The Mara River is a river in
Africa, flowing through
Kenya and
Tanzania, and lies across the migration path of ungulates in the Serengeti/Masai Mara game reserves. The Mara River basin covers a surface of 13,504 km2, of which approximately 60% is located in Kenya and 40% in Tanzania. From its sources in the Kenyan highlands, the river flows for about 395 km and originates from the Mau Escarpment and drains into Lake Victoria. The basin can be roughly divided into four land use and/or administrative units:
The Mau Escarpment: The Mara River originates from the Napuiyapi swamp (2932m), with the main perennial tributaries being the Amala and the Nyangores, which drain from the western Mau Escarpment. This part of the basin supports besides forests, both small scale agriculture (less than 10 acres) and medium-size farms (often tea farms up to 40 acres).
The Kenyan Rangelands: In this area, the Amala and Nyangores rivers flow out of the Mau Escarpment and converge to form the Mara River. The River then meanders further through open savannah grasslands that is mostly governed by Maasai group ranches and used as pasture for livestock and for both small — and large-scale agriculture.
The Protected Areas: Eventually the river flows into the
World-famous Masai Mara National Reserve, where it merges with three of the four mentioned tributaries. On the Kenyan-Tanzanian border, the river flows into the Serengeti National Park and is joined by the fourth major tributary.
Downstream Tanzania: Just after the Mara River flows out of Ikorongo Game Reserve (which borders Serengeti National Park) it meanders sharply northwards.
Altitudes & Ranges
The altitudes in the basin range from 2,932 m around the sources in the Mau Escarpment to 1,134 m around Lake Victoria. The amount of precipitation varies according to these altitudes. The Mau Escarpment receives most rainfall with a mean annual rainfall between 1,000 and 1,750 mm. The transboundary middle savannah grasslands receive an average between 900 and 1,000 mm, and the Kenyan lower Loita hills and the area around Lake Victoria only about 700 and 850 mm rain per year. On top of this rainfall variability in space, the region is also known for its rainfall variability in time, which means that the different areas all receive variable amounts of rainfall over the year. The rainfall seasons are bi-modal, with the long rains starting in mid-March to June with a peak in April, while the short rains occur between September and December.
Mara's Effects
The river is a vital source to grazing animals nearby. Although during the dry season it may often appear shallow, it may swell to up to twice its normal size after heavy rainfall. This can create rapids in the river, which may lead to shortage of food for predators that cannot cross the river to hunt. Between the 1950s and 2006, the seasonal water quantities in the Mara have changed significantly in the sense that are now higher peaks and lows in the river flow. These dynamics are associated with changes in land use in the catchments area: decreasing vegetation covers are causing a faster run-off of rainwater. Near the river mouth in Tanzania, the rapidly fluctuating water levels in Lake Victoria of the previous century have further added to discharge difficulties of the Mara River. Consequently, floods have become more common and large parts of the Tanzanian Mara wetlands have become more permanent instead of temporary wetlands.
