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WEB QUERY SYSTEM USER'S GUIDEThe StreamNet web query system is a powerful tool for locating, displaying and downloading data from the StreamNet database. The best way to learn how to use the query system is to try it. This User's Guide walks you through an example of how to use the query system to find information. Be sure to check out the General Guidelines and Tips at the end of this guide. If you get lost or make a mistake you can always use your browser's Back button. By selecting New Query at the top of a page, any existing query will be cleared and you will be ready to start afresh. If you experience problems in either accessing or using the StreamNet data, please contact StreamNet by clicking the "Contact us" button at the top of the page. We are happy to help! Getting StartedAccess the query system by clicking the Query the main database link on the left side of any StreamNet web page. The Select Criteria box comes up containing all of the criteria available. You may choose any combination of criteria for which information is available. Most criteria are one of four broad types:
If you are unsure of which criteria are appropriate for your needs, hover your mouse over the question marks next to each criterion for more information about that criterion. The system queries the database each time a criterion is selected and returns only those remaining values that contain data. This prevents building a query that results in no data. If a value does not appear at a subsequent step, that means that there are no data of that type for the criteria you have already selected. For example, chum salmon will not appear in the species list if you have already selected State = Idaho, where chum salmon are not found. The only criterion that is required is the Data Category. (This is the key thing you will need to know to use this system). You can select criteria in any order. In general, select the criterion that is of primary concern first and then narrow your search from there. For example, if you are interested in a specific kind of information, then choose Data Category first. If you are most interested in a specific species, select the Species of interest and then proceed to a geographic area, a data category, or other criterion. If instead you wish to view data for a given location, select the geographic area first. Select no more criteria than you need. EXAMPLEIn the following step-by-step example we perform a data query starting with a geographic area. Let's say we know we want information for a specific Columbia River subbasin (as defined by NPCC in 2001 for subbasin planning purposes).
On the maps, green indicates data exist for that area.
As each criterion is selected it appears under Your Criteria in the right side of the query box. You can remove a criterion by clicking the X for that criterion under Clear on the far right side of the query box.
Note: Inconsistent information can show on this page. In this example the Location in the header says this redd count occurs from river mile 0 to 9.3, the Trend Comment in the header says the reach is 2.5 miles, and the Miles Surveyed in the table ranges from 0.5 to 3.0 miles. This is instructive in several ways. 1) Sometimes the area surveyed really is inconsistent among years. That was the case for this survey, where in the early years the best survey location was being determined -- all surveys after 1966 are 2.5 miles. 2) Because the exact 2.5 mile reach has not yet been georeferenced we purposely avoid misleading precision in the Location and define it as the entire stream length. Precision will be added as we further develop the database. 3) To help sort out such issues, we provide links to the source documents for all data. Clicking the number in the Reference column takes you to the list of references used for the trend. Click the reference title to see detailed information on a reference. A copy of the report for any reference can be obtained from the StreamNet Library. Another inconsistency you may encounter is a Count Per Mile that does not match the Count column divided by the Miles Surveyed column. These cases occur when the source document is inconsistent. We try to provide all the information available; in these cases the Count Type indicates which parameter is primary, as reported by the agency that conducted the survey.
Note: This screen always graphs the "counts," even when a "count per mile" is the primary variable of interest. In this example we see that "Redds per mile" is the primary parameter reported by the data collector, but number of redds is graphed. Note: Let's take a detour: Two screens back, on the Trend List page's blue toolbar, was a link to a Summary Graph. This returns a line graph of the summed counts for all the listed trends, superimposed on a bar chart showing number of observations contributing to each value, as shown below. When the same set of time series contribute to a range of years the summary graph can be a useful visualization of the combined data sets. But use caution in interpreting summary graphs. Varying numbers of observations per year, varying survey lengths, and other complications can result in misleading graphs.
Now let's return to where we were. Click your browser's Back button.
The download file is zipped to compress the data and save space, allowing the download to run faster. The file must be unzipped before use. If you have questions about doing this, please contact us by clicking the Contact Us button above or by telephone at 503-595-3100.
Once the file is downloaded to your computer it can be unzipped. After unzipping, open the file in an appropriate application, such as Microsoft Excel. If you need to analyze data from several locations or of related types, it may be necessary to download several individual data files and then combine them for analysis. Note: The same data can be associated with more than one geographic area, though, so if you combine data sets be sure to look for duplicate data. It is possible to download large portions of the database. However, the size of the download files may be too large to easily work with. If you need a large file, contact us by using the Contact Us button or by phone at 503-595-3100 and we will be happy to run the query and provide the file. Another Query ApproachBesides the standard query system, you can also use the interactive StreamNet Mappers. This method lets you work interactively with a map to select your area of interest and then obtain the data available for that area. This query approach is much different and has it's own help page.
General Guidelines and TipsBe patient. The system queries the database each time a criterion is selected, which takes time. This prevents building a query that results in no data. Beware of huge downloads. A little forethought will give you a hint of how large a download you are requesting. If you select Stream or Dam as the first criterion, you will get a list of thousands of items, which can take minutes to download and even longer for your web browser to render. For this reason we limit to 1000 the number of items that can be shown on screen. Narrowing your search strategically will help you avoid these roadblocks. No matter how many records you select, though, you can always create a downloadable file of all records in the set. Narrow your search criteria as quickly as possible. In general, use the fewest criteria necessary. For example, there is no need to click State then Subbasin then HUC 4 if you know what HUC you want data for. You can go to the HUC 4 criterion directly. Multiple data. The query system currently does not allow locating data for multiple streams, locations, or species at the same time. If you need such data, you will need to download the individual data sets and combine them. (But, see "Data crossing boundaries" below.) Alternatively, you can download a superset of the items of interest and then cull the data that are not needed. Contact us! Because of the complexity of the StreamNet database, it can require some experience to become proficient at using the query system. We find that too many people give up when they are not certain what to do next. We are happy to answer questions or to provide guidance on how to meet your objectives. We can even run queries for you and provide the results! Just use the Contact Us button, or phone us at 503-595-3100 and ask for the StreamNet office. We are usually able to respond to questions and requests within one business day. Data crossing boundaries. The data in the StreamNet database are biological in origin and generally relate to natural features such as streams or subbasins. Political boundaries generally do not coincide with natural boundaries, or in other cases the natural feature is the boundary and it is thus in two jurisdictions. This results in some waters and associated data occurring in two political units. This creates a potentially difficult situation for managing these data. For example, if a count transect on a stream crosses a county line it would be possible to double count the data if queried separately for each county. Please be aware that as a general convention, the StreamNet database links data to a political unit if any portion of the observation occurred within that unit. Though less common, the same occurrence will happen if a data set crosses subbasin or HUC boundaries. Thus, you must be aware of the possibility of double counting if data are totaled for several political (county, state) or geographic (HUC, subbasin) units. Also, because some sample sites may cross unit lines, the total for a unit might also include some data obtained from outside that unit. It is generally impossible to split data that cross unit boundaries. We can provide assistance and advice if you are faced with these problems. |












