follows the axis of an epeirogenic flexure. Elevation extremes: lowest point: junction of the Runde and Save rivers 162 m highest point: Mount Nyangani 2,592 m Natural resources: coal, chromium ore, asbestos, gold, nickel, copper, iron ore, vanadium, lithium, tin, diamond, platinum group metals Land use: arable land: 10.49% permanent crops: 0.31% other: 89.20% (2011) Irrigated land: 1,735 km² (2003) Total renewable water resources: 20 km3 (2011) Natural hazards: droughts; floods and severe storms are rare Environment – current issues: deforestation; soil erosion; land degradation; air and water pollution; the black rhinoceros herd – once the largest concentration of the species in the world – has been significantly reduced by poaching; poor mining practices have led to toxic waste and heavy metal pollution Environment – international agreements: party to: Biodiversity, Climate Change, Desertification, Endangered Species, Law of the Sea, Ozone Layer Protection signed, but not ratified: none of the selected agreements Hydrology: The country is divided into six drainage basins. The largest are the Zambezi and the Limpopo. Western parts of Matabeleland connect to the Okavango inland drainage basin through the Nata river. Most of southern Mashonaland and adjacent parts of Masvingo drain through the Save river into the Indian Ocean. Two smaller drainage basins cover parts of Manicaland, and drain into the Indian Ocean through Mozambique. These are the Pungwe river to the north and the Buzi river to the south. Sediment transport has been studied for rivers in Zimbabwe using the HBV hydrology transport model. Main land use type: Above 1050 mm/annum with some precipitation in all months of the year Afforestation, fruit, tea, coffee and intensive livestock production. 750–1000 mm/annum seasonally confined with well-defined dry season Large scale intensive crop and livestock production. 650–800 mm/annum with regular mid-season dry spells Livestock production with fodder crops. Marginal production of maize, tobacco and cotton. 450–650 mm/annum with periodic seasonal drought and severe rainy season dry spells. Livestock production and drought resistant crops. Too low and erratic for even drought resistant fodder and grain crops. Extensive livestock and/or game ranching. Extreme points This is a list of the extreme points of Zimbabwe, the points that are farther north, south, east or west than any other location. Northernmost point – unnamed location on the border with Zambia in the Zambezi river immediately north of the town of Kanyemba, Mashonaland West province Easternmost point – unnamed location on the border with Mozambique