Using Satellite Imagery to effectively Deploy Critical Resources

In the wake of the bushfire disaster, there has been an urgent need to get water and food to native wildlife. However, it’s not easy to make sure supplies are going where they are most needed. By using the latest satellite imagery technology, the Science for Wildlife team are assessing where and when wildlife are in need of food and water supplies, so we can send our amazing team of volunteers into targeted areas.

The impact of recent rainfall

Recent rainfall, which extinguished some of the most persistent bush fires we have seen this season, came as a huge relief to many across the state. The Science for Wildlife Research and Volunteer teams were incredibly thankful to see the Blue Mountains bushfire threat ease during early February. However, despite the unprecedented rain fall and relief it has brought to our forests, our wildlife crisis and the broader bushfire relief mission have only just begun.

“Now that we have received some rain, a key question going forward is whether we stop installing water stations for wildlife or continue putting them back out? In light of recent rainfall, many now assume that our wildlife will have access to ample water sources throughout this next stage of recovery. Unfortunately, this is not the case – in the burnt areas many of our water sources are now contaminated with ash and other run off contaminants. On top of that, the ash beds that have been washed away would normally provide nutrients to help vegetation recover. This rain has not yet broken the drought and the bush is likely to take some time to bounce back.”

Dr Kellie Leigh, Executive Director of Science for Wildlife

Providing clean water sources for wildlife for as long as it is needed, particularly for our koalas, continues to be a priority area for the Science for Wildlife team. To ensure we are efficient and accurate with the set up and management of our water stations, we have started utilising satellite mapping to map vegetation condition throughout our focus areas. This is allowing us to monitor the recovery of the land, and as a result know when and where water is still needed.

Water supplies

The installation and management of clean water stations has been a core project for our organisation over the past few months. So far, we have fitted 75 water stations across 3 sites and have arranged for the installation of another 30 large water towers. We’re collecting data using remote camera surveys to get an idea of how effective this has been in helping animals affected by the bushfire crisis.

For koalas, their hydration comes from the leaves they eat. Until the canopy condition improves and while we continue to experience hot weather, koalas are likely to continue needing access to clean water. By putting out arboreal drinking stations, one of our core aims has been to enable arboreal animals to remain in the trees and not have to come to ground for water, in an effort to keep them safe from ground predators like foxes and cats. We have also continued to put out pellets, for macropods, wombats and smaller native animals.

Using satellite imagery to map vegetation

Satellite imagery allows us to look at vegetation quality and determine the water and food needs across the district. The technique uses different bandwidths of light (red and near-infrared) to tell us how much chlorophyll or green vegetation is in an area. This is a widely used index called the Normalised Difference Vegetation Index (NDVI). As we measure forest vegetation, the main thing we can observe in the satellite imagery is the condition of the canopy. This helps to indicate the areas where wildlife will still need assistance with food and water.

In the maps below you can observe the canopy condition prior to the drought, during the drought (just before the bush fire season), and finally after the fires. It is important to note that even the vegetation that didn’t burn, which can be seen to the north of Black Range Road, is still in very poor condition. For example without these images it woud be easy to assume, incorrectly, that the unburnt areas are healthy and wildlife there doesn’t need support.

A big thank you to our volunteer Ariane Weiss, who has been assisting with this critical mapping technology.

1.Black_Range_NDVI_20190125

– Above: Satellite image prior to the drought – 25/01/2019

2.Black_Range_NDVI_20191027

– Above: Satellite image during the drought – 27/10/2019

3.Black_Range_NDVI_20200130_burnt edge

– Above: Satellite image after the bush fires – 30/01/2020

Why is this technology important?

By using this satellite imagery, we are able to more effectively contribute to wider wildlife conservation in the area. Specifically, the technology allows us to:

  • Use science to determine when we should take the water stations out and stop deploying them
  • Track forest canopy rehabilitation over time
  • Target and test areas for browse collection from Black Range (for our koalas at Taronga) and monitor how quickly the canopy improves after rain.

We are also using fire intensity mapping (Google Earth Engine Burnt Area Map) to guide where we allocate resources, and where it is safe to take our field teams.

How can this technology help us in the future?

Science for Wildlife will soon begin conducting post-fire surveys to observe how canopy condition and fire intensity correlates with where koalas have been spotted. This will allow us to compare our koala locations after the fires, to those prior to the drought and heat stress. Koalas are fussy eaters so it’s bound to be complicated, but we might be able to use this as a predictor of where our koalas are likely to head when released, and where we might find more koalas post-fires.

The ongoing bushfire relief project would not have been possible without the support of our fantastic volunteers who have been on the ground assisting with setting up and maintaining water stations and food drops, and who will be back at our study sites with us soon doing koala surveys and radio-tracking.

All of these contributions remind us of the value of community support and involvement, as community ties such as this ensure that we deliver the highest quality conservation outcomes for our wildlife.

For projects updates and to learn more about Science for Wildlife community, visit our projects page here.