Index
Abstract
Water
on the Web (WOW) is an NSF-funded project that allows college and high school students to monitor Minnesota lakes over the Internet. WOW integrates
state-of-the-art environmental monitoring with geographic information systems,
data visualization, and in-depth educational materials. The goal of the project
is to train students to work with real-world
data to identify and resolve problems in water resource management.
Environmental
monitoring in WOW is based on a Remote Underwater Sampling Station (RUSS)
developed by Apprise Technologies, Inc. RUSS consists of a mobile underwater
sensor package tethered to a floating platform containing an on-board computer,
solar panels and telemetry equipment. RUSS units provide remotely-programmable
vertical profiling of temperature, dissolved oxygen, pH, conductivity, and
turbidity. Instructions for lake profiling are transmitted to RUSS via cellular
phone; resulting data are returned to web server in real time. In 1998, RUSS
systems were installed in Ice Lake, an urban mesotrophic lake in Grand Rapids,
MN and Lake Independence, a relatively eutrophic lake in an agricultural
watershed. In 1999, we placed a RUSS unit in Grindstone Lake, a deep
two-story lake supporting both warm and cold-water fisheries. With additional funding through the US EPA’s
EMPACT program, two additional RUSS units were deployed in Lake Minnetonka, a
large, heavily-used lake complex in the suburban Minneapolis area. RUSS units
will soon be placed in the St. Louis River, which discharges into Lake Superior.
The RUSS
units currently collect data profiles every 4 to 6 hours.
WOW
seeks to develop a technologically competent work force, and to deliver
interpretable water quality information to the public.
The WOW web site can be visited at http://wow.nrri.umn.edu.
Introduction
Technological and
scientific literacy have been identified as critical areas for educational
reform if the United States is to remain competitive in the global economy (AAAS
1993; NRC 1996). At the same time these issues are
challenging education, advancing technology is providing improved access to data
and resources through the Internet. As former U.S. Secretary of Education Terrel
Bell stated, “The technological revolution that has greatly enhanced the
efficiency of industry, business, and publishing has had little impact on the
classrooms of America…..American education is truly wobbling down the
electronic avenue in an ox-cart.” (Bell, quoted in Lockard, Abrams, and Many 1994, p. 388)
Water on the Web is an effort to improve the
technological and scientific literacy of our future work force. Water on the Web (WOW) is a science curriculum project
involving state-of-the-art technologies and real environmental data for college
and advanced high school students. WOW integrates environmental
monitoring with geographic information systems, data visualization, and in-depth
educational materials. The ultimate goal of the project is to contribute to the
training of a more scientifically and technologically competent workforce who
can solve real-world problems. Through the Water on the Web lessons students
learn and apply basic science concepts through the use of real-time remote
sensing technology, geographic information systems, data visualization, computer
supported data management and data analysis, and the Internet.
Water on the Web originated with the development of the
Remote Underwater Sampling Station (RUSS) technology, which allows remote
monitoring of water quality in lakes, along with a desire to use this technology
not only for its monitoring value, but its ability to deliver real-time
information to the classroom. A grant from the National Science Foundation's
Advanced Technology Education program to a consortium of investigators from the
University of Minnesota, Minnesota Sea Grant, local community colleges, and
private industry has made this program possible. Now entering its third
year, Water on the Web had developed a comprehensive web site of curriculum
lessons and resource materials that are available not only to the high schools
and colleges currently participating in the grant, but anyone with Internet
access and the desire to use these resources.
This manuscript provides a guided tour of the Water on
the Web project, including explanations of the technology and software behind
the RUSS systems, the web site, and the
supplemental materials that support the curriculum exercises.
The hypertext links in this manuscript connect to locations within the
Water on the Web Internet site.
Water
on the Web Technology: The
Remote Underwater Sampling Station
Water
on the Web centers around a suite of advanced-technology remote sensors
developed at the Natural Resources Research
Institute of the University of Minnesota – Duluth, in cooperation with a
number of departmental and commercial partners.
