7.2 Land Use Mapping for Structure Plan
Level of expertise required for this Chapter: Planner; specifically for LUPMIS @ TCPD
7.2.1 Concept and Preparation of Land Use Map
Spatial components of land use planning are based on an assessment of current land use. An inventory or map might already be available, issued and surveyed by Survey Department or other institutions, but in most cases TCPD has to perform a rapid land use survey. This should be based on satellite imagery or aerial photography (see Annex 2.4 for orthophoto production).
In preparing the basic land use map, the person can initially identify blocks of land with what appears similar types of development, or similar densities. But the person will need to go to the field to confirm this. Using the GPS, he/she should be able to identify the extent (boundaries) of the various uses (mixed, predominantly commercial, predominantly residential), and so record them onto the base land use map as polygons. The field work is necessary to draw any boundaries between areas with different densities of development. (Exception may be large compounds like head post office, or some educational complexes with secondary, middle and primary schools serving whole or large part of urban area).
The level of detail (i.e. detail of land use classification and location accuracy) has to be well balanced between a rapid reconnaissance level (‘quick and dirty’) on one side and a mapping ‘overkill’ on the other side.
This land use map is the main geographical input to the Structure Plan. Therefore, a mapping scale of slightly larger than 1:25,000 will be sufficient. It is proposed to identify land use at the scale of 1:15,000 (or 1:10,000). Remember: 1 cm at the map is equivalent to 150 m on ground at 1:15,000.
Geographical accuracy and minimum mapping unit:
Geographical accuracy: 3-5 mm = 45-75 m (at 1:15,000)
Minimum mapping units: 5 x 5 mm = 75 x 75 m. Smaller units do not have to be identified.
See also part F of Annex 2.4 for description and samples of resolution and pixel sizes, which can be useful for land use mapping, part B of Chapter 5.3.1 for the procedure to identify the pixel size of an image.
The proposal for the classification (i.e. identification of units to be mapped) is listed in Annex 6.1. A mapping scale of 1:15,000 has a more general classification than the Local Plan at the scale of 1:2,500.
It is recommended to identify land use units on a hardcopy first.
1. Print an orthophoto map (or satellite imagery map) of the area to be mapped at the scale of 1:15,000 with overlay of borders, main roads, rivers, major contour lines (if terrain is steep).
2. Trace the units, which can be differentiated, with a thick marker.