By Suraj Ashok Jadhav (Shivaji University Student)
Unlocking the Power of Remote Sensing
Vegetation indices are quantitative measures obtained from satellite or airborne sensor observations that assist in determining the presence, health, and vigor of vegetation. They are computed from reflectance values in certain spectral bands—typically in the visible, near-infrared NIR, and shortwave infrared SWIR parts of the electromagnetic spectrum. They are very important in reducing complicated spectral information into a single value that is related to vegetation properties like chlorophyll content, leaf area, and water content. Vegetation indices have wide applications in agriculture, forestry, hydrology, and the environment to monitor plant health, identify stress conditions, and inform resource management decisions. This paper discusses three popular vegetation indices—Land Surface Water Index LSWI, Triangular Vegetation Index TVI, and Visible Greenness Index VIgreen—presenting their definitions, calculation formulas,
➢ What is LSWI?
LSWI is a water-sensitive spectral index that is responsive to the content of water in vegetation and soil moisture. LSWI is particularly useful in detecting the presence of surface water and plant water stress. ➢ Formula:
LSWI = NIR – SWIR/ NIR + SWIR and real-world applications in different industries.
Land Surface Water Index LSWI
Where:
• NIR = Near-Infrared reflectance
• SWIR = Shortwave Infrared reflectance Use Cases:
• Agriculture: Crop water stress detection and irrigation schedule planning.
• Forestry: Drought monitoring and fire hazard assessment.
• Wetland Mapping: Boundaries of water-logged and saturated areas.
Industry Impact:
Applied by agricultural agencies, conservationists, and hydrologists on a large scale, LSWI assists in precision irrigation as well as drought forecasting models.
Triangular Vegetation Index
TVI ➢
What is TVI?
TVI measures vegetation health and chlorophyll levels by creating a geometric triangle based on spectral reflectance within red, green, and NIR bands.
➢ Equation:
TVI = zero point five times one hundred twenty times
NIR minus Green minus two hundred times
Red minus Green Where:
• NIR = Near-Infrared
• Red and Green = Visible spectral bands
Applications:
• Ecology:
Biomass and chlorophyll concentration estimation.
• Land Monitoring:
Identification of stress and degradation in vegetation cover.
• Climate Studies:
Quantifying vegetation response to climate variability.
Industry Impact: TVI is essential in ecological modeling, carbon stock estimation, and forest health assessments.
Visible Greenness Index VIgreen
➢ What is VIgreen?
VIgreen approximates greenness based on visible spectrum measurements, providing rapid and effective indication of vegetation presence without requiring NIR bands.
➢ Formula:
VIgreen = Green minus Red divided by Green plus Red Where:
• Green and Red = Reflectance in the visible spectrum
Use Cases:
• Urban Greening:
Mapping urban green spaces.
• Crop Monitoring:
Measuring early crop stress.
• Environmental Research:
Monitoring long-term changes in phenology.
Industry Impact:
VIgreen is well-suited for low-cost drones and cameras, so it would be valuable in quick-response veg analysis for city planners and small farmers.
Conclusion:
Major Applications Agriculture, Hydrology, Forestry Ecology, Climate Research, Land Use Urban Planning, Crop Stress Detection With the era of environmental woes and data-based decision-making, vegetation indices such as LSWI, TVI, and VIgreen are a necessity. Their capacity to derive useful information from satellite and drone images facilitates smarter agriculture, green forestry, urban resilience, and environmental conservation. As remote sensing technology advances, these instruments will become increasingly stronger and accessible.
References and Sources
• Wikipedia. 2024. Vegetation Index.
https://en.wikipedia.org/wiki/Vegetation_index
• USGS Earth Explorer. 2024. Vegetation Indices Overview.
https://earthexplorer.usgs.gov
• ResearchGate. 2023.
Various figures and benchmarking visualizations: o LSWI: TVI: https://www.researchgate.net/figure/Land-Surface-Water-Index-LSWI-over-West Bengal-during-July-2021normal-year-and-2022_fig7_369118154
https://www.researchgate.net/publication/358044519/figure/fig22/AS:1154366534889473@165223 3837974/Benchmarking-of-triangular-vegetation-index-TVI-2020.png o
VIgreen:
https://www.researchgate.net/profile/Lalu Jaelani/publication/357174687/figure/fig2/AS:1103046734020612@1639998243941/Visualization of-Greenness-Index-on-a-April-b-May-c-June-d-July-e-August-f.png
Research Contributors:
By Suraj Ashok Jadhav (Shivaji University Student)