Now produced by Apprise
Technologies, Inc., the Remote Underwater Sampling Station or RUSS unit
represents the state-of-the-art in water quality sampling technology. The RUSS unit consists of a floating platform containing
solar panels, a series of deep-cycle batteries, and an on-board computer and
communications package (Figure 1). A
data cable connects the computer to a combination leveling device and sensor
package that floats freely below the RUSS unit.
The leveler uses a buoyancy compensation technology to position the unit
at programmed depths within the water column.
The leveler is designed to accommodate standard water quality sensor
packages (e.g. Yellow Springs Instrument, Hydrolab sensors). The
unit is powered by deep-cycle cell batteries that are recharged by solar cells.
Buoyancy compensation technology is used to move the sensor package up and down
the water column; this system can sample at user-specified intervals to depths
of 100 m with a precision of 0.2 m of the requested depth. The RUSS units are
thus able to provide near real-time water quality data at user-specified
sampling intervals, virtually independent of lake conditions (Betts, 1998; Water
Environment Federation, 1997).
 |
| Figure 1. Schematic of the Remote Underwater
Sampling Station. |
The RUSS units currently
sample five critical water quality parameters: pH, conductivity, turbidity,
dissolved oxygen and temperature. The only effective time limitations to
sampling frequencies are the times required for the sensor unit to descend to a
specified depth and for the individual sensors to equilibrate. In reality, the
relevance of the data is specific to the event being sampled; turbidity might be
relevant on a daily basis, whereas oxygen profiles may change hourly. The
precise sampling frequency depends, therefore, on the question being asked. The
RUSS unit has been initially programmed to collect 1 m interval profiles
periodically (every 4-6 hours) over each 24 hour period, seven days per week.
The data is then transmitted to the Water on the Web server (http://wow.nrri.umn.edu/data).
Data is stored on the RUSS
unit and transmitted to the base station as comma-separated ASCII data.
A parsing program on the server converts the raw data into a spreadsheet
format, and adds it to a comma-separated value (CSV) data archive; one data
archive is maintained for each lake. Data
is also incorporated into an object-oriented database for access by customized
data visualization utilities. This use of multiple formats allows the data to be
accessed with a variety of tools, from simple visual inspection of the raw data,
to analysis by standard spreadsheet and statistical software, to advanced
analytical and visualization tools.
RUSS units are currently deployed on four Minnesota lakes, representing
a wide range in size, morphometry, depth, and seasonal dynamics (Figure 2).
Ice Lake is a small (16 ha area, 16 m depth) lake in a residential
district of Grand Rapids, MN. Grindstone
Lake, in contrast, is nearly 50 m deep, and supports both warm and
cold-water fisheries.
Three units are located in the suburban Minneapolis region, two in
contrasting bays of Lake Minnetonka, and one in the largely agricultural
watershed of Lake
Independence. The
differences in size, morphometry, and surrounding land use among these lakes
provide a unique opportunity to compare and contrast fine-scale temporal
dynamics in water quality variables.
 |
| Figure 2. Locations
of the Water on the Web and Lake Access RUSS units. |
Water on the Web: The Web Site
The
Water on the Web site is an expansive and dynamic site that provides data from
the RUSS units, advanced tools to analyze the data, curriculum materials
tailored to students and teachers, and a rich body of interpretive materials,
web links, and other supporting materials.
The WOW web site is located at http://wow.nrri.umn.edu,
a Windows NT-based server located at the Natural Resources Research Institute at
the University of Minnesota - Duluth.
The following sections describe the architecture and
content of the web site.
You may want to view the system
requirements before following the hyperlinks to the web site.
Water
on the Web: A Guided Tour
The Water on the Web site is divided into 5 sections that address
different aspects of the project:
·
OVERVIEW
– describes the project, the people, the companies and other fundamental
information on WOW.
·
UNDERSTANDING
– describes the technology, the tools, and the lakes, including primers on
lake ecology, geographic information systems, and other key parts of the
project.
·
DATA –
allows users to view, manipulate, analyze the data distributed every 4-6 hours
from the RUSS units.
·
STUDENTS
– a series of curriculum exercises that students can work through, on their
own or in a classroom.
