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AL Map Reading Exercise

AL Map Reading Exercise

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AL Map Reading Exercise

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  1. AL Map Reading Exercise

  2. What are the major elements of a map? • Scale • Conventional signs • Grid reference • Title

  3. 10 cm 5 cm Scale • Scale 1:20,000 • 1cm = 20,000cm = 200m = 0.2km • 1:20,000

  4. 14 12 13 29 28 27 Grid reference Grid square 1328 Grid reference 134276

  5. What does a map tell us? • location • land use • relief • communication • drainage • vegetation

  6. Main road Secondary road Main road Main road Secondary road 934830 934860 Transect Rural residential Farmland Woodland Vacant land Recreational Squatter Farmland Public housing

  7. Main road Secondary road Main road Main road Secondary road 934830 934860 Transect Rural residential Farmland Woodland Vacant land Recreational Squatter Farmland Public housing

  8. 1997

  9. Favourable factors for farming • fertile alluvial soil along lower course of river • adequate fresh water supply from dense network of streams • flat and gentle relief as indicated by winding/ meandering river channels and absence of closely spaced contours

  10. Yuen Long as market town and collection / distribution centre well-developed road networks / highways facilitate transport of farm products • electricity supply as indicated by presence of power line

  11. Major changes in land use • filling up of fish ponds • for industrial land use (Yuen Long Industrial Estate) • And residential land use (Tin Shui Wai) • As part of the development of Yuen Long new town • increase in transportation land use

  12. Yuen Long Highway and light rail transit • to improve accessibility of Yuen Long new town • increase in recreational land use • Tin Shui Wai Park and Yuen Long Park • for rising population

  13. Impact of urbanization • farmland becomes fragmented by the construction of road networks • farmland formerly at outskirt of town substituted by urban land uses • former land left vacant or used as open storage of container

  14. depots at outskirt of town and along major transport / extensification • routeways while waiting for urban development I speculation • fish ponds at Tin Shui Wai totally taken up for urban development • intensification I market gardening

  15. Reasons of Flooding • concentration of heavy rainfall in summer from June to August extensive flat and low land serves as the flood plain as indicated by the presence of winding / meandering river channels impermeable bedrock layer indicated by the presence of fish ponds inhibits draining of flood water • urban development increases water-proof land surface which • helps to retain flood water

  16. Damages of Flooding • inundation of fields ruins crops • (sample grid square: 9484 / 9584) • - disruption of road transport • (sample grid square : 9285 / 9286) • - inundation of villages as they are closed to farmland in low-lying areas (sample grid square: 9285/9384 /9485 /9585)

  17. Human Effort road embankments e.g. Yuen Long Highway to minimize impact from flood effectiveness depends on scale of floods effectiveness depends on scale of floods and silt content of flood water straightened river channels (e.g. Shan Pui River) to drain flood water in a faster rate dredging of channels has to be done during low water seasons to maintain flow

  18. 1995 Scale Key

  19. People modified the channel • straightening the river channel • constant width

  20. Reasons for such modifications • increase velocity of the river • i.e. improved efficiency of the channel slope, reduce friction, therefore increase velocity and transport capacity • less deposition • avoid silting • prevent flooding • less pollutants accumulate in the river

  21. Reasons of Flooding • heavy rainfall with long duration / prolonged rain storm • low-lying relief • changing type of land use / illegal change of land use • increase in abandoned land • old car dumping and open storage • increase soil erosion

  22. Reasons of Flooding • increase loads in the river • silting of river • more construction work i.e. compaction and development of concrete surface • lower infiltration • more surface runoff

  23. 1991 on level land below 20 metres on slopes of foothills up to 50 metres require extensive flat land, alluvial soils, ample water supply for irrigation require well-drained soils on foothills

  24. Impact of Ferry Pier(economic) • improve accessibility to urban area, • facilitates marketing of agricultural products, • better income from non-rural employment (part-time farmers), • services provided to visitors from urban area generate employment and earnings

  25. Impact of Ferry Pier (environmental) • Traffic volume increases, • higher risk for coastal water to be polluted, danger of air and noise pollution, • influx of urban visitors, • scenic beauty of countryside disrupted

  26. Village House Tai Tei Tong (B2) Pak Ngan Heung (B1) Tsoi Yuen Tsuen (A1) Luk Tei Tong (B3) Occupied (%) 88 84 90 65 Unoccupied (%) 12 11 6 15 Ruined (%) 0 5 4 20 Sub-total (%) 100 100 100 100 Total number 70 44 59 25

  27. Ruined and occupied houses in Luk Tei Tong • Emigration/rural depopulation/rural-urban migration, • small village, • poor accessibility, • lack of services • (e.g. no schools, clinics)

  28. Changes to rural housing • increasing proportion of ruined houses and unoccupied houses, • resettlement in public housing estates, • derelict houses in remote sites abandoned, • better housing due to increased income

  29. 1992 center of higher order services more higher order services e.g. fire station, police station center of lower order services services less than Yau Uk Tusen’s

  30. sited near to main road located at a nodal point / more accessible larger catchment area / serving a greater number of population / a larger marketthreshold connected by road of single width less accessible less people come to here smaller market threshold / catchment area

  31. null-hypothesis statement • There is no significant relationship between the gradient / slope angle and the density of vegetation growth

  32. Findings • The more exposed the slope, the less the vegetation • Vegetation is less on spurs / hill-tops • Vegetation is denser in valleys • Areas(valleys) are sheltered / less disturbed • Environmental change in valleys being more gradual, etc. therefore better growth

  33. (c Agricultural Research Station : for plant crop (with grid reference) Inland site / slope / contour as evidence Fishery Research Station : for fish crop ( with grid reference) Water body / level land as evidence

  34. Sampling

  35. Sampling reduce difficulties and danger Time saving

  36. Sampling

  37. example of human impacts irrigation – for cropping water drained / stored – for settlement / domestic use catchwater – for reservoirs

  38. 1996

  39. Evidence of Different Zone on the city margin / at the foothill/ small and irregular buildings layout high building density / rectangular blocks/large lower building density / more open space temporary housing Larger blocks, usually on reclaimed land

  40. Sampling procedure • stratified sampling • select same number or proportional number of sample points from each land-use zone • random / systematic sampling • within the land-use zones, sample points are to be located either through systematic or random sampling

  41. Advantage & Disadvantage • sampling points are selected objectively without any bias • Samples of different types of land use are included • the selected sample point may be inaccessible

  42. Redevelopment

  43. Redevelopment opportunity • the urban airport • major source of noise pollution in urban Kowloon • A new airport is built in the suburban area • military land use (barrack) • occupy very accessible locations • symbolic value of military land uses in the inner city is diminishing

  44. Redevelopment opportunity • the old public housing estates • They were built long time ago • The design and infrastructure arc outdated. • older residential districts • decaying areas • vacant land

  45. Squatters are not included • the redevelopment opportunity of an area is determined by the value of land after redevelopment • and the existence of institutional barriers

  46. 1999

  47. Changes on farmland • the farmlands at the east and south of the typhoon shelter area abandoned, • secondary growth are seen on the sites • this is also true of the fields north of Lantau link e.g. Tai Lung , Lau Fa Tsuen • the farmlands extending from Tung Wan Beach towards Tin Liu disappear under reclamation, the land is barren

  48. Adverse Effects of Construction • transport at the north, e.g. the link between Tin Hau Temple and Ma Wan Town is disrupted, causing inconvenience • air and sound pollution may affect the inhabitants e.g. Tin Liu villagers • as drainage pattern is altered, and soil is unprotected, bays in the east, e.g. Tung Wan, may be heavily polluted