System Dynamics -- Research Proposal
Watershed Model
of the interconnections between quantity and quality of runoff
from Red Butte and Emigration Canyons
Written by Charles H. Call, Jr. P.E.
Pd.D. Student Civil Engineering
University of Utah
Description
The purpose of this project will be to prepare a comprehensive watershed model using STELLA. The model will be used to study the system dynamics of the quantity and quality of runoff from Red Butte and Emigration Canyons. This will be done through correlation to historic data and sensitivity analysis of the individual process elements.
Introduction
One of the current areas of national emphasis for the Environmental Protection Agency (EPA) is to evaluate water quality based on the capacity of watersheds. In fact they have initiated use of a tool called BASINS BASINS to aid stakeholders in collecting and displaying watershed data.
EPA has also introduced the concept of total maximum daily load (TMDL) to differentiate between watershed needs and enable solving watershed water quality problems on an individual basin basis. This is based on the concept that each watershed varies based on specific characteristics of the basin.
TMDLs help identify actions and best management practices needed to restore and protect watersheds. The TMDL process is flexible and allows local stakeholders to develop the understanding of their watershed and then choose their own solutions. It is outside the scope of this project to determine TMDLs for these watersheds but the system models developed could be effectively used in the TMDL process.
For this project two adjoining watersheds, Red Butte and Emigration Canyons, offer an unusual opportunity to evaluate the effects of manmade changes (Table 1, Figure 1 and Figure 2). Red Butte [Description of Red Butte Issues] is a Research Natural Area (RNA) and has been controlled by the National Forest Service since about 1900. No watershed development has occurred. Emigration on the other hand has had somewhat uncontrolled development since the pioneers entered the Salt Lake Valley in 1847.
The concepts learned by this model and comparison of the two study watersheds could be transferred to other water supply watersheds (Table 2). An extension of this project might be to evaluate the process of policy making based on the "system" understanding developed through the use of an object-oriented model such as STELLA and visualization using GIS.
Methods and Approach
The water budget approach will be used with annual and monthly time steps. Quantity will be evaluated using a storage representation of the watershed based on the fundamental concept that inflow minus outflow equals change in storage. This watershed scale model will show the relationships and linkages between runoff, precipitation and evapotranspiration (Figure 3). Processes that produce the water quality constituents (Table 3) of the runoff will be linked into the quantity system model (Table 4). These quality impacts will be from both point and non-point sources (Table 5).
Several field trips to the study watershed will be made to evaluate input parameters for the STELLA model and understand watershed processes (Figure 4).
Discussion
The process of system analysis in environmental stewardship uses tools to guide understanding and aid in policy making. The tools can include object-oriented system programs such as STELLA, geographic information systems (GIS), and other engineering and biologic analysis programs. These tools become a means to evaluate, quantify, understand, visualize and address the complex issues (Table 6) related to watershed management (Figure 5). The hypothesis of the system analysis process is that effective use of the available tools can develop a "shared vision" for all "stakeholders" of a watershed. A type stakeholders list could include —
A watershed view of water issues and the effects of development can be can be very complex. System analysis with STELLA can be used to evaluate these complex processes (Table 4). System analysis is something we all do. We form mental models of how the pieces fit together. With tools like STELLA and GIS, we can more easily visualize and focus our system understanding.
The synapses between watershed processes are complex and the goal of this project will be gain a better understanding how the processes are interconnected and how they effect each other.
Map of the system
Glossary of watershed terms
References to be researched
Contact with Research Leader
Contact Chuck Call, Chief Engineer for Salt Lake City Public Utilities
Phone numbers: (801) 483-6840 and FAX (801) 483-6818
Email: Chuck Call or kabenet@aol.com
