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Gisat involved in several mapping project in Africa

New land cover map for Kivu * Refugee and IDP mapping in the Horn of Africa * Land cover monitoring in IGAD countries

New land cover map for Kivu

Gisat contributed to production of unique land cover map for the two Kivu provinces.

The eastern part of Democratic Republic of Congo (DRC) ranks among world’s least secure areas. Long-term and extremely violent conflict between shifting alliances of foreign and indigenous armed groups and militias, national government, and foreign governments’ forces has been raging for more than a decade. Attacks on civil population are reported almost on daily basis. Environment and local rich natural resources can play a role in the onset, duration and termination of conflicts and, despite not being the only factor; they may play a key role in their dynamics. Earth observation (EO) data could help to measure both environmental and certain socio economic factors.

In framework of the project G-MOSAIC a service chain “Exploitation of Natural Resources” was activated for the two Kivu provinces in the eastern DRC. In cooperation with project partners from consortium coordinated by the Joint Research Centre (JRC), Gisat carried out land use change detection from recent high resolution data (Landsat, DMC). EO based change detection allowed synoptic analysis of large areas for identification of hot-spots for further analysis. Transition zones with natural resources decrease were detected from the imagery and could have been linked with other conflict and socio economic information.

During the course of the service activation the need for up-to-date, detailed land use / land cover map for Kivu provinces emerged from the service users. There are land cover maps available at national level for DRC, but for regional applications they are insufficient in terms of detail provided and their up-to-datedness. Gisat provided its expertise with land use / land cover classification of complex African landscapes from EO data. It played a key role in the service chain comprising satellite data processing and classification of Landsat and DMC scenes acquired in 2009-2011. Common problem present in equatorial areas, extensive cloud coverage, has had to be resolved by utilizing of multiple backup scenes for cloudy areas. Mosaic of atmospherically and terrain corrected images was created which served as a basis for object-based image classification, post-classification interpretation and enhancements. Resulting vector dataset is categorized into 9 LCCS compatible hybrid land use / land cover classes and at given scale it provides unrivaled detail referring to the source data resolution (30 m) and the minimum mapping unit (5ha). It has been mapped more than 125,000 square kilometers in total, which is for instance more than sum of the areas of Austria and Switzerland together. On top of vector results digital Land cover map of North and South Kivu with scale 1:300,000 and related Land cover atlas with scale 1:250,000, both referencing to the status as of 2010, were created by JRC. Attached land cover vector dataset enables analysis up to scale equivalent to 1:100,000.

Huge effort was devoted to validation of thematic accuracy of the product. Therefore, multi-level approach consisting of 3 independent steps was implemented:

  • Standard accuracy assessment using interpretation of set of random points in reference EO data carried out by Gisat
  • Accuracy assessment by cross-matching with available reference LU/LC products (FACET) carried out by the JRC
  • In-field accuracy assessment organized by the JRC was carried out by local staff of various NGO organizations active in the Kivu.

Each validation method showed high overall accuracy rate of the classification. With this respect and taking into account its characteristics reflecting user-driven requirements, release of the land cover map and atlas for Kivu provinces is supposed to be great success both for Gisat and JRC as involved service providers and for G-MOSAIC consortium as a whole. Product has been distributed to several NGOs and other entities from various application fields: natural conservation agencies, human rights agencies and local government organizations, who will take benefits from utilization of validated GMES services and products developed in framework of the G-MOSAIC. Last but not the least they may serve as a basis for further land use / land cover change analysis as a reference 2010 baseline.

The service has been provided in the frame of G-MOSAIC (FP7 EU-funded project aimed at identifying and developing products, methodologies and pilot services for the provision of geo-spatial information in support to EU external relations policies and at contributing to define and demonstrate the sustainability of GMES global security services).

More information at GISAT

Refugee and IDP mapping in the Horn of Africa

Gisat participated in emergency response mapping in support of UN agencies mitigating food insecurity and situation of refugees and internally displaced people (IDP) in Horn of Africa. Horn of Africa, one of the world’s least stable and insecure areas, is subject to continuous ethnic and military tension, droughts and consequent negative impacts on civil population in form of malnutrition and recurrent famines. In early 2012 Gisat responded the requests of various UN agencies and participated in emergency response activations aimed at Refugee/IDP mapping in Ethiopia and Somalia.

