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Geography Factsheet: 200. Hampshire's Chalk Rivers - issues and management

  • Geography Factsheet: 200. Hampshire’s Chalk Rivers - issues and management

Geography Factsheet: 200. Hampshire's Chalk Rivers - issues and management

  • Price £3.00
  • Code: GEA-FSPI-200
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    Characteristics of chalk rivers There are 35 chalk streams in Hampshire, many of which drain into the rivers Test and Itchen (see Table 1). They have general characteristics:

    • Sourced from groundwater and springs

    • Stable water temperatures (spring water of the Test is 11°C )

    • Regular regimes - flash floods are rare because rainwater infiltrates

    the chalk

    • The source of the river varies with the level of the watertable, creating

    winterbournes

    • Channels are often braided and gravel-based

    • Clear, sediment-free channels because groundwater is filtered though

    chalk and the gravel beds

    • High levels of biodiversity, typically more than 50 aquatic species per

    kilometre:

    o within the fast flowing channels, water crowfoot, water-starworts

    and lesser water parsnip grow in patches streamlined by water,

    supporting invertebrates and crayfish.

    o along the margins, watercress grows as water levels decrease

    through the summer