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Judd Curran
Home » People » Judd Curran » Tutorial 2e


        Welcome to the prototype tutorial.  Here, you will be guided through a series of tasks to become familiar with Internet-based geographic information services and associated online analytical tools by examining the data, tools, and functionality of the prototype.  Please follow and perform each of the tasks outlined in this tutorial.  You will be asked specific questions about the prototype related to the tasks outlined in this tutorial in a questionnaire administered at the end of this evaluation.

       As a professional, you are participating in a final expert evaluation that is focused on identifying the usability, functionality, strengths, and weaknesses of the prototype for use in accessing, analyzing, querying, and retrieving hydrologic data for decision-making within water resource management.  Your responses in the questionnaire at the end of this tutorial will provide a means for evaluating the likelihood of web-based geospatial information services and analytical tools  to be an effective mode of managing real-time surface water hydrology.  In addition, the future application of this technology to other hydrologic or environmental data may be influenced by your feedback.

This tutorial is composed of three main sections.  In the first section, you will be guided by step by step instructions through a series of tasks to become familiar with the prototype.  Additionally, you will be guided through a simple spatial-temporal analysis scenario.  In the second section, you will be asked to explore the prototype in an attempt to identify aspects that might be specifically useful to your profession.  Finally, in the third section, you will be asked to compare the prototype with the existing USGS NWIS-web real-time California data website.

The right column below contains illustrations and examples pertaining to the text on the left.  If you accidentally close the prototype window, you must close all Internet browser windows and re-open Internet Explorer from the desktop.  The prototype can only be accessed via the green button on the introduction page.

Section I - Guided Exploration with Spatial-Temporal Analysis


     Locate the toolbar that is on the left side of the "Interactive California Hydrology" prototype website (see illustration).  The toolbar contains all of the interactive functions that are available for examining, querying, and analyzing the data presented.  We can group these tools into the following categories:

Presentation:  Legend, Overview, Zoom In, Zoom Out, Initial Active, and Previous.

Navigation:  Pan, Move N, Move S, Move W, and Move E.

Information:  Real-time, Identify, Query, and Find.

Analysis:  Measure, Set Units, Buffer, Select, and Clear.

In addition, a print tool is available.  You will be introduced to most of these tools and their functions.


     Now, locate the center map viewer window.  Here, you can interactively use the tools to explore, analyze, and interpret the map data.  Initially, the state of California is displayed with major hydrologic units.  Note the small version of the map in the upper left corner of the viewer window.  This is the Overview Map.  When you zoom into the main map, a red box will appear in the overview map to show you where you are.  You can move this red box to navigate around the state.  Let's try it...

Select the "Zoom In" tool Zoom Infrom the toolbar.  Then click and drag on a portion of NW California.  A red box will be drawn as you drag your cursor to indicate the area that will be zoomed into (Fig.1).

Once zoomed in, a red box will appear in the Overview Map (Fig.2).  Move this red box to Southern California by clicking on the Overview Map on Southern California.  This will display the zoomed in area of Southern California on the main viewer window.

When the Overview Map is not being used, it can be removed from the main map to free up space.  Click on the "Overview" tool Overview  to remove the Overview Map from the main viewer window.

     To navigate around California, we need a basic introduction to a few of the Navigation and Presentation tools.  These tools will allow us to easily display the map at different scales (close up vs. far away) and move around.

The "Pan" tool Pan provides the ability to grab onto the map and move it around to expose new areas or hide previously viewed areas.  Select the "Pan" tool and move your cursor over the main map.  Click and drag the map around to pan to different areas nearby.  Note that the map may take a few seconds to refresh between pan commands.

Similarly, the "Move" tools Move will shift the map in a fixed direction due North, South, West, or East.  With these tools, you do not have to click on the map.  One click of a "Move" tool will shift the map once in the specified direction.  Click on the "Move N" tool.  Notice that the map displays a new section to the North with a little bit of overlap to reference the previously viewed section.

The "Zoom Out" tool Zoom out will allow you to zoom out by a fixed amount.  Select this tool and click once in the center of the main map.  The map zooms out to a new scale.

The "Previous" tool Previous will redisplay the last map scale.  Like the "Move" tools, clicking on the map is not necessary for this tool.  Click once on the "Previous" tool.  Notice that the map now displays the region that was previously displayed before you zoomed out in the prior step.

Finally, use the "Initial" tool Initial to display the entire map in the main window as seen when the website is first opened.  Click once on this tool.


     Locate the section on the right side of the prototype website, currently displaying "Data Layers"(Fig.3).  This section is used to display Data Layers information as well as Map Legend information and useful web links.  To change the contents of this section from Data Layers to Legend, we use the "Legend" tool Legend located in the Tools section.  Click on "Legend" and note the change that occurs (Fig.4).  Click "Legend" again and re-display the Data Layers list.  Now, we will discuss these two sections in more detail...

