SMT201 AY2018-19T1 EX2 Tan Jie Ting Christine

Part 1: Map Layers

Gombak and the Target Roads

Gombak and Buildings

Gombak and the Target Natural Features

Gombak and Digital Elevation

Gombak and the Target Natural Features

Part 1: Decision Factors

Economic Factor

The selected site should avoid steep slope. This is because construction at steep slope tends to involve a lot of cut-and-fill and will lend to relatively higher development cost. According to Legal Eagle Contractors, Co. [1], "Less than 10% incline is considered slight and is the easiest to build on, while 11-20% is considered moderate. Anything above 20% is deemed steep.". Hence, I used that as the measure to deem if an area is too steep for building the site.

Using the following matrix, I used a ranked model to compute a score for the economic factor.

Percentage of Incline	Score
Less than 10%	2
10-20%	1
More than 20%	0

Accessibility Factor

The selected site should be close to existing local roads, namely: service roads and tracks. This is to ensure easy transportation of building materials during the construction stage. I assume that for the site to be accessible, the site must be at least 200m away from local roads. I used a binary model, where I gave a score of 1 for the areas that were within 200m from a local road, and a score of 0 for the areas that were more than 200m away from a local road.

Health Risk Factor

The selected site should be away from population i.e. housing areas and offices in order to avoid disease spreading to the nearby population. I assume that for the site to be sufficiently far away from buildings, it needs to be minimally 250m away from buildings. I used a binary model, where I gave a score of 1 for the areas that were at least 250m away from buildings, and a score of 0 for the areas that within 250m away from a building.

Natural Conservation Factor

The selected site should be away from forested land, park and water. I assume that for the site to be sufficiently far away from natural conservation sites, the site must be at least 200m away from natural sites. I used a binary model, where I gave a score of 1 for the areas that were at least 200m away from natural sites, and a score of 0 for the areas that within 200m away from a natural site.

Final Output

I used the Raster Calculator to calculate the final scores to deduce where would be the best area to build the site, with the formula "Economic@1" + "Accessibility@1" + "HealthRisk@1" + "Natural@1", where the variables refer to the factors as listed above respectively.

References: [1] https://legaleaglecontractors.com/building-house-on-slope-challenges/