Research
(Daene C. McKinney)
Dr. McKinney's research interests include developing and applying numerical
methods for simulation, optimization, and uncertainty analysis of environmental
and water resource management problems, and the development of laboratory
and field experimental techniques for the characterization and remediation
of aquifer and groundwater contamination. He is currently engaged in research
on:
-
Water Resource Management
in the Aral Sea Basin
-
Management and Modeling
of the Edwards Aquifer in Central Texas
-
Large_scale_Water_Balance_Computations
-
Expert Geographic Information
Systems for Water and Environmental Management
-
Optimal Aquifer Management and
Remediation
-
Characterization and
Remediation of Subsurface NAPL Contamination
-
Modeling of Bioremediation
in NAPL Contaminated Aquifers
-
Risk-Based Decision
Analysis Approach for Aquifers Contaminated with NAPLs
Home
Management
and Modeling of the Edwards Aquifer in Central Texas
Dr. McKinney has been developing techniques that can
be used for the conjunctive management of surface and groundwater systems.
Recent events in the San Antonio area of Texas have provided a good opportunity
to test some of these methods on an actual aquifer. The springs of the
Edwards aquifer provide habitat for several endangered species, the economic
base for a large recreation industry and a source of water supply for downstream
users. Recent attempts to develop drought management plans have been plagued
by a lack of statistical analysis of the uncertainty present in all water
resources planning activities.
This research has developed stochastic process modeling
procedures to generate synthetic recharge sequences for the Edwards aquifer
in the San Antonio region. The processes are multivariate, first-order
autoregressive and fit to a 58-year historical record based on USGS recharge
estimates for the nine river basins of the Edwards aquifer recharge zone.
The synthetic recharge sequences for the Edwards Aquifer are used in a
groundwater simulation model of the aquifer to determine the statistical
characteristics of low spring flow periods. In addition we have investigated
methods of augmenting springflows in the event of a severe drought.
In addition, one of Dr. McKinney's major research projects
has been to study available methods for the augmentation of spring flows
from the major springs of the Edwards aquifer in order to protect endangered
species. This project was a multidisciplinary effort in which Dr. McKinney
directed the efforts of water resources engineers, geologists, and biologists
from The University of Texas and two federal agencies (U.S. Geological
Survey and the U.S. Bureau of Reclamation). The result of this project
was a report which is being used by both state and federal government agencies
to develop species preservation and drought management plans for the San
Antonio region.
Dr. McKinney maintains an active interest in the management
and modeling of the Edwards aquifer. Several ongoing research projects
are using this as an example system to test some of the water resources
management tools being developed by Dr. McKinney's research group. These
include an object oriented geographic information system based hydrologic
modeling system which links the surface and subsurface hydrologic systems
and allows decision makers easy and graphic access to the model results.
Another research project is considering the development of optimal long
range development of water resources in the region taking account of the
stochastic nature of the hydrologic systems.
Top
Large-scale
Water Balance Computations
Methods for large-scale water balance computations at
the regional and continental level are being developed by Dr. McKinney
and Co-PI Dr. D. R. Maidment in this research. These methods make use of
geographic information systems and object oriented programming techniques
to determine the availability of water resources (surface and ground water)
for large river basins and their associated aquifers.
Top
Expert Geographic
Information Systems for Water and Environmental Management
Dr. McKinney and Co-PI Dr. D. R. Maidment have developed
automated methods for long range, regional water resources development
at the state-wide level. These tools and techniques consist of a combination
of expert systems and geographic information systems operating in conjunction
with a network flow balancing algorithm to determine minimum cost water
allocations for large regions. Currently, Dr. McKinney is adapting this
new water planning methodology to the allocation of water in the Lower
Colorado River Authority (LCRA) service area in central Texas.
Top
Optimal Aquifer Management
and Remediation
A new optimization method, the genetic algorithm, has
been adapted and applied by Dr. McKinney to groundwater management problems.
This new method significantly broadens the ability to solve aquifer remediation
design problems which account for the fixed costs of installing well fields
and the performance of treatment systems. The performance of genetic algorithms
and the more conventional nonlinear programming algorithms in the design
of aquifer remediation systems has been investigated and compared. Through
this research, genetic algorithms have been shown to be very effective
at solving groundwater management problems. The incorporation of treatment
process design performance into remediation system design has been developed
and demonstrated for the first time.
In addition, Dr. McKinney has developed methods for optimizing
the design of remediation systems to cleanup aquifers contaminated by nonaqueous
phase liquids (NAPLs). These methods include linking multiphase aquifer
simulators with both nonlinear programming and genetic algorithms on serial
computers and the development of a completely new parallel genetic algorithm
method for use on massively parallel computers.
Top
Characterization
and Remediaiton of Subsurface NAPL Contamination
Laboratory and field experimental and computer simulation
techniques are being developed by Dr. McKinney and Co-PI Dr. G.A. Pope
for the use of partitioning interwell tracer tests (PITT) for the detection,
estimation, and remediation performance assessment of aquifers contaminated
by nonaqueous phase liquids (NAPLs). Experiments have been conducted and
results obtained from partitioning tracer tests in sand columns. Using
these data, new method of moments and inverse modeling techniques have
been developed and demonstrated for estimating NAPL saturation in subsurface
formations. The partitioning interwell tracer tests can be used to estimate
the amount of NAPL contamination before remedial action and as remediation
proceeds. The tracer test method has been demonstrated in simulations of
a three-dimensional (3D), heterogeneous saturated and unsaturated zones.
The experimental and simulation results demonstrate that PITTs can be used
as an innovative and effective technique to detect and estimate the amount
of residual NAPL, and for remediation performance assessment in both saturated
and unsaturated zones. Field-scale experiments demonstrating partitioning
tracer technology for characterizing NAPL contamination and remediation
assessment have been conducted in the vadose zone at a Sandia National
Laboratory site in New Mexico and in the saturated zone at the Hill AFB
Operable Unit 2 site in Utah.
Top
Modeling of
Bioremediation in NAPL Contaminated Aquifers
This research involves the development and testing of
a three-dimensional simulation model capable of evaluating NAPL contaminated
aquifer remediation methods using enhanced dissolution of NAPLs trapped
at residual saturation in aquifers (with Co-Pi's Drs. G.A. Pope, K. Sepehrnoori,
G.E. Speitel Jr., and M.M. Sharma) . One of the main tasks of this research
that Dr. McKinney is most actively involved in on this project is to co-direct
(with Dr. G.E. Speitel Jr.) the development of a new microbiological population
model to be incorporated into the NAPL simulation model.
Top
Risk-Based
Decision Analysis Approach for Aquifers Contaminated with NAPLs
Dr. McKinney and Co-PI Dr. R. Gilbert are developing
a risk-based decision analysis approach for remediating aquifers contaminated
with dense, nonaqueous-phase liquids (DNAPLs). Remediation of DNAPLs is
an important research problem because DNAPLs pose a significant threat
to aquifers and because they are extremely difficult to remediate. Sixty
percent of Superfund sites with groundwater contamination contain DNAPLs.
DNAPL contamination is difficult to detect and characterize. Conventional
pump and treat remediation technologies are ineffective and costly for
remediating DNAPLs. Other remedial alternatives, such as natural attenuation
and in situ bioremediation, do not have a proven track record. Therefore,
there are numerous uncertainties involved in developing site assessment
programs, selecting and designing remedial alternatives, establishing feasible
performance criteria for remediation, and designing monitoring systems
to confirm long-term performance. The objective of this research is to
implement a decision analysis approach that provides the ability to account
rationally for these uncertainties throughout the remediation process.
Top
Home