CROOKS CORNER EarthCache
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EarthCach Description: Crook's Corner
This EarthCache is found in the Pafuri Area in the far northern part of Kruger National Park.
This has been a favorite visiting spot since I was a small boy and I enjoy coming back here often to see the changes in the vegetation and the river after the rain season but also after all the flooding this area has suffered in recent years.
Crooks Corner / Limpopo River Basin / Makuleke Wetland
The region where Crook’s Corner was established is considered one of Kruger's biodiversity hot-spots, with some of the largest herds of elephant and buffalo, leopard and lion and incredibly prolific bird life.
In May 2007 the biological significance of the area was recognized in its declaration as a Ramsar site - a wetland of international importance.
Many people visiting the modern Limpopo expecting the “great grey-green greasy Limpopo” of Kipling fame and yet seeing a great sand filled body instead. This is, however, a recent phenomenon, probably due to a great extent to the over utilization by agriculture of the water resources of the river. As recently as 1950, a Zambezi shark was caught at the confluence of the Luvuvhu and Limpopo rivers.
About the Ramsar Convention:
The Convention on Wetlands (Ramsar, Iran, 1971) -- called the "Ramsar Convention" -- is an intergovernmental treaty that embodies the commitments of its member countries to maintain the ecological character of their Wetlands of International Importance and to plan for the "wise use", or sustainable use, of all of the wetlands in their territories.
The Convention on Wetlands came into force for South Africa on 21 December 1975. South Africa presently has 21 sites designated as Wetlands of International Importance, with a surface area of 554,136 hectares Makuleke Wetlands. 22/05/07; Limpopo; 7,757 hectares; 22°23'S 031°11'E.
National Park. An excellent example of a floodplain vlei type, most of which lies within the Kruger National Park, bordered by Zimbabwe and Mozambique to the north and east. Prominent features include riverine forests, riparian floodplain forests, floodplain grasslands, river channels and flood pans. Flood pans are depressions in the floodplains which are intermittently filled from floods and rains - they are of great importance in this ecosystem as they hold water right into the dry season, thus acting as a refuge point for wildlife and waterbirds during both winter and summer months, and there are 31 of them found on these floodplains, where herds of Hippopotamus (Hippopotamus amphibious) are found. The floodplains attenuate floods, resulting in reduced flood damage in downstream areas of Mozambique, are important for groundwater recharge, and maintain riparian and floodplain vegetation. In the Makuleke Region of the National Park there is an attempt to harmonize biodiversity protection with the interests of rural dwellers through cooperation between the Community Property Association of Makuleke community, South African National Parks Board, and many government departments. The proclamation of the Great Limpopo Transfrontier Park (GLTP) in 2002 through an international treaty between South Africa, Mozambique, and Zimbabwe aims at jointly managing the bordering National Parks and conservation areas, and the Ramsar site will benefit from that protection status. Ramsar site no. 1687. Most recent RIS information: 2007.
Geography of the Limpopo River Basin:
At 408 250 km², the Limpopo River basin is one of the largest drainage areas in the SADC region, covering large portions of Botswana, Mozambique, South Africa and Zimbabwe (LBPTC 2010).
The Limpopo River flows north from the confluence of the Marico and Crocodile Rivers, where it creates the border between South Africa and Botswana, then the border between South Africa and Zimbabwe, before crossing into Mozambique, where it runs across a broad floodplain and into the Indian Ocean.
Source: LBPTC 2010
The Limpopo River basin consists of 24 individual tributaries - 13 on the north bank and 11 on the south bank. However, for management purposes, the Limpopo River Basin has been divided into 27 sub-basins (LBPTC 2010). This topic is described in more detail in the Hydrology section below.
As the river basin intersects four countries, traversing various geographical regions and biomes, and supporting a wide array of water demands, there is a great need for Integrated Water Resources Management.
Hydrology of the Limpopo River Basin
The Limpopo River basin is located in a region classified as arid to semi-arid, where water resources are under huge pressure from the environment alone, even before human development demands are factored in (CGIAR 2003). Therefore, water is seen as a limiting factor in development in the region (CGIAR 2003).
The hydrology of the Limpopo River basin is classified in the following principles:
• Surface water;
• Groundwater;
• Surface water/groundwater interactions; and
• Water balance.
Surface water:
Surface water is water on the surface of the planet such as in a stream, river, lake, wetland, or ocean
The Limpopo River begins at the confluence of the Marico and Crocodile Rivers in the Limpopo Province of South Africa, it flows north to form the border with Botswana where it arcs east, and is joined by the Shashe River to form the border with Zimbabwe. From here it flows down the Great Escarpment and east into Mozambique at Pafuri, across the coastal plateau to the Indian Ocean at Xai Xai.
The Olifants River originates near Witbank, to the east of Johannesburg, running east, across the southern portion of the basin, to join the Limpopo River in Mozambique just after Massingir Dam.
The River basin has 24 distinct, main tributaries, which are listed in the table below; however, the Joint Limpopo River Basin Study Scoping Phase report proposes a further subdivision to create 27 more equally sized and geographically homogenous sub-basins.
The contributions to the overall flow of the Limpopo River are somewhat determined by rainfall.
Groundwater:
Groundwater is the water located beneath the earth's surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table. Groundwater is recharged from, and eventually flows to, the surface naturally; natural discharge often occurs at springs and seeps, and can form oases or wetlands. Groundwater is also often withdrawn for agricultural, municipal and industrial use by constructing and operating extraction wells. The study of the distribution and movement of groundwater is hydrogeology, also called groundwater hydrology.
