Chapter 1: The Role of Remote Sensing in Environmental Health

Remote sensing plays a crucial role in assessing the state of our environment (credit: ASVMAGZ on Shutterstock). With the simultaneous occurrence of three major planetary challenges—climate change, pollution, and biodiversity decline—it is vital for us to alter our behaviors, enhance sustainability, and nurture our planet responsibly. Understanding the current state of our environment is key to developing effective strategies for sustainable practices.

One can evaluate environmental health through various methods, such as observing animal behavior (for further exploration, see: How Animals Can Indicate Environmental Pollution), analyzing animal vocalizations (for more information, refer to: How Animal Sounds Aid in Climate Change Understanding), and measuring emitted or reflected electromagnetic radiation. This radiation encompasses visible light, radio waves, gamma rays, and X-rays.

Remote sensing, the practice of collecting this radiation data from a distance, enables efficient and automated data gathering. This allows for the accumulation of extensive spatial data linked to specific timestamps, covering vast areas with increased frequency. Typically, this data is integrated into a Geographic Information System (GIS) for management and analysis.

Data collection can be achieved through active and passive remote sensing methods. Some common technologies include:

• Passive Sensors: These detect radiation without emitting any themselves. For instance, optical sensors capture reflected visible or infrared light, while thermal sensors measure infrared radiation to assess heat.

• Active Sensors: This category includes devices like lasers, which send beams to objects and measure the reflected light, and radar systems that emit microwaves and analyze the returning signals. For example, synthetic aperture radar can monitor vegetation even under cloudy conditions. Drones provide higher spatial resolution, whereas satellites cover larger areas effectively (for additional insights, see: How Satellites Monitor Our Planet's Health).

Using these remote sensing technologies, we can assess various environmental health indicators. Regular monitoring allows us to observe changes over time, which helps in evaluating environmental conditions.

Section 1.1: Vegetation Characteristics

One approach to assessing environmental health through remote sensing is by examining vegetation characteristics. Key indicators include:

• The density of plant populations in a given area and any fluctuations in their numbers. This is typically measured by analyzing the amount of red visible light and near-infrared light since photosynthetic plants absorb red light while reflecting near-infrared waves.
• The health of the plant population. The same technology that detects plant numbers can also evaluate their size and leaf count, as well as identify unhealthy plants.
• The distribution of different species across the landscape, which can be achieved by dividing mapped areas into smaller quadrants.

Section 1.2: Microhabitat Characteristics

Remote sensing can also provide insights into microhabitat characteristics, defined as smaller habitats that differ from the broader environment. Measurements can include:

• Tiny patches of semi-natural grasslands, detectable through satellite imagery.
• Individual plant features, such as tree crown shapes, captured by drones.
• The quantity of flowers and fruits on plants, which can be assessed with drones equipped with color-sensitive sensors.
• Different flower species, where AI can enhance recognition accuracy (for further reading, see: How AI Simplifies Recycling Efforts).

Section 1.3: Habitat Structure

Another method involves analyzing habitat structure, which refers to the components that constitute an ecosystem. This includes elements such as trees, water bodies, and rocks. Key measurements include:

• Water levels from melting glaciers, monitored by satellites like Terra.
• Surface structures, including tree heights, which can be measured using lasers or photogrammetry techniques.

Section 1.4: Light Pollution Detection

The fourth method of assessing environmental health through remote sensing involves identifying light pollution, which arises from artificial light sources like street lamps. This excess light can disrupt wildlife behaviors and physiological processes. Satellites, airplanes, and drones can all be utilized to measure and monitor light pollution levels.

Conclusion

In summary, remote sensing serves as a valuable tool for evaluating environmental health by analyzing vegetation characteristics, microhabitat traits, habitat structure, and light pollution levels.

Taking Action

Here are some actionable steps you can take to enhance environmental health:

• Advocate for the installation of street lights that dim when not in use.
• Limit outdoor lighting to what is necessary.
• Ensure outdoor lights are directed downwards, minimizing upward light spill.
• Increase greenery on private properties by planting trees and plants.
• Support reforestation initiatives by distributing seed bombs.

Do you have any additional suggestions for improving our environment? Please share your thoughts in the comments to inspire others.

Credit

This article draws from:

Rhodes, M. W., Bennie, J. J., Spalding, A., ffrench-Constant, R. H., & Maclean, I. M. (2022). Recent advances in the remote sensing of insects. Biological Reviews, 97(1), 343–360.