GOBABEB DESERT RESEARCH STATION UNDERTAKES BIO-DIVERSITY RESEARCH

Namibia is one of the biggest and driest countries in sub-Saharan Africa. It is characterised by high climatic variability in the form of persistent droughts, unpredictable and variable rainfall patterns, fluctuation in temperatures and scarcity of water.

Some 100 kilometres southeast of the coastal town of Walvis Bay lies the Gobabeb Desert Research Station on the northern bank of the Kuiseb River. At Gobabeb, water is available from only three sources: fog, rain and the river. The station is situated on the ecotone between fog and rain, enhancing its unique capacity for desert research. It also supports a variety of weather stations and monitors to cover aspects of climate – ranging from standard Meteorology and atmospheric gases to fog and dust.

In one of the latest studies, Ailly Nambwandja, a Student Associate, is using drone (remote) sensing to monitor photosynthesis in Namibia’s distinct lichen communities. Lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an alga. Nambwandja’s research,titled Biodiversity Monitoring Using Drone Technology for Monitoring Lichen Responses to Fog, will provide a low-impact method for monitoring lichen flora and lead to better conservation strategies, identifying in particular where surface traffic (on foot or in vehicles) should be avoided. Nambwandja, a natural resources management student at the Namibia University of Science and Technology (NUST), used a DJI Phantom 4 Pro quadcopter, equipped with a Sequoia Multispectral Camera, to map and record the responses of lichens to fog inputs. This was to determine the efficacy of remote sensing tools to monitor vegetation and rehabilitation in areas sensitive to disturbance.

As for collecting multispectral imagery with drones in the Namib Desert, she explained that the study provided opportunities to learn through trial and error. From July to September 2020, the team undertook 18 trips into the defined study areas for imagery collection at the BIOTA Gobabeb Observatory, Swartbank and the Utuseb Lichen Experimental Sites. It was planned to conduct all flights within three hours of solar noon (immediately before and after noon), or at most within six hours of solar noon.

However, this also presented challenges for the team. Early in October, during one of the image acquisition missions at Swartbank, the quadcopter tilted over during take-off and one of its propellers snapped. The mini-USB connection to the Sequoia Sunshine Sensor mounted on top of the DJI Phantom Pro was dislocated in the process.

“As far as we could determine, the cost to replace these, using funds available from Gobabeb, is reasonable and competitive. We have therefore ordered a Sequoia Sunshine Sensor from DroneNerds in the USA in order to continue the project. For ordering replacement propellers, extra batteries and a DJI Phantom Drone we will use our Nedbank Namibia’s Go Green Funds, to make these payments as soon as possible,” the determined young conservationist said.

Nedbank Namibia initiated the Go Green Fund in 2001 together with the Namibia Nature Foundation (NNF). Over the past two decades Nedbank, in partnership with NNF, has supported more than 160 conservation projects across Namibia which focus on the protection and wise management of Namibian habitats and indigenous plant and animal species.

The Gobabeb Research Station is a crucial part of building an understanding of climate and its drivers, but it is just one of the many projects that Nedbank supports. Already considered a pioneering initiative and Namibia’s corporate torchbearer for environmental protection, the Go Green Fund has disbursed funds amounting to millions of dollars to a host of deserving projects and initiatives. The Fund further promotes the sustainable use of natural resources, enhances the understanding of indigenous species and natural ecosystems, and it disseminates information on environmental issues among communities.

“It is important to note that the mission planning should consider measurement requirements in conjunction with practical limitations, such as battery use and flight duration, since the accuracy and resolution of the data collected by the unmanned aerial vehicle (UAV) are affected not only by the parameters of the flight mission itself but also by ground control points (GCPs), plate design, platform, sensor configurations, topography and meteorological conditions. What’s more, UAV survey requirements are obviously linked to the specific research question being addressed. Therefore, the data type and quality (resolution, precision, accuracy, repeat frequency, etc.) required for each variable being assessed should be identified in advance, to achieve sufficient detail for appropriate intra-survey and inter-survey”, Ailly Nambwandja says.

“In summary, it is insufficient to simply load a flight plan, attach and calibrate a multispectral camera, and then execute a data collection mission. These findings were consistent with advice from literature, which recommends that, prior to conducting drone flights for data collection, a set of informal experiments should be conducted to find the optimal set of camera and flight parameters that would eliminate such artefacts from acquired imagery,” she added.