Learn ArcGIS
By: Jyothi Gupta
Tags: Data Science, Data Visualization, Arcgis, Geospatial, GIS

Can you tell how many trees (‘Positioned Nonconiferos tree’) are in this area? Hint. Use ‘Select By Location’.

- Can you compare the number of trees at different thresholds? Try to modify the ring area transparency to for a clearer view of the data.

Hint. Use the toolbox and proximity and multiple ring buffer. Use ‘Symbology’ from the Layer Properties.

- At what distance is the furthest tree?

Hint. First create a centroid of the UCL main building, you may use Point Distance from the toolbox

Network Analysis Task3:

Find the shortest path between two points on the network of road. Hint: build a network in ActCatalog and import road data, then work with Network Analyst in ArcToolbox.

Network: to perform a shortest path analysis we need to build a network first. In ArcCatalog create a new feature dataset and then import or copy highways into it.

Network analysis

ArcGIS — Network Analysis

Let’s work with some other data sources, and data formats. We can import csv files, WMS and use APIs. Let’s start creating an air pollution map of London using available data on the web. It is point observations [x,y, contc], nearly 4m points. We can load data into event layer, interpolate data [to make raster], and do some raster analysis.

In order to find the shortest path (or any other network analysis) please make sure your network extension:

Task 4:

Create the raster map of air pollution in London using csv file of air quality data from data.london.gov.uk , https://data.london.gov.uk/air-quality/

Let’s work with some other data sources, and data formats. We can import csv files, WMS and use APIs. Let’s start creating an air pollution map of London using available data on the web. It is point observations [x,y, contc], nearly 4m points. We can load data into event layer, interpolate data [to make raster], and do some raster analysis.

Air quality data for UK

And create some raster outputs like and/or get some histogram and quantitative results:

To do spatial analysis, please make sure the extension is enabled. And now you can use the spatial analysis tool with some functions like interpolation (you will learn more about these analyses later!)

ArcGIS — Conversion tools

Spatial Analyst Tools for ArcGIS

So far, all interpolation raster has been stored just in memory. For further analysis we need to save it:

Export data in ArcGIS

Export Raster data in ArcGIS

ArcGIS as a WMS client

We can send a getMap request to a server with no GISoftware what so ever.

Copy and paste the following GetCapabilities request in your browser address bar:

http://www.gebco.net/data_and_products/gebco_web_services/web_map_service/mapserv?reque st=getCapabilities&service=wms&version=1.1.1

The response includes information about the available Layers, SRS (Spatial Reference System), and Formats of the image (map), see below:

OGC Web services: Web Map Services

code of ARCGIS

Then you can send the GetMap Request (via your browser). Please note you don’t need any GIS software to get this:

http://www.gebco.net/data_and_products/gebco_web_services/web_map_service/mapserv?reque st=getmap&service=wms&BBOX=- 90,30,5,65&srs=EPSG:4326&format=image/jpeg&layers=gebco_latest&width=900&height=600&ver sion=1.1.1

Try to play with the BBOX (Bounding Box), Map size (width and height), Image format and see what you can get in response. For the above request we should get below map/image:

map size image for getMap request

Now you can send the same request through your software (Arc, QGIS). You can do the same in your software and use the map/image as the background, or even analyse it. Here is the example in ArcCatalog.

The ArcCatalog application is used to organise and manage various types of geographic information for ArcGIS for Desktop. ArcCatalog can be used for managing geodatabase schemas, search for and add content to ArcGIS applications, documentation, manage GIS servers, and manage standards-based metadata. ArcCatalog allow working with variety of sources/types of data. They include Geodatabases, Raster files, Map documents, globe documents, 3D scene documents, and layer files, Geoprocessing toolboxes, models, and Python scripts, GIS services published using ArcGIS for Server.

Here we try to send the same WMS request we had sent last week (remember?

http://www.gebco.net/data_and_products/gebco_web_services/web_map_service/mapserv?reque st=getmap&service=wms&BBOX=- 90,30,5,65&srs=EPSG:4326&format=image/jpeg&layers=gebco_latest&width=900&height=600&ver sion=1.1.1)

WMS server

And now you can use the response map as the background of other layers or analyse the (georeferenced) raster file itself.

(georeferenced) raster file

ArcGIS difficult — The big difficulty is that ArcGIS (the standard) has a user interface out of the 90’s, constantly changes names and locations of things across editions, and is generally the most finicky piece of software with which I’ve ever worked. The ways in which it can randomly go from OK to FUBAR are amazingly varied.They will look just as they did in ArcMap with the same layouts and symbology. Actually, maps created in ArcMap may look even better after being imported because ArcGIS Pro uses anti-aliasing so lines and text are more crisp and clean.

ArcGIS Uses — It is used for creating and using maps, compiling geographic data, analyzing mapped information, sharing and discovering geographic information, using maps and geographic information in a range of applications, and managing geographic information in a database.

ArcGIS Cost — The license costs $100 for a 12-month period. This annual fee allows for the home use or personal use of the ArcGIS suite of GIS software along with its most popular extensions. If you’re a student attending an educational institute running a qualified Esri Campus-Wide Site Licenses, the deal is even better.

GIS is a subject that can be self taught using online tools. As you have no doubt learned using search tools, a plethora of courses including several that are free. GIS in itself is not terribly difficult to learn.

Open source technology means that its source code is freely available to use, modify, and redistribute. Esri encourages a hybrid model for open source technology depending on users’ needs. Esri Geoportal Server and ArcGIS Editor for OpenStreetMap are examples of Esri’s open source projects.

More to come, stay tuned!