Potentially Affected Zones by the Mudflow in southeastern Freetown, Sierra Leone

This map shows landslides mapped from satellite imagery following the Regent event on 15 August 2017. The main landslide outline in Regent has been updated from the product released by UNITAR-UNOSAT (published 16 August, version 1.0) using the updated UNITAR-UNOSAT georectification of the satellite image on 17th August. The main Regent landslide event is 6 km long, including source area and run-out to the sea. It is interpreted as a debris slide in its upper reaches, transitioning to a debris flow and then a sediment-laden flood. The two smaller landslides are interpreted as debris flow events. The analysis has not yet been verified in the field.

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.

This map illustrates satellite-detected water bodies and inundated areas in Mocoa city, Putumayo department in Colombia as seen on Resourcesat-2 satellite imagery collected 04 April 2017. Heavy rainfall in the area caused flooding, landslides and mudflow that affected the city. UNOSAT extracted a water index from the satellite image to determine areas of standing water as well as soils with varying levels of water content (i.e. mud). Within the city of Mocoa and the current map extent, about 18 km of roads are potentially affected. About 2900 buildings are within areas which experienced floods and mudflow. It is likely that flood waters and inundation have been systematically underestimated along highly vegetated areas and within built-up urban areas because of the special characteristics of the satellite data used. This analysis has not yet been validated in the field. Please send ground feedback to UNITAR /UNOSAT.

**UNOSAT code: FL20220418ZAF** This map illustrates satellite-detected landslides/mudflow in Umdloti village, eThekwini Metropolitan Municipality, KwaZulu-Natal Province, South Africa as observed from a NewSat image acquired on 13 April 2022. Within the analyzed area, 14 buildings appear to be affected and 13 are potentially affected. Affected roads were also identified. 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).

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.

**UNOSAT code: FL20220418ZAF** Webmap of satellite based analysis related to the Floods and landslides of 13 Apr. 2022 in KwaZulu-Natal (Republic of South Africa).