Lab 5 Digitizing

 Exercise 13A 

Exercise 13B

Definitions of the Key Words from Chapters 11, 12. 13

Feature Dataset- a dataset that has related feature classes that can be grouped together

For example, we have a shapefile with streets and we combined that dataset with a shapefile that has all stop signs as points. This would create a new feature dataset.

Attribute Domain- established and enforces valid values or ranges of values for an attribute field

This would be used to fix the correct values that can be inputted for a attribute. For example, if we were talking about computers being occupied the two domains would be occupied or vacant and no other values could be put into the attribute.

Digitizing- drawing on top of maps, aerial, or satellite images with digital devices

For our class, we use digitizing on the computer and trace on aerial photographs, scanned maps, and other spatial data.

Vertex- points that define a line or a polygon

An example of this would be when we are tracing polygons, we plot vertices around the polygon to create a shape.

Endpoints- points that mark the end of a line segment

We use endpoints when we are drawing lines such as streets from point A to point B. Endpoints are also used when polygons are drawn using the editing tool.

Edge- segments between vertices

The edge is used when we are drawing polygons. They are also the sides of the polygons.

Edit Sketch- this is before a feature is saved when drawing a polygon or during an edit session

This is when the polygon you have drawn is highlighted in blue in ArcMap.

Edit Session- when you click start editing and in this mode one can add features or modify features

Edit session is used when we want to trace around features for example in these lab exercises we used it to trace around playgrounds.

Snapping- editing operation where points or features within a specified distance are moved to match with each other’s coordinates

We use snapping to only show features where we are currently working or looking at. For example, during chapter 12 we were only looking at streets that were relevant to what we were doing.

Map Topology-temporary set of topological relationships between parts of simple features on a map that will behave as if they are connected

We used map topology in chapter 13 when we changed the boundaries of the neighborhoods because when we moved that edge it changed the shape of both polygons where the edge was touching.

Geodatabase Topology- arrangement that constrains how point, line, polygon, features share geometry, allows you to enforce rules within and between feature classes

You can use this to manipulate maps to be exactly how you want by enforcing rules. An example would be that you want all your lines to be connected. This is a faster way to ensure that your map will be the product you want. 

Which California Counties Received Drought Aid in 2014?

The question I was trying to answer with this map was, which counties received aid for the extreme drought in 2014? I chose the choropleth scheme of qualitative because it displayed the information in the least confusing way possible. I decided that the best way to convey the drought aid data was to only show two colors on my map. It clearly shows which counties received aid and which did not for that specific month. The color red was used because I was linking the color with the idea that the drought is bad and that it has become even worse as the year has progressed. My extent map is showing where California is in relation to the west coast of the United States for people who do not know where California is. I chose this extent because I assume that people already know that California is on the west coast of the United States. I chose to create three maps because it made the message of which counties received aid the most clear. When the different months were layered over each other, the message was confusing to which counties received aid in a specific month. The three maps takes away the confusion of the overlap.

The intended application of this map is for viewers to see the different counties in California that received aid in 2014. It allows the viewers to understand how the drought progressively intensified as the year 2014 continued. This map also shows viewers which counties were hit harder by the drought in relation to other counties in California. This map could be used for policy makers and land managers because they can easily see where the problem areas of drought are. This would make it easier for them to apply drought restrictions for water usage. Other intended audiences for this map would be citizens of California and the surrounding states. This would effect the citizens' water usage around the drought areas. This map would be considered a time series analysis due to the fact it is comparing different times within the year 2014. The intended purpose influenced the map style because the message had to be clear enough for viewers to understand. The separation of the three different months was influenced because when they were layered upon each other the message was not as clear.

California's Drought

The question that I was asking with this map is how bad has the drought become after a couple years in California. I started with the map for 2015 first and after I perfected it then I created the map for 2012. After the two data frames were created, I then added finishing touches to the complete map. I also created an extent map for people who are not familiar with the western side of the United States. As you can see since the 2012, the drought has become more severe in California. The measurement for the map is the intensity of the drought on a scale of 0-4 on the drought meter.

This map could be used by land management and policy makers to see which counties would need the biggest water restrictions. This map could also be used by the general public to see the conditions of the drought and how it affecting different parts of the state and specific counties. This map can help to shape how the state uses water and how much water is being used in the future. The information from this map can really show the affects of the drought and can have an effect on the public and how their usage of water.

State Parks and Faults

I was questioning how state parks might be effected by the potential danger of faults that run throughout the state of California. This map shows the proximity of faults to northern California state parks. Faults could be dangerous because if there is movement within the fault it could cause harm to people that are visiting those state parks.

This map could be potentially useful to visitors of state parks because if there is a lot of earthquake activity then they may not want to visit a state park that is close to a fault. This map could also be useful to state planners who are planning to create state parks because they may not want to establish a park close to fault lines due to the potential danger of a major earthquake.

I chose to leave out information such as California counties, Geology of California, and California vegetation because they were not relevant to the question that I was asking and the message that I wanted to convey with my map. The fault lines are in the color red because this color really draws the attention of the viewer to the faults and the yellow for the state parks pops out as well to catch the attention of the map users.