Near real-time vegetation loss detection in Southwestern Ethiopia

Ubicación
Ethiopia
Fecha
2021-03-02
Author
M. Arisema, K. Mulatu, W. Abera, P. Paz, L. Desta
Categoría

Near real-time vegetation loss detection in Southwestern Ethiopia: calibration, validation, and implementation of the Terra-i system

Anthropogenic led deforestation is a serious problem in Ethiopia resulting in severe degradation of natural resources and related ecosystem services. Monitoring of forest coverage and health is essential to take appropriate measures in protecting the last remaining natural forests in the country, and for ensuring the success of reforestation activities. Tools that can provide vegetation loss alerts in near real-time are needed to take timely corrective measures. The Terra-i forest monitoring system developed by a team of experts at the Alliance of Bioversity and CIAT enables performing this task and has been piloted in Latin America and Asia with great success. Considering the successful use of the tool in other regions and the fact that deforestation is a serious challenge in Africa, the team applied Terra-I in Southwestern Ethiopia, the project area covered is 12,544,751 hectares. The Southwestern part of Ethiopia was selected to pilot the tool as the region hosts dense forest cover and is among the global biodiversity hotspots yet facing large pressure from anthropogenic disturbances. The region is also the origin of coffeea arabica, a major export crop for the country bringing tremendous income. The main objective was to calibrate the existing Terra-i tool for Ethiopian vegetation conditions, and pilot it at selected sites to validate its performance in mapping the events of deforestation. The project was founded by the David and Lucile Packard Foundation and implemented by the Aliance of Bioversity International and CIAT in partnership with the iCog Labs Ethiopia team, with support of local partners.

Near-real time data on vegetation loss

National context

The Terra-i system uses vegetation index and precipitation data to detect alerts of vegetation change in the pantropical areas. The alerts have a spatial resolution of 250m and a temporal resolution of 16 days. One Terra-i alert has a size of 250m x 250m, around 6.25 hectares.

According to the result obtained in the calibration of the Terra-i alerts, in Ethiopia, during the 17 years analyzed, a total vegetation loss of 106,364 alerts (664,775 ha) was detected, equivalent to an average deforestation rate of 6,257 alerts/year, approximately 39,100 ha/year. In 2004, an annual 186 alerts/year (around 1,160 ha) rate of vegetation loss was detected in the country, while in 2019, an annual rate of 885 alerts/year (around 5,530 ha) was detected (Figure 1). This is equivalent to an increase in vegetation loss of 49% between 2004 and 2019.

Figure 1. Annual rate of vegetation cover loss alerts in Ethiopia using the Terra-I forest monitoring tool

The results indicate that at a national level, the natural vegetation covers are shrinking at an increasingly alarming rate, particularly in the Oromia and SNNPR regions (Figure 2). In addition, the two most impacted ecosystems are Ethiopian montane forests and Ethiopian montane grasslands and woodlands, with a total habitat loss of 39270 (around 245,400 ha) and 37389 alerts (around 233,600 ha) respectively.          

                                   

Figure 2. Annual rate of vegetation cover loss alerts by top 3 regions using the Terra-I forest monitoring tool in Ethiopia

South west project area

The zones in the study regions with the most accumulated alerts are Jimma and Kefa with 13,183 alerts (approximately 82,390 ha) and 12,081 alerts (approximately 75,500 ha) of habitat loss, respectively (figure 3). Finally, the Woreda Gurafereda and Gog have recorded the highest loss alert of 3642 (around 22,760 ha) and 2589 (around 16,180 ha) respectively.

 

Figure 3. Zonal distribution of vegetation loss alerts in South Western Ethiopia using the Terra-I forest monitoring tool

The data are available from January 2004 to August 2020 to download and explore on Terra-i website (figure 4).

 

Figure 4. On the Terra-i website, the year detection of alert of vegetation loss is represented by scale colors between yellow to purple, where old alerts from 2004 are yellow and the recent alerts from 2020 are purple.      

Major drivers of vegetation loss

Terra-i alerts recently detected from 2018 and 2019 were validated using high-resolution imagery and field survey. The major drivers behind the loss of vegetation detection are found to be agriculture (mainly coffee plantations), grazing, infrastructure, and logging.

Figure 5. Drivers of vegetation loss observed at validation sites: agricultural conversion

 

Launch event of the Terra-i tool in Ethiopia

The results of the analysis were presented during a stakeholder meeting in Addis Ababa, Ethiopia. Partners from the study sites, the Ethiopian Environment, Forest and Climate Change Commission, some of the Packard supported project members and national and international researchers attended the workshop (Figure 5).  The tool was also introduced to forestry experts from the Oromia region, during a forest and biodiversity monitoring training organized by the Alliance and Oromia agriculture research institute. Participants recognized the relevance of the work and appreciated the approaches used and results obtained. The participants indicated the need for capacity building, and suggested the application of the tool for monitoring changes in the other parts of the country. Suggestions are also given to adopt the tool to enable the assessment of restoration efforts in the country.

  Figure 6: Terra-i sensitization workshop participants (left) and training session (right)

We would like to thank all of those involved in the implementation of Terra-I system and in the execution of fieldwork. The project was co-implemented by the Alliance of Bioversity International and CIAT and the iCog Labs team. Financial support was made by the David and Lucile Packard Foundation.

More information about the project:

Ethiopia - LT.Desta@cgiar.org

Terra-i - l.reymondin@cgiar.org / p.a.paz@cgiar.org

Artículos principales de la categoría Destacadas

Artículos principales de la categoría Noticias