Describe how remote sensing indices such as NDVI or NDSI are used in sustainability risk assessment.

• A. They measure soil nutrient content directly.
• B. They replace weather data entirely.
• C. They only indicate water quality.
• D. They quantify vegetation health (NDVI) and snow/ice/land cover (NDSI) to monitor ecosystem status, drought risk, and climate-related stress impacting business operations.

Answer: (D)

The main idea is using remote sensing indices to quantify how ecosystems are faring and how climate-related stress might affect risk and operations. NDVI looks at vegetation health by comparing red and near-infrared reflectance; when vegetation is lush and vigorous, NDVI values rise, and when plants are stressed or sparse, NDVI falls. This makes NDVI a useful indicator of ecosystem productivity, drought impact on crops, and vegetation trends that matter for supply chains, forestry, and land management.

NDSI, on the other hand, uses green and shortwave infrared bands to detect snow and ice cover and related land cover changes. It helps track snowpack, seasonal snow disappearance, and shifts in land surface reflectance due to snow or ice loss. Together, these indices provide a picture of how water resources and land surfaces are responding to climate conditions, which informs drought risk, water availability, and climate-related stress on operations.

In sustainability risk assessment, these indices offer timely, region-wide context that can be integrated with weather, soil moisture, and hydrological data to assess resilience and guide mitigation planning. They do not measure soil nutrients directly, do not replace weather data, and are not limited to indicating water quality.