1 What type of damage did agricultural fields suffer?
There are several types of damage:
- Direct crop destruction by uprooting, salt poisoning, flood, etc...
- Erosion and scouring that modifies the topography, land levelling and the elimination of bunds (for paddy fields)
- Soil fertility losses when upper layer is washed away
- Deposition of (saline) sediment
- Salt infiltration
- Trash and debris accumulation.
2 Is the intensity of damage the same on all flooded agricultural fields?
NO, the intensity of damage provoked by a tsunami depends on three main characteristics at that particular location: the energy of the flood, the type of soil coverage and vegetation, and the soil hydraulic properties including drainage capacity.
The energy of the stream coming in and stream receding at a particular location influences the erosion and physical destruction. The energy is mainly related to the velocity of the stream but also to the stream load in sediment and debris.
As a result of the high energy along the first inland stretches it is likely that erosion is very high, however, when the wave penetrates further inland the energy decreases (velocity diminishing) and that results in a deposit of sediments.
The type of soil coverage in the affected fields influenced the velocity of the water. In general, a bare soil is likely to experience high velocity and therefore higher erosion, whilst a dense coverage and small trees will absorb energy and reduce the velocity of the water, dense cereals such as rice are likely to be overturned ensuring some protection to the soil (at least for a while).
The duration of the sea water flood obviously depended on the drainage capacity. Well drained areas were flooded for only a limited time (several hours), while water logged areas have been under sea water for weeks, causing contamination through infiltration of salt water.
3 What are the priorities in reclaiming affected lands?
The immediate and critical priority in the case of sea water floods is to ensure quick drainage in order to get rid of the salt water on the fields and surrounding water bodies and later leach out salts that have been fixed in the soil.
The second priority is to restore the physical integrity of the fields: the removal of debris and trash, the restoration of appropriate topographical conditions, for paddy fields it means ensuring land levelling and reconstruction of bunds where they have been washed way.
4 Is there always salt deposit associated with a tsunami?
YES, salt sediment deposit is almost always associated with a tsunami. In fact, the study of this deposit allows palaeontologist to trace similar historical events. For instance in Japan , a recent study on 13 tsunamis which occurred between 1026 and 1933, show that the thickness of deposit on the flooded soil may vary from 30 cm up to 1 meter depending on the run-up of the tsunami.
5 What to do with the salt sediment deposit?
Two options can be considered: immediate removal of the deposit or integration into the existing soil profile with salt removal. For agricultural fields only the latter is practically acceptable.
Removal of the deposit requires technical and financial means which makes it out of reach for most farmers. Removing a layer of 10 cm of deposit would be the equivalent to removing about 1000 m3 of deposit per hectare, i.e. about 1500 tons. This would have to be removed to a nearby site. Even if it was possible all of this would have to be done with the help of costly scrapers, trucks, etc.
A more viable option is:
1) Integration in the soil profile of finer elements as after ensuring removal of coarser elements (rocks, debris, trash,...)
2) Leaching out salts from the profile through regular watering by rainfall and/or irrigation to get rid of salt.
Obviously, the deposit is likely to modify the texture and structure of existing soils. That might create difficulties in the next cropping seasons, for instance when a sandy deposit is mixed with the heavy clay soil of paddy fields.
6 How does salt affect plant growth and what are the symptoms?
Salt affects plant growth mainly through:
(a) toxicity from excessive uptake of salt substances such as sodium,
(b) reduced water uptake, known as water stress and
(c) reduction in uptake of essential nutrients particularly potassium.
Early signs of salinity damage are (a) darker leaves than the normal color of bluish-green, (b) smaller leaves and (c) stems with shorter spaces between leaf nodes. When the problem gets more serious, leaves (a) become yellow (chlorotic) and (b) are affected by "burning" (firing, browning) and the death of leaf edges.
7 What are the priority crops for relief and rehabilitation?
As a starting point FAO staff has worked with national agriculture staff to develop a tentative cropping calendar and priority crops for relief and rehabilitation (provide link to the cropping calendar). Actual distribution of the seed depends on needs assessments and time of planting will need to take into account the salinity issue.
