Spatial and seasonal variability in surface water chemistry in the okavango delta, botswana: A multivariate approach

Anson W. MacKaỳ, Thomas Davidson, Piotr Wolski, Richard Mazebedi, Wellington R.L. Masamba, Huntsman Mapila Philippa, Martin Todd

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The annual flood pulse in the Okavango Delta (Botswana), has a major influence on water chemistry and habitat. We explore spatial and temporal patterns in a suite of chemical variables, analysed from 98 sample points, across four regions, taken at different stages of the flood cycle. The major pattern in water chemistry is characterised by an increasing gradient in ionic concentration from deepwater sites in the Panhandle to more shallow, distal regions to the south. Concentrations of cations, anions, dissolved organic carbon, and SiO2 are significantly higher in the seasonally inundated floodplains than in permanently flooded regions. Several variables (including Na and total nitrogen) significantly increase from low flood to high flood, while others (including HCO3, SiO2, and Cl) increase in concentration, initially between low flood and flood expansion, before declining at maximum flood extent. Redundancy analysis (RDA) revealed that hydrological variables (water depth, flow velocity, flood frequency, and hydroperiod class) significantly explain 17% variation in surface water chemistry. Predictions of increasing flood volume in the near future may result in a decline in alkalinity and dilution of DOC. Our study provides an important baseline from which to monitor future change in the Delta.

Original languageEnglish
Pages (from-to)815-829
Number of pages15
JournalWetlands
Volume31
Issue number5
DOIs
Publication statusPublished - Oct 1 2011

Fingerprint

Surface waters
water chemistry
surface water
Water
hydroperiod
flood frequency
flow velocity
Alkalinity
alkalinity
Organic carbon
dissolved organic carbon
floodplain
anion
Flow velocity
water depth
Dilution
dilution
Anions
Redundancy
Cations

All Science Journal Classification (ASJC) codes

  • Environmental Chemistry
  • Ecology
  • Environmental Science(all)

Cite this

MacKaỳ, Anson W. ; Davidson, Thomas ; Wolski, Piotr ; Mazebedi, Richard ; Masamba, Wellington R.L. ; Philippa, Huntsman Mapila ; Todd, Martin. / Spatial and seasonal variability in surface water chemistry in the okavango delta, botswana : A multivariate approach. In: Wetlands. 2011 ; Vol. 31, No. 5. pp. 815-829.
@article{72d5f82255e2433b840177a5a89bc378,
title = "Spatial and seasonal variability in surface water chemistry in the okavango delta, botswana: A multivariate approach",
abstract = "The annual flood pulse in the Okavango Delta (Botswana), has a major influence on water chemistry and habitat. We explore spatial and temporal patterns in a suite of chemical variables, analysed from 98 sample points, across four regions, taken at different stages of the flood cycle. The major pattern in water chemistry is characterised by an increasing gradient in ionic concentration from deepwater sites in the Panhandle to more shallow, distal regions to the south. Concentrations of cations, anions, dissolved organic carbon, and SiO2 are significantly higher in the seasonally inundated floodplains than in permanently flooded regions. Several variables (including Na and total nitrogen) significantly increase from low flood to high flood, while others (including HCO3, SiO2, and Cl) increase in concentration, initially between low flood and flood expansion, before declining at maximum flood extent. Redundancy analysis (RDA) revealed that hydrological variables (water depth, flow velocity, flood frequency, and hydroperiod class) significantly explain 17{\%} variation in surface water chemistry. Predictions of increasing flood volume in the near future may result in a decline in alkalinity and dilution of DOC. Our study provides an important baseline from which to monitor future change in the Delta.",
author = "MacKaỳ, {Anson W.} and Thomas Davidson and Piotr Wolski and Richard Mazebedi and Masamba, {Wellington R.L.} and Philippa, {Huntsman Mapila} and Martin Todd",
year = "2011",
month = "10",
day = "1",
doi = "10.1007/s13157-011-0196-1",
language = "English",
volume = "31",
pages = "815--829",
journal = "Wetlands",
issn = "0277-5212",
publisher = "Springer Netherlands",
number = "5",

}

Spatial and seasonal variability in surface water chemistry in the okavango delta, botswana : A multivariate approach. / MacKaỳ, Anson W.; Davidson, Thomas; Wolski, Piotr; Mazebedi, Richard; Masamba, Wellington R.L.; Philippa, Huntsman Mapila; Todd, Martin.

In: Wetlands, Vol. 31, No. 5, 01.10.2011, p. 815-829.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Spatial and seasonal variability in surface water chemistry in the okavango delta, botswana

T2 - A multivariate approach

AU - MacKaỳ, Anson W.

AU - Davidson, Thomas

AU - Wolski, Piotr

AU - Mazebedi, Richard

AU - Masamba, Wellington R.L.

AU - Philippa, Huntsman Mapila

AU - Todd, Martin

PY - 2011/10/1

Y1 - 2011/10/1

N2 - The annual flood pulse in the Okavango Delta (Botswana), has a major influence on water chemistry and habitat. We explore spatial and temporal patterns in a suite of chemical variables, analysed from 98 sample points, across four regions, taken at different stages of the flood cycle. The major pattern in water chemistry is characterised by an increasing gradient in ionic concentration from deepwater sites in the Panhandle to more shallow, distal regions to the south. Concentrations of cations, anions, dissolved organic carbon, and SiO2 are significantly higher in the seasonally inundated floodplains than in permanently flooded regions. Several variables (including Na and total nitrogen) significantly increase from low flood to high flood, while others (including HCO3, SiO2, and Cl) increase in concentration, initially between low flood and flood expansion, before declining at maximum flood extent. Redundancy analysis (RDA) revealed that hydrological variables (water depth, flow velocity, flood frequency, and hydroperiod class) significantly explain 17% variation in surface water chemistry. Predictions of increasing flood volume in the near future may result in a decline in alkalinity and dilution of DOC. Our study provides an important baseline from which to monitor future change in the Delta.

AB - The annual flood pulse in the Okavango Delta (Botswana), has a major influence on water chemistry and habitat. We explore spatial and temporal patterns in a suite of chemical variables, analysed from 98 sample points, across four regions, taken at different stages of the flood cycle. The major pattern in water chemistry is characterised by an increasing gradient in ionic concentration from deepwater sites in the Panhandle to more shallow, distal regions to the south. Concentrations of cations, anions, dissolved organic carbon, and SiO2 are significantly higher in the seasonally inundated floodplains than in permanently flooded regions. Several variables (including Na and total nitrogen) significantly increase from low flood to high flood, while others (including HCO3, SiO2, and Cl) increase in concentration, initially between low flood and flood expansion, before declining at maximum flood extent. Redundancy analysis (RDA) revealed that hydrological variables (water depth, flow velocity, flood frequency, and hydroperiod class) significantly explain 17% variation in surface water chemistry. Predictions of increasing flood volume in the near future may result in a decline in alkalinity and dilution of DOC. Our study provides an important baseline from which to monitor future change in the Delta.

UR - http://www.scopus.com/inward/record.url?scp=84863717559&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84863717559&partnerID=8YFLogxK

U2 - 10.1007/s13157-011-0196-1

DO - 10.1007/s13157-011-0196-1

M3 - Article

AN - SCOPUS:84863717559

VL - 31

SP - 815

EP - 829

JO - Wetlands

JF - Wetlands

SN - 0277-5212

IS - 5

ER -