Binary NDVI Change [pre-event (6/17/2025), post-event (7/8/2025, 7/9/2025, & 7/10/2025)] for the Flooding in Texas, July 2025

Date of Image(s): Post-Event: July 8, 2025; July 9, 2025; July 10, 2025 Pre-Event: June 17, 2025 Date of Next Image: Unknown Summary: Normalized Differential Vegetation Index (NDVI) maps are produced by converting pixel values to NDVI = (Red – NIR)/(Red + NIR), NIR indicates the near infrared band. The dynamically generated Normalized Difference Vegetation Index (NDVI) layer is an index for quantifying green vegetation. It reflects the state of vegetation health based on how vegetation reflects light at certain wavelengths. NDVI change was created by subtracting the cloud-masked post-event NDVI from the cloud-masked pre-event NDVI to show areas of potentially impacted vegetation as negative values (darker shades) and healthy/unimpacted vegetation in positive values (lighter shades). NDVI change can give insights to impacts from an event (like the scouring of vegetation from the riverbeds) but can also show changes in unrelated areas like the clearing of agriculture fields. This layer is a binary NDVI change polygon (threshold of areas where NDVI decreased by -0.25 or more) for July 8, 9, and 10 as compared to Pre-event imagery on June 17. Suggested Use: NDVI change is commonly used to distinguish healthy/active vegetation (positive values) from potentially unhealthy/impacted vegetation (negative values). Gaps in the dataset indicate clouds in the Planet imagery used to create this product. Satellite/Sensor: PlanetScope. This product includes copyrighted material of Planet Labs PBC. All rights reserved. Resolution: 3 meters Credits: PlanetScope: Includes copyrighted material of Planet Labs PBC. All rights reserved.