Groundwater is used extensively throughout the southern African region, including the Limpopo River basin, supplying a large percentage of water for irrigation and rural water supply schemes (FAO 2004). This is especially true in rural areas, located away from surface water resources. Groundwater is also used extensively by the mining industry in the basin (CGIAR 2003).
Surface water / Groundwater interaction:
Groundwater levels in the region are traditionally relatively shallow, particularly in the riparian zone and in the dry river beds during periods of low-flow.
The building of dams in the Limpopo River basin has lead to increased interaction between groundwater and surface water. This is because for long periods of the year the lower and middle reaches of the Limpopo River are dry (LBPTC 2010), with the water flowing instead in the alluvial aquifer of the river bed.
Many of the rivers in the north of the basin are non-perennial, flowing at the surface only during and following heavy, episodic rainfall events, characteristic of the wet season in the region.
There is further evidence of observed river run-off reducing at Chokwé, with flows decreasing year after year since the installation of the flow gauging station (LBPTC 2010).
The lack of consistent, basin-wide information about groundwater/surface water interactions is one area of concern raised in the LBPTC Scoping Study (2010). This concern was raised because not only does abstraction of groundwater from an alluvial aquifer, or an aquifer located close to a river channel, have an influence on local water availability, it also has an impact on downstream water users (human and environmental; LBPTC 2010).
Water balance:
Water balance is a concept used to understand the availability and the overall 'state' of water resources in a hydrological system. A hydrological system is usually a standard surface water unit such as a quaternary catchment or, in the case of the Limpopo River, a River basin. This concept is also sometimes referred to as a Water Budget.
This holistic approach takes into account all of the water inputs into the system and the extractions take out of the system or out of circulation.
Inputs include:
• Precipitation - rain or snow
• Groundwater influx from an adjacent aquifer or a trans-boundary (trans-river basin) aquifer
• Snow melt
• Inter-basin transfer - water transferred into the basin from an adjacent river basin
Extractions include:
• Evaporation
• Evapo-transpiration
• Extraction for consumptive use from streams and rivers - water for industrial or domestic use and irrigation
• Extraction for consumptive use from groundwater aquifers
• Inter-basin transfer - water transferred out of the basin to adjacent river basin
A simple approach to a water balance equation could be considered as:
P + R + B - F - E -T = ΔS
Wanielista et al. 1997
Where:
P = Precipitation
R = Runoff or excess rainfall
B = Subsurface flow
F = Infiltration
E = Evapotranspiration
T = Transpiration
S = Change in storage in the saturated zone - soil or groundwater
A short history of Crooks Corner – how it all started:
Called “The Haven of Scoundrels” - In the early 1900's this area was known as Crooks Corner, a no-man’s land, on the boundary of where three countries come together.
This triangular border of 3 countries, situated between the Luvuvhu and Limpopo rivers, is the most north-easterly corner of the old Transvaal (now Limpopo province). Since 1913, the Luvuvhu River acted as the northernmost boundary of the Kruger National Park, up to where it joined the might Limpopo River.
The Limpopo River has always been the border between South Africa and Zimbabwe (formerly Southern Rhodesia). At the spot where the two rivers meet, their confluence also formed a natural corner between these two countries and Portuguese east Africa (now called Mozambique).
This extremely remote area where one of few areas of South Africa, only accessible via long, arduous wagon roads through thick bush and in very hot conditions.
In the 1900s this area was a safe-haven for gun runners, poachers, fugitives and anyone else dodging the law. It was an easy hop across the river whenever police from one particular country approached.
There is a large plaque here commemorating the legendary ivory hunter Cecil Barnard (Bvekenya), who hid on an island in the middle of the Limpopo to avoid being tracked down by pursuing rangers and police in the 1920s. Ironically, Barnard later became a ranger himself. A police station was later built here.
At the corner where the rivers meet, there is a wonderfully useful beacon. To the east lay the Old Portuguese territory, to the north was Southern Rhodesia, to the west laid the union of South Africa and to the south was this huge tract of land that eventually became the Kruger National Park.
Now if the long arm of the law started to catch up with any of these “shady” characters, all they needed to do was to remember the beacon, and if you were on the opposite side of the beacon, the law couldn’t reach for the fear of violating an international boundary.
Even if lawmen from the three different countries arrived at the same time, you could sit on top of the beacon and watch the lawmen fight over who takes you into custody. This is how the “crooks” of Crooks Corner managed to live long and healthy lives.
The road to Crook's Corner today passes under majestic fig trees, jackal berries and a forest of fever trees. This is the spot where 2 rivers and three countries meet.
Sources:
• Sign board at the Crooks Corner parking site
• (visit link)
• (visit link)
• (visit link)
Crooks corner forms a triangle between which 3 countries?
What 2 rivers can you see from this point?
Crooks Corner is also known as?
Name the 4 principles of hydrology that exist in the Limpopo River basin
What water animals did you spot in the river when you were at the lookout point?
In the nearby area on your way to Crooks Corner, did you spot any flood level signs in the trees? What date did they have on them?
Many rivers to the north of the basin are non-perennial. What does non-perennial mean?
A large plaque was erected to commemorate a great ivory hunter in the old days of Crooks Corner – what was his name?
You are welcome to take a picture of yourself at the sign board or with the river in the background and submit along with your log – not compulsory.
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