scholarly journals Suspended silt concentrations in the lower Olifants River (Mpumalanga) and the impact of silt releases from the Phalaborwa Barrage on water quality and fish survival

Koedoe ◽  
1995 ◽  
Vol 38 (2) ◽  
Author(s):  
Y. Buermann ◽  
H.H. Du Preez ◽  
G.J. Steyn ◽  
J.T. Harmse ◽  
A. Deacon
Keyword(s):  
Water Quality ◽  
National Park ◽  
Management Strategy ◽  
Kruger National Park ◽  
Physico Chemical ◽  
Concentration Changes ◽  
Olifants River ◽  
Fish Survival ◽  
The Impact ◽  
Chemical Water

Silt loads in the Olifants and Sabie river systems inside the Kruger National Park, were monitored by collecting water samples every consecutive week for a period of 20 months. The variation in silt concentration, changes in selected physico-chemical water quality variables and fish mortalities during flushing (i.e. release of silt, by sluicing) of the Phalaborwa Barrage, were also monitored. The Olifants River inside the Kruger National Park carried high silt loads in summer; in the dry season the suspensoid load was greatly reduced. A similar pattern was observed in the Sabie River, but the silt loads were generally lower. It was apparent that silt loads released from the Phalaborwa Barrage led to large variations in the natural silt loads of the Olifants River. These increased amounts of silt (25 000 mg/1 to >70 000 mg/1) caused drastic reductions in the dissolved oxygen concentration of the water, ranging from >6 mg/1 to 0 mg/1. Depending on the severity and duration of the flushing, fish succumb to such silt loads. These findings, as well as published information, indicate that the management strategy of flushing to improve storage capacity is ecological unacceptable. It is therefore suggested that the use of the Phalaborwa Barrage as a future reservoir should be critically re-evaluated.

scholarly journals The implementation of an aquatic toxicity index as a water quality monitoring tool in the Olifants River (Kruger National Park)

Koedoe ◽  
1999 ◽  
Vol 42 (1) ◽  
Author(s):  
V. Wepener ◽  
J.H.J. Van Vuren ◽  
H.H. Du Preez
Keyword(s):  
Water Quality ◽  
Water Quality Index ◽  
National Park ◽  
Quality Index ◽  
Aquatic Toxicity ◽  
Temporal Trends ◽  
Kruger National Park ◽  
Toxicity Index ◽  
Olifants River

Large sets of water quality data can leave water quality managers and decision-makers totally overwhelmed. In order to convey the interpretation of the data in a simplified and understandable manner, the water quality results from bi-monthly surveys undertaken at seven different sampling sites in the Letaba, Olifants, and Selati rivers over a two year period (February 1990 to April 1992) were reduced to index values, using a water quality index. The water quality index (Aquatic Toxicity Index or ATI) revealed spatial and temporal trends. The higher index values, recorded for the sampling sites towards the eastern part of the Kruger National Park (KNP), revealed that the water quality was better than the quality measured in the Olifants River on the western bound-ary. The lowest index values were calculated for the Selati River, with index values consistently below 50. Index values indicate that the water quality in the Selati River was unsuitable for supporting normal physiological processes in fish. The water quality of the Selati River had an immediate impact on the water quality of the Olifants River directly below the confluence. Lower index values recorded at sites further downstream was also attributed to the influence of the Selati River since there are no known point sources of contaminants within the boundaries of the KNP. The index scores also elucidated temporal trends with lower scores evident during winter months. This was due to reduced flow in the Olifants River and a greater contribution of contaminated water from the Selati River. Index values increased following the first seasonal rains due to a dilution effect. Very low index values were recorded at certain sites during flood periods due to increased turbidity, reduced oxygen, and increased metal concentrations.

scholarly journals Assessment of the Impact of Small Hydropower Plants on the Ecological Status Indicators of Water Bodies: A Case Study in Lithuania

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 433
Author(s):  
Laima Česonienė ◽  
Midona Dapkienė ◽  
Petras Punys
Keyword(s):  
Water Quality ◽  
Benthic Macroinvertebrates ◽  
Suspended Solids ◽  
Ecological Status ◽  
Fish Abundance ◽  
Water Bodies ◽  
Small Hydropower ◽  
Hydropower Plants ◽  
Physico Chemical ◽  
The Impact

