S.O.S.--Save Our Slopes

The next step in the methodology was to do a 'fuzzy overlay', where different values were assigned to different variables. The values assigned were as follows: Slope- 1.75, Rain- 1.5, Wind- 1.25, Fire hazard- 1.0. Out of this computation, the 'Potential failure planes' map was created. 

 

Next was to identify the land use of LA County. I elected to use: residential land, education, forest/green space, and highways. The bottom layer used is the DEM of LA County, then it is the Area of Concern , followed by the different land use types. 

 

Following this step, I decided to do an extract by mask of land type on the Area of Concern. After completing this step, ARC-GIS created a map of residences and schools that fall in the boundaries of the area of concern; yellow represents households and the orange are institutions. To put things into perspective highways are included in blue.

 

After the extract by mask, I decided that it would be helpful to locate the highways that may fall in the way of a potential land slide or debris accumulation. In order to do this I had to do a raster calculator on the area of concern. Next I converted the highways into a raster. After this I completed another extract by mask. For this extract by mask I extracted the areas of concern with the raster highways. From this, I derived the last map of the locations of highway in potential danger.