Fig. 1 shows a proposed tidal barrage across the mouth of an estuary. The scheme would generate electricity and include lock gates for fishing boats. Howeve...
Question 1 Report
Fig. 1 shows a proposed tidal barrage across the mouth of an estuary. The scheme would generate electricity and include lock gates for fishing boats. However, salt-marsh channels and mudflats occur upstream, where birds feed at low tide. Students are using the study figure to consider how human intervention could alter coastal processes, habitats and the local economy. The arrows show the normal movement of tides before the barrage is built.
(a) Identify the renewable energy source used by the barrage. [1]
(b) Describe how a barrage changes the movement of tidal water through an estuary. [3]
(c) State three possible benefits of the scheme for the town. [3]
(d) Explain why environmental groups may object to the barrage proposal. [9]
Answer Details
(a) The barrage uses tidal energy. [1]
(b) A barrage holds back water or releases it through gates and turbines. This alters the natural speed and timing of tidal flow and may change tidal range or water levels upstream. [3]
(c) Benefits can include renewable electricity, jobs, improved flood control, a crossing or transport route, and local investment. Any three gain credit. [3]
(d) Environmental groups may object because altered flow changes erosion and deposition. Mudflats may shrink or stay submerged longer, reducing feeding habitat for wading birds. Salt-marsh plants may not tolerate changed salinity or inundation, and fish migration can be obstructed. Sediment may build up upstream, slower water can reduce water quality, and construction disturbs habitats. These long-term ecological impacts may outweigh the energy benefits. [9]
Download The App On Google Playstore
Everything you need to excel in your exams
