Using GIS to describe natural water systems
requires a means to describe the connectivity of
water flow through the landscape. It is not enough
to know that there are geographic data layers of
water features like streams, aquifers, and wells. It
also matters which streams contribute water to
a particular aquifer and which wells are drilled
into that aquifer to supply water for domestic
consumption or irrigation. Only in this way can
we understand the inflow and outflow of water,
in particular groundwater systems, and thus
manage these systems wisely. This book, Arc Hydro
Groundwater: GIS for Hydrogeology, describes a geographic
data model for hydrogeology, using the
Edwards Aquifer in Texas as a vehicle for developing
and explaining concepts. The surface water
components are described in the book Arc Hydro:
GIS for Water Resources (Maidment 2002), which
is planned to be updated to reflect the new Arc