Shapefiles showing coastal erosion hazard zones in St. Kitts and Nevis have been created as part of the Coastal Erosion Hazard Mapping component of the OAS/USAID Post-Georges Disaster Mitigation (PGDM) Project - St. Kitts and Nevis. These files are available as a zip archive: bcherosz.zip.
Components of the shapefiles are list in Table 1.
Table 1: Beach Erosion Hazard Zone Shapefiles Components |
||
Beach Erosion Hazard Zone Shapefile Components |
Description |
|
St. Kitts |
skb_bchhazzone.shp |
Geometry file |
skb_bchhazzone.shx |
Index file |
|
skb_bchhazzone.dbf |
Database file |
|
skb_bchhazzone.avl |
Legend file |
|
Nevis |
nev_bchhazzone.shp |
Geometry file |
nev_bchhazzone.shx |
Index file |
|
nev_bchhazzone.dbf |
Database file |
|
nev_bchhazzone.avl |
Legend file |
Steps for viewing shapefiles as a theme using ArcView GIS (version 3.0 or higher):
Creation of Beach Erosion Hazard Zone Shapefiles
Hazard Zone (Hazzone_PP) = EV +
ER * PP + Ero_sl- the maximum or extreme beach width retreat/change(m) associated with a worse case storm. In St. Kitts, extreme beach width data is available for only one Hurricane (Luis) while Nevis has datasets for two hurricanes (Hugo and Luis). NB: the two data datasets in Nevis will be averaged. Where there are data gaps, EV is assigned zero.EV
PP -
the planning period (years)- time span associated with the useful life of a structure. A 50 year period was be assumed.Ero_sl - beach erosion due to relative sea level rise (m) over period PP.
ER - Long term beach erosion trend due to sediment budget considerations (m/yr). Generally, very little information is available on sediment budget for beaches and sediment budget analysis is beyond the scope of site investigation that is currently done. For this calculation, the annual beach erosion is used for ER. In cases where annual erosion rate values are positive, ER is assigned zero.
Originator:
Edsel B. Daniel, Box 1625, Station B, Nashville, TN 37235, U.S.A, [email protected]
Field Name |
Field Type |
Field Width |
Decimal Places |
Units |
Field Description |
Id |
Integer |
2 |
NA |
NA |
Identification number assigned by originator. |
Beach_Name |
Character |
NA |
NA |
Assigned beach name. |
|
Beach_Code |
Character |
3 |
NA |
NA |
Unique beach code assigned by originator. |
MABC |
Real |
6 |
2 |
Meters per year |
Mean annual beach change rate. Calculated from beach rate change data collected under the UNESCO+-COSLAC^ project. |
EV |
Real |
6 |
2 |
Meters |
Extreme values (EV) for beach recession due to Hurricane. Taken from Cambers (1996): Hurricane Impact on Beaches in the Eastern Caribbean Islands: 1989-1995. |
PP |
Integer |
3 |
0 |
Years |
Planning Period. |
ER |
Real |
6 |
2 |
Meters per year |
Erosion rate values. Negative values of MABC. |
REC |
Real |
6 |
2 |
Meters |
Projected erosion based on COSALC beach change rate (ER) values. = ER x PP. Where ER > 0, REC is assigned zero. |
S_Lev_R |
Real |
6 |
2 |
Meters per year |
Project sea level rise. Based on IPCC#, sea level rise projections 0.09 - 0.88 meters(average- 0.79m) over period: 1990 -2100. 0.79m/110 yrs = 0.007 m/yr |
Ero_sl |
Real |
6 |
2 |
Meters |
Projected erosion rate due to sea level rise = S_Lev_R x (100)* x PP. *The IPCC reports that 1 cm rise in sea level erodes beaches about 1 m horizontally. |
Hazzone_50 |
Real |
6 |
2 |
Meters |
Hazzone_PP = EV + Rec + Ero_sl; where PP= 50, 40, 30, and 20 years. NB: Hazzone_50 values were used to create the erosion hazard zones. Hazzone_40, Hazzone_30 and Hazzone_20 values were added for reference. |
Hazzone_40 |
Real |
6 |
2 |
Meters |
|
Hazzone_30 |
Real |
6 |
2 |
Meters |
|
Hazzone_20 |
Real |
6 |
2 |
Meters |
+ UNESCO United Nations Educational, Scientific and Cultural Organization.
^ COSALC Coast and Beach Stability in the Caribbean
#
Intergovernmental Panel on Climate Change (www.ipcc.ch)USAID/OAS Post-Georges Disaster Mitigation: http://www.oas.org/pgdm | Page last updated on 20 Sep 2001 |