·
TEACHERS
– lesson plans designed to assist teachers in using or modifying the
curriculum materials for their own situations.
The
following sections provide a brief walkthrough of the WOW site.
The hyperlinks presented here link to the site itself – as a result,
you should use the Back button in your web browser to return to this manuscript;
the Home button on the WOW site will take you to the WOW home page.
Overview
The Overview provides a summary of the rational
and primary objectives of Water on the Web. It also provides links to the
project personnel. In addition to
the project staff, WOW works with a number of curriculum writers –
faculty at Minnesota community colleges and high schools who are writing and
evaluating curriculum lessons developed around the RUSS data. We also meet regularly with a national advisory team,
a group of industry, federal agency, and university personnel who provide
insight, suggestions, and evaluations of the overall project. Lastly, we have a
number of agency and industrial collaborators who support WOW through
advice and in-kind support.
Understanding
The Understanding section is a collection of background
information on a number of topics, including a Primer on Lake Ecology, a guide
to Geographic Information Systems, and information on the RUSS units and
parameters.
It also includes background
information on each of the lakes in the WOW program.
The Understanding section provides as a set of resource materials for
both students and teachers.
An extensive on-line reference called understanding
lake ecology is a major resource for students and teachers. This lake
ecology primer provides a context for understanding the WOW water quality
parameters and how they relate to each other. Lake ecology information is
provided from physical, chemical, and biological perspectives. This important
resource section of WOW offers illustrations and links to other sites that help
students understand the science concepts that provide a basis for our
understanding of lake ecology.
A
complementary section describes the fundamentals of Geographic Information
Systems (GIS), a computerized mapping technology that allows students to
make relationships between activities which occur within a watershed (e.g.
agricultural land use, commercial development) and the quality of water in lakes
and streams.
The site uses ESRI's Internet Map Server@ (IMS) technology to allow students to
work interactively with
maps. IMS allow students to obtain progressively more map detail as
they "zoom in" to an area, and to use an information tool to acquire
information on individual map objects (i.e. the area of agriculture within a
watershed).
The
entire Water on the Web site is based on water quality parameters measured by
the RUSS unit. An introduction to these parameters identifies the reporting
limits and instrument accuracy for each of the parameters. For students who are
just becoming familiar with water quality, a synopsis is presented for each of
the RUSS parameters: temperature,
dissolved
oxygen, pH,
conductivity, and
turbidity. These summaries explain why the parameter is important, describes why
there may be natural variations in the measurements of this parameter, and
suggests how measurements of this parameter may be affected by pollution and
other factors (Figure 3).
 |
| Figure 3. Sediment plumes in the western
arm of Lake Superior. |
The
Understanding section also includes a glossary for discipline-specific
terms that may need definition for students. All glossary terms are linked to
definitions throughout the entire web site. In addition, some terms are linked
to pop-up explanations so students do not have to take the time or effort to
navigate to the glossary section and then back to the text.
Data
The data page provides access to the RUSS data in a
variety of formats, including ASCII data, Excel spreadsheets, and HTML
format.
Data from individual lakes can be selected through an interactive query,
or through a data map that displays the entire set of data viewing options for
all lakes. Data are displayed in a variety of tabular formats, from the
raw data as it comes off the RUSS units, to data summarized by layer or time
period.
It is difficult for many students to see and interpret patterns in
numerical data. For this reason WOW also offers several interactive data
visualization applications that allow data to be viewed in line graph, color
plots, or animated formats. Teachers may use these data visualization approaches
to motivate students by illustrating trends or relationships among the data. Key
data visualization techniques provided as of this printing include: the Profile
Plotter, the Color Map Plotter, and the Depth by Time (DxT) Profiler. All of
these tools are coded in JAVA, and designed to run as applets on the student’s
computer.
These utilities are described briefly below, and in detail in a web-based
manuscript (Host et al. In review).
The
Profile Plotter
Limnologists typically display data in the form of lake profile
plots, in which the upper end of the Y-axis represents the surface of the lake,
and the values of selected variables are plotted along the X-axis (Figure 4). Because we acquire four to six profiles per lake per day, there is
a large number of potential plots that could be created.
