Week 8 Assignment

In the "Difference, 1990 to 2000" map, I noticed that population change occurred the most in the bigger cities such as Los Angeles and New York. There was negative population change mostly in the north west and some counties in almost every state. I noticed that the scale of population change provided by the Census may be confusing to some while reading the map and would need further explanation. I also believe that the color ramp makes the map easy to navigate and the colors aren't too close to each other. 

In the "Number of People, 2000" map,  I noticed that the number of people was greater in metropolitan cities. For example, Los Angeles county had a higher number of people compared to other counties in Nevada. The scale is more helpful than the scale for the "Difference, 1990 to 2000" map in that there are no negatives. I noticed that the color ramp may confuse some people in that some colors are close to one another.

 

In the "Percent Change, 1990 to 2000 Total Population" map, I noticed that there was a high percentage change in some Nevada counties. There were some negative percentage change in some counties in Texas as well. The scale is helpful, however the color ramp isn't helpful. The color ramp makes it difficult to decipher the two dark shades from one another, they both look black. Other than the two dark colors, everything else makes the maps easy to read.

 

In the "Population Density, 2000" map, I noticed that Los Angeles county has a dense population as well as other metropolitan cities. Some counties in Texas and Nevada had a low population density as well. I also noticed that the scale and color ramps were helpful. However, if someone is looking at the map from a distance, then they may have trouble telling the difference between the lighter green and white.

Working on the Census map series tutorial was slightly more difficult than the previous tutorial that we worked on in that the instructions weren't too clear. For example we were asked to sort the table, however it couldn't be done because the related rankings and columns wouldn't match when sorted. Another issue was the mismatched tables, if the error wasn't written in the instruction sheet, it would have made the map incorrect. Working with GIS has become easier than before due to practice and I'm getting more used to it. Also I'm realizing how much can be done with GIS and how easy it is to create a map with correct data.

Week 7 Assingment - Dalal

The following DEMs are of aspect, slope, hillshade, as well as a 3d image of the location. DEM of the 3d image is from "ned_03854530". The datum, geographic coordinate system used is GCS North American 1983 and the extent is 39.8° top and 39.38° bottom. The extent from the left is -105.79° and from the right is -104.97°.

Week 5 Assignment - Dalal

Equidistant Projection measurements from Washington, D.C. to Kabul:

• Sinusodial Projection: Geodesic = 6,930.97 mi., Loxodrome = 8,088.14 mi., Great Elliptic = 6,909.31 mi.
• Equidistant Conic Projection: Geodesic = 6,976.59 mi., Loxodrome = 8,112.06 mi., Great Elliptic = 6,915.06 mi.

Equal Projection measurements from Washington, D.C. to Kabul:

• Bonne Projection: Geodesic = 6,918.66 mi., Loxodrome = 8,112.06 mi., Great Elliptic = 6,915.06 mi.
• Cylindrical Equal Area Projection: Geodesic = 6,994.40 mi., Loxodrome = 8,112.06 mi., Great Elliptic = 6,930.98 mi.

 

Conformal Projection measurements from Washington, D.C. to Kabul:

• GCS WGS 1984 Projection: Planar = 10,106 mi.
• Mercator Projection: Planar = 7,110 mi.

In this week's assignment, we produced different map projections based on the data that was given to us as well as the data that we added. We made Washington, D.C. and Kabul stand out with blue markers and then measured the distances between the two with each projection. Measuring was a little difficult than it seemed because every time I measure the same projection, I received different measurements. The measurements weren't drastically different but they were a couple numbers off. This made me realized that it can be difficult to receive precise measurements. I even compared my measurements for the conformal projections with my neighbor and noticed that our measurements were a little different. Having different measurements may raise alarm, unless I wasn't doing it properly. It also made me think of the perils of map projections and their significance since measurements vary.

As mentioned in class lecture, map projections vary and the distance between two points on each projection is rarely the same. Also in order to work with map projections and layering on ArcGIS, we have to make sure that spatial attributes on the layers are all the same for the shapefiles. If the spatial attributes aren't the same, then the layers and measurements will be completely off. For those who are new to ArcGIS, like myself and others, it can easily be brushed over unless we are taught to double check the spatial attributes, such as this assignment. Not double checking the spatial attributes or knowing that you need to match them up can cause problems and is a peril of map projections. In all of my map projections above, I made sure to double check my spatial attributes when working on the maps.

The significance of the various map projections is the different purposes they have and points they want to make. Each map projection has different story to tell as well as point of view. Some projections center their maps according to the country it is produced from while others make their own country look bigger than others when in reality it is the opposite. For example, in the Mercator projection under the conformal projections, Alaska looks bigger than Brazil when that's not the case. Making a country look bigger and in the center of a projection makes that country look more "powerful".

The potentials of map projections are to show the different points of views based on the producers of the projections. Also, the various projections allow for various purposes as well as specific purposes. For example, some map projections show the shortest distances from one location to another if the projection is accurate. Overall, map projections can be helpful to map users, however, the user has to be weary of the projection and fully understand various projections.  

Week 4 Assignment - Dalal

This week was the first time using ArcMap through a lengthy tutorial. I was unaware of various aspects of ArcGIS and didn't know there was such a thing as ArcGIS. The level of intimidation got to everyone and there seemed to be a rush of getting it done quickly which was impossible. I had some trouble with the ArcMap tutorial, but overall it was a positive experience. However, I found it to be a little long and tedious due to how long it took to complete this lab. I did find some buttons and functions to be a little confusing since there are other similar buttons found on the different tool bars. However, with the thorough directions, I was able to figure out the similar buttons.

ArcGIS is an important tool and used in all fields whether it be entertainment or engineering according to class lecture. Through ArcGIS, you are able to efficiently model specific data sets according to class lecture. It can be used to create maps and show points of interests at various levels based on the data that is given about that point. ArcGIS is almost always used for development, as well as preservation in order to figure out whether an area can be used for development, as well as other factors with data layering and design. This is effectively done with correct and proper data in order to produce the most accurate ArcMap. 

The pitfalls of ArcGIS is that if the data isn't accurate, then the map produced will be incorrect. Also working with ArcGIS is tricky to work with and it works best with someone who is very computer savvy/literate. Also you need a lot of experience in ArcGIS in order to be comfortable and understand everything you need to do and how to do it. ArcGIS isn't available to everyone since it needs to be purchased, especially the most used made by ESRI. However, there are other companies which vary based one the information you put in and what kind of output you want to receive according to class lecture.

Overall, ArcGIS has its peaks and pitfalls and it mostly depends on experience and availability. It has a lot of potential and advantages and an important tool used in almost all fields. All new technology has its peaks and pitfalls, but it depends on the perspective of each person.

My ArcMap