【姓名】陈木子
【导师】王玉印、袁文魁
【导图解说】
这幅导图是对中学高年段地理第四单元“coasts”第一章“How and why are coastal environments different and dynamic”的预习导图。中心图是我临摹的网上的简笔画，自认为还不错吧。Coast上不同颜色的色块指的是coast上的不同部分。
Main Branch 1: Topic. This gateway is about how and why are coastal environments different and dynamic, “coastal environments” in short.
Main Branch 2: Terms & Definitions. Coast is defined as the area where the lands meets the sea(hence meet and sea are connected) and covers the area of land that is affected by waves and tides. It can be divided into 5 zones: offshore, nearshore, foreshore, backshore and dunes. Coastal environment is the result of interactions between the lithosphere, hydrosphere, atmosphere and biosphere.
Main Branch 3: Variations. Coastal environments vary in landforms. They can be cliffed, sandy, muddy or rocky.
Main Branch 4: Why dynamic. There are six main factors affecting coastal environments. They are: waves, tides, currents, geology, types of ecosystems and human activities.
Main Branch 5: Waves. Terminologies of waves: wave length, wave height, crest and trough. Energy carried by waves is affected by wind speed, wind duration and fetch.
Main Branch 6: Affection of waves. Waves on the beach experience swash and backwash. There are two types of waves, namