Sunday, May 14, 2017

Lab 4 Where is the Best Place to Live in Denver?

Introduction:

L ab 4's goal was to create a spatial question and use geoprocessing skills to answer the question. The project required using 4 tools using 3 different ones. The spatial question I chose was where is the best place to live in Denver, Colorado. In order to be a desirable spot the location needed to be at least 1 kilometer away from major highways, a majority of the residents needed to be between 20 to 34 years of age, and finally the location needs to be within 500 meters walking distance of a park. Multiple tools were used to achieve this answer. Buffer, Dissolve, and Erase were used to spatially answer the question. The intended audience for this spatial question would be people who are looking to live in Denver at a young age and be nearby outdoor recreational places. 

Data Sources:

In order to answer this question it required using data showing highway locations, park locations, and block groups obtained from the city of Denver. the data i used was found in the states section of the metadata from ESRI, and block group information was obtained from the City of Denver (https://www.denvergov.org/opendata/dataset/city-and-county-of-denver-addresses). from the Block Group data set, i utilized the age ranges 20-24 and 25-34. Some concerns i have with the data is what year it came from, if it is older data the map may be off by the current years standards. 

Methods:

In order to answer this spatial question information needed to be obtained, from previously listed data sources, that would be useful for applying to the criteria for a desired living area. The data needed was first the shape of Denver county, then  a clip of highways running through Denver, block groups in Denver, and parks within Denver county. First off the Denver Highways were buffered b 1 Kilometer to satisfy the distance from highway criteria. Then the Buffer was dissolved to remove the lines in the buffer and make it smoother (Figure 1).
(Figure 1) This figure shows the flow model for the 1 kilometer highway buffer.

The block group clip was then used to select the age group that is desired to live around in this case age 20-34. this was performed by selecting by attributes the ages 20-24 greater than 200, and the ages 25-35 greater than 200. After selecting the block groups with the desired age range, they were dissolved to remove the dividing lines, this produced the layer "Maj_Age_Dissolve" (Majority age) (Figure 2).

Figure 2: This figure shows the attribute selection and dissolve of the Block Group age range 20-34.

Next the dissolved 1 Km buffer was erased from the Maj_Age_Dissolve to produce the Layer Maj_Age_Dissolve_1kmbuff. This layer is the desired living area with the correct age range and distance from highways. Before adding the final criteria of being within 500 meters of a park. 
Figure 3: This figure shows the Erase performed between Maj_Age_Dissolve, and the dissolved_1km_buffer.

Next the Parks feature class was buffered 500 meters and then clipped and erased to form the Desired living area in Denver. The Parks Buffer was erased and then clipped to only leave the Desired location with an age range of 20-34 and within the buffer of the parks (Figure 4). 
Figure 4: This is the entire flow model showing every step to produce the desired living space based on the criteria of 1 kilometer from highways, a majority age group of 20-34, and within 500 meters of a park. 


Results:

The Result of the spatial question of where is the best place to live in Denver is shown in the map below that illustrates the desired locations away from a highway, around an age group of 20-34, and in walking distance of a park (Figure 5)

Figure 5: a Map showing highways parks and the desired living area in Denver based on the criteria for the projects. 

Evaluation:

My impression of this project was that it is very useful in making us think about where to obtain information and how to use it without having step by step instructions explaining what to do. If I were to repeat the project I would probably choose a better spacial question that could have more criteria too it. 

 Sources:



Monday, May 8, 2017

Lab 3 Vector Analysis with ArcGIS

Goal:

The goal of this lab is to utilize geoprocessing tools and spatial operations for vector analysis to develop a map of suitable bear habitat in Marquette County Michigan. 

Background: 

Utilizing bear sighting points that have been recorded in the study area of Marquette Michigan, we were to determine where suitable bear habitat within the county are. In order to be a suitable location for bear habitat, the locations were required to fall in either Mixed Forest Lands, Forested Wetlands or Evergreen Forest Lands. We also had to determine how close some bears are in proximity to a stream. We also eliminated habitat that is in close distance to urban areas. Then a data flow model was created to show the steps taken in developing the analysis.

Methods:

Objective 1:

In objective 1 we created an XY coordinate for the bear sightings around Marquette county. We did this by using the XY tool and joining an outside excel files that shows the XY coordinates of bear sightings. then we geo referenced it by applying the NAD 1983 HARN Michigan GeoRef (Meters). then we exported this into the Database that is being used.

Objective 2:

For objective 2 we determined the 3 bear habitats that most sightings were found in. The three locations were: Mixed Forest Lands, Forest Wetlands, and Evergreen Forest Lands. These are the three land cover types that are used as most suitable for bear habitat. Then I created a layer of these three land types and called it suitable bear habitat.

Objective 3:

then we determined the proximity of bears located near streams. This was done by buffering the streams by 500 meters and selecting the bear sightings that fall within the buffer. After selecting the Bear locations within the stream buffer, a new layer was created called bear cover. 72% of bears fell within the stream buffer. This means that these are important habitat areas for bears.

Objective 4:

Next we needed to determine habitat that fell within the stream buffer and is also one of the three land cover types that is most inhabited by bears. To do this you need to query the land cover types and create a new layer then you intersect this layer with the stream buffer and then this layer needs to be dissolved this layer shows land that meets the criteria of being within 500 meters of a stream and within a suitable land type.

Objective 5:

Next we need to make recommendations to the Michigan DNR for a bear management plan. This required using the DNR management layer, and clipping it to the size of the study area. this gave us the DNR managed areas within the study area. This layer needed to be dissolved to make the polygons consistent. This new layer that was created shows land that is in a suitable area and in DNR managed lands.

Objective 6:

Next we needed to determine the Urban areas within the study area and buffer them 5 kilometers. After buffering the urban areas a new feature class was created called urban and built up land. Then the erase tool is used to get rid of suitable habitat areas within the urban buffer. This gives a layer of habitat away from urban areas.

Objective 7:

Objective 7 was to create a cartographically pleasing map that shows location of bears, streams, and the suitable habitat. a small locator map was created showing where Marquette county falls within the upper peninsula of Michigan.

Objective 8:

The goal of this objective was to use and learn how to python code tools within ArcGIS. The first code created a 1 Kilometer buffer around the streams feature class.

>>> import arcpy
>>> arcpy.Buffer_analysis("streams", "streams_buf", "1 kilometer", "Full", "ROUND", "ALL")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\streams_buf'>

The second line intersected the stream buffer and suitable bear habitat.

>>> arcpy.Intersect_analysis(["streams_buf","suitable_habitat"], "land_stream")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\land_stream'>

The last code ran was to erase urban and built up land from suitable land layer created in the previous code.

>>> arcpy.Erase_analysis("suitable_habitat","Urban_area_buff","suitable_hab_outside_URBAN")
<Result 'H:\\Documents\\ArcGIS\\Default.gdb\\suitable_hab_outside_URBAN'>


Results:

Objective 1: The results gave the locations of bear habitat. 
Objective 2: I found the top 3 land cover types which were Mixed forest land, forested wetlands, and evergreen forest land.
Objective 3: The results found that 72% of bears are sighted within 500 meters of a stream.
Objective 4: the results gave us bear habitats within 500 meters of a stream, and also in the top three land cover types.
Objective 5: The results produced DNR managed areas in the suitable habitat.
Objective 6: The results produced habitats that are 5 kilometers away from Urban areas.

Objective 7: The results created a cartographically pleasing map showing location of bears, streams, DNR managed habitat, and suitable bear habitat all within the study area. A reference map was also produced to show the location of the study area. A data flow model was also produced showing the steps involved in creating this map.

Objective 8: Created a buffer, intersect, and an erase tool using python code.

Sources:

http://gis-michigan.opendata.arcgis.com/

http://www.mcgi.state.mi.us/mgdl/nlcd/metadata/nlcdshp.html

http://www.dnr.state.mi.us/spatialdatalibrary/metadata/wildlife_mgmt_units.htm

http://www.mcgi.state.mi.us/mgdl/framework/metadata/Marquette.html