Environmental Engineering Reference
In-Depth Information
can be derived from digital elevation models, topographic maps, or Google Earth.
The general perimeter and area can be estimated, which will help in planning the
number of survey points and the time required for surveying. While this broad
overview can also provide initial insight on the types of equipment and gear that
will be required for conducting a survey, a pre-survey site visit is essential.
In most cases, it is essential to contact property owners or public lands managers
for permission to access a wetland. State or county permits may be required if
biological sampling is part of the plan. Advanced planning ensures that the field
work will not be interrupted or postponed, potentially leading to missed
opportunities related to seasonal water levels.
Finally, before beginning field work, being aware of the appropriate safety
measures is important. Safety measures may include bringing a first aid kit, adequate
communications devices (walky-talkies, cell phones, or satellite phone), and personal
protection gear (bug spray, sun screen, hardhat, boots, personal floatation devices,
and safety vests). The necessary equipment will vary with local conditions (weather,
proximity to infrastructure, etc.). In general, you want to be as prepared as possible to
reduce the risks of accidents or injury.
2.3 Wetland Survey Techniques
2.3.1 Recording Field Data
There are many established techniques for bathymetric and topographic mapping.
They all have one thing in common: their data are only as valuable as the quality of
the comments and notes that describe the methods and features being surveyed.
Without clear field notes, survey data are just numbers with no context. Standard
survey notes should be adhered to if the goal is long-term monitoring. Professional-
quality notes should be unambiguous, and understood by anyone who tries to
re-survey the site. Because some long-term monitoring projects can span generations
of students and professors, consistency and reproducibility are key features of data
collection. Experience shows that a weatherproof notebook (such as “Rite in the
Rain”) and a #3H mechanical pencil lead will create a long-term archive of survey
data and field notes. Electronic data records are in common use, but storage media
change through the years, so maintaining a hard copy of original survey data and
notes in the office is essential.
Information recorded in standard field notes should include date and time, site
description (field sketches of key elements such as bench mark locations are
valuable), purpose of the survey, type and serial numbers of survey instruments,
names and roles of team members, general weather conditions, and wetland
characteristics. The notes that record a specific survey should fully describe the
benchmarks and datums that were used. Specific survey shots are recorded in a
series of data columns. Depending upon the survey technique, these columns might
