scholarly journals Dry-season Water Quality in the San Gabriel River Watershed

Author(s):  
Drew Ackerman ◽  
Eric D. Stein ◽  
Kenneth Schiff
2016 ◽  
Vol 12 (3) ◽  
pp. 4383-4393
Author(s):  
Osabuohien Idehen

This study takes a look into groundwater quality at Ugbor Dumpsite area using water quality index (WQI), 2-Dimensional (2-D) geophysical resistivity tomography and vertical electric sounding (VES).The geophysical resistivity methods employed revealed the depth to aquifer, the geoelectric layers being made up of lateritic topsoil, clayed sand and sand. Along the trasverse line in the third geoelectric layer of lateral distance of 76 m to 100 m is a very low resistivity of 0.9 to 13 m from a depth range o f about 3 to 25 m beneath the surface- indicating contamination. Water samples were collected and analyzed at the same site during the raining season and during the dry season. The value of water quality index during the raining season was 115.92 and during the dry season was 147.43. Since values at both seasons were more than 100, it implies that the water is contaminated to some extent and therefore poor for drinking purpose. The Water Quality Index was established from important analyses of biological and physico-chemical parameters with significant health importance. These values computed for dumpsite area at Ugbor were mostly contributed by the seasonal variations in the concentrations of some parameters, such as, conductivity, total dissolved solids, hardness, alkalinity, chlorides, nitrates, calcium,  phosphates, zinc, which showed significant differences (P<0.01 and P<0.05) in seasonal variation.


2021 ◽  
Vol 638 (1) ◽  
pp. 012091
Author(s):  
Jiaxiang Zou ◽  
Shiyan Wang ◽  
Chang Liu ◽  
Zhen Han ◽  
Bei Zhu ◽  
...  

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.


2004 ◽  
Author(s):  
Pradeep Kumar Goel ◽  
Ramesh P. Rudra ◽  
Javeed Khan ◽  
Bahram Gharabaghi ◽  
Samaresh Das ◽  
...  

1998 ◽  
Vol 33 (4) ◽  
pp. 519-550 ◽  
Author(s):  
Paul A. Zandbergen ◽  
Ken J. Hall

Abstract The use of indices in ecosystem management is attractive because it allows for the representation of a complex set of information on ecosystem variables in a simple fashion. Recently the British Columbia Ministry of Environment, Lands and Parks developed the British Columbia Water Quality Index (BCWQI). As this index is currently being considered as the basis for other provincial indices and a national water quality index, the character of the BCWQI needs to be carefully considered. This study evaluates the performance of the BCWQI and assesses how useful and appropriate it is as a management tool at the watershed level. For this purpose the index is used to express the results of two sampling programs, one by the British Columbia Ministry of Environment, Lands and Parks, and the other by the Westwater Research Centre, of two relatively small watersheds in the Greater Vancouver area: the Brunette River watershed, heavily impacted by urbanization, and the Salmon River watershed on the urban-rural fringe. For both watersheds the intended use is the protection of aquatic life and only those water quality objectives are considered. The results indicate that the BCWQI is extremely sensitive to sampling design and highly dependent on the specific application of water quality objectives. A comparison is made with another type of index in widespread use in North America: the National Sanitation Foundation Water Quality Index (NSFWQI). This index appears promising for stream stewardship groups because of its simplicity and ease of use. For watershed managers, an alternative to the BCWQI is suggested, based on exceedance factors for individual objectives. This Simple Water Quality Index (SWQI) recognizes the importance of objectives that are specific to a particular water body, but overcomes some of the limitations of the BCWQI. A presentation format is suggested for objective exceedance factors, with a clear indication of exactly which objectives were included — without this, the final numerical index value is meaningless. This study suggests that the BCWQI in its current form has serious limitations for comparing water bodies and for establishing management priorities. If local watershed managers use the BCWQI in guiding efforts to protect aquatic resources, they should consider these limitations carefully.


2012 ◽  
Vol 8 (3) ◽  
pp. 845-858 ◽  
Author(s):  
Augusto Tomazzoni Lubenow ◽  
◽  
Paulo Costa de Oliveira Filho ◽  
Carlos Magno de Sousa Vidal ◽  
Grasiele Soares Cavallini ◽  
...  

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