Hampshire - Physical Geography

Physical Geography

Hampshire's geology falls into two categories. In the south, along the coast is the "Hampshire Basin", an area of relatively non-resistant Eocene and Oligocene clays and gravels which are protected from sea erosion by the Isle of Purbeck, Dorset, and the Isle of Wight. These low, flat lands support heathland and woodland habitats, a large area of which forms part of the New Forest. The New Forest has a mosaic of heathland, grassland, coniferous and deciduous woodland habitats that host diverse wildlife. The forest is protected as a national park, limiting development and agricultural use to protect the landscape and wildlife. Large areas of the New Forest are open common lands kept as a grassland plagioclimax by grazing animals, including domesticated cattle, pigs and horses, and several wild deer species. Erosion of the weak rock and sea level change flooding the low land has carved several large estuaries and rias, notably the 16 km (9.9 mi) long Southampton Water and the large convoluted Portsmouth Harbour. The Isle of Wight lies off the coast of Hampshire where the non-resistant rock has been eroded away, forming the Solent.

In the north and centre of the county the substrate is the rocks of the Chalk Group, which form Salisbury Plain and the South Downs. These are high hills with steep slopes where they border the clays to the south. The hills dip steeply forming a scarp onto the Thames valley to the north, and dip gently to the south. The highest point in the county is Pilot Hill, which reaches a height of 286 m (938 ft), and lies on the border with West Berkshire. Butser Hill near Petersfield is the second highest point at 271 metres (889 ft) and lies in the South Downs National Park. The highest village in Hampshire is Bentworth, near Alton. The downland supports a calcareous grassland habitat, important for wild flowers and insects. A large area of the downs is now protected from further agricultural damage by the East Hampshire Area of Outstanding Natural Beauty. The Itchen and Test are trout rivers that flow from the chalk through wooded valleys into Southampton Water. Nestled in a valley on the downs is Selborne, and the countryside surrounding the village was the location of Gilbert White's pioneering observations on natural history. Hampshire's county flower is the Dog Rose.

Hampshire has a milder climate than most areas of the British Isles, being in the far south with the climate stabilising effect of the sea, but protected against the more extreme weather of the Atlantic coast. Hampshire has a higher average annual temperature than the UK average at 9.8 to 12 °C (50 to 54 °F), average rainfall at 741–1,060 millimetres (29.2–42 in) per year, and higher than average sunshine at over 1541 hours per year.