Tag Archives: imagery

#TimeLapse Tuesday – Spot the Change – Urban Growth of Ankeny, Iowa

What changes do you notice in this Landsat time lapse video?

1) The areas of purple and white in the image are urban areas. Throughout the video they fill in the area from the bottom to the center. The pink areas are farm land.

2) Did you notice the increase in the number of retention ponds (dark blue specks in the urban areas) over time? Retention ponds are used to prevent flooding and provide for water storage in urban areas. As areas become urbanized there is often more surface covered in concrete, parking lots and buildings. There are fewer places for the water to flow directly into the ground.

3) Did you spot the golf course on the northern edge of the city?


This year we are celebrating 50 years of the Landsat earth observing satellite mission. Landsat data helps us observe changes in our communities and environment over time.


This video was created using Google Earth Engine. You can create your own time lapse videos by visiting: https://emaprlab.users.earthengine.app/view/lt-gee-time-series-animator.

Summer 2021 NAIP Imagery Now on ISU Orthoserver

Iowa Statewide summer 2021 imagery is now available as a webservice from the Iowa Geographic Map Server. https://ortho.gis.iastate.edu/arcgis/rest/services/ortho
Please note: you may have to adjust the symbology to get the best color.

Here are some suggestions for doing this is ArcGIS Pro, within the Symbology tab, use the dropdown menus to adjust the color.

  • Change Stretch type to Minimum Maximum.
  • Also consider changing the Statistics from Dataset to DRA (Dynamic Range Adjustment). See the example below.
Before Adjustments

After Adjustments

ISU Mapathon Greatest hits…show the highlights reel!

Over the past few years the ISU GIS Facility has hosted a number of mapathons. Most of our mapathons have a time set aside for mapping in Iowa and then a time where we focus on international projects.

It is amazing what even a small group of mappers can do to add to the OpenStreetMap basemap in a small town in Iowa. Below are three examples of demonstrating how a mapathon event can add to the OpenStreetMap.

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Happy GIS Day 2020! #GISDay

As a way to celebrate GIS Day and OpenStreetMap, we are encouraging everyone to go online either during this week or on GIS Day and contribute to the OpenStreetMap basemap. You may consider improving the basemap in your own community. Here are several projects to consider:

Public Lab Mongolia – https://tasks.hotosm.org/projects/9560/
Public Lab Mongolia (PLM), a local non-governmental organization in Mongolia, is leading the Mongolian chapter for volunteer mappers through the HOTmicrogrant COVID-19 project, as part of their mission to promote open data and disaster preparedness. This mapping will also help with COVID-19 response efforts. This project is to map Ulaanbaatar capital city of Mongolia, is organized by PLM in collaboration with the Mongolian Geo-spatial Association and local universities.

Hurricane Eta – Nicaragua – https://tasks.hotosm.org/projects/9765
Hurricane Eta brought wind, rain and storm surge to the coast of Nicaragua. This project is to finish the basemap of Bilwi (Puerto Cabezas) by digitizing buildings from MAXAR imagery. Available to beginners, there may be tricky tasks in this project as some areas have been partially mapped with older imagery and vegetation can often hide parts of structures. Make sure to review the instructions for tips on how to overcome these challenges and provide high quality data.

Explore your own project: https://tasks.hotosm.org/explore

And now for something weird: Joseph Kerski’s Weird Earth

Today we will be joining Joseph Kerski, a Geographer and GIS education enthusiast, exploring Weird Earth: Exploring the Earth with Interesting, Bizarre, and Odd Imagery. Joseph provides a narrated video on Youtube (primarily targeted at educators) but you can also explore these fascinating places on your own using this ArcGIS Online map. Thank you, Joseph, for taking us to new places and uncover hidden gems on our planet!

What does social distancing look like? – A View from Space

A couple weeks ago Bloomberg News posted an interesting article (click here to read the article) showing how the stay at home orders are effecting areas around the world using high resolution satellite imagery. Below is an example showing Venice, Italy on October 20, 2019 compared to March 18, 2020 after the residents were asked to stay at home. It is interesting to compare the water clarity and traffic.

Venice, Italy: Notice the change in water traffic and water clarity after the Italy began ordering residents to stay at home. Source: Bloomberg.com

The article highlights numerous sites around the globe including: Wuhan, China (before shutdown / after shutdown); Mecca in Saudia Arabia; Venice, Italy; Epcot Center in Florida, USA; Tianjin, China; and Miami Beach, Florida, USA.

Resource: What It Looks Like From Space When Everything Stops, Eric Roston, March 24, 2020, Bloomberg.com

Loess Hills: Iowa Landforms Revealed

Obscured from view by vegetation and built structures, Iowa’s often subtle landforms are revealed through a LiDAR-derived bare earth digital elevation model in a Geographic Information System. Geological and human made features can be seen in this series of LiDAR color hillshade maps from across the State.

Loess

Deep deposits of wind-blown silt define the Loess Hills region of western Iowa. Intricate drainage networks and agricultural terraces are visible in this map from along the West Nishnabotna River near Hamburg.

Click on image to explore.
This image is of part of the Loess Hills in southwest Iowa.

Algona Moraine: Iowa Landforms Revealed

Obscured from view by vegetation and built structures, Iowa’s often subtle landforms are revealed through a LiDAR-derived bare earth digital elevation model in a Geographic Information System. Geological and human made features can be seen in this series of LiDAR color hillshade maps from across the State.

Algona

The elevated curved features in this map are glacial moraines deposited during the most recent period of glaciation in north-central Iowa. The largest in this view is called the Algona Moraine.

The Algona Moraine is located in north central Iowa.

Oneota River Valley: Iowa Landforms Revealed

Obscured from view by vegetation and built structures, Iowa’s often subtle landforms are revealed through a LiDAR-derived bare earth digital elevation model in a Geographic Information System. Geological and human made features can be seen in this series of LiDAR color hillshade maps from across the State.

Oneota

Originally called the Oneota, the central river feature in this map is the Upper Iowa River. The well-defined drainage features are characteristic of the Driftless area of northeast Iowa.

Click on the image to explore in detail.
The Oneota River Valley is located in northeastern Iowa.

Introducing Iowa Landforms Revealed

This spring, Gregg Hadish of USDA Natural Resource Conservation Service and staff member of ISU GIS Facility put together a series of images called Iowa Landforms Revealed. The project looks at Iowa geological features using LiDAR. Gregg also used interesting color ramps to give these images an artistic component, inspired by the USGS Earth as Art project. The initial project includes a series of 4 images which debuted at the Iowa Technology And Geospatial (ITAG) Conference in West Des Moines, Iowa, this summer. We will be highlighting each image over the next several weeks as a special series feature on the IowaView blog. Please feel free to leave comments or suggestion for future landforms for us to explore.