1- Compare and contrast an attribute selection and spatial selection

    1- Compare and contrast an attribute selection and spatial selection . Why might you use one or the other?2- Explain the function of dissolve. Make a sketch showing the function.3- Explain the function of buffer and why you might use this tool. Make a sketch showing the function.4- Describe in words and diagrams variable distance (a.k.a. variable width) buffers. Include why you might use this method of buffering.5- What is map overlay?6- Explain the function of clip. Make a sketch showing the function.7- List two examples of raster data that can be used in GIS.8- In Raster GIS, define “class”, “zone” and “value”.9- What is map algebra?10- What is a Digital Evaluation Model (DEM) and why are they used so often in spatial analysis.11- In addition to slope and aspect, what are two additional attributes that can be derived from Digital Evaluation Model (DEM)? 12- What is viewshed analysis? Give an example of where this analysis might be used. Long answer question:1- In term of map overlay, what is the difference between Union and Intersect? Describe why you would see Union and not intersect and vice versa. Draw a sample sketch to illustrate these two map overlay techniques.2- Describe the “mixed pixel” problem in raster GIS. How does the resolution of pixels affect this problem? How might you assign a value to a pixel that is “mixed”? draw picture to illustrate the problem and at least one method to solve this problem. 3- Define slope and aspect. Describe how these two-derivative surface can be used within a GIS. Give examples where you might need to drive slope and aspect.