{
"name":"DISASTERS_202607_FLOOD_TX/202616_sentinel1_FloodDetection",
"title":"DISASTERS_202607_FLOOD_TX/202616_sentinel1_FloodDetection",
"type":"Map Service",
"typeKeywords":["ArcGIS Server","Service","Map Service"],
"description":"<div style='text-align:Left;'><div><div><p style='margin:0 0 11 0;'><span>Post-Event: May 1 to July 1, 2026<\/span><\/p><p style='margin:0 0 11 0;'><span>Pre-Event: July 18, 2026<\/span><\/p><p><span style='font-weight:bold;'>Date of Next Image:<\/span><\/p><p style='margin:0 0 11 0;'><span><span>Dec 11, 2025<\/span><\/span><\/p><p><span style='font-weight:bold;'>Summary:<\/span><\/p><p><span>We developed a rapid-response workflow to map flooded areas during this emergency event using multi-temporal Sentinel-1 SAR data. Sentinel-1\u2019s SAR backscatter characteristics are particularly effective for detecting surface water: water surfaces typically exhibit low backscatter, whereas non-water areas show higher backscatter. Leveraging this physical property, we distinguished between water and non-water surfaces from both pre- and post-flood observations.<\/span><\/p><p><span>To highlight flood-induced surface changes, we computed the differenced co-polarized VV backscatter (dVV = VV_post \u2013 VV_pre). This change detection technique enhances the visibility of newly inundated areas. We then applied a simple threshold to the dVV image to separate flooded from non-flooded areas.<\/span><\/p><p><span style='font-weight:bold;'>Suggested Use:<\/span><\/p><p><span>The final output is a binary raster product, where pixels with a value of 1 represent flooded areas (dark blue color).<\/span><\/p><p><span>A permanent water body layer and a binary layer incorporating land cover are also included.<\/span><\/p><p><span style='font-weight:bold;'>Satellite/Sensor:<\/span><\/p><p><span>Sentinel-1 /Synthetic Aperture Radar (SAR)<\/span><\/p><p><span>Resolution:<\/span><\/p><p><span>10 meters<\/span><\/p><p><span>Credits:<\/span><\/p><p><span>Dr. Khuong H. Tran (Khuong.tran@nasa.gov)<\/span><\/p><p><span>Esri REST Endpoint:<\/span><\/p><p><span>See URL section on right side of page<\/span><\/p><p><span>WMS Endpoint:<\/span><\/p><p><span>https://maps.disasters.nasa.gov/ags03/services/NM_FIre_202506/sentinel1_flood/MapServer/WMSServe<\/span><\/p><p><span /><\/p><\/div><\/div><\/div>",
"extent":[[-98.83528267848925,-98.80306774895226],[29.02932786944089,29.05704769253086]],

"url":"https://gis.earthdata.nasa.gov/gis05/rest/services/DISASTERS_202607_FLOOD_TX/202616_sentinel1_FloodDetection/MapServer"
}