4. Pollution risk of Garorim Bay
4.1. Evaluation of impact probability of oil spill
The impact probabilities of spilt oil on the coastline and aquaculture
farms in the winter are shown in Figs. 6 and 7, respectively. In the winter,
the impact probability of spilt oil is the highest due to strong wind
and tides. In Fig. 6, the impact probability in the coastline is as high as
20% in the Daesan harbor region, and most of the harbor region is
exposed to an oil spill risk. On the other hand,most of the Bay coastline
region is not exposed to an oil spill, except for the Jigok area where the
impact probability is less than 12%. The estimated length of the contaminated
coastline is ~45 km, and regarding the impact probability in
aquaculture farms, the area between the entrance of the Bay and Jigok
coast is exposed to a risk of contamination with an impact probability
of less than 20%, as shown in Fig. 7. However, the south-west region of
the Bay is relatively safe. The estimatedmaximumarea of contaminated
aquaculture farms is ~ 524 ha.
4.2. Estimated first impact time of spilt oil
Another subpart of the risk assessment is to assess the first impact
time of spilt oil. Figs. 8 and 9 show the first impact time of the split oil
in the winter for the coastline and aquaculture farms, respectively. As
shown in Fig. 8, the estimated first impact times for Nanji island and
Daesan harbor are ~4 h and ~6 h, respectively. For aquaculture farms inside
Garorim Bay, the first impact time is in the range of 6 to 11 h, as
shown in Fig. 9.
4.3. Evaluation of the oil spill pollution risk in subareas
The impact probability and the first impact time of the spilt oil are
integrated to compute the risk in the subarea. The entire Garorim Bay
area is divided into 6 subareas, as shown in Fig. 10, and Table 3 summarizes
the maximum oil spill contamination damage in each subarea of
Garorim Bay among 80 different simulations.
In Table 3, subarea II (where Daesan harbor is located) shows the
largest contaminated coastline length of ~14.6 km and the shortest
first impact time of 0.2 h among the 6 subareas. Subarea VI will be the
largest damaged aquaculture farm area of ~315.9 ha, and subarea II
shows the shortest first impact time of 1.4 h.