Southern England. Peter Friend

      FIG 2. Satellite image over Britain showing artificial lighting at night. (Copyright Planetary Visions Ltd/Science Photo Library)

      There is a further enjoyment that people find in landscapes and scenery that is more difficult to understand. Is it just the physical challenge that causes people to walk and climb to the tops of hills, mountains and other viewpoints? Why do people enjoy the work of landscape painters and photographers? Why do so many tourists in cars choose to take ‘scenic’ excursions rather than the shortest routes, and why is the preservation of ‘unspoilt’ or wilderness areas now such a popular cause? It is difficult to understand the various emotions involved, and trying too hard to analyse them may be missing the point. So it seems best to hope simply that this book will help to satisfy some people’s curiosity, and at the same time add to their enjoyment of our natural landscapes.

      MAPPING AND ANALYSING SOUTHERN ENGLAND

      The detailed discussions of most of the rest of this book have involved dividing Southern England into a number of Areas that form the ‘building blocks’ for the coverage of Southern England (Fig. 3). Each Area is based on a double-page spread of the size used in many of the larger road atlases available for Britain. In this case I have used the Collins Road Atlas, Britain. This means that total coverage of Southern England is provided, and it is easy for the reader to navigate from place to place. At the beginning of each Area description, a location map of the Area and its neighbours is provided. Ordnance Survey (OS) National Grid References are provided for the edges of the Area, in km east and north of the arbitrary OS Grid origin some 80 km west of the Scilly Isles.

      FIG 3. Division of Southern England into Regions and Areas.

      For convenient reference the Areas – numbered 1 to 16 – are grouped into five Regions. Each Region forms a chapter and starts with a general introduction:

CHAPTER	REGION	AREA
Chapter 4	Southwest	1 West Cornwall 2 East Cornwall and South Devon 3 North Devon and West Somerset
Chapter 5	South Coast	4 East Devon, Somerset and Dorset 5 Hampshire and the Isle of Wight 6 Sussex 7 East Sussex and Southeast Kent
Chapter 6	Severn Valley	8 Bristol 9 The Cotswolds and the Middle Severn
Chapter 7	London and the Thames Valley	10 The Cotswolds to Reading 11 London 12 The Thames Estuary
Chapter 8	East Anglia	13 Northampton to Cambridge 14 Suffolk and North Essex 15 Leicester to the Fens 16 Norfolk

      Even the Area building blocks are relatively large, with arbitrary boundaries, and it has generally been helpful to discuss smaller areas within and across these boundaries that are based on natural features of the scenery (Fig. 4). I have called these smaller areas Landscapes, because they are characterised by distinctive features, usually reflecting aspects of the bedrock or distinctive events in their evolution.

      These Landscapes correspond closely to area divisions of England that were defined by the Government Countryside Agency (www.countryside.gov.uk). This scheme divides England into 159 ‘character areas’ on the basis of natural features of the scenery along with aspects of its human settlement, past and future development, land use and vegetation and wildlife, so they are likely to be familiar divisions to many readers of the New Naturalist series. Other Government agencies (particularly the Department for Environment, Food and Rural Affairs) that administer the funding of land management use the same character area division.

      FIG 4. Examples of the three levels of division adopted in the treatment of Southern England.

      Maps displaying patterns of elevation of the countryside above sea level are an important part of the discussions. The elevation data on the maps in this book have been compiled and made available as part of the LANDMAP project, which provides a computer-based digital survey of Britain for research and educational use. LANDMAP Digital Elevation Maps (DEMs) are based on satellite radar survey measurements which divide the land surface into a grid of 25 m by 25 m pixels. The average height of each pixel is then measured to produce a terrain model with a vertical accuracy of about ± 5 m. A standard colour shading scale is used to represent heights, ranging from greens for the lowest ground, through yellows and browns, to greys for the highest ground. It is best to use the full range of colours for each map, no matter what numerical range of heights is involved. This makes it possible to convey the fine detail of slopes etc., whether the map is for the Fens or the high moors. To make it possible to compare between maps using this colour scheme, we have quoted the maximum elevation reached in each Area on each map.

      I have used ESRI ARC Geographic Information System (GIS) software in the processing and manipulating of the map data. This software makes it possible to present artificial hill-shading, which makes the topography easier to understand, and to provide maps representing slope patterns in certain areas.

      In addition, data on roads, railways, coastlines, town boundaries, rivers, etc. suitable for reproduction at a scale of 1: 200,000 has been made available by the Collins Bartholomew mapping agency. For any further details of the areas covered, it is recommended that Ordnance Survey Landranger (1: 50,000) maps are consulted.

      LANDSCAPE CHANGE

      We tend to think of rural landscapes as unchanging features of our surroundings, in contrast to the man-made scenery of cities and towns. Yet we all know of local catastrophes, such as a sea cliff collapsing during a storm, or a flooding river removing its bank and wrecking the nearby buildings, and these are the sorts of local events that do result in change. Despite the excitement, individual changes of this sort are small and can usually be regarded as local modifications. However, over time, the accumulated effects of many such modifications can cause whole landscapes to change.

      Size and time clearly both play key parts here. The collapsed cliff or eroded river bank will probably be tens to hundreds of metres long at most, while the larger landscape features picked out in this book are tens or even hundreds of kilometres across. Noting the length scales involved in this way is an important way of keeping such differences clearly in mind.

      Moreover, while local events such as the destruction of landforms or buildings may be immediately newsworthy, more long-term patterns of change in the natural scenery are rarely apparent during the life spans of people, and even during the hundreds of years of written records. So it becomes necessary to use indirect and circumstantial evidence – to play the detective – to find out what long-term changes have been going on.

      An important step in thinking about the natural landscape is to look at it in terms of modifications to complex surfaces defined by the ground. On land, we tend to be most aware of erosional processes removing material, but it is important to realise that the material