National Character Area 114

Thames Basin Lowlands - Landscape Change

The full NCA Profile landscape change page, is temporarily unavailable until publication of the Defra 25 Year Environment Plan Indicator G1 later in May 2024.

Monitoring Landscape Change

Drivers for change
The Thames Basin Lowlands is a highly urban low-lying plain, with ongoing development pressures related to the proximity of London and its peripheries. Sprawl and new development at the edges of the city may increase housing density into an area already affected by fragmentation. Additionally, flooding is a significant issue and heavier winter rainfall may increase the potential number of properties affected, while lower summer river flows could lead to reduced water quality and pollution.

Monitoring landscape change
This section is temporarily unavailable until publication of the Defra 25 Year Environment Plan Indicator G1 later in May 2024.

Additional information on landscape change

Landscape change reported in 2014

Recent changes and trends (reported in 2014)


  • The farmed landscape character has changed quite markedly. According to statistics from the Defra census, the total farmed area within the NCA declined by 9 per cent between 2000 and 2009.
  • Grass or uncropped land rose by 6 per cent, reflecting an increase in the amount of grazing and use for horse paddocks. Oil seed rape increased by 51 per cent while other arable crops fell by 64 per cent and cereals by 35 per cent.
  • Livestock numbers also decreased during the same period; sheep by 4 per cent but cattle and pigs quite dramatically by 77 per cent and 75 per cent respectively.

Boundary features

  • Many hedgerows suffer from a lack of appropriate management due to over-trimming and intensive land use. In some areas, this has led to a significant loss of hedgerows and hedgerow trees. In addition, the increased use of land for horse pasture and pony paddocks on the urban fringe has resulted in more use of post and wire fencing and sometimes the removal of hedges altogether.
  • Recently, however, the number of agri-environment schemes with hedgerow options within the NCA has been increasing and, although still very low, now accounts for about 7per cent of the total estimated boundary length.

Coast and rivers

  • The chemical status of the rivers was considered to be good in 1995 and most continue to achieve a good status. The Wey is now judged to be failing for the presence of benzo (ghi) perelyene and indeno (123-cd) pyrene. The biological quality was also judged to be predominantly good in 1995 but rising levels of phosphate and low numbers of fish mean that the Wey is now considered to be moderate and the Mole, Hogsmill and Wandle poor.

Historic features

  • The area’s historic parkland landscapes and their characteristic features such as imposing mature ornamental trees, avenues and roundels, are in some cases being lost or degraded through neglect, lack of management and occasionally through direct removal. Conversion of parkland from grazing to arable, recreation or horticulture has reduced the distinctiveness and landscape setting of parkland features.


  • There is currently no extraction of minerals in this NCA.

Semi-natural habitats

  • Sites of Special Scientific Interest condition is gradually improving with the majority (59 per cent) of designated sites in favourable condition and the remainder (41 per cent) in unfavourable but recovering condition.
  • A reduction or lack of traditional grazing on some commons has led to the diminution of biodiversity interest with areas of heathland becoming increasingly scrubbed over, invaded by gorse and birch.

Settlement and development

  • Green Belt designation around Guildford and Greater London covers 41 per cent of the NCA. This has limited the rate of development outside urban areas.
  • The exception to this has been on the western fringes of Greater London around Epsom and Ewell where there has been some expansion into the peri-urban area. Within urban areas, in particular Croydon, Merton and Sutton but also within Aldershot and Guildford, the density of housing has increased considerably.
  • The presence of the A3 and M25 and development within their road corridors has had a significant impact on the landscape character of the NCA.

Trees and woodlands

  • The proportion of woodland and trees covered by a Woodland Grant Scheme management agreement nearly doubled between 1999 and 2003 from 18 per cent to 35 per cent. Over the same period, the proportion of ancient semi-natural woodland covered by a Woodland Grant Scheme rose slightly from 31 per cent to 34 per cent.
  • The majority of woodland (89 per cent) within the NCA is broadleaved or mixed but suffers from a lack of regular management. The re-introduction of active management and traditional practices such as coppicing would improve age structure and biodiversity interest.

Drivers of Change (reported in 2014)

Climate Change

  • A reduction in river flows during summer months due to low rainfall could lead to reduced water quality through diffuse pollution. The demand for water abstraction from agricultural businesses could increase with a greater need for irrigation. Higher temperatures would also increase demand for potable water. The aquifer recharge capacity of the North Downs, South Downs and Hampshire Downs (which provide the headwaters for the Wey, Mole, Hogsmill and Wandle) could become slower.
  • Conversely, winter rainfall may be heavier, increasing the likelihood of flooding events as well as the number of properties affected, in settlements close to rivers such as Guildford and Cobham.
  • Non-native invasive species may gain a stronger foothold if higher temperatures prevail.
  • Continental European species may extend their range into Britain. This is already happening with some species of butterflies and dragonflies.
  • Prolonged droughts in summer may change the biodiversity value of the wet riparian woodlands along the rivers Wey and Mole.
  • Woodland cover, especially ancient semi-natural woodland, may experience a decline or change in species composition as drier sites become more vulnerable to fire and some species struggle to adapt to drier conditions and higher temperatures. The capacity of the woodland resource within the Thames Basin Lowlands to adapt to climate change may be reduced because of its fragmentation.
  • Veteran trees within parkland or wood pasture such as those on Ashstead Common may not be able to withstand long periods of drought. This may also lead to the loss of specialised species associated with them such as fungi and invertebrates.
  • Hedgerows can be sensitive to drought, leading to die-back of hedgerow trees and possibly to hedgerow removal. Berry-bearing species may be affected by a reduction in the number of frosts as many require low winter temperatures to stimulate flower production. A decrease in berries, seeds and fruit would also reduce winter food available for wildlife.

Other key drivers

  • There has been a considerable amount of development in recent years particularly within Croydon, Guildford and the Epsom area. However, the high proportion of land designated as Green Belt will continue to have a strong influence on the development of the landscape.
  • The decline in the importance of agriculture to the local economy is likely to continue because of the proximity of the NCA to London and other large urban areas.
  • An increase in population may put additional recreational pressure on sensitive sites in adjacent NCAs such as the Thames Basin Heaths and the Surrey Hills AONB as well as on local water resources which are already stretched.