9. Spill exercise case studies
To study the predictive capability of the model the two field exercises were carried out in the summers of 1994 and 1995 on the two rivers of West Siberia, River Kiya and River Irtysh.
The observed date available are for the time of slick arrival to the marks,for the leading edge of the oil slick along the river, slick length, slick width and the distance of the slick centre from the left bank.
9.1 River Kiya spill exercise
The next picture presents the slick locations and contamination areas for two cases as :
(a) the wind blowing in indicated direction at 8 mps and
(b) no-wind conditions.
As shown the resulting impact of the two cases is very different. In case (a) most of the oil hits the right shore and slowly leaks back into the water.
The model results agree remarkably well with observed location of contamination area.
9.2 River Irtysh spill exercise
Oil slick in River Irtysh Field exercise, August 1995,1
Oil slick in River Irtysh Field exercise, August 1995, 2
The movement of oil on the surface of the River Irtysh subsequent to a spill for a wind conditions is shown on the next panels.
The wind of 7mps is blowing from left down corner.
Pictures are as follows:
Table 1. Field measurements vs simulations
Two simulations were made, a quick forecast and a longer calculation. Both simulations were carried out BEFORE the results were known, but with knowledge of the wind conditions.
The predicted results are in good agreement with the measurements, although the length of the slick is underpredicted. The time for the slick to arrive at a fixed point downstream was predicted very accurately.