The Data Layers section contains a list of all data that is available to display at the current map scale shown in the main map window (Fig.3).  By placing a check mark in the square box next to an item in the list (under the "Visible" column), that item will be drawn in the main map window when the "Refresh Map" button is pushed.  Let's try it...

Currently, Precipitation and Counties are unchecked.  Uncheck Major Hydrologic Units.  Check Counties and then click "Refresh Map" to redraw the main map to include county boundaries.  Now, zoom into San Diego County in Southwestern California.  Notice that at this new scale, additional data layers have been added to the list and drawn on the map.

In addition to displaying and removing data layers, you can choose a particular layer to be "Active".  Only one layer can be made active at any given time.  Activating a layer allows you to search, query, select, and identify features within that layer.  For example, if you activate lakes, then you can search for, select, and get more information about a particular lake.  The data layers that are not active are merely displayed and cannot be interrogated.  Let's try it...

In the Data Layers list, make Lakes the active layer by placing a mark in the circle next to Lakes in the Active column.  Now, lets find some information about a few lakes that are displayed on the main map.  Click the "Identify" tool Identify in the Tools section.  Click on a lake in the main map window.  In the grey box at the bottom of the main map, information is displayed about the lake you clicked on.  If Lakes is not chosen as the active layer, no information will be displayed.  For more experience, activate the Rivers and Streams layer and identify a few rivers using the "Identify" tool (Click Here for video demonstration).

All maps require a legend to define the symbols, colors, and lines used to represent different data.  The Legend in this prototype defines the data that is listed in the Data Layers section (Fig.4).  Legend information is automatically updated when the Data Layers list is updated.  So, if you are having trouble determining which lines are roads versus rivers, the Legend will help!


     The "Select" tools (Fig.5) can be used to highlight and analyze one or more features on the main map.  Let's try it...

1.  Zoom into the greater San Diego area.
2.  Locate the San Diego River
3.  In the Data Layers section, make Rivers and Streams the active layer, check the Lakes box to make lakes visible, Uncheck Roads and Highways, and Refresh Map.
4.  Click on the "Select" box tool and draw a box in the main map over a portion of the San Diego River near La Mesa.

Notice that the full length of the river is highlighted from the coast to El Capitan Reservoir.  Information about the river selected is displayed at the bottom of the main map.  Now that this river is selected, we can discover the usefulness of the "Buffer" tool (Fig.5).  Let's assume that the dam at El Capitan has a bad leak and could fail at any moment.  We need to notify authorities to close all major highways downstream of the Reservoir within a 1 mile radius of the river.  Let's use the buffer tool to find out which major roads are affected.....

1.  With the San Diego River still selected, click on the "Buffer" tool.
2.  In the gray box at the bottom of the map viewer, change "Highlight Features From" to "Major Highways" and "within a distance of" 1 Miles.
3.  Check the "Display Attributes" box and click on "Create Buffer"

Notice that the affected major highways within 1 mile of the river are highlighted in red on the main map and listed at the bottom.  To clear the buffer and selection, click the "Clear" tool (Fig.5). 


     The following analysis will allow you to further explore the functionality and usability of the prototype.  You will be guided step by step through the following scenario....

The Scenario:
Your name is Pat, owner of Pat's River Rafting Company.  You have been hired to guide a group of students on a river rafting trip down a section of the Tuolumne River below Hetch Hetchy Reservoir.  On the scheduled date of your trip, the reservoir will be releasing water at a rate of approximately 3800 ft3/s (+/- 400ft3/s).  Before you depart, you want to find out the average speed you will be rafting down the chosen route.
       This can be determined through an analysis of the movement of prior release flow between two USGS stream gages below the dam.  The stream gages are located at the starting and ending points of your rafting route.  The time is noted when the upstream gage records the rise in the river associated with a release from Hetch Hetchy of approximately 3800 ft3/s (+/- 400ft3/s).  Then, as the release travels downstream past the second stream gage, the rise in the river is recorded and the time noted.  By measuring the distance between the two gages and noting the time elapsed for the release to travel from the upstream gage to the downstream gage, an average travel time and rate of travel in miles/hr can be calculated.  This analysis can be repeated for a different time period to verify results.  Let's begin!

The following steps will guide you through the analysis:

1.  First, we need to find the Tuolumne River below Hetch Hetchy Reservoir and the two USGS stream gages (Station #11276500 and #11276600).

A.  Click "Initial" tool.  Then, click the "Zoom In" tool and draw a zoom box tightly around California and Nevada to zoom in closer and eliminate most of the outlying area.  In the Data Layers section, mark Rivers and Streams as "Active".

B.  Now that Rivers and Streams is the active layer, we can search for the Tuolumne River.  Click the "Find" tool Find.  A search text box appears in the gray section below the main map.  Type in "Tuolumne River" (spelling is important) and press enter.  A list of rivers and streams associated with the Tuolumne River are displayed.  Scroll to the bottom of this list and click on "Zoom to These Records" (in blue text).  The map will zoom into the vicinity of the river and the river will be highlighted in yellow.