Hydropower plants produce renewable and sustainable energy but affect the river’s physico-chemical characteristics and change the abundance and composition of the aquatic organisms. The impact of large HPPs on the ecological conditions of surface water bodies have been extensively studied, but less attention has been paid to environmental impact studies of small hydropower plants (SHPs). The impact of hydropeaking on both the river flow regime and ecosystems has been well-studied for peaking mode plants, mainly medium to large-sized ones. However, for small hydroelectric power plants, and especially for those in lowland rivers, the available information on water quality, benthic macroinvertebrates communities and fish abundance, and biomass is not sufficient. Ten small hydropower plants were selected, and the ecological status of water bodies was assessed in different parts of Lithuania. The studies were performed at the riverbed upstream from the SHPs, where the hydrological regime has not changed, and downstream from the SHPs. It was found that the small hydropower plants do not affect the physico-chemical values of the water quality indicators. This study demonstrated that the total number of benthic macroinvertebrates taxa (TS) is influenced by the concentration of nitrogen and suspended solids, the water flow, the river area, and the current speed; the number of EPT (Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies)) taxa is influenced by the concentration of nitrogen and suspended solids. The studied indicators do not have a significant impact on biomass. The SHPs affect the fish abundance and biomass. The Lithuanian fish index (LFI) is influenced by the average depth and area of the river. Some SHPs operating in lowland areas may yield somewhat significant hydrograph ramping but more detailed investigation is needed to support the significance of this impact on the biological indices.

scholarly journals The influence of the 1991/92 drought on the woody vegetation of the Kruger National Park

Koedoe ◽  
1995 ◽  
Vol 38 (2) ◽  
Author(s):  
A.J. Viljoen
Keyword(s):  
National Park ◽  
Woody Species ◽  
Aerial Photographs ◽  
Woody Vegetation ◽  
General Area ◽  
Variable Intensity ◽  
The North ◽  
Olifants River ◽  
Area North ◽  
The Impact

All observations and data related to the impact of the 1991/92 drought on the woody vegetation, excluding the riverine vegetation of major rivers, are summarised. This includes data from a visual estimate of damage from aerial photographs, surveys on selected sites, and general observations. Despite lower rainfall, the area north of the Olifants River (excluding the far-northern part) was less affected than the area south of it, suggesting that the woody vegetation in the north is more adapted to drought. A characteristic of the drought was the localised distribution pattern and variable intensity of damage to the same species in the same general area. Information on 31 species are presented briefly. Although a large number of woody species was to some extent damaged, when the woody vegetation is considered as a whole, the influence of the drought was not very severe.

Mitigating the Impact of Large Mammals on Wooden Electrical Distribution Poles in the Kruger National Park, South Africa

2018 ◽  
Vol 48 (2) ◽  
pp. 023006
Author(s):  
Samantha K. Page-Nicholson ◽  
Gareth Tate ◽  
Constant Hoogstad ◽  
Megan Murison ◽  
Megan Diamond ◽  
...  
Keyword(s):  
South Africa ◽  
National Park ◽  
Kruger National Park ◽  
Large Mammals ◽  
Electrical Distribution ◽  
The Impact

scholarly journals The impact of the provision of water for game on the woody vegetation around a dam in the Kruger National Park

Koedoe ◽  
1991 ◽  
Vol 34 (2) ◽  
Author(s):  
I. Thrash ◽  
P.J. Nel ◽  
G.K. Theron ◽  
J. Du P. Bothma
Keyword(s):  
Relative Density ◽  
Woody Plants ◽  
National Park ◽  
Dominant Species ◽  
Canopy Cover ◽  
Kruger National Park ◽  
Woody Vegetation ◽  
Colophospermum Mopane ◽  
The Impact ◽  
Combretum Apiculatum

Quantitative inventory surveys were done on the woody vegetation in permanently marked plots at distance intervals from the Wik-en-Weeg Dam, Kruger National Park, in 1973. The surveys were repeated in 1990 so that changes in the community composition, the density and the canopy cover and the survival of the woody vegetation could be determined in relation to distance from the dam. Relationships with distance from the dam were shown for the relative density ofCombretumapiculatum in all height classes, the relative canopy cover of the second height class of woody plants, the relative canopy cover of C. apiculatum plants, the survival of all height classes of woody plants and the survival of C. apiculatum and Colophospermum mopane plants. It was concluded that the provision of water for game at the Wik-en-Weeg Dam had an impact on the woody vegetation in the vicinity. The relationships of parameters of the two dominant species, Combretum apiculatum and Colophospermum mopane, with distance from the dam were compared. Combretum apiculatum parameters were more sensitive to impact associated with the dam than those of Colophospermum mopane.

scholarly journals Assessment of Anthropogenic Impact of Surface Water Quality, South Africa

2018 ◽  
Vol 6 (2) ◽  
pp. 12
Author(s):  
Dipitseng Manamela ◽  
Omotayo Awofolu
Keyword(s):  
South Africa ◽  
Water Quality ◽  
Surface Water ◽  
Anthropogenic Activities ◽  
Treatment Plant ◽  
Surface Water Quality ◽  
Total Coliform ◽  
Mean Values ◽  
Physico Chemical ◽  
The Impact

