New ADWR “Story Map” Uses High-Tech Imagery To Tell Story Of Willcox Area Land Subsidence

ADWR Story Map image

Since the dawn of modern science – since Copernicus struggled to bring around 16th century skeptics to his evidence of a heliocentric solar system – illustrating complex science to a general audience has proved challenging.

A century or so after Copernicus, Galileo and his famous telescope would (eventually, at least) help illustrate the Polish astronomer’s claim that the earth revolved around the sun, as opposed to the other way around.

Proving, in other words, that images matter. Text is good. Text and way-cool images? Even better.

Following in Galileo’s footsteps, researchers in the Arizona Department of Water Resources’ Hydrology Division have developed one of the department’s most visually appealing presentations ever:

A “story map” depicting land subsidence in the Willcox Groundwater Basin, where ADWR recently completed work on a comprehensive groundwater-flow model.

Focusing on the prevalence of land subsidence in the Willcox Basin, the story map uses interactive imagery as a compliment to textual descriptions of the area’s subsidence issues. Together, they paint (quite literally) a clear picture of the dramatic subsidence issues facing the region.

Produced for ADWR by GIS Application Developer Karen Fisher and Brian Conway, supervisor of the Geophysics/Surveying Unit, the “story map” brings together into a single, user-friendly package a wide assortment of the tools that hydrologists employ to analyze groundwater conditions.

“This story map is the first of hopefully other story maps that combine (geographic information system, or “GIS”) maps, data analysis, images/multimedia content, and a summary of various Water Resources topics in an easy to read format to tell a story,” said Conway.

Fisher said they selected the Willcox Basin as the subject of the story map due to the area “having the highest annual magnitude of land subsidence in Arizona,” as well as “a number of active earth fissures.”

Fisher designed the story map using ArcGIS mapping and analytics software, a product of Esri, a global market leader in GIS.

“Esri has story-map templates that they have been encouraging their users to use,” said Fisher.

“Brian and I both thought of the idea and wanted to highlight land subsidence in hope that it would inspire other groups at ADWR to put their projects into a story map.”

As described by Esri, story maps “are a simple yet powerful way to inform, engage, and inspire people with any story you want to tell that involves maps, places, locations, or geography.”

The web applications, the firm notes, “let authors combine beautiful maps with narrative text, striking images, and multimedia, including video.”

The narrative text is the other beauty of the ADWR land-subsidence story map.

Its text is general-audience friendly – scientifically precise while, at the same time, expressing the complex land-subsidence issues the map depicts clearly enough for a high-school age, would-be hydrologist to appreciate.

In addition to the direct link found above, the story map is available at the ADWR Hydrology eLibrary, which can be found here: https://new.azwater.gov/hydrology/e-library

Groundwater flow model of Willcox Basin completed

drill rig

As a result of continuing observations of groundwater level declines in the Willcox Basin, the Arizona Department of Water Resources (ADWR) initiated development of a numerical groundwater flow model in late 2015.

The Willcox Basin covers an area of approximately 1,911 square miles in southeastern Arizona and is essentially a closed basin.

That modelling has been completed. Major findings of the modelling include:

• The three-year ADWR modelling project finds high rates of groundwater pumping in Willcox Basin altering the groundwater flow system “to a significant extent.”

• Evidence of the amount of groundwater removed from storage between 1940 and 2015 ranged from 4.9 million to 6.2 million acre-feet (an acre-foot equals 325,851 gallons of water, or the amount of water needed to cover an acre of land a foot deep).

• Projecting forward to simulate a period of time between 1940 and 2115, the modelling concluded a net “change in storage” – meaning, in this case, a reduction in storage – ranging from 19.8 million acre-feet to 24 million acre-feet.

• Going forward to 2115, the modelling simulated long-term “draw down” in various portions of the aquifer range from a minimum of 354 feet (in the aquifer system north of the Willcox Playa) to as much as 917 feet (in the aquifer system near Kansas Settlement).

• Both data and modelling indicate that significant declines in regional groundwater levels continue to occur.

• Based on the Willcox Model results, pre-development estimates of groundwater in storage circa 1940 ranged from 80 to 97 million acre-feet. Recent estimates of groundwater in storage (2015) range from 73 to 92 million acre-feet. Projection estimates of remaining groundwater in storage range from 57 to 77 million acre-feet. However it must be noted that a significant portion of the remaining groundwater in storage is found at considerable depth and may not practical to remove.

The Groundwater Flow Model of the Willcox Basin may be found here

An Executive Summary of the results of the Flow Model may be found here

For more information regarding this matter, please contact Sally Stewart Lee, Public Information Officer at sslee@azwater.gov  or (602) 771-8530.