UMBC High Performance Computing Facility
Dynamic Coupling of the Water Cycle with Patterns of Urban Growth
UMBC: C. Welty (PI), Andrew Miller, Bernadette Hanlon, Michael P. McGuire, Aditi Bhaskar, Kwabena Gyimah-Asante
Princeton: James Smith (PI), Mary Lynn Baeck
Shippensburg: Claire Jantz (PI), Scott Drzyzga
LLNL: Reed Maxwell (PI)
USGS: Gary Fisher (PI)
The objective of this project is to link an urban growth model
(SLEUTH) with a fully-coupled, physically-based three-dimensional
hydrologic model (PARFLOW-CLM) to evaluate the effects of growth on
water availability and limits to water supply using the Baltimore
metropolitan region as a case study. The urban growth modeling will
consist of a rigorous and fully validated implementation of the SLEUTH
model coupled with a spatial statistical model of urban suitability and
demographic data. This approach will define a suitability map for urban
land cover based on the conditions that are associated with current
urban land and areas of recent urban land cover change. Landscape
variables, such as soil suitability and non-urban land cover (e.g.
forest and agriculture) will be used to define appropriate conditions
for urbanization. Socio-economic variables, including lands that are
protected through regulatory policies or parks, population density, and
others, will also be included. In addition to providing a platform where
both landscape characteristics and socio-economic variables can be
integrated, this model will provide the opportunity to test and quantify
the influence of each of these variables in either attracting or
resisting development. Because the model will have a better
representation of the landscape in terms of where development is more or
less likely to occur, we also anticipate an improvement in the model’s
performance. Implementation of the hydrologic component of the project
will include intensive field studies at the local scale that will focus
on a single highly urbanized watershed, Dead Run, which is a tributary
to the Gwynns Falls, the primary study watershed of the Baltimore
Ecosystem Study NSF-funded long-term ecological research site. Detailed
process studies will be carried out in conjunction with application of
the EPA SWMM model to achieve an integrated understanding of controls on
water stores and fluxes at the subwatershed scale in a highly urbanized
area. Subwatershed fine-scale modeling results results will then be used
to determine large-scale effective properties as inputs to PARFLOW CLM
of the entire metropolitan region. Combining a physically-based regional
hydrologic model with an urban growth model will allow an assessment of
the coupled feedbacks between growth projections (and the socio-economic
variables that affect growth) and surface and subsurface water
resources. Changes in stream baseflow and groundwater availability may
in turn influence regulatory decisions on development permits in exurban
areas.
A long-term goal of hydrologic modeling activities in the Baltimore
region is to establish an “end-to-end system” of field-deployed sensors
and sensor networks feeding real-time data into hydrologic models to
enable prediction of water fluxes in streams and aquifers. One objective
is to understand how the urban landscape and infrastructure partitions
water in the components of the hydrologic cycle. This understanding is
critical to quantifying biogeochemical cycles, a main focus of the BES
LTER. This project will advance our objective of tying smaller-scale,
process-based studies to a larger scale regional understanding of how
the water cycle operates. This project will also advance several
long-term goals for urban land cover modeling. Most significantly will
be an opportunity to develop the links between urbanization and
hydrologic systems in a spatially explicit context. The importance of
water resource management to serve the public interest is a topic of
growing importance to the State of Maryland precisely because of
stresses induced by patterns of growth but with inadequate tools and
insufficient data currently available to support decision-making. This
work will help to close that gap. This effort is also of interest to the
Chesapeake Bay program, in its work toward addressing questions about
critical thresholds – e.g., when a critical threshold is reached and
why, and what needs to be done to reach a sustainable condition.
Interaction with state and local agency personnel will be carried out in
order to incorporate their questions and policy concerns into modeling
scenarios and to discuss the implications of our findings.