This article investigates the impact of anthropogenic activities on an important surface water from physico-chemical, chemical and microbial perspectives. The surface water, referred to as Blesbokspruit is in the West Rand District of South Africa. Potential impactors include wastewater treatment plant, mines, farmlands and informal settlements. Water samples were collected from nine purposively selected sampling points and analysed in 2014. The mean values of analysed variables across sampling sites and periods ranged from pH: 7.4-8.4; EC: 93.0 - 146.6 mS/m; TSS: 11.3 – 39.0 mg/L; TDS: 590.3 - 1020.3 mg/L; COD: 15.6- 34.8 mg/L. Those for anions varied from NO3-: 0.2- 2.1 (mg/L) N; PO43- : 0.4-0.9 mg/L and SO42-: 118.6 - 379.5 mg/L. The metallic variables ranged from As: 0.01-0.06 mg/L; Cd: 0.02-0.06 mg/L; Fe: 0.04-0.73 mg/L; Cu: 0.02 – 0.05 mg/L and Zn: 0.05 – 0.15 mg/L. The Faecal coliform varied from 15.9-16878.5 cfu/100 ml; Total coliform: 92.9-430294 cfu/100 ml and HPC from 4322.5-39776 cfu/1ml. Detection of toxic metals and pathogenic organisms above target safety limits indicate unsuitability of the water for domestic use with impact on the health of aquatic ecosystem. The study generally revealed the impact of anthropogenic activities on the surface water quality.

scholarly journals The contemporary geomorphology of the Letaba River in the Kruger National Park

Koedoe ◽  
2001 ◽  
Vol 44 (1) ◽  
Author(s):  
B.P. Moon ◽  
G.L. Heritage
Keyword(s):  
South Africa ◽  
Flow Regime ◽  
Field Observation ◽  
National Park ◽  
Kruger National Park ◽  
The Other ◽  
Northern Province ◽  
Sediment Delivery ◽  
North East ◽  
Olifants River

The Letaba River drains part of Northern Province in north-east South Africa. Its catchment has been modified significantly by human activity which has affected the flow regime; it experiences only ephemeral flows through the Kruger National Park to its confluence with the Olifants River. Although the Letaba is similar to the other rivers in the Kruger National Park in that it displays some bedrock influenced channel features, increased sediment delivery from the degraded catchment upstream has resulted in extensive alluviation within the channel. Sections of channel flowing over bedrock with no sediment covering are rare, and the river comprises a series of channel types: mixed anastomosing, alluvial braided, mixed pool-rapid and alluvial single thread. Each is characterised by a different combination of morphological units which relate to the degree of alluviation in the channel. These channel types are described in detail and inferences are made concerning their formation and maintenance from field observation and measurement.

scholarly journals Assessment of The Impacts of Trout Farming on Water Quality Using Macro Invertebrates as Bio- Indicators

2018 ◽  
Vol 22 (2) ◽  
pp. 175-182
Author(s):  
Anuradha Rai ◽  
Archana Niraula ◽  
Payaswini Ghimire ◽  
Aastha Pandey ◽  
Anu Gurung ◽  
...  
Keyword(s):  
Water Quality ◽  
Similarity Index ◽  
Small Scale ◽  
Multiple Site ◽  
Reference Sites ◽  
Chemical Parameters ◽  
Physico Chemical ◽  
Invertebrate Assemblages ◽  
Trout Farms ◽  
The Impact

The study was conducted to assess the impacts of trout farming on water quality using macro invertebrates as bio-indicators. Two trout farms were selected for the study, viz., Gandaki Trout Farm (GTF) in Kaski district and Fall & Trout Fish Farm (FTF) in Nuwakot district. Reference and impacted sites were selected in each trout farms from where macro invertebrates were collected and physico-chemical parameters were measured. Sorensen’s Index and Multiple Site Similarity Index were calculated to compare the macro-invertebrate assemblages between the impact and the reference sites. Water quality classes were also calculated using macro invertebrate-based tool, NEPBIOS/ASPT scores. Altogether 24 families of macro invertebrates were observed at GTF and 12 families at FTF. The Sorensen’s Similarity Index was greater than 0.5 between reference and impacted sites at GTF; whereas it was only 0.28 at FTF indicating comparatively low level of similarity. In addition, Multiple Site Similarity Index (0.64) at GTF also indicated high similarity between the macro invertebrate assemblages. Reference sites showed higher scores with higher diversity of macro invertebrates. Both farms had suitable water quality for trout (dissolved oxygen and temperature) and most of the physico-chemical parameters did not show significant differences except pH and turbidity at GTF probably due to small scale operation and production. Journal of Institute of Science and TechnologyVolume 22, Issue 2, January 2018, Page: 175-182

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