Tag: GPS

Guest post by Michael Grasso, Environmental Studies ’13 and Dan Ladd, Middlebury College ’14

The G.I.S. team started the Miller Run Restoration Project at Abby Lane in and around an oat field adjacent to the driving range at the Bucknell golf course. We spent the majority of the first day becoming accustomed to the equipment. Some of us took continuous topographical measurements with the mobile RTK-OPUS GPS unit and the others used the theodolite Total Station to collect coordinate and elevation data at the culverts in the area. Culverts are concrete or corrugated steel structures jutting out of the ground where drainage pipes release water. There were 5 culverts in this first area we worked on. The water these culverts expel is polluted and travels at a high velocity which unnaturally increases the flow of the stream, disturbing the ecosystem. That problem will hopefully be alleviated (if not solved) by the creation of the wetlands at the culmination of the Restoration Project.

Actually using the equipment to get measurements is fairly simple. The aspect that we spent the most time learning was setting up the equipment and getting it ready to record data. On that first day it took us 30-45 minutes to set up the Total Station, but now it takes us only 5-10 minutes. To prepare the equipment, we first set up the theodolite tripod directly over a point marked with a nail in the ground. Then, using a bubble level, we adjust the tripod to make it as level as we can. When we put the theodolite on the tripod, we can achieve a more accurate measure by using a level that’s part of the theodolite. Once the equipment is as level as possible, we look through an eyepiece located on the theodolite which has a mirror that is angled directly at the ground with a cross hair in the view. We are able adjust the theodolite to position the cross hair at the middle of the nail. We are then ready to begin syncing the equipment. This process is time consuming because when we look through the eyepiece more often than not we cannot adjust the theodolite enough to get it directly over the nail, so we have to go back to step one and reposition and re-level the tripod.

After the first day of week one at Abby lane, we began the real work. That was the week of the heat wave when temperatures were 95+ everyday, so we agreed to meet at the geology building to get the equipment at 7am (an hour earlier than we usually meet) to try to beat the heat. The rest of the week was spent collecting elevation and coordinate data. After the second day we had taken all the continuous topographic measurements we could before the farmer harvests his crops, so we focused on taking cross sections of the stream. The stream bed was almost completely dry at this point, so we had two people collecting measurements and two up ahead looking for the stream bed and pushing the vegetation out of the way so it was easier to see. Thursday and Friday of that week the part of the stream we were collecting data from was in an area of very thick vegetation that towered over us. We were given machetes and sickles to clear a path along the stream bed so we could record data. Professor Duane Griffin pointed out certain plants we should avoid hacking because they were native and would be included in the vegetation that will be added to the wetlands. A large majority of the plants we cut down were Japanese knotweed–an invasive species that chokes out most other vegetation in the area. There were at least 3 different significant stream beds in this area, so we did a lot of hacking and searching.

Once we finished taking cross sections and stream profile points at Abby Lane, we moved across the driving range to the other side of Smoketown road and began collecting data in front of the Sunflower daycare building. It was much easier to get points there because there was little vegetation and flowing water. As we moved downstream towards the mods, however, the vegetation became much thicker than it was over by Abby Lane, so we contacted facilities and asked them to clear the brush. There were large areas covered with poison ivy so the school wanted to minimize the amount of contact between us and the vegetation. After facilities cleared paths for us, and if weather permitted, we collected continuous topographic and stream profile data, and took cross sections every 2-3 meters on Miller Run right in front of the mods.We also recorded dense continuous topographic data for the area between the mods and the stream (near where the solar panels are). This is an area of interest to the Miller Run restoration committee as this is a proposed area for a possible wetland.

Currently we are waiting for the farmer to harvest so we can finish collecting data by Abby Lane. Once we finish the data we collected will be combined and merged into a Digital Elevation Model (DEM) that can be used by Geologists, Geographers, Biologists and Environmental Scientists to figure out flow models, habitat zones and decide where to place wetlands.