Introduction
Historic USGS Topographic Maps
The history of the USGS Topographic Maps dates back to the late 19th century, when the USGS set out to create detailed maps of the entire United States. The 1:24,000 scale, also known as the 7.5-minute quad map, became one of the most widely used scales. Each map covers an area of 7.5 minutes of latitude and longitude, detailing an area of approximately 64 square miles (166 square kilometers).
A subset of these has been incorporated into the overall collection of approximately 81,000+ maps, and future improvements and additions will be made. Metadata includes state names, place names, and scale. Texas, California, and other states are not being added directly, but may be added over time.
In the United States, the USGS (United States Geological Survey) topographic map is an important map series that plays a vital role. These maps have a rich history dating back to the late 19th century and have grown into a powerful resource for a variety of applications. Of the various scales used, the 1:24,000 scale stands out for its importance in striking a balance between detail and coverage.
The history of USGS topographic maps dates back to the late 19th century, when the USGS set out to create detailed maps of the entire United States. The 1:24,000 scale, also known as the 7.5-minute quad map, became one of the most widely used scales. Each map covers an area of 7.5 minutes of latitude and longitude, detailing an area of approximately 64 square miles (166 square kilometers). These maps have become indispensable tools for scientific research, land-use planning, recreational exploration, and many other activities.
Importing these tens of thousands of maps (over 6.86 TB in total) into the Google Earth Engine collection is a daunting task. The effort is worth it, though, because this vast archive of historical maps now offers researchers, historians, and enthusiasts an unprecedented peek into the past. From understanding how landscapes have evolved over time to comparing historical and contemporary features, the possibilities for exploration and visualization are endless.
USGS Topographic Maps in Earth Engine with Collars
When stitching together the individual map sheets, a key challenge arises due to the presence of collars. These map collars contain important metadata such as map legends and other details, but prevent seamless stitching of adjacent maps.
USGS Map Index 1:24,000
To address this issue, we developed a feature that utilizes the 1:24,000 map index layer. By clipping the collar lines, the maps can be precisely aligned, creating a uniform and comprehensive representation of the region. I've also added metadata a step further, so these atlases have region and location information in addition to year and state, which can be used for aggregation.
The 1:24,000 scale USGS collection of historical topographic maps, part of the insiders list, is now generally available in the upcoming 1.0.9 release and will continue to be tweaked and improved. You can find details and links here. This work was not only an ambitious attempt to discover and preserve historical data, but also an opportunity to learn about traditional map-making techniques and the art of cartography. Some states, such as California and Texas, have not been included due to limitations on the number and size of assets.
Examples of USGS acquisitions at different scales in GEE
USGS topographic maps at a scale of 1:24,000 provide a fascinating window into the past, providing valuable insight into America's changing landscape. Digitizing, ingesting, and stitching the more than 81,000 maps in this trove was challenging, but ultimately a comprehensive and valuable resource for researchers, educators, and map enthusiasts. Through this project, I can pass on my love of historical maps to others, while also celebrating the evolution of mapping methods and the timeless importance of cartography in understanding our world.
quote
United States Geological Survey. (2019). Yosemite National Park [Topographic map, Map No. 12345]. 1:24,000. U.S. Geological Survey.
the code
var usgs_topo = ee.ImageCollection("projects/sat-io/open-datasets/USGS/historical_topo");
var map_index = ee.FeatureCollection("projects/sat-io/open-datasets/USGS/TOPO_24K_MAPINDEX");
print(usgs_topo.first())
print(usgs_topo.aggregate_histogram('state'))
print(usgs_topo.aggregate_histogram('year'))
var items = usgs_topo.toList(1000)
var item = ee.List(items).shuffle(false)
var img = ee.ImageCollection(item).first()
Map.centerObject(img,10)
var snazzy = require("users/aazuspan/snazzy:styles");
snazzy.addStyle("https://snazzymaps.com/style/38/shades-of-grey", "Greyscale");
//Function to clip to 24K grid & remove map collars mostly
function clipper(image){
var center = image.geometry().centroid()
var main_geom = map_index.filterBounds(center)
return image.clip(main_geom).copyProperties(image)
}
var mapped = usgs_topo.map(clipper)
Map.addLayer(mapped,{},'USGS Mosaic')code link
License & Terms of Use¶
USGS topographic maps are typically in the public domain, which means they are not protected by copyright and can be freely used, reproduced, and distributed. The USGS allows the public to access and use its maps for various purposes without the need for a formal license or permission.
Provided by: USGS
Curated in GEE by : Samapriya Roy
keywords: USGS, Historical Topographical Maps, Orthophoto mosaics, Topography,Cartography
Last updated on GEE: 2023-07-21