The two most fundamental types of data stored in the Cross Section Viewer database are surveys and cross sections. A cross section is a single transect of surveyed points across a river. The word cross section or transect are used interchangeably within the software. Essentially a cross section is a single line across a river, typically perpendicular to flow. Within the software, cross sections are considered permanent, monumented transects that are surveyed repeatedly. Each cross section is identified by a database ID and a river mile. The database ID can be user defined or assigned by the software. The river mile is always user defined and represents a positive distance upstream from a user defined position (typically but not necessarily river mile zero, where the river terminates at the confluence with another water body).
A survey is a collection of cross sections that were collected as a single initiative. This might represent one field season’s worth of data, or smaller campaigns perhaps strategically related to some kind of flow. The most common use of surveys is to think of them as a single visit to each monumented cross section. Repeat surveys would then represent repeat visits to each cross section. In practice, surveys don’t always include every cross section.
Most analytical tools within the software are based on either a single survey or comparing two surveys together, so it’s important for users to develop a consistent strategy for organizing their survey data.
To view a list of surveys in the current database, select
Surveys. A list of surveys is displayed showing the river mile of the most downstream and upstream cross section surveyed as well as the total number of cross sections included in the survey.
To add survey, select
Add and enter Name and Remark fields. Each survey must possess a unique name within the current database. Names can be anywhere between 1 and 255 characters long.
To edit survey properties, select (double-click, or right click and
Edit) on the survey of interest. Edit the desired fields and then click
- Importing data into a survey is covered in the Import section.
- To export a list of surveys or delete survey data, see the Edt Menu Items help page.
- For more information on Adjusting Survey Data Vertical Elevation, see its help page.
It is important to understand the distinction between a cross section definition and a cross section survey. These two concepts crop up throughout the software and, for the sake of saving space in the software user interface, are not always labeled consistently.
A cross section definition represents a fixed location along a river, analgous to a monumented transect location. This location does not change over time. It is identified by a database ID and a river mile. Sometimes these definitions are monumented with concrete structures, signs or other markers. Often each definition possesses a pair of start and end coordinates used for navigation.
A cross section survey represents a single visit to a cross section definition and the collection of a set of survey points along the defined cross section.
Each survey can only include each cross section definition once.
To view the set of defined cross sections within the current database, select
Cross Sections. The table that appears contains one row for each defined cross section and a column for each survey in the database. A
1 is displayed where the particular cross section definition was captured during the survey.
You cannot add, edit or delete cross section definitions directly. Rather, cross section definitions are created while importing survey data.