Effects of annual flooding on dissolved organic carbon dynamics within a pristine wetland, the Okavango Delta, Botswana

Mladenov, Natalie; McKnight, Diane M.; Wolski, Piotr; Ramberg, Lars

doi:10.1672/0277-5212(2005)025[0622:eoafod]2.0.co;2

Cited by 98 publications

(88 citation statements)

References 41 publications

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“…These previous studies, with the exception of those of Mackay et al (2011) andMladenov et al (2005), were either strictly localised or focused mainly along the Jao-Boro channel (Fig. 1).…”

Section: Figurementioning

confidence: 88%

“…Significantly higher DOC in the Xakanaxa floodplain surface waters than in the channel suggest that the Xakanaxa floodplain may be a source of plant-derived DOC from floodplain soils and plant litter (Cronberg et al, 1996a;Mladenov et al, 2005), which was remobilised with the arrival of the annual flood. This is consistent with the results of Mladenov et al, (2005) and Gondwe and Masamba (2014), who found greater DOC concentrations in floodplains of the seasonal swamps than in nearby channels. Despite the observed higher concentrations in the floodplain waters than channel waters, most solute concentrations were not significantly different along the three channel-floodplain gradients studied.…”

Section: Local Gradientsmentioning

confidence: 99%

“…During this study, floodplains were inundated and saturated with floodwaters, suggesting that the soils were likely reduced. This may consequently affect Fe and Mn concentrations in pore water; for example, under reducing conditions DOC has an important role in Fe dissolution and mobilisation (Mladenov et al, 2005). It should be emphasised that the lack of data on sediment or pore water physicochemical parameters, for example, pH and redox conditions, limited the determination of the most likely processes that affect pore water solute concentrations.…”

Section: System-scale Longitudinal Gradientmentioning

confidence: 99%

“…The processes dominating the cycling of solutes in surface-and soil waters of the Delta, before they eventually precipitate or are sequestered in highly saline groundwater beneath island centres, are not fully understood, however. While there have been studies on water chemistry in the Okavango Delta (Sawula and Martins, 1991;McCarthy and Ellery, 1995;Cronberg et al, 1996a;Cronberg et al, 1996b;Mladenov et al, 2005;Bauer et al, 2007;Mackay et al, 2011;Cawley et al, 2012), the scope was primarily focused on concentrations of solutes in surface water and groundwater;…”

Section: Introductionmentioning

confidence: 99%

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Variability in chemistry of surface and soil waters of an evapotranspiration-dominated flood-pulsed wetland: solute processing in the Okavango Delta, Botswana

Mosimane¹,

Struyf²,

Gondwe³

et al. 2017

WSA

Self Cite

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“…These previous studies, with the exception of those of Mackay et al (2011) andMladenov et al (2005), were either strictly localised or focused mainly along the Jao-Boro channel (Fig. 1).…”

Section: Figurementioning

confidence: 88%

Section: Local Gradientsmentioning

confidence: 99%

Section: System-scale Longitudinal Gradientmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Variability in chemistry of surface and soil waters of an evapotranspiration-dominated flood-pulsed wetland: solute processing in the Okavango Delta, Botswana

Mosimane¹,

Struyf²,

Gondwe³

et al. 2017

WSA

Self Cite

View full text Add to dashboard Cite

“…DOM is also important in trophic dynamics [5,6], which promote the growth of heterotrophic microorganisms [7,8]. Furthermore, the incorporation of nitrogen and phosphorus into the DOM pool can influence nutrient cycling in lakes and reservoirs [9][10][11][12]. DOM can negatively impact water treatment directly through taste, odour and colour issues and during chlorination through the production of disinfection by-products.…”

Section: Introductionmentioning

confidence: 99%

Tracking Inflows in Lake Wivenhoe during a Major Flood Using Optical Spectroscopy

Aryal

Grinham

Beecham

2014

Water

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Lake Wivenhoe is the largest water storage reservoir in South-East Queensland and is the primary drinking water supply storage for over 600,000 people. The dam is dual purpose and was also designed to minimize flooding downstream in the city of Brisbane. In early January, 2011, record inflows were experienced, and during this period, a large number of catchment pollutants entered the lake and rapidly changed the water quality, both spatially and vertically. Due to the dendritic nature of the storage, as well as multiple inflow points, it was likely that pollutant loads differed greatly depending on the water depth and location within the storage. The aim of this study was to better understand this variability in catchment loading, as well as water quality changes during the flood event. Water samples were collected at five locations during the flood period at three different depths (surface, mid-depth and bottom), and the samples were analysed using UV and fluorescence spectroscopy. Primary inflows were identified to persist into the mid-storage zone; however, a strong lateral inflow signature was identified from the mid-storage zone, which persisted to the dam wall outflow. These results illustrate the heterogeneity of inflows in water storages of this type, and this paper discusses the implication this has for the modelling and management of such events.

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Spatial variability of chromophoric dissolved organic matter in a large floodplain river: control factors and relations with phytoplankton during a low water period

2015

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Chromophoric dissolved organic matter (CDOM) affects ecological processes in freshwater environments. Few studies assessed its spatial variability and relations with phytoplankton in floodplain rivers. Therefore, these topics were examined in a hydrological connectivity gradient in the Middle Paraná system. Absorption coefficients at 250 and 365 nm were measured to estimate CDOM concentration and molecular weight (MW), to find their explanatory limnological variables (Redundancy Analysis, RDA), and to assess their contribution to the explanation of phytoplankton structure (Canonical Correspondence Analysis, CCA). Conductivity and turbidity explained CDOM significantly. Increased conductivity from the main channel to floodplain lakes was associated with increased CDOM concentration. The lake indirectly connected to the river showed the highest turbidity associated with high-MW-CDOM, while the isolated lake showed the highest conductivity associated with low-MW-CDOM. Phytoplankton structure was significantly explained by conductivity, turbidity, and high-MW-CDOM (CCA). Environments directly connected to the river (with the lowest conductivity) were associated with diatoms. Phytoflagellates were associated with turbidity and high-MW-CDOM in the lake indirectly connected to the river, whereas Cyanobacteria were associated with conductivity and low-MW-CDOM in the isolated lake. The combined effect of physical factors and CDOM explained the highest fraction of species variation (partial CCA). As a conclusion: (1) CDOM increases as hydrological connectivity with the river decreases; (2) lake sediment resuspension is linked to an increase of high-MW-CDOM; (3) lake isolation from the river corresponds to an increase in low-MW-CDOM; and (4) CDOM explains phytoplankton structure significantly and should be considered as an important variable in studies of microalgal assembly.

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Effects of annual flooding on dissolved organic carbon dynamics within a pristine wetland, the Okavango Delta, Botswana

Cited by 98 publications

References 41 publications

Variability in chemistry of surface and soil waters of an evapotranspiration-dominated flood-pulsed wetland: solute processing in the Okavango Delta, Botswana

Variability in chemistry of surface and soil waters of an evapotranspiration-dominated flood-pulsed wetland: solute processing in the Okavango Delta, Botswana

Tracking Inflows in Lake Wivenhoe during a Major Flood Using Optical Spectroscopy

Spatial variability of chromophoric dissolved organic matter in a large floodplain river: control factors and relations with phytoplankton during a low water period

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