river in the vicinity of Estcourt, Natal, is described. The pollution arose mainly from wastes discharged from a boardmill, a milk-processing factory, and a sewage-disposal, irrigation farm. The effects of these effluents on the chemistry of the river waters, and on the biological communities in them is described.The communities at polluted stations have been classified in relation to the degree of pollution, and the equivalence of the classification with the systems described by other workers has been indicated. Differences observed between communities in normal and polluted stretches of the rivers are suggested as indices of pollution. 相似文献
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Hydrobiological consequences of the addition of phosphate precipitants to inlet water of lakes 总被引:1,自引:0,他引:1
B. A. Bannink J. H. M. Van Der Meulen J. C. H. Peeters J. C. Van Der Vlugt 《Aquatic Ecology》1980,14(1-2):73-89
Summary In three model reservoirs (LUND, 1975) a method reducing bluegreen algal blooms in lakes was studied. Iron or aluminium were added to inlet waters for chemically binding the inflowing phosphorus.The research program, started in 1975, includes intensive monitoring of many chemical and hydrobiological variables, the determination of water and mass balances and since 1977 measurements or primary production rates with14C. In this paper only the results found in 1977 are discussed. An attempt is made to describe quantitatively how growth rates and changes in biomass are interconnected and how phosphorus precipitation changes these variables.In all reservoirs a large discrepancy was observed between the actual rate of increase in the algal population and the relative production rate. The latter appeared to be higher by one order of magnitude. The relative death rate due to grazing can account for the large difference between these growth rates only when selective grazing of zooplankton on phytoplankton is assumed.It can be concluded that treatment of inlet water with AVR, an aluminium salt, is unsuccessful in reducing algal development. Treatment with ironsulphate may be successful, but a reduction of the relative growth rates was not observed. The effects of grazing of zooplankton andDreissena polymorpha need further investigation. 相似文献
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Comparative performance of benthic diatom indices used to assess river water quality 总被引:1,自引:2,他引:1
Grazer-periphyton interactions were investigated in 11 laboratory streams holding a range of densities of three herbivore taxa during a 32-d experiment. Effects of grazers on algae were strongest with Dicosmoecus gilvipes caddisflies, intermediate with Juga silicula snails, and weakest with Baetis spp. mayflies. Algal standing crop, export, and gross primary production declined logarithmically with increasing grazer density. Algal turnover rate, however, increased with grazer abundance. At high densities of all grazers, responses in most algal parameters converged, suggesting that high grazing pressure, regardless of taxon, will similarly affect periphyton. Growth of both Dicosmoecus caddisflies and Juga snails was density-dependent, with the highest growth rates occurring at the lowest densities. Caddisflies displayed high growth rates but low efficiency in resource use. Snails had lower growth rates but were more efficient in resource use. The coexistence of Dicosmoecus and Juga, or other competing herbivores, in natural streams may be related to these fundamental differences in life history strategies.Department of Fisheries and Wildlife 相似文献
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Various diatom indices are routinely used in European countries to monitor water quality in waterways. In order to assess their sensitivities and their integration interval after a sudden and lasting environmental change, epilithic diatom biofilms were transferred from several polluted rivers to an unpolluted stream. To monitor the changes of the index values, the biofilms were sampled in a first experiment 20 and 40 days after transfer, and in a second experiment 30 and 60 days after transfer. Sensitivities of the indices to the water quality improvement were assessed calculating the differences between the index values of the reference and the transferred assemblages. Some indices have intermediate sensitivities (BDI, GDI, ILM, SLA), others higher sensitivities (CEE, EPI, ROT, SPI, TDI). The integration interval of these indices was 40–60 days. Some differences were observed between the indices, but their results were homogeneous when compared to those obtained with other metrics such as Bray-Curtis or Chord distances, used to assess the difference between the transferred and the reference diatom assemblages. These other metrics showed that even after 60 days, the transferred assemblages still differed from the reference. This underlines that metrics do not have the same integration intervals and do not assess the same stresses; the choice of the metric used to assess water quality is of prime importance. 相似文献
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Use of benthic diatom communities to evaluate water quality in rivers of southern Poland 总被引:12,自引:0,他引:12
Janina Kwandrans Pertti Eloranta Barbara Kawecka Krzysztof Wojtan 《Journal of applied phycology》1998,10(2):193-201
Biological and chemical data were processed to estimate trophic stage and degree of pollution in several streams and rivers
in southern Poland. The majority were eutrophic and some of them heavily polluted; only a few were oligo-mesotrophic. The
differences in the water quality of the rivers were reflected by different types of diatom community and also by the values
for some diatom indices, which were calculated using the latest version of the 'Omnidia' database software. Except for the
Sládeček's index, all diatom indices correlated significantly with organic load (COD), oxygen concentration, conductivity
and most of the measured ions. Some indices showed a significant negative correlation with trophic level (expressed by NH4-N and PO4-P). In general, IPS (Specific Pollution Sensitivity Index) and GDI (Generic Diatom Index) indices gave the best results.
