The effects of population growth on the groundwater quality of a sandy rural catchment
Authors:
- 2 September 2018
- journal article
- research article
- Published by Taylor & Francis in Transactions of the Royal Society of South Africa
- Vol. 73 (3) , 243-253
Abstract
Maputaland is a natural environment situated along the northeast coast of South Africa. Within this area a small section of about 8000 ha was studied with respect to the quality of water from incoming rainfall, the groundwater, the streams and lakes to the outflow through the small Mgobezeleni Estuary. The study area is a representative sample of the Maputaland Coastal Plain that runs from the Lake St Lucia World Heritage site to the Mozambican border. All the water in the area emanates from rainfall with no rivers flowing into the area. Projects initiated from the 1960s by the government in order to improve the welfare of the local population have resulted in a large influx of people, both residents and tourists. The population in the catchment is made up of a relatively small local population that has risen from almost zero in 1970 to about 15 000 in 2015. There is a large annual visiting population of up to 250 000 that is economically valuable to the small resident population. The result is that accommodation facilities have increased together with the necessary infrastructure of water supplies and sewage facilities. The groundwater quality indicates that the sewage facilities are impacting the nitrogen and phosphorus concentrations but that these levels are not present in the lakes into which the groundwater flows. The presence of large amounts of fringing macrophytes in one lake and a high density of cyanophyte microalgae (or cyanobacteria) in the other indicates that sewage pollution is the cause. However, the lakes appear to be removing much of the sewage pollution because the estuary water below the lakes has a high quality. These data suggest that similar pollution might adversely affect other areas of Maputaland, which have a growing tourist population attracted to the Maputaland game parks.Keywords
Funding Information
- Water Research Commission (K5/2259)
This publication has 15 references indexed in Scilit:
- Impact of septic tank systems on local groundwater quality and water supply in the Pearl River Delta, China: case studyHydrological Processes, 2007
- Recent advances in the understanding and management of eutrophicationLimnology and Oceanography, 2006
- The role of dust in supplying nitrogen and phosphorus to the Southeast MediterraneanLimnology and Oceanography, 2002
- Atmospheric input of nitrogen and phosphorus to the Southeast Mediterranean: Sources, fluxes, and possible impactLimnology and Oceanography, 1999
- Phosphorus in rainwater: Partitioning inputs and impact on the surface coastal oceanLimnology and Oceanography, 1999
- Macroalgal blooms in shallow estuaries: Controls and ecophysiological and ecosystem consequencesLimnology and Oceanography, 1997
- Biodiversity of the Maputaland Centre1996
- Atmospheric inputs of dissolved organic nitrogen to the oceansNature, 1995
- Nitrogen in the Burkea Savanna1982
- SURVEY OF MGOBEZELENI LAKE-SYSTEM IN ZULULAND, WITH A NOTE ON THE EFFECT OF A BRIDGE ON THE MANGROVE SWAMPTransactions of the Royal Society of South Africa, 1975