Soil Erosion in Jamaica is Being Reduced Using Nuclear Techniques

Jamaica is the third largest island of the Greater Antilles of the West Indies, situated south of Cuba, with a population of approximately 2.6 million. Jamaica has a maximum length, from east to west, of about 235 km; the maximum width is approximately 80 km. The total area of the country is 11244 km2. Kingston is the capital and largest city of Jamaica. The mountainous island is divided into three main types of land forms: (i) series of interior mountain ranges dissected by steep ravines, (ii) upland plateau and hills, and (iii) coastal plains and interior valleys. The principal range, situated in the eastern section of the island, is the Blue Mountains with Blue Mountain Peak being the highest summit with 2256 m a.s.l. The climate is tropical and is affected by the northeast trade winds. The average annual rainfall is 1980 mm. The wettest periods are between May to July and September to October. In 1945, more than 50 years ago, the awareness of the impact of soil degradation through soil erosion was highlighted by a report of the Economic Policy Commission acknowledging that: 'Steps should be taken to meet this grave concern and widespread menace before it is too late'. Exploratory studies completed during the 1950s and 1970s listed the following causes of soil erosion: (i) unstable hillside agricultural practices (e.g. cultivation on the steep slopes, use of slash and burn and cultivation without implementing soil conservation measures); (ii) inappropriate selection of arable lands; (iii) illegal settlements on hillsides; (iv) unauthorized sand mining and quarrying; (v) improper construction and lack of road maintenance; (vi) thin and erodible soils; (vii) and unpredictable magnitude of climatic events (e.g. tropical storms). The large scale removal of forest cover for lumber and charcoal production has greatly contributed to the deforestation of the island. Along with forest fires during extended periods of droughts, these are factors that helped compound the soil erosion processes. The effects of soil erosion in Jamaica have had significant on-site and offsite impacts that can be summarized as follows: (i) increased siltation of rivers and reservoirs, (ii) increased marine and coastal contamination and degradation, (iii) reduced tree and vegetative cover, (iv) reduced water quality and quantity, and (v) increased flooding and associated landslides resulting in loss of human lives, property, roads and crops. For example, in the aftermath of Hurricane Gilbert in 1988 the cost for repairing roads was estimated US$ 19 million. Only scarce soil erosion data based on investigations using conventional techniques (e.g. USLE modelling or sediment traps) conducted in the 80's are available. These studies suggested the occurrence of important land degradation due to soil erosion in agricultural and forested lands reaching up to 300 t/ha/a. Recently, the use of nuclear techniques was promoted in Jamaica through its participation in the Regional Latin America Technical Cooperation Project RLA5051 on Using Environmental Radionuclides as Indicators of Land Degradation in Latin America, Caribbean and Antarctic Ecosystems (ARCAL C). This project aims to enhance the regional capacity for sound assessment of land degradation and improved national and regional policies for soil conservation and environmental protection throughout the region using fallout radionuclide inventories measurement. In Jamaica, to date, soil sampling equipment has been received and training in the use of fallout radionuclide (i.e. 137Cs) based techniques for estimating soil redistribution rates has been completed. At Seibersdorf Laboratory Mr. Williams has been trained in the different aspects of the use of Fallout Radionuclides. During this fellowship, the selection of a suitable reference site was discussed and the sampling design finalized. Through this training the basis has been laid for the future successful implementation of the RLA5051 project activities in Jamaica. This will lead to the development of more sustainable land management practices and soil conservation measures in order to ensure sustainable food security and soil re-source protection in Jamaica