C.  Let's find the two stream gages that are going to help us with the analysis.  Mark USGS Stream Gaging Station as "Active" in the Data Layers section.  Then, select the "Query" tool Query.  The Query tool can search for multiple features at the same time.  In the "Field" box, select "STA_NUM" for station number.  In the Operator box, select "=".  In the value box, type "11276500".  Then click on "Add to Query String".  Click the "OR" button.  In the value box, type "11276600", then click on "Add to Query String".  Finally, click "Execute" to locate both station numbers.  Both stations become highlighted in yellow in the main map and are listed below the main map.  Scroll to the bottom of the list and click "Zoom to These Records"(may be in light gray text).

D.  To verify that we are in the right location, let's check to see if Hetch Hetchy Reservoir is just upstream of our two selected gages.  If the lake name does not automatically appear over the lake, use the "Identify" tool, verify that the upstream reservoir is Hetch Hetchy.

E.  Great!  The stretch of river that will be navigated on your rafting trip is located between the two previously selected gages below the reservoir.  We are in the right spot.

2.  Second, we need to measure the distance between the two gages.

A.  Distances on the map can be measured in miles using the "Measure" tool Measure.  Select the measure tool.  Starting at the upstream gage, click multiple times in short segments along the river to determine the length.  After the last click at the downstream gage, the distance of each of your segments along the river will be added up in the "Total" box located in the main map window in the upper left corner. (Click here for a Video Demonstration)

B.  The approximate distance that you should have calculated is 10 miles.

3.  Next, we will access the USGS real-time streamflow data for both stations and search for recent release flow that is at a rate close to 3800 ft3/s (+/- 400ft3/s).  Once found, we will record the date and time of the increase in flow associated with the release.

A.  The prototype website is designed to link directly from stream gages in the main map to real-time USGS stream flow data.  To use this feature, the USGS Stream Gaging Station layer in the Data Layers section must be set as the "Active" layer.  Mark this layer as active.  Select the "Realtime" tool Realtime and click on the upstream station (#11276500).  A new Internet browser window will automatically open to the homepage for this station.  Resize this page to fit the right half of your screen.

B.  On the station homepage, click on "Realtime".  Change the graph output days to 31 and click "get data".  Locate two recent instances on the graph when releases occurred that caused an increase in flow to approximately 3800 ft3/s (+/- 400ft3/s) (around June 24th and 28th).  To determine the precise date and time that the release began to pass this gage, let's take a look at the data in table format.  Under "Output Format", select table and click "get data".  Scroll to June 24th and find the first instance when the flow began to rise on the increase to approximately 3800 ft3/s (+/- 400ft3/s).  Record the time.  Then, repeat on June 28th and record the time.

C.  Repeat the steps in 3 A-B using the downstream gage (#11276600).  What was the difference in time between the recorded release of June 24th for the upstream gage vs. the downstream gage?  And for June 28th?  Below are the approximate results....


1st Instance of Rise in Flow From Release

1st Instance of Rise in Flow From Release


(1O Miles)

June 24



3.75 hours

2.7 miles/hr

June 28



4.25 hours

2.4 miles/hr

D.  The end result of the analysis indicates that rafting in this section of the Tuolumne River under current conditions will produce an average speed of 2.55 miles/hr.  This type of analysis could be done for predicting peak flood event times at downstream locations and incorporates the influence of current channel conditions on travel times.


Tools 1  Tools 2





 Fig 1

Example of Cursor being dragged over map to designate area to
be zoomed into.


Viewer 2
The Overview Map




























Data layers

Data Layers

The Legend



































Buf Sel Clear
FIG. 5
Buffer, Select,
and Clear Tools






























 Kearsarge River







Click Here to
Send an Email

Section II - Free-form exploration of prototype

       In this section, no step-by-step instructions are given.  Instead, explore the prototype in an attempt to identify any aspects that might be specifically useful to you in your profession.  Perform a general decision-making or mapping task and see if you can implement your own spatial-temporal analysis scenario that might be useful for decision-making during flood events.  Try to use several different tools in the process.


Section III- Comparison of prototype with existing NWIS-web.

     Several web links are located below the Data Layers section of the prototype website.  Click on the green "California NWIS Homepage" link.  The California NWIS homepage is the current, active homepage of real-time hydrologic data produced by the USGS for the state of California.  This homepage includes an interactive map of California with clickable station points that are color-coded to convey current streamflow conditions.  Using this map, select the same two stations on the Tuolumne River that were used in the prior analysis. (#11276600 and #11276500).  Compare this interactive map with the prototype website side by side and make a note of the advantages and disadvantages of each.







Last Updated: 12/30/2014
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