A New Map App for Visualizing the Magnitude of Pumping

PDF of slides presented at the 2018 Pennsylvania Groundwater Symposium, State College, Pennsylvania, May 2018.

WellFootprint and ModelMuse – A New Map App for Visualizing the Magnitude of Pumping

By Daniel J. Goode, Richard B. Winston, Matthew D. Conlon, and Dennis W. Risser

Abstract

Groundwater withdrawals at wells are often shown on maps as circular symbols at each well, with the size (area) of the symbol proportional to the volumetric rate of pumping. A new GIS mapping algorithm, “WellFootprint”, has been developed to improve this visualization in two ways: first, overlapping symbols at two or more closely spaced wells, which under-represent withdrawals, are merged into an irregularly-shaped combined ‘symbol’, called a ‘footprint’, the area of which proportionally displays the combined withdrawals; second, the scale of the symbols (“Depth-Rate Index”, DRI: the ratio of the volumetric rate to the area of the symbol) can be defined as a water-resource metric, such as the recharge rate, so that the map shows how large the withdrawals are relative to that metric. Input data needed are limited to well locations, withdrawal rates, and the user-defined DRI. We demonstrate ModelMuse and WellFootprint for preparation of well withdrawal footprint maps in Adams Country, State College, and parts of the Delaware River Basin Commission’s Southeastern  Pennsylvania Ground Water Protected Area. We stress that a footprint map does NOT show areas that contribute recharge to wells, or capture zones – it is solely a visualization of the withdrawal magnitudes, centered on the wells.