LEC.314 Practical 6: Raster Analysis – Map Overlay

Flashcards about Raster Analysis – Map Overlay

What is the primary objective of this week’s practical?

To determine suitable sites for the location of a wind farm in the District of Lancaster using simple and weighted map overlay approaches.

What are the two methods used for map overlay in this practical?

Simple Map Overlay and Weighted Map Overlay.

What scale are input rasters standardized to in the Weighted Map Overlay technique?

0.0 (least suitable) to 1.0 (most suitable).

What tool is used to reclassify primary raster layers to create secondary raster layers?

The Reclassify tool.

What tool combines secondary raster layers into a final raster layer to identify suitable site locations?

The Raster Calculator tool.

What is the purpose of the Region Group tool?

To combine contiguous pixels into discrete groups.

What tool maintains original values while assigning NODATA values to areas that are too small?

The Set Null tool.

What should proposed sites NOT fall within (regarding SSSI)?

A designated SSSI (Site of Special Scientific Interest).

What is the maximum allowed road density for suitable sites?

Less than 2km of road per km2.

How far should sites be from existing water sources?

Not within 200m of existing water.

How far should sites be from existing woodland?

Not within 200m of existing woodland.

How far should sites be from a building?

Not within 100m of a building.

What is the maximum allowed slope for suitable sites?

Less than 5 degrees.

In the context of the Weighted Map Overlay, are higher or lower wind speeds more suitable?

Higher wind speeds are more suitable.

In the context of Weighted Map Overlay, what is the suitability of areas with lower road density?

More suitable

What does standardizing layers in Weighted Map Overlay ensure?

Values of 1.0 are assigned to the most suitable cells, and 0.0 to the least suitable cells.

What tool is used to assess where a windfarm site can be seen from?

Visibility tool

What is the formula to convert pixel count to area in m^2?

Count x 50 x 50 = area (m^2)

What are the 4 suitable sites identified near?

Cockerham Moss, Caton Moor, Goodber Common, Tatham Fells

What is the tool chain to convert raster to lines?

Raster to Polygon -> Polygon to Line