8 What specific crops would work best in the flooded, salt-water saturated soils?
As short cycle crops in substitution of potatoes we may suggest to grow one of the following vegetable crops.
Vegetable species with certain degree of tolerance to salinity:
• Pumpkin: Cucurbita moschata (Duchesne) More adapted to high temperatures and wet tropics than Cucurbita maxima
• Bottle gourd (Lagenaria siceraria), Bitter gourd (Momordica charantia), Snake gourd (Trichosanthes cucumerina)
Leafy vegetables:
• Purslane (Portulaca oleracea)
• Kale ( Brassica oleracea var alboglabra)
• Swiss Chard ( Beta vulgaris L. var cicla), Spinach (Spinacia oleracea L.)
Fruit vegetables:
• Tomato (Lycopersicon esculentum).
The cultivars should be adapted to the local consumers preference and also availability of seeds. Do check soil salinity before starting the next crop season.
9 How can we assess the damage to livestock?
It is important to include all types of farm animals (poultry, sheep, goats, pigs, cattle and buffalo) in any assessment. Also, there are different types of production systems that need to be taken into account. Many rural/coastal households will have kept a few 'backyard' livestock but there may also have been more commercial or semi-commercial enterprises affected. Animal shelters, including any stored feed, will have been destroyed by the direct impact of the Tsunami. There might also be indirect consequences that need to be taken into account such as the loss of local support services (extension and veterinary services) feed storage and milling, AI centres and product processing facilities i.e. milk collection centres. There might also be longer-term damage to the primary source of feed supplies due to salination etc. which would need to be assessed.
The information required from assessments to assist the rehabilitation programme would include:
• the number and type of households/enterprises keeping livestock that were affected
• an estimation of the loss animals and feed supplies
• an estimation of economic production losses
• damage to buildings and infrastructure
• the current situation with regard to shelter, feed supply, health of the remaining animals, and any animal welfare issues
• an assessment of the impact on ancillary goods and services
10 What types of animals have been affected?
All animals or birds that were housed, tethered or caged in the affected areas will have been lost. The main casualties were poultry, pigs, goats, sheep and, to a lesser extent cattle and buffaloes.
11 How important are domestic farm animals for the livelihoods in the affected areas?
For many of the coastal communities, keeping livestock makes an important contribution to the household economy. Livestock are important converters of waste products from the artesian fishing industry into cash and assets. Likewise, any surplus coconuts found in coastal areas are an important feed source that encourage people to keep animals.
12 What can be done to rehabilitate households that have lost animals and infrastructure?
Rehabilitation of the livestock sector is likely to include:
• Provision of appropriate materials to reconstruct shelters, feed stores etc, that have been destroyed. There might be an opportunity to improve the design and construction of these buildings.
• Restocking can be supported once suitable shelter is available. It is important that any restocking introduces animals/birds that are appropriate and well-adapted to the particular production system. In most cases, it is expected that animals/birds for restocking will be available from the hinterland (areas inland from the coast) and it is unlikely that any major importation of stock will be required.
• Provision of adequate feed supplies for the remaining and reintroduced animals. Immediate needs for compound (ready mixed and balanced rations) is probably available nationally and it can be procured locally. It is important that any support involves, and not disrupts, the private sector supply chain. There may also be longer-term requirements in terms of seeds, and fertilizer to re-establish pastures and fodder crops.
• Local veterinary services might need material assistance to combat the outbreak of infectious diseases, especially zoonoses - those diseases that can affect humans.
13 If we want to help with restocking - where should we get animals and what sort should we look for?
As only parts of countries are affected, it is recommended to buy the animals locally, in order to minimize the risks of importing diseases and to make sure the animals are well-adjusted to the local environment. Wherever possible, purchased animals should be young breeding stock, well grown for their age, physically inspected for signs of illness or abnormalities, provided with prophylactic cover (deworming, vaccination, antibiotics) based on local veterinary advice, and any stress in transportation should be kept to a minimum.
14 If many of the resorts and more urban towns have to be rebuilt - should the keeping of urban and peri-urban animals be discouraged?
