Preserving the Harare wetlands
Fresh from celebrating their sixth birthday alongside their siblings across the southern hemisphere, Zimbabwe Flying Labs have stepped in to help remap the wetlands in the country’s capital, Harare, which have been under increasing pressure from urbanisation of late.
The Zimbabwean flying labs franchise, one of whose reasons for existence is to offer drone and robotics solutions to humanitarian problems, has been working with a local environmental lobby group to find modern ways of protecting the remaining natural habitat in the country’s capital.
It is actually funny when you think about it.
There was a time in colonial Zimbabwe when native workers – having brought up in rural settings and still very much rooted to the art of good old agriculture – refused to take up residencies offered by their employers in high-density locations in mostly southern and western Harare, because they always believed they would return to their rural homes some day and never return to the city.
So; what did they need two homes for, they would sarcastically ask.
But independence brought with it a new kind of eye-openers, with massive urban-rural migration that put a strain on the city’s infrastructure; housing being among the most affected. Far removed from their parents and grandparents’ dreams of eventually returning to their villages of origin, the current generations of Harareans understand the value of urban property so much that they have literally occupied every available space to raise new homes.
Not to mention peri-urban farming too, which has prospered in recent years in the city.
Unfortunately, some of these property developments and farming practices have been on land reserved as wetlands, which help maintain a balanced ecosystem between humans and nature and provide a natural mechanism for cleaning the city’s water supply, while at the same time providing a natural habitat for diverse wildlife.
Images went viral during the just-ended rainy season – one of the wettest Zimbabwe has seen in recent times – of new homes submerged under water in the capital, and its dormitory town of Chitungwiza – because they had been built in areas recognised as wetlands by municipal and environmental authorities. Of late, the local authority has had to resort to forcing people to take down the new structures in order to reclaim the wetlands’ virginity.
That has not always worked though – a large mall build on the edge of a perennial stream is still standing today, even as it took shape amid vehement protests about its wetland location from environmentalists.
One of the environmentalist groups has therefore been scrambling to preserve the remaining wetlands in Harare, so they do not suffer the fate of their siblings across the city.
“The Harare Wetlands Trust, a community-led environmental organisation that oversees some wetland areas, particularly Monavale Vlei (a few kilometres to the northwest of central Harare), has made it their mission to do all they can to safeguard the remaining wetland water sources,” said Zimbabwe Flying Labs in its report about the work they did for the trust recently.
“However, one challenge faced by environmental organisations like Harare Wetlands Trust is a lack of up-to-date topographical and digital maps of the identified wetland areas — without which they cannot accurately monitor and determine the extent and impact of degradation and encroachment into the wetlands.
So Zimbabwe Flying Labs contacted the Harare Wetlands Trust, offering their game-changing drone solutions in support of the trust’s efforts though leveraging drone-gathered data.
“After our initial engagement, we discovered that one of the Ramsar Wetlands sites, Monavale Vlei, has not been mapped since the early 2000s — nearly 20 years ago. At that time, the survey was conducted by plane and photographer. Today, the primary data they rely upon is satellite imagery, but it is not as detailed or up-to-date enough to monitor ground activities.
Zimbabwe is one of the 171 countries signed up for the Ramsar Convention on Wetlands of International Importance Especially as Waterfowl Habitat – an international treaty for the conservation and sustainable use of wetlands that came into being in 1971. As of 2014, there are seven sites around the country designated as Wetlands of International Importance (Ramsar Sites), and three of them are located in the greater Harare area.
“Between June and August of this year, Zimbabwe Flying Labs embarked on an aerial mapping exercise at Monavale Vlei, an area covering over 100 hectares, to produce digital map data for a base map to monitor changes in the wetland area. They can use this data to support their decision-making process — turning data into action.
“Using an RGB sensor mounted on a multi-rotor drone, the Zimbabwe Flying Labs team conducted aerial mapping over three days, including a trial mapping exercise for the key stakeholders. The trial mapping exercise included principals from Harare Wetlands Trust and students from the University of Zimbabwe studying environmental science.”
After flying their drones around the area in question and gathering aerial data, which they then processed on their computers, the flying labs produced updated high resolutions of a digital terrain model, a digital surface model, and an orthomosaic map, now available in greater detail for use by the Harare Wetlands Trust to determine the extent of wetland degradation from land uses that include property development and crop cultivation by nearby residents.
“After seeing the usefulness of the data, the Harare Wetlands Trust proposed that aerial mapping be done more regularly (seasonally) to have comparative data over time, and Zimbabwe Flying Labs looks forward to a continued partnership with them,” the report said.