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

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.

Datasets Variable Type Source Wind potential zones Vector http://www.nrel.gov/gis/data_wind.html Roadways   http://egis3.lacounty.gov/dataportal/ 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

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

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

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

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

Final Map

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.