agroecology poster
TRANSCRIPT
Rainwater Harvesting for Agriculture in the Bahamas –
A Feasibility StudyGenevieve Diamond
Department of Earth and EnvironmentProblems Facing Bahamian Farmers
.
Conclusions and Recommendations
Bahamas Average Annual Rainfall (inches) 1971-2000
0
10
20
30
40
50
60
70
80
90
1971
1973
1975
1977
1979
1981
1983
1985
1987
1989
1991
1993
1995
1997
1999
Year
Ra
infa
ll (
Inc
he
s) Abaco
Andros
Long Island
New Providence
Ragged Island
Water Resources
Data source: Bahamas Dept. of Meteorology
Land tenure – most farm land held in some form
of non-ownership
Difficulty obtaining financing due to lack of tenure
Lack of irrigation during dry season
Lack of refrigerated storage of crops in most islands
Inadequate transportation for crops in Nassau in Nassau
Lack of alternate markets
Purpose of the Study
Proposed Harvesting/Irrigation
Methods for Bahamas
Rainfed Groundwater Harvested
Rainfall
Ridge and
Furrow
Solar-Powered
Pump/Drip
Method
Collection and
StorageSystem
Drip Method
The Commonwealth of the Bahamas has been a net importer of food for
decades, but since the early 1990s the government has had a goal of
increasing food security by increasing agricultural yields. The availability
of irrigation water has improved crop yields in many areas of the world
and increased food security in those areas. However, most agriculture in
the Bahamas is rainfed, and infrastructure for irrigation is generally
lacking. Also, although rainfall is abundant in the larger agricultural
areas, the pattern is seasonal, with marked wet and dry
seasons. Most of the rainfall is received during the summer months.
Due to climatic factors such as hurricane activity during the wet summer
months, most crops are grown during the dryer winter months. Although
some rain occurs during the winter, rainfall during those months is not a
reliable source of irrigation. Therefore, Bahamian farmers would benefit
from a system of irrigation for those months. However, available
freshwater is scarce on most of the islands, as rainfall is the sole source
of recharge of the aquifers, and they are highly vulnerable to saltwater
intrusion resulting from overpumping. The purpose of this study was to
identify methods of rainwater harvesting for agriculture that have been
used successfully in other countries that would be effective in the
Bahamas.
Some Facts about the Bahamas
Method
Quantity of Agricultural Output for the Bahamas
1997-2004
0
5000
10000
15000
20000
25000
30000
1997 1998 1999 2000 2001 2002 2003 2004
Year
Ag
ric
ult
ura
l o
utp
ut
(sh
ort
ton
s)
Export crop
Domestic crop
Poultry
Agricultural Output
UN Environment Programme ranked Bahamas 194 out of 199
nations in freshwater resources
Population in 2000 was 306,000 (Bahamas Dept. of Statistics)
Total Land Area – 13,939 km2 -19 populated islands; hundreds of cays
and rocks
Located in the western Atlantic off the SE coast of Florida to NE coast
of Cuba – Tropic of Cancer transverses the central islands
Climate - subtropical temperate in the far north
to semi-arid in far south
Northern islands support forests of pine; coppice in central Bahamas;
scrub in south
Soils – poorly developed, sandy
Farming methods – “banana hole” on coppice islands; large-scale on
some northern pine islands
A survey of irrigation and
rainwater harvesting for agriculture methods
from several areas was done to determine their suitability
for use in the Bahamas. This was done based on the soil
conditions, rainfall amounts, and transmissivity. In situ systems
in use in the Gansu province of China were studied, as well as
microcatchments in the Negev Desert in Israel, RWH in
Tanzania, and artificial recharge of groundwater in the Wakal
River basin in the Rajasthan State in India, in Barbados
and Jamaica in the West Indies, and Argentina and
Paraguay in Latin America.
Potential for rainwater harvesting is high in the
Bahamas because of the abundant rainfall
enjoyed by the country.
Population in rural areas of the Bahamas is still
low, which offers an excellent opportunity for
development of infrastructure and policy.
A comprehensive plan for managing all of the
country’s freshwater resources should be
formulated. This includes seeking ways to
ensure participation of all stakeholders.
Farmers need assistance and training in
rainwater harvesting and irrigation in the field.
Government should make it part of policy to
institute training for farmers in sustainable
farming methods to maintain the health of the soil
and the water resources.
Development of more refrigerated storage,
especially in the central and southern islands, as
well as additional transportations should be
undertaken.