GIS in the Jungle
April 1, 2009
More than 1 billion people do not have access to safe drinking water, according to the World Health Organization. A group of surveyors and engineers from the Fort Collins, Colo., chapter of Engineers Without Borders-USA (EWB-USA) is working to shrink that number and, in the process, clean up a boundary dispute.
EWB-USA is a nonprofit humanitarian organization that partners with developing communities worldwide to improve their quality of life. The Fort Collins chapter recently offered assistance and expertise to the Peruvian village of Santa Rosa de Dinamarca, which is home to about 750 families. While the village is located only about 40 kilometers (24 miles) in a straight line from the provincial capital of Pucallpa, traveling to the village requires a six-hour boat trip down the winding and dangerous Ucayali River, a branch of the Amazon.
The EWB team developed plans to drill a new well, install solar-powered pumps and filters, and provide a storage tank and water distribution system for the village. Surveyor John Von Nieda, PLS, of TST Inc. Consulting Engineers is one of a small team of EWB members who volunteered for the project. He enlisted the assistance of Bryan Baker from Frontier Precision Inc., one of Trimble’s largest and oldest mapping/GIS and survey dealers. Frontier Precision agreed to help sponsor the trip by providing all of the Trimble equipment and covering Baker’s time and expenses.
The team first visited the village in July 2007 with plans to map the existing facilities and develop details for the water system. But the villagers had a new priority that radically changed the scope of the EWB project.
Mapping the DetailsSanta Rosa de Dinamarca is home to the indigenous Shipibo people, whose lands and culture are protected by the Peruvian government. While the ownership of their land is guaranteed, boundary lines exist only on rudimentary maps and drawings. The Dinamarcans were concerned that non-Shipibo people from the north were encroaching into their land. When the Dinamarcans learned that the EWB team included surveyors, they asked them to solve the boundary issue.
“We were asked to establish the boundary for a 100-square-kilometer (38.6-square-mile) parcel covered by thick jungle and swamps,” Von Nieda says. “They handed us a tattered survey map from the 1991 government grant to the Shipibo that described the parcel. But getting that boundary tied to the ground was a major challenge.”
A quick search of Google Maps showed that the Shapefiles received from the local government were outdated and that the location of the Ucayali River had shifted by miles over the past 17 years. Because of these discrepancies, the boundary maps and existing riparian boundary data were useless.
As a first step toward obtaining spatially accurate boundary data, Von Nieda and Baker plotted the river’s location using a Juno ST hand-held GPS receiver. To mark the boundary on the ground, they relied on the Trimble GPS equipment, information from the local residents and their own skill.
Von Nieda and Baker brought with them a multipurpose set of Trimble equipment. Baker’s expertise with mapping and surveying hardware and software made it possible to easily assimilate the data from multiple hardware and software sources required for this project.
For GPS surveying, they had two Trimble R8 GPS receivers, a Trimble TSC2 controller and an array of batteries, poles and accessories. They also had a Nikon NPL-352 total station for use under jungle canopy. Baker added a Juno ST hand-held for use in GIS mapping and data collection. All work in the village was done with an audience of curious onlookers.
To begin their boundary work, the EWB surveyors set out into the jungle--aided by two dozen machete-wielding villagers--to locate the north boundary of the Shipibo land. Using the pocket-sized Juno ST hand-held, the team navigated toward a point where the villagers believed the northern boundary might be located. The villagers were eager to blaze a trail along that line, but the team needed to collect more evidence and do additional research back in the states. They used the Juno hand-held to map the locations of huts, trails, streams and anything else that might be helpful to relate aerial imagery to geodetic positions and determine the boundary placement.
Once the EWB team finished their topo and planning surveys, they returned to the United States to begin processing the data they had collected.
Tying in Aerial DataOver the winter and spring, the surveyors completed extensive research and calculations. One by one, Baker and Von Nieda addressed and answered critical questions such as the 600-meter closing error in the survey map’s boundary and the lack of notation regarding which geodetic datum formed the basis for the original survey.
They then returned to Peru in June 2008. This time, the team was equipped with a high-performance Trimble Nomad hand-held field computer and GPS receiver, which is designed for use in harsh environments such as under forest canopy, and a Trimble GPS Pathfinder ProXH receiver for advanced GPS positioning. “This is by far the thickest, densest jungle environment I have ever seen, with canopy so thick it can feel like dusk in the middle of a clear, sunny day,” Baker says.
Their first stop was in Pucallpa, where they met with national government officials to review Von Nieda’s work. After detailed discussions, the officials accepted the minor boundary modifications and geodetic placement to coincide with the land title and agreed to send a representative to the village to inspect and approve the location on the ground. The officials were surprised by the extent of incursions into the land given to the Shipibo people and promised to stop further encroachment.
To provide details on the encroachments, Baker conducted an aerial inventory of the area surrounding the village by using the Trimble Nomad hand-held and GPS Pathfinder ProXH receiver. Working at an airfield near Pucallpa, he mounted digital still and video cameras to the side of a small airplane. He connected the cameras to his laptop computer and recorded the images coming from the cameras.
The pilot of the plane put the GPS coordinates for the boundary corners into the plane’s GPS system. Using those coordinates to navigate the plane, the team flew along the Shipibo boundary collecting photos and video. After the flight, Baker correlated the images with positions from the Trimble GPS unit to document the characteristics and locations of the encroachments. Finally, it was time to mark the boundary on the ground. The team loaded up the boat and made the river trip to Santa Rosa de Dinamarca.
Again accompanied by a group of villagers with machetes, Von Nieda and Baker used the Trimble Nomad hand-held and ProXH receiver to locate the boundary they had calculated over the winter. Using a base station run by a local government agency in Pucallpa, the team found that the post-processed data from the GPS Pathfinder ProXH receiver was accurate to within 30 centimeters. “The ‘Edison’ moment came when we were able to acquire the high-resolution aerial photography taken more or less at the same time as the territorial survey was conducted,” Von Nieda recounts. The curve of the riverbank in the survey and on the photo were nearly identical, and in overlaying the boundary on the photo, they found that all other surveyed physical evidence corroborated this placement.
The villagers are now working with the local government agencies and the georeferenced data provided by Von Nieda to legally deal with any encroachments and to permanently establish monuments and boundaries around their communal lands. Work has continued on the original water system project, as well. As an interim step, EWB delivered 300-bucket filtration systems to the village. While work on the boundary survey was under way, other EWB members installed the new filters and trained the villagers in their use.
To ensure clean water in the village, there is more work to be done. Von Nieda is planning two more trips to the village with the goal of having the well, pump and storage tank operating by the end of 2009. Thanks to these efforts, the people of Santa Rosa de Dinamarca will soon have ample clean water to go with their official, well-defined boundary. Additionally the Peruvian government and representatives of the larger Shipibo community have asked the surveyors for assistance in defining boundaries for as many as 24 other territories. “This prospect obviously presents a whole larger set of challenges,” Von Nieda says, “but it is one we will somehow find a way to take up.”