Nature’s Lung
The Olifants River in Kruger National Park has been described as
one of the most environmentally polluted rivers in Southern
Africa which is located next to the Palabora mine pit, the largest
copper mine in South Africa. Untreated water can be used for
many purposes including irrigation, recreation, consumption, and
domestic purposes, and The famous “Big Five” wildlife, especially
elephants, are often seen around the Olifants River. The pollution
problem has plagued the health of local residents and wildlife for
the past decade.
The pollution was caused by a long-term drought in South Africa
that caused groundwater to backflow, carrying harmful elements
from the mine into the river and sediment.At the same time, due
to the excessive weathering of the land caused by the drought,
the polluted sediment is easy to accumulate on the riverbed in the
flood season, which accelerates the shrinkage of the river in the
dry season and the reduction of the water retention capacity of the
river.
Sediment Safari
Olifants Rivers, Kruger National Park
The climate of the site is dry savanna type, with annual rainfall between 400 and 500 mm/a, potential evapotranspiration between 1,600 and 2,600 mm/a. In general, rainfall events occur in a short period of time through thunderstorms between October/November and March/April. Due to the erosion of sediment caused by the alternating climatic characteristics of long-term drought and flood periods, resulting in river shrinkage caused by river sediment stagnation.There is also serious concern about groundwater contamination caused by prolonged dry seasons. As groundwater contributes to basal flow to Rivers in the dry season, contamination of groundwater stores can have major longer-term impact on the water quality of both the Selati and Olifants Rivers, endangering wildlife health and even triggering the death of large numbers of fish and elephants.The purpose of this design is to form an ecological circulation system to maintain surface water retention.
The Existing Condition
Groundwater-Surface Water- Interactions
The analysis of the seasonal variations of groundwater and river water levels represents the conceptual model of the sand river aquifer system and the respective hydrological processes in dry season and flooding season. groundwater discharges into the river throughout most of the dry season. revealing the high permeability of the aquifer, groundwater levels are higher than the river level throughout the dry season. This means that harmful substances in groundwater are very easy to contaminate river water during dry periods. Water level rise during the flood season is extremely fast but temporary.Recharge occurs through quick infiltration from flood waters into very permeable sands, which are directly linked to the natural discharge of the sand river aquifer system to sustain the groundwater-surface water interaction after the rain season. However, after a long-term drought, the weathered sediment is easily washed away by the speed of the water flow, causing the flow and precipitation in the dry season, resulting in the depth of the river gradually becoming shallower in the next drought period,
Tutors
Sanne van den Breemer
Filip Geerts
Ilmar Hurkxkens