Virtual Terrain

The landscape is characteristic of a northeastern coast in Atlantic Europe. The 3-dimensional view is based on a digital terrain model with a grid resolution of 250m. Layers containing information about different features can be displayed through overlays. Three main areas exist: the uplands, lower slopes and central lowlands.

- uplands: the region is ringed by an upland national park with blanket peat bogs, moors and grassland lying over granite. Here the water from rainfall does not permeate below the surface but seeps out from the peat into smaller streams that feed into the main tributaries of the lowland basin.

The park is effectively a boundary between a warmer south-east climate and a cooler, wetter north-west type. The landscape and biodiversity is therefore highly sensitive to even slight changes in temperature and rainfall. Climate change could just ‘tip the balance’ to make the bogs unstable. The blanket of peat on the summits depends on high and unpolluted rainfall, so wetter winters under climate change could help maintain the bogs. But higher temperatures and drier conditions in summer could also result in fungal and bacterial decomposition. [The scientific community is still not clear about the precise effects of climate change on peat uplands]. Other rare montane plants are likely to decline and even go extinct. Large areas would be taken over by bracken, which would do well in a warmer wetter climate, although it is vulnerable to late frosts. Early drought would give heather a competitive advantage over bracken.

The incidence of moorland fires will increase under the warmer and drier conditions, leading to the replacement of heather moorland by grass, with serious implications for evapotranspiration, soil erosion and visitors enjoying activities such as grouse shooting, bird watching and walking.

• lower slopes: below the national park, the underlying geology changes to sandstone and Carboniferous limestone with sandy soils on top. The slopes are covered with mixed forest and woodlands and grass. Here rainfall permeates into the groundwater reservoirs as well as flowing into the main tributaries of the lowland river system. The rivers have average daily mean flows of 1.23m3s-1 (northeastern slope) to 0.83 m3s-1 along the southwestern slopes.

The long-term effects of warming on limestone grasslands and the mixed forest and woodlands are generally reassuring; experiments have shown that this type of vegetation is remarkably resistant although sedges are likely to become threatened by the spread of invasive grasses. The extra grass growth in winter could encourage a trend towards all-year grazing.

Snow melt will be affected by the extent of forestry as well as the mildness of winters; there is likely to be a higher flood risk for rivers under a pattern of windy mild weather following short-lived snowy periods on the hilltops.

• central lowlands: the underlying geology in the lowlands is made up of sandstone and chalk; soils include sandy loamy clays and muds in the low lying area in the south, loamy clay to the west, shallow loam along the coast in the north and freely drained loamy soils along the estuary and rivers of the central area. A major city lies at the centre at the intersection of two large rivers, with average daily mean flows of up to 18m3s-1 and a tidal estuary, and connected by major trunk roads and an airport.

In the surrounding areas are several towns and villages and areas of horticulture, intense agriculture, woods and several special sites of scientific interest (SSSIs) and habitats of conservation importance. Along the estuary and southern coast there is a port and smaller harbour facilities; on the northern coast there is large industry and several small resorts.