Among the investigated diatom communities, only a few taxa indicated oligo-mesotrophy and oligo-β-mesosaprobity. Most of the
sites were characterised by a greater relative contribution of eutraphent and tolerant ones as well as α-mesosaprobic and
polysaprobic diatoms. This study suggests that the structure of benthic diatom communities and diatom indices, especially
GDI, can be applied for monitoring rivers in Poland.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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连续可调式沉水植物网床对河道水质的修复 总被引:1,自引:0,他引:1
在太湖贡湖水源保护区陆域的一条长约200 m的污染河道内构建了一系列连续可调式沉水植物网床,形成了以菊花草、苦草、伊乐藻、轮叶黑藻和菹草等沉水植物构成的水生植物群落;跟踪监测了总氮(TN)、铵态氮(NH4 +-N)、亚硝态氮(NO2--N)、硝态氮(NO3--N)、总磷(TP)和磷酸盐(PO43--P)等水质指标,分析沉水植物网床引导沉水植被恢复对污染河道的水质修复效果.结果表明:沉水植被网床构建后,水体透明度显著升高,由修复前的0.5m提高到1.7 ~1.8 m;在沉水植被网床构建后的第5天和第20天,TN和TP的削减率分别为35.6%、66.3%和29.4%、63.2%;5个月后,修复河道水体内NH4+-N、NO2--N、NO3--N、TN、PO43--p和TP的浓度比对照组显著降低,削减率分别达到92.4%、76.8%、72.7%、73.9%、90.5%和92.0%.由连续可调式沉水植被网床引导恢复的水生植物群落可用于河道,特别是陆域浅水污染水体的生态修复. 相似文献
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Abraham Suriadikusumah Oviyanti Mulyani Rija Sudirja Emma Trinurani Sofyan Muhammad Hilda Rizki Maulana Asep Mulyono 《农业工程》2021,41(3):177-182
River pollution is still a problem in most countries, especially in developing countries, such as Indonesia. Several methods have been used to reduce the level of pollution across these water sources. In West Java Indonesia, Cipeusing is one of the highest polluted rivers that need analysis of pollution index to produce a value for indicating the relative pollution levels of the water quality standard.The study was conducted between 2016 and 2017 at the Cipeusing River, to assess it's pollution levels using the Pollution Index (PI) method. The results showed that the water pollution changed from 2016 to 2017. In terms of physical, chemical and microbiological analysis using the PI method in 2016, Cipeusing River gave a value of 5.05–7.07 (moderately polluted), and in 2017, this value was 15.65–17.65 (severelly polluted). The highest pollution index was at the downstream area of the river. Thus, efforts are needed in order to control the water pollution levels at the Cipeusing River. 相似文献
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A. Dulma 《International Review of Hydrobiology》1979,64(6):709-736
The waters of Mongolia can be classified according to their catchment areas into three hydro-geographic regions: basin of the Arctic Ocean, basin of the Pacific Ocean, Central Asian basin without outlet. After a short historical survey of the exploration of the lakes of the Mongolian People's Republic, the formation and the classification of the lake system is briefly dealt with. Recent hydrobiological findings are presented in addition to hydrological data. As far as possible, statements are made on the size and the depth of the waters, the growth of macrophytes and the trophic level of the lakes. A distinction is made between ultraoligotrophic, oligotrophic, mesotrophic, eutrophic and dystrophic waters. They are characterized by data on the biomass of the plankton and the ichthyofauna. In the zooplankton of the Central Asian basin, 17 copepod, 29 cladoceran and 58 rotatorian species, and in the waters belonging to the drainage basin of the Pacific Ocean 16 copepod, 40 cladoceran and 37 rotatorian species have already been identified. The results represent the basis for an intensification of fishery in the Mongolian People's Republic. 相似文献
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Contribution of space remote sensing to river studies 总被引:1,自引:0,他引:1
- 1 A review is presented of types of satellite remote-sensing data currently available, and their recent uses in studies of river systems.
- 2 Broad-scale assessments of relative water quality may be carried out, although precise indication of water quality requires samples to be taken in situ.
- 3 In the event of flooding, the extent of inundation may be determined and damage assessed quickly. Some radar data allow measurements of flood water even when obscured by vegetation.
- 4 Riparian vegetation may be mapped over large areas, although the recognition of specific tree species remains difficult.
- 5 One of the most basic and widely used applications of remote-sensing data for rivers is that of mapping, both as a single event and over time to follow changes, e.g. channels in a delta. Entire catchments may be mapped, although the efficiency of detection of low-order streams is dependent upon the characteristics of the system used.
- 6 Remote-sensing data has been widely used in all of the above types of study, but is rarely employed on a long-term basis. Several factors can explain this situation, including, for example, the absence of reliable absolute relationships between spectral data and ecological parameters.
- 7 A clear definition of observational needs (e.g. spectral bands, ground resolution, acquisition frequency) of stream ecologists, together with the identification of ecological parameters that may be collected relatively easily from space, will improve remote sensing as an ecological tool in many restoration and management situations.
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River quality analysis using fuzzy water quality index: Ribeira do Iguape river watershed, Brazil 总被引:4,自引:0,他引:4
Andr Lermontov Lídia Yokoyama Mihail Lermontov Maria Augusta Soares Machado 《Ecological Indicators》2009,9(6):1188-1197
Intrinsic uncertainties and subjectivities of environmental problems have been increasingly dealt by using computation methods based on artificial intelligence. In order to evaluate this tool's applicability, this study proposed the creation of a new water quality index based on fuzzy logic, the fuzzy water quality index (FWQI). The performance of the index proposed in the present work is assessed through a comparison with several water quality indices (WQIs) suggested in the literature, using data from hydrographic surveys of the Ribeira de Iguape River, in the southwestern part do São Paulo State, Brazil, from 2004 to 2006. The index was reasonably close to the other indices and showed a good correlation with the WQI traditionally calculated in Brazil. This new index may also be used as an alternative tool for decision-making in environmental management. 相似文献