A decision support framework (DSF) to guide watershed management planning in St. Lucia was developed. The DSF, supported by three components, integrated physiographic criteria in spatially defining sustainable land management regimes, crop suitability based on agro-ecologic zoning criteria, and water quality modelling tools. / In the first component, a methodology for agricultural and forestry land management zoning based on decision-rule frameworks was developed, employing GIS-based spatial multiple-criteria integration techniques. Land capability, recommended land management regimes, crop suitability and broad agricultural/forestry land utilization type zones were derived for the country. Sixteen broad agricultural and forestry land utilization types (LUTs) based on FAO agro-ecologic zoning guidelines were spatially defined over the island. These LUT zones represent relative suitability for rain-fed annual and perennial crop production, grazing and forestry. / In the second component, field research to quantify rainfall, runoff and erosion from two small watersheds under contrasting land management regimes was undertaken. Over the study period the erosion rate from an intensively cultivated, degraded agricultural watershed was 20 times that of a completely forested watershed. SCS curve numbers were evaluated for both watersheds based on rainfall-runoff relationships. / The third component demonstrated the application of a distributed-parameter hydrologic/water quality model, AnnAGNPS, in land management scenario evaluation, in terms of runoff and soil erosion. Data from the second component were used to calibrate and validate the model in simulation of daily runoff and erosion losses from the two watersheds over the study period. The model generally performed better in runoff simulation for the agricultural watershed compared to the forested watershed. Average annual erosion rates under current land management regimes were estimated at 73.3 and 7.2 t/ha for the agricultural and forested watersheds respectively. The model was applied to simulate runoff and erosion losses from the agricultural watershed under alternative sustainable land management regimes derived in the first component. Simulated average annual erosion losses were reduced to 9.2 t/ha. / This study demonstrated the application of efficient and powerful computer-based tools in the development of a decision support framework for watershed management planning for small islands.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.82848 |
| Date | January 2003 |
| Creators | Cox, Christopher Anthony |
| Contributors | Madramootoo, Chandra (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Agricultural and Biosystems Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001984883, proquestno: AAINQ88443, Theses scanned by UMI/ProQuest. |
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