Saint Vincent - Climate

St. Vincent and the Grenadines (SVG) enjoys a tropical climate. The northeast trade winds blow across the islands, releasing some of their moisture as they do so. The islands as a whole receive an average of 150 centimeters of rainfall per year; in the mountains, however, the average is 380 centimeters per year. Seventy percent of this precipitation falls during the rainy season from May to November. Temperatures average 28°C. Although the island group lies in the hurricane belt, it is not often subjected to massive damage. In recent history, hurricanes struck the island in 1956, 1967, and 1980. Tropical Storm Danielle did about US$9 million in damage to the banana crop in 1986.

Hurricane Tomas affected the island at the beginning of November 2010, bringing heavy rains and high winds which caused flooding, loss and destruction to several buildings, agricultural plots, livestock and the natural landscape. Persons were displaced from their homes. The impact of the hurricane on the community was exacerbated because most residents did not initially expect the system to affect the country and failed to prepare adequately. Before most residents recovered fully from the impact of Hurricane Tomas, a severe flash flood occurred in April 2011. The flood damaged homes and water pipes. Georgetown was without a piped water supply for about one month. Consequently rainwater harvesting is now commonplace is some households, but needs to be further promoted and integrated in the community, perhaps with appropriate financial assistance mechanisms.

In Georgetown, the psychological impacts of disasters are very evident, especially in men. Some men were unable to manage the burden of recovering and providing for their family or families. Men who had responsibility for their families felt a greater strain than those who did not and suffered a weakened sense of pride when they were unable to fulfil their duties. It has been reported that as a result they resort to heavy drinking and becoming intoxicated.

In the dry season there is sometimes no rain for days. It usually takes the form of short heavy showers which are soon over and leave the streams in raging flood, and not unfrequently an inch of rain falls in an hour, and a rainfall of several inches in a day often takes place. This is sufficient to make streams which are usually quite dry, rise and overflow their banks in floods which sweep everything before them to the sea. Even the smaller brooks, which are often dry in fine weather, have their channels filled with very large boulders, 8 feet or more in diameter, which show by their rounded and worn surfaces that they have been transported for some distance.

There were numerous instances in which streams apparently of trifling size had moved large rock masses, and had done great damage to bridges, retaining-walls and other structures. Engineers encountered great difficulties in making roads to withstand the devastation occasioned by the heavy rains. All the less important thoroughfares and the bridle-paths are frequently rendered impassable by the water cutting across the road and washing out deep channels.

These deluges of rain not only greatly increase the cutting power of the streams, but they also saturate the soil and render it particularly liable to slip when it is lying on steep ground. So deep and narrow are the valleys, that on each side the material is resting practically at the angle of repose, and anything which facilitates interstitial movement or lessens the cohesion of the particles, is sufficient to cause a landslide. Thus it will be readily understood that in a typical Caribbean valley the experienced eye can perceive how every feature of the surface is determined by the underlying geological structure.

St. Vincent & the Grenadines is already experiencing some of the effects of climate variability and change through damage from severe weather systems and other extreme events, as well as more subtle changes in temperature and rainfall patterns. The 2009 drought resulted in significant losses to farmers; food prices rose and produce had to be imported from other is lands to supplement the limited supply in St. Vincent. From 2010 to 2014 Saint Vincent and the Grenadines experienced four distinct climate anomalies – from flood to drought to hurricane – each of which produced double-digit hits to our GDP. In December 2013, three hours of unseasonable flooding caused loss and damage amounting to 17% of our Gross Domestic Product. Climate change effects are evident in the decline of some coastal tourism resources, but also in the socioeconomic sectors which support tourism, such as agriculture, water resources, health and biodiversity.

Detailed climate modelling projections for St. Vincent & the Grenadines predict:

• an increase in average atmospheric temperature;
• reduced average annual rainfall;
• increased Sea Surface Temperatures (SST); and
• the potential for an increase in the intensity of tropical storms.

And the extent of such changes is expected to be worse than what is being experienced now.

A 1 m sea level rise [SLR] places 10% of the major tourism properties at risk, along with 1% of road networks, 50% and 67% of airport and sea port lands respectively. With 2 m SLR, 24% of major tourism resorts will be impacted and 75% of airport lands. With 100 m of erosion (resulting from approx. 1 m SLR), 76% of the major tourism resorts will be impacted. Annual losses in tourism resulting from the reduced amenity value from beach loss is estimated to be between US $46 million by 2050 to US $174 million by 2080 for a mid-range SLR scenario.