Keeping farm animals in urban areas poses both environmental and human health risks and the practice should not be encouraged. Any rebuilding of existing or new towns should take the opportunity to explore introducing by-laws that either restrict or prohibit keeping farm livestock in urban environments.
It is also important to the rapid spread of zoonotic diseases. In peri urban areas it depends on the control measures that could be established for control of zoonotic diseases, on the importance of animal production for urban consumption and for small holders livelihoods.
15 What can be done for veterinary public health?
The animal health service and in particular the Official Veterinary Public Health authorities should be restored immediately to provide the minimum basis for rational control of zoonoses and food borne diseases. In addition, infrastructure such as safe water supplies, abattoirs, and markets must be rehabilitated. Measures to strengthen sanitation infrastructure and access to veterinary and medical care should be implemented immediately.
16 What general measures could be applied to control animal diseases?
Rehabilitation of Animal Health Services:
Firstly it is important to rehabilitate Veterinary Services as well as livestock infrastructure in order to improve animal disease surveillance, early warning and early reaction systems to prevent the spread of animal diseases. Diseases known to be endemic in the tsunami affected area are:
• Poultry: Highly Pathogenic Avian Influenza and Newcastle virus disease
• Pigs: Classical swine Fever, FMD, Nipah virus, Japanese encephalitis
• Sheep and goats: PPR, pasteurellosis
• Cattle: PPR (in India ), Hemorrhagic septicaemia and FMD.
They should be monitored and where appropriate animal disease control procedures should be implemented to curb the spread of transboundary and other animal diseases.In specific instances, restocking should be considered after going through the necessary quarantine period.
Animal Health Care Capacities (private):
Support to animal health care capacities will mainly involve the private sector. Animal disease control for restocking and maintaining animals will address the main following activities:
• Vaccination against i)Poultry: Newcastle virus Disease, b)Pigs: Classical swine fever and Pasteurellosis c) Small ruminants: PPR, pasteurellosis and clostridial diseases, d) Cattle: PPR (in India ), Hemorrhagic septicaemia, clostridial diseases and anthrax
• Anthelmintic treatment campaigns
Adequate supplies of vital veterinary medicines, food and water, can make the difference between life and death for animals in the aftermath of the disaster.
17 Is there a human health risk if there are animal disease outbreaks? Is there a specific risk for the spread of Avian Influenza?
Yes, there is always a risk of spread of infectious and parasitic diseases, including zoonotic diseases (common to animals and humans) such as rabies and Avian Influenza.
Concerning Avian Influenza, there have been no confirmed outbreaks of this disease associated with the tsunami crisis. However, in view of the prevailing circumstances with the rapid movement of poultry associated with people movement, the lack of sanitation and housing and the breakdown of surveillance systems there is a high potential of risk for outbreaks of this disease in the first weeks after the tsunami.
The immediate reestablishment of animal disease surveillance through the rehabilitation of the Veterinary Services, will allow early detection and early reaction to potential outbreaks of avian influenza. This will permit the adoption of counter epizootic measures such as vaccination and disease awareness campaigns to prevent the spread of avian influenza infections.
18 Is it true that there have been outbreaks of rabies? What can be done to control this disease from spreading?
Rabies is endemic in the region affected by the tsunami. An increase in stray animals directly increases the chance of human to animal contact. Thus there is more possibility of dog bites with the consequence of an increase in rabies incidences. The immediate control of dog movements and the vaccination and identification of dogs and awareness campaign on preventive measures against rabies is highly recommended. Dog bites should be immediately reported to the veterinary and medical services for prompt attention. Suspected dogs should be quarantined for a minimum of 10 days, under the proper veterinary observation.
• The needs of individual households and communities will vary. It is important that any support is targeted at what they really need and want, and not necessarily what they will accept if offered. A menu of appropriate interventions should be available from which beneficiaries can choose which would best suit their needs best.
• Direct or in-direct (credit) assistance will also be required to re-establish the commercial and semi-commercial enterprises that supply the urban and tourist markets.
19 Where should we go for more information and assistance?
FAO Representatives in Sri Lanka , India , Thailand , Indonesia and Myanmar will be able to provide advice and assistance. Specialised staff in FAO Headquarters and in its Regional Office in Bangkok will also help wherever possible.
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