This research develops an integrated approach for understanding coastal eutrophication processes. This is based upon numerical modelling of the production of land-based nutrients and their transport to coastal waters, using GIS and remote sensing. This addresses primarily non-point sources (e.g. runoff from agricultural land and soil erosion), but recognises the importance of point sources (e.g. sewerage effluent). Whereas the latter are discharged at identifiable locations with quantified runoff volumes, non-point sources are diffuse and seasonably variable depending on the climate and rainfall. This makes their determination using a modelling approach especially important. The specific focus was the south-east of Malta. The methodology was based upon: 1) a flow routing model, derived from a DEM, to determine the patterns of drainage to the coast; 2) coupling this with the Soil Conservation Service (SCS) model to estimate runoff volumes for given rainfall and classified land use data. 3) an Export Coefficient (EC) Model to estimate nitrate and phosphate loadings; 4) the EROSION 3D model to predict the rate of soil erosion as a potential source of soil-bound phosphorus and contributor to turbidity in coastal waters; 5) inclusion of sewage discharge volumes and nutrient input from coastal point sources; 6) estimation of the spatial distribution of the water mixing time, using Rhodamine dye tracing techniques, in order to quantify dilution; and 7) water quality mapping in coastal waters to assess the effects of nutrient loading upon coastal waters. Corrections for the interfering influences of bottom effects were implemented.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:595342 |
| Date | January 2001 |
| Creators | Adami, E. T. |
| Publisher | University of Cambridge |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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