Mapping project a game-changer for restoration

Student journalist Alex Zhang discovers how drone footage and geospatial software is making working on our restoration easier, and more inclusive.

A groundbreaking mapping initiative led by university student Matthew Wardle has revolutionised restoration at Rosedale Park.

Utilising advanced drones and geospatial software, Matthew has generated interactive 2D orthophotos and 3D point-cloud models of Te Hōnonga a Iwi's restoration site. The digital platforms allow for restoration workers to identify locations for supplementary planting, monitor changes throughout time, and provide virtual accessibility for stakeholders, benefactors, and school students who cannot physically visit the site.

At the heart of the project is a series of ultra-high resolution 2D orthophotos. Unlike standard aerial maps, orthorectified images place every pixel on a specific ground coordinate, allowing viewers to spot incredibly small details such as patches of bare earth, rock formations, and even individual leaves!

By flying over the site at intervals, workers can compare successive images to measure vegetation growth, determine soil erosion, and monitor invasive species. Through using 2D orthophotos, viewers can also easily identify different plant communities and distinguish native species from weeds, allowing work on the restoration site to be more efficient.

This high-resolution map also helps to locate existing infrastructure such as fences, boardwalks and drain lines. This allows teams to pinpoint exactly where to plant next and plan out equipment and access routes without even setting foot on the ground. Furthermore, the orthophotos provides a detailed view of the site that can be shared easily with volunteers, funders or the wider community.

Apart from 2D imagery, Matthew’s 3D point-cloud model also provides the organisation with a virtual sculpture of the terrain. In order to generate this, drones take overlapping images of the site from many angles, allowing a photogrammetry software to stich these into a cloud of millions of points, each with its own X-Y-Z coordinates.

These points together form an interactive virtual landscape that the viewer could navigate. Due to its ability to be tilted and zoomed, restoration workers can use the model to “walk through” the terrain and examine canopy structure, measure volume, and extract slopes.

The model’s 3D properties also come in handy when analysing water retention features, checking drainage, or identifying spots prone to erosion. It can be used for estimating tree heights, canopy density and shrub layering, proving itself critical for measuring habitat complexity or carbon stocks.

Finally, the 3D point-cloud model’s virtual landscape allows for stakeholders to explore hazardous areas virtually and it also makes a far more compelling feature than flat photos during presentations to the public, thus making it a vital asset for spreading awareness during public occasions.

The advantages of this twin-mapping approach extend far beyond technical purposes. The use of these high-tech models also allows for more youth and community volunteers to be involved directly. Participants are encouraged to explore the maps, mark points of interest and suggest new ideas for survey lines or restoration zones while at the same time learning basic mapping skills themselves. Local schools are also welcome to use the maps in environmental education, allowing their students to tour Rosedale Park’s landscapes as part of their curriculum.

For a better understanding of the models, check them out online.

Behind all of this is restoration leader Matthew Wardle, whose involvement with Te Hōnonga a Iwi started last year, when he joined a sustainability programme at North Harbour Hockey. Matthew has always loved the environment, and he is glad that he is able to help with the initiative in his own way. He has also added that he enjoys being outside, and that it is especially rewarding for him to see the changes and impact he has made throughout the year.

What appeals to Matthew the most is the diverse nature of the restoration: each worker has his or her own speciality, and as he himself says, “There is always something for everyone here”.

Matthew is now working towards a double university degree in law and environmental science, and his mapping work with Restoring Rosedale Park is directly related with his field of study. As part of a recent university assignment, he conducted a study on a restoration site in the Bay of Plenty, focusing on analysing vegetation structure and plant density using drones.

This connection to his academic studies also reflects the models’ importance in all categories of environmental work. Later in the year, Matthew will assume the role of Secretary of Te Hōnonga a Iwi Incorporated Society, putting him in a position to support the organisation through communication development.

As Matthew streamlines mapping processes and passes on essential mapping skills for other youth leaders, Rosedale Park is becoming an exemplar of restoration based on data and technology. At the crossroad of leadership, academic study, and leading mapping tools, Te Hōnonga a Iwi is mapping towards more resilient and diverse urban parks – both virtual and real.