1 The 2004 tsunami in Aceh
The earthquake and tsunami resulted in great human loss in Aceh’s coastal farming communities, inundated productive land with salt water, destroyed standing crops, eroded and scoured topsoil, deposited marine sediments and debris on fields, silted irrigation and drainage channels, destroyed field bunds, changed land levels and drainage patterns, and significantly altered parts of the coastline (Moore 2007). The type and nature of damage were highly variable—west coast settlements and agricultural land were more severely affected than those on the east coast—as a result of the location of the earthquake, and the height and power of the tsunami (Figure 4).
An estimated 70,000 ha of agricultural land and 22,000 ha of plantation crops were affected by the tsunami, and nearly 2 million livestock animals were lost (Alimoeso 2006). Other estimates are that the tsunami directly affected 92,000 farms and rural enterprises (Luther 2010), and more than 60,000 farmers (World Bank 2008). The livelihoods of 331,360 working people, mainly from fishing and agricultural enterprises, were affected to the extent that they required food and financial assistance in 2005 (FAO 2005a).
In Burma, similar effects were reported on agriculture from seawater inundation and sediments due to storm surges following Cyclone Nargis in 2009 (FAO 2009).
Box 1 FAO post-tsunami damage classifications
After the 2004 Indian Ocean tsunami, the Food and Agriculture Organization of the United Nations (FAO) classified agricultural land damage in tsunami-affected areas into four main categories, based on field damage indicators (FAO 2005a). The classification system was primarily developed for Indonesia, where land damage was most extensive. The categories are as follows.
Class A: Minor damage—return to normal without intervention
This category includes fields where cultivation is achievable without major intervention.
Class B: Medium damage—return to farming depends on specific interventions
This category includes fields that require debris removal, salt leaching and levelling. This work means that it may be some months before the land can be cultivated.
Class C: Highly damaged areas—return to normal dependent on major interventions (C1) or not achievable (C2)
This category includes fields affected by erosion, debris, sediment and infrastructure damage, and fields flooded by brackish water for weeks or months after the tsunami, as a result of poor drainage. Methods for reclamation may have to be tested on pilot areas, and one or several cropping seasons will be missed. In some cases (C2), the damaged land may not be suitable for agricultural production, and other groundcover alternatives may need to be considered to protect soil and water.
Class D: Lost area
Along the west coast of Aceh, some fields and areas disappeared completely, covered by sea or brackish water. This category of land is permanently lost to agriculture.
The FAO provides further detail on assessment of post-tsunami damage, particularly with regard to salinity (FAO 2005b).
Assessments of the total area of agricultural land damaged in Aceh ranged from 65,000 to 85,223 ha. All assessments agreed that the amount of land lost to agriculture on the west coast was 15,000 ha. Agricultural damage to the east coast was divided evenly between categories A and B/C, established by the Food and Agriculture Organization of the United Nations (see Box 1).
In some rare cases on islands along the coast of Sumatra, uplift caused by the 2004 earthquake led to the establishment of new agricultural land (Figure 5).