Colombia - Satellite detected potentially affected zones by the mudflow in Mocoa.

This map illustrates areas potentially affected by the mudflow, extracted from a Pleiades and GeoEye-1 satellite images acquired on the 10 April 2017 over Mocoa city and its outskirts, in Putumayo Department, Colombia. Inside some neighbourhoods of the city of Mocoa, flood waters and mudflow have receded compared with previous analysis performed by UNOSAT using an image from 4 April 2017. The situation as of 10 April 2017 reveals: 22 km of roads seem potentially affected and about 1,300 buildings are within areas which are still experiencing floods and mud flow. It is likely that flood waters and mudflow could have been systematically under or overestimated along highly vegetated areas and within built-up urban areas. This analysis has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

Following a large mudflow that hit the city of Mocoa (Department of Putumayo, Colombia) on 31 March 2017 as a consequence of the heavy rains, the International Charter Space and Major Disasters has been activated upon the request of the National Unit for Disaster Risk Management (UNGRD) / Unidad Nacional para la Gestion del Riesgo de Desastres, IDEAM. In response to this emergency, UNITAR-UNOSAT has carried out satellite based damage analysis to assess (visible) building structural damage caused by mudflows. This map illustrates satellite-detected damaged structures including building damage density in Mocoa city and its surroundings. Analysis has been undertaken by using post satellite imagery acquired by Pleiades and Geoeye-1 satellites on the 7 and 10 April 2017 and pre satellite images acquired by Worldview-2 & 1 satellites on the 21 December 2016 and 26 December 2013. As result of UNOSAT satellite analysis, a total of 1,082 buildings were detected as damaged of which 736 observed as destroyed or washed out by mudflow and 346 observed as severely damaged. Due to the pronounced incident angle and cloud cover of the satellite images, UNITAR-UNOSAT has also used orthophotos collected by Corpoamazonia in order to validate satellite based analysis. Orthophotos and additional baseline data were provided by OSM Humanitarian Mapping Unit and UMAIC (Unidad de Manejo y Analisis de Informacion de Colombia) who is also providing information management coordination support for this event. Kindly note that the number of damaged structures could have been underestimated due to the parameters of the images. This analysis has not yet been validated in the field. Please send ground feedback to UNITAR-UNOSAT.

Posterior al deslizamiento de tierra que sembró el caos en la ciudad de Mocoa (Departamento de Putumayo, Colombia) el 31 de marzo de 2017 como consecuencia de las fuertes lluvias, el International Charter Space & Major Disasters fue activado bajo la petición de la Unidad Nacional para la Gestión del Riesgo de Desastres, IDEAM. En respuesta a la emergencia, UNITAR-UNOSAT ha llevado a cabo análisis visible de daño en las edificaciones causado por el deslizamiento de tierra, usando imágenes satelitales de alta resolución. Este mapa ilustra edificaciones dañadas detectadas en imágenes satelitales y la densidad de daño asociada en la ciudad de Mocoa y sus alrededores. El análisis ha sido conducido utilizando como imágenes post emergencia las adquiridas por los satélites Pleiades y GeoEye-1 el 7 y el 10 de abril de 2017 y como imágenes pre emergencia las adquiridas por los satélites WorldView-2 y WorldView-1 en las fechas del 21 de diciembre de 2016 y 26 de diciembre de 2013. El resultado del análisis conducido por UNOSAT revela un total de 1,082 edificaciones dañadas, de las cuales 736 aparecen como destruidas en la imagen o arrastradas por el deslizamiento de tierra y 346 presentan daño severo. Debido al acusado ángulo y la cobertura de nubes de las imágenes satelitales, UNITAR-UNOSAT ha utilizado orthophotos colectadas por Corpoamazonia como fuente auxiliar de validación del análisis realizado con las imágenes satélites. Las orthophotos y otros datos secundarios fueron provistos por OpenStreetMap & la Unidad de Mapeo Humanitario y UMAIC (Unidad de Manejo y Análisis de Información de Colombia), quienes también han provisto apoyo en la coordinación y gestión de la información durante esta emergencia. Por favor, note que el número de estructuras dañadas ha podido ser infra-estimado como consecuencia de los parámetros de las imágenes satelitales utilizadas. Este es un análisis preliminar que aún no ha sido validado en el terreno. Por favor, envíen sus comentarios a UNITAR-UNOSAT.

This map illustrates satellite-detected landslides and mudflow that affected Regent area south eastern Freetown using a GeoEye-1 acquired the 15 August 2017 compared with a pre-crisis image acquired the 03 March 2017. UNOSAT extracted areas affected by the landslide and subsequent mudflow and could identify 349 damaged structure and 1.3 km of damaged roads within the analysed area. This analysis has not yet been validated in the field. Please send ground feedback to UNITAR /UNOSAT.

**UNOSAT code: FL20241112COL, GDACS ID: 1102988** This map illustrates satellite-detected water extent in Riosucio Municipality, Chocó Department, Colombia as observed from a TanDEM-X radar image acquired on the 17 November 2024. Within the analysed area of about 1,130km², a total of about 12 km² of lands appear to be affected with flood waters. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to the United Nations Satellite Centre (UNOSAT). Important note: Flood analysis based on radar images may underestimate the extent of standing water in built-up or densely vegetated areas due to the radar signal's backscattering properties.

This map illustrates satellite-detected standing water over the Cochabamba department in Bolivia, as of the 10 February 2018, following the heavy rainfalls that caused severe flooding in the area. The analysis was conducted using Sentinel -1b and Radarsat-2 images as of 9, 10 and 12 February 2018 respectively. UNITAR-UNOSAT identified in the analyzed area of the Cochabamba Department, around 1,300 Ha of land seem to be inundated, which almost 35% ,450 Ha, are in the province of Punata. It is likely that flood waters have been systematically underestimated within built-up urban areas because of the special characteristics of the satellite data used. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to UNITAR UNOSAT.