Catastrophic Coastline Change in Nias

(Indonesia)

Environmental context and methods:

The NIASE project examines the ecological impact of coastline degradation and social response to intensive environmental change on the island of Nias (Indonesia) after the 2004 tsunami and 2005 earthquake. More specifically, the 2005 earthquake caused substantial coastal uplift on the western side of the island, while the eastern coast literally fell into the sea as much as 2 meters, resulting in ca. 400m of coastline loss.

The sudden and remarkable environmental changes that ensued from these back-to-back disasters have now had five years of gestation on Nias and we can investigate which ‘social responses” to environmental change yielded sustainable results, as well as those that have had adverse ecological impacts. We are in the process of applying for funding for the acquisition and GIS analysis of high-resolution satellite data (2.5m resolution) to generate detailed mappings of the incremental changes in land-use, coastline geography, vegetation, and hydrology of Nias island on a annual basis over the past five years.

The pilot phase of this research was focused on the assessment of the contemporary state of environmental impact on the Island of Nias and on determining the availability of data sources and their analytical efficacy for facilitating the (current) proposed research.  In November 2009, our team carried out a two-week visit to Nias to establish viable study sites and ground truth the issues described above.

Results of the pilot visit to Nias:
The island of Nias and its inhabitants have been considerably affected by the environmental changes resulting from both the 2004 tsunami and 2005 earthquake.  Although nearly all of the aid groups have closed operations on Nias, local villagers are still heavily engaged in new strategies for coping with the altered shorelines and coastal ecology in the aftermath of the 2005 earthquake.

Traveling to Nias resulted in the identification of two study sites suitable for intensive analysis.  The first study site is the town of Afulu, whose beaches extending along the Northwestern coastline to Lahewa, where tectonic uplift significantly extended the coastal geography.  In Lahewa, the uplift elevated a major trade port and fishing dock, which today has been rebuilt.  In the more rural sectors of Afulu, new beaches and exposed reefs have caused a variety of shifts in fishing practices, as well as expanding agricultural practices.

These observed changes significantly guide our perspective on the cumulative impacts of environmental changes in these case studies, and provide substantial cases for analyzing how development efforts and local strategies have together reformed these villages. 

With these appropriate sites identified, our energy in continuing the pilot research has been devoted to developing a working digital platform to begin more detailed analysis in GIS.  Work is underway in the SAIE laboratory digitizing and compiling openly available data to assess quantitatively the degree of coastal change.  As noted in the proposal, the result of these efforts has been positive, but has also illustrated that the free, low resolution data currently available is not appropriate for the level of analysis required.  Thus, although not enabling us to carry out the necessary analysis at this stage, our initial modeling and mapping in GIS has illustrated that more nuanced approaches will be successful for achieving the proposed goals of the project.

Having only returned from the field 3 months ago, we have made steady progress in developing an international and multi-disciplinary team of colleagues interested in growing this project. In addition to the co-PI, Dr. Patrick Daly, Dr. Kerry Sieh of the Earth Observatory of Singapore at Nanyang Technical University are working together to promote the project through future collaboration. These aspects of the project are currently being negotiated and the PI, co-PI, and Dr. Sieh are in regular contact as the project progresses to the next phase.

Discovery Highlights

Pilot Project:
Traveling to Nias resulted in the identification of two study sites suitable for intensive analysis:

The first is the town of Afulu, whose beaches extending along the Northwestern coastline to Lahewa, where tectonic uplift significantly extended the coastal geography.  In Lahewa, the uplift elevated a major trade port and fishing dock, which today has been rebuilt.  In the more rural sectors of Afulu, new beaches and exposed reefs have caused a variety of shifts in fishing practices, as well as expanding agricultural practices.

The ecological impacts observed along the Northwest coastal sites of Afulu/Lahewa during our visit include: 
  • Uplift causing more than 200m of new beach front
  • Overgrowth of new territory, government seizure of new land
  • Impact on reef ecology
  • Reduction of apex predators (sharks)
  • Overfishing of extant reef
  • Sand extraction and coral collection from new beaches

At the second identified study site, Bozihona (located on the SE coast) the geological subsidence had more drastic ecological effects. Bozihona lost nearly 500m of shoreline, and the entire village was reconstructed in areas which were previously jungle.

In Bozihona, we observed the following changes in the ecology and practices of local villagers:
  • 25-50 hectares of coconut palms destroyed
  • Village has been rebuilt 1km back from the shore
  • Intensive gardening has transformed immediate vegetation, while the selection of crops has transitioned to faster yield cash crops, rather than established commodities such as coconuts
  • Salinization of river impacts water use
  • Loss of pasture