Following on fighting in Blue Nile State in Sudan in fall 2011 the UN Refugee Agency (UNHCR) set up refugee camps in western Ethiopia to absorb the influx of refugees. Tongo camp was one of the largest and in terms of mapping urgency also one with the highest priority. In close cooperation with UNHCR, who delivered in-situ data, Gisat carried out semi-automatic object-based classification of very high resolution satellite imagery identifying single tents in the camp and land cover/land use categories in its surroundings. Main emphasis was put on correct identification of agriculture fields. Situation analysis was supplemented by extraction of additional assets such as existing settlements and villages, individual houses and road network as well as hydrographic and topographic features. Despite the activation wasn’t carried out in rush mode, timely delivery of the map outputs and related vector data was critical issue. Resulting products were immediately utilized for site planning and further camp construction and extension.

The Vulnerability Analysis and Mapping unit of the World Food Programme (WFP) Somalia requested large scale mapping to assist in estimating the current agricultural production and population density in the several districts in Somalia. The request reflected the food insecurity linked to long-term presence of large amount of IDPs and several rounds of fighting between government forces and Islamic militias in recent years. Mapping performed by Gisat supported the WFP activities in Beled Weyne district. Agriculture change assessment maps based on interpretation of very high resolution imagery from previous 3 years were produced as well as population density and population density change maps, which were based on detection of individual dwellings using state-of-the-art object-based classification algorithms. Classification was followed up by subsequent manual interpretation and validation. Genesis of IDP camps at urban fringe of Beled Weyne could have been clearly detected from multitemporal imagery. Agriculture and population change assessment was supplemented by information dossier summarizing statistics obtained from analysis of results in GIS environment. The dossier included additional information on crops development related to vegetation vigour during a couple of recent harvesting periods in the area. The analysis was based upon series of MODIS NDVI 16-day composites and it demonstrated the benefits of utilization of low spatial resolution data for monitoring of vegetation and agriculture change in the emergency response mapping domain. The outputs were delivered to VAM unit of WFP where they serve as a basis for decision making.

The output products from both mappings were appreciated by the responsible UN experts. They prove the strength of satellite data and subsequent geo-spatial analysis for monitoring of up-to-date status or retrospective change detection and assessment for the sake of Refugees/IDP related humanitarian needs.

The service has been provided in the frame of SAFER (FP7 EU-funded project focusing on the development of the pre-operational GMES emergency response service). Mappings in non-rush mode (emergency support services) serve to support preparedness and prevention as well as recovery activities and long-term development projects of humanitarian community.

More information at GISAT

Mapping East Africa

Results of land cover monitoring in IGAD countries presented at AMESD conference.

The „Conference on the Use of Earth Observation to Support Environmental Policy Making in Africa“ was the last activity planned under the direct responsibility of AMESD Program Coordination Team (PCT). It was held in Addis Ababa – Ethiopia the 22nd and 23rd May 2012 with the theme “Showcase the use of AMESD services for policy making”.

The AMESD program addresses the need for improved environmental monitoring towards sustainable management of natural resources in five regions of sub-Saharan Africa, namely CEMAC, ECOWAS, IGAD, IOC and SADC (RECs). The purpose of the program is to increase the information management capacity of African regional and national institutions in support of decision makers at different levels and to facilitate sustainable access to Africa-wide environmental information derived from Earth Observation technologies. Its goal is to help African governments in designing, implementing, monitoring and evaluating their regional and continental policies towards sustainable development.

The conference included also the poster section. In this section Geoland-2 SATChMo-Africa (the Seasonal and Annual Change Monitoring Service) contributed with presenting research and application results. The objective of SATChMo-Africa is to provide assessment of land cover and land cover change products for the Environmental Country Profiles in East Africa countries; namely IGAD region – Kenya, Ethiopia, Uganda, Somalia, Sudan, Djibouti and Eritrea; by statistically relevant sampling scheme, the so-called Area Frame Sampling. The base for this monitoring is the Earth Observation satellite data from LANDSAT and DMC with spatial resolution of 30 m.

In the frame of SATChMo activities Gisat has done extensive mapping focused on land cover monitoring in IGAD region. The main products of the project are status land cover layer of reference year 2000, change layers 1999-2000 and 2000-2009 and summary statistics indicating the status and development of land cover during the period of interest.

More information at GISAT