Coal is found in deeper layers of earth. To retrieve coal from those layers, underground tunnels need to build. These underground tunnels tend to fill with ground water. To prevent this, steam pumps were installed to keep the tunnels dry. The groundwater pumped out of the mines is “comparatively clean” (Wilkinson 2011, 3).
Once the steam pump is shut off, the underground water is able to fill up the abandoned mine over years. After all tunnels are filled up, the water finds a way to release itself. This is called natural drainage water (Wilkinson 2011, 3). In case of the project, this happens through the outfall which is right above high water spring tide. The water that is released through the outfall is not as clean as the actively…show more content… During spring tide, the tidal amplitude is very large.
The opposite is called ‘neap tide’ and occurs when sun and moon are at right angles. The gravitational attractions act in opposition and the tidal amplitude is very low.
7.4 Rocky shore
These shores were shaped by different natural forces. Those forces include the rise and fall of tides, wind, intensity of waves and variation in temperature. They consist of rocky ledges, boulders and pebbles. Furthermore, pools with seawater can be found.
Rocky shores can be divided into different zones, according to vertical height. The zones vary in diversity (see Fig. 6) and most species are adapted to a specific zone (Little 2009, 17).
The top of the shore is bare rock and living organisms such as littorinid snails or lichens can be found there. This zone is called ‘splash zone’ as it above high tide mark and therefore perpetually out of water (Little 2009, 18).
The second zone is called ‘littoral zone’ (or intertidal) and has its boundaries defined as distance between very highest and very lowest spring tide. The lower, middle and upper shore are included into this zone and there is a varying degree of exposure to seawater, depending on the tide. Organisms living there must be able to cope with fluctuating air and breaking waves. Rock pools and Fucus spiralis are found in this part of the rocky shore (Little 2009, 18).
The lowest zone is the so called ‘sublittorial zone’ and