I. Executive Summary
II. Data and Methods
III. Results
IV. Conclusions
In February 2013, AAAS received reports from Amnesty International, USA (AIUSA) of increased fighting in the Sudanese border state of Blue Nile. AIUSA reports indicated that several villages were targeted with aerial bombardment, heavy artillery, and ground forces. Among these villages was Ulu, located near the border between Sudan and South Sudan (Figure 1), where AIUSA reported that rebel forces pushed back an advance by the Sudanese Armed Forces (SAF) on 23 January 2013.
Figure 1: Blue Nile and the village of Ulu
To investigate these reports, AAAS acquired and analyzed two high-resolution satellite images of the area in and around Ulu (Table 1). These images were compared to identify burned areas, destroyed structures, and other conflict-related damage.
| Table 1: Imagery Information | ||
| Date | Sensor | Image ID |
| 12 December 2012 | Geoeye-1 | 2012121208180701603031603825 |
| Worldview-2 | 28 Janusary 2013 | 103001001fa6f500 |
Analysis of the images revealed 27 structures that had been damaged or destroyed between 12 December 2012 and 28 January 2013. These destroyed structures were clustered in two areas with 15 destroyed structures in cluster A and 12 structures destroyed in cluster B (Figure 2). Cluster A (Figure 3) also included structures that had been destroyed prior to 12 December 2012. In cluster B (Figure 4), over 25,000 m2 (6.17 acres) of land had been burned. The image taken on 28 January 2013 revealed that this area was still on fire at the time. This blaze is believed to be responsible for the destruction of the 12 structures and at the time of image acquisition, threatened at least one more structure (Figure 5).
Figure 2: Damage to two clusters of structures in Ulu
Twenty-seven structures (purple) visible in the before image (top) have been destroyed in the after image (bottom). Areas of damage prior to 12 December 2012 are outlined in black. Images © 2013 DigitalGlobe, Inc.
Figure 3: Damage in cluster A
Fifteen structures (purple) were destroyed between 12 December 2012 (top) and 28 January 2013 (bottom). Areas of damage prior to 12 December 2012 are outlined in black. Images © 2013 DigitalGlobe, Inc.
Figure 4: Damage to cluster B
Twelve structures (purple) were destroyed between 12 December 2012 (top) and 28 January 2013 (bottom). Note the flames at the right-most edge of the burned area (bottom). Images © 2013 DigitalGlobe, Inc.
Figure 5: Fire still burning in cluster B
Flames are visible on the right edge of the burned area and a structure (red dot) lies directly in their path. Images © 2013 DigitalGlobe, Inc.
Imagery acquired and analyzed by AAAS reveals the damage or destruction by fire of 27 structures in the village of Ulu between 12 December 2012 and 28 January 2013. Information provided by AIUSA indicates that military activity had occurred in and around Ulu between these dates. It cannot be determined from the imagery whether the fires were started by military activity rather than natural causes. In cluster A, the ground cover around the 15 destroyed structures shows minimal signs of fire damage, suggesting that separate fires destroyed each structure rather than one large conflagration. In cluster B, the ground cover shows extensive fire damage as well as a still burning leading edge and the presence of smoke. This indicate that the fire or fires that burned cluster B were ignited more recently than the fires that burned cluster A. The extensively burned area in cluster B does not preclude multiple ignition points but could indicate that a single event ignited one large fire. Though the exact causes of these fires cannot be determined, the imagery clearly shows that 27 structures in Ulu were burned while military forces were reported to be active in the area.