In addition, it is informative to compare profile plots over time to
observe how a variable changes over time. For
this reason, we developed an application known as the Profile Plotter to allow
students to “step through” the data sets and observe how factors such as
temperature change on a daily or seasonal basis.
The Profile Plotter contains a control panel that allows users to select
a lake, a date, and which variables to plot. The key feature of the
Profile Plotter, however, is the ability to animate the profiles. The single and double arrow VCR controls in the center of the
control panel allows the user to step forward or backward through individual
data sets (single arrow), or let the program automatically step through the data
sets. Using this animation option,
students can adjust the rate at which the ‘movie’ will play. You
can experiment with a live version of the Profile Plotter by clicking here.
 |
| Figure 4. Example screen output from the Profile
Plotter. |
Color
Map Plotter
The Color Map Plotter is an extension of the Profile Plotter
described above. It allows one
variable to be mapped as a color ramp in the background while a second variable
is superimposed as a line plot. Figure
5 shows temperature mapped in the background with oxygen concentration as a
line plot, and illustrates a striking depletion of oxygen below the thermocline.
As with the Profile Plotter, the Color Map Plotter can step through data
sets in a manual or automatic format.
The translation of point data into a color ramp requires
the ability to interpolate values vertically between data points. We use a
simple linear interpolation to predict values at intermediate points between the
1m depth samples. There are also
provisions for extrapolating from the shallowest reading (1 m below the surface)
to the actual surface, and from the deepest reading to the bottom of the lake.
Under frozen lake conditions, the surface temperature is set to 0 C, and
ice thickness can be superimposed onto the image. You
can experiment with a live version of the Color Map Plotter by clicking here.
 |
|
Figure 5. Example screen output of the
Color Map Plotter. |
Depth
x Time (DxT) Profiler
A final application allows students to view trends in
data over time (Figure 6). The DxT Profiler allows a
student to select specific time windows for plotting a selected data profiles. The profiler is quite
flexible, allowing students to set the time window for the display, add grid
lines, show the actual data points, and perform various degrees of interpolation. The
DxT Profiler can interpolate data over both depth (vertical) and time
(horizontal). For both
interpolations, the user can manually set the range of depths or hours over
which the interpolations will occur. Currently,
this utility is used to create GIF images for posting to our web site; a future
version of this will be an interactive tool that allows users to illustrate
temporal trends at varying levels of resolution (e.g. hourly, daily, seasonal).
 |
| Figure 6. Control panel of the DxT Profiler, showing
changes in seasonal oxygen concentrations in Lake Independence. |
The
data visualization utilities described above provide a powerful tool for analyzing data.
Teachers must decide, however, when it is best to use the data
visualization approaches offered through WOW. There are strong advantages in
having students work first with original data using spreadsheets and standard
statistical tools. Teachers may
decide to project data visualizations for the whole class to set the stage and
motivate students for the assignment. In other cases teachers may want to use
data visualizations in closure to a lesson in order to reinforce the concepts
that have been learned by analysis of primary data.
Student
The Student section of the site
provides student lessons in two formats: a directed study format that provides step by
step instructions to achieve specific results, and a inquiry-based format, in
which students are free to use the data and tools present on the site to resolve
a specified problem. All lessons have been designed for college freshmen and advanced high
school students, although the lessons vary in complexity.
A summary of the existing and planned lesson plans by subject area and topic is
presented in Appendix A. The site currently
contains 26 student lessons on 13 topics, plus a tutorial that guides students
on using the site.
As an
example, the Thermal
Stratification lesson integrates hands-on experimentation using water at
different densities with data from the RUSS units. Student create
stratified layers of water in beakers, record temperatures to create a depth
profile, and then predict what will occur when a colored ice cube is placed in
the beaker (Figure 7). After completing the laboratory portion of the exercise,
the students are directed to data sets on area lakes, where they interpret
temperature profiles collected in different seasons. The combination of
the wet lab and remotely sensed data allows the students to make the link
between what the observe in the laboratory and the conditions observed in the
field.
|
| Figure 7. Lake Superior College students
Stacey
Honkala (left) and Katie Mahai (right) work with
WOW National Advisory Team member Earl Byron on the Thermal Stratification
exercise. |
Teacher
The Teacher page leads to the set of
teacher lesson plans indexed by discipline, topic or title.
This page
also provides a tutorial and links to supporting resource data that allows
teachers to tailor the lessons to their particular needs.
In general, the WOW lessons are designed for infusion into an existing
curriculum. The lessons are structured so they may be assigned for the students
as homework, or may be completed in class in a laboratory and computer lab
setting. Portions of each lesson are delineated so that they may be completed
within a standard class period. Appendices B
and C show the key considerations in developing curricula and integrating
technology into current school curricula; these factors were developed in
consultation with the WOW National Advisory and Curriculum Development teams.
Based
on the advice of our advisory and curriculum
teams, the WOW lesson approach incorporates six components that are critical to
improving scientific and technological literacy : knowledge base, experimental
design, data collection, data management and analysis, interpretation of
results, and reporting results. One
component may be emphasized more than the others in a lesson; however, the
lesson model provides a thinking framework that should enable students to use
science and technology to investigate real world problems. The
current lesson plans reflect input from teachers gained through pilot-testing of
draft curriculum materials.
The Heat
Budget of Lakes exercise presents an example of a structured
lesson, whereas the Rain
Storms, Landuse and Lake Turbidity lesson illustrates an inquiry based approach.
Water on the Web continues to grow as a collection of
independent, free-standing but related lessons designed to enrich and enhance student
learning in general science courses. The lessons are developed for infusion into
the existing science curriculum. Teachers of introductory science classes are
almost certain to find a WOW lesson that illustrates or applies a basic concept
that is taught in their class. The ability to enhance student knowledge, not
only in terms of the biological and physical systems of the lake, but in
developing data analysis and presentation skills, learning to effectively use
the Internet, and learning to apply reasoning skills to real-world issues should
result in students more prepared to enter an increasingly-competitive workforce.
Elaine
Ruzycki, Del Nordman, Lindsay Anderson, Brian Vlach and Justin Watkins have gone beyond the call of duty in
keeping the RUSS units up and running. Norm
Will developed the data management and visualization applications used in the
WOW site and maintains the WOW server.
Alexander Tokhtuev developed RUSS
programming software and has assisted in debugging and maintenance of the
units. Scott Robertson and Debbie Kaminov of the Minnesota Sea Grant
program designed the past and present versions of the WOW web site.
We are indebted to our Curriculum Development and National Advisory teams
for their creative input in developing the project and for providing content.
Apprise Technologies, Inc. has provided valuable support and advice in
maintaining the RUSS units.
Environmental Systems Research Institute (ESRI)
has generously provided ARCVIEW GIS software to cooperators in the project
Water
on the Web is supported in part through the National Science Foundation’s
Advanced Technology Education Program under grant # NSF/DUE 9752017.
We also acknowledge support in part from the Environmental Protection
Agencies’ EMPACT program, through our Lake
Access project, an effort to bring RUSS data and interpretive information to
the public. Lake Access a partnership with the Suburban Hennepin Regional
Park District. This is Contribution
Number 261 of the Center for Water and the Environment, Natural Resources
Research Institute.
American
Association for the Advancement of Science. 1993. Benchmarks for Science
Literacy. Oxford University Press, New York.
Betts,
K. S. 1998. Technology Update: All-weather water quality monitor. Environmental
Science and Technology 32(3):85.
Host,
G. E., N. R. Will, R. P. Axler, C. J. Owen, and B. H. Munson. Interactive
technologies for collecting and visualizing water quality data. URISA
journal. In review.
Lockard,
J., Abrams, P.D., and Many, W.A. 1994. Microcomputers
for Twenty-First Century Educators (3rd ed.).
New York: Harper Collins.
National
Research Council. 1996.
National Science Education Standards.
Washington, DC: National Academy Press.
Water
Environment Federation. 1997.
Sampling data in minutes. Water, Environment, and Technology 9:74-75.
Maintainer: AWRA Webserver Team
Copyright © 1999 American Water Resources Association
