1. GIS-based wind farm site selection using spatial multi-criteria analysis (SMCA): Evaluating the case for LA County
The threat of global warming has caused many to explore a switch to alternative, renewable energy sources(Janke 2010).. This study identifies suitable areas in LA County for siting wind farms.
Manju Narmada U.
GEOG 588

2. Research Objective
To develop automated GIS tools to identify areas that are suitable for wind farms using multi-criteria GIS modelling techniques for LA County. Suitability mapping involves using a variety of data sources in which weights are assigned to geographical criteria and analyzed based on priority.

3. Datasets Variable Type Source Wind potential zones Vector
Roadways
Railways
Sanctuaries
Significant ecological zones
Streams
Wetlands
Forests
LA block groups
Provided as part of coursework at Cal State Long Beach
Land use shape file
LA DEM
Raster

4. Methodology STAGE 1 STAGE 2 STAGE 3 STAGE 4
IDENTIFYING ERASE AREAS
IDENTIFYING PRIORITY AREAS
IDENTIFYING CONSTRAINT AREAS
SITE PRIORITY MAP
DATA COLLECTION & PROCESSING
STAGE 1
STAGE 2
STAGE 3
STAGE 4

5. Stage 1 : Identifying Erase Areas
SIGNIFICANT ECOLOGICAL REGIONS
RESIDENTIAL AREAS
WATER POINTS BUFFER
LANDUSE
STREAMS
STREAM BUFFER
FORESTS
SANCTUARIES
WETLANDS
SELECT LAYER BY ATTRIBUTE
BUFFER
ERASE AREAS
UNION
WATER POINTS

6. Stage 2: Identifying priority areas
PRIORITY AREAS AREAS
UNION
VACANT LAND
REQD WIND ZONES
PROXIMITY TO RAIL
WIND POTENTIAL ZONES
LA BG
PROXIMITY TO ROAD
LOW ELEV
SBA:WPC > 3
SBL
LANDUSE
SBA:LU = VACANT
LA DEM
RASTER CALC: ELEV <300 m
W=1
W = 3 to 7
W = 1
CONVERT RASTER TO VECTOR

7. SUITABILITY SCORES –RECLASS TO SUITABILITY INDEX
Stage 3: Identifying constraint regions
CONSTRAINT AREAS
UNION
FIRE ZONES
FLOOD ZONES
VERY HIGH RISK = -3
HIGH RISK = -2
LO W RISK = -1
PRIORITY AREAS
SUITABILITY SCORES –RECLASS TO SUITABILITY INDEX

8. Final Map

9. Discussion:
These automated tools present repeatable and flexible methods for evaluation and prioritization of a large number of site suitability studies in many other areas.
The wind farm site selection tool presented in this paper provides insights into the most feasible sites for a large geographic area based on user inputs.
The model can further be extended to calculate the total wind potential available based on the area available for locating wind farms and also calculating the total cost that may be incurred for putting up the turbines.
Limitations
The absence of some data like the dataset of existing power transmission lines contributes to the inability to weight the factor. If the input existed, it could be weighted and applied to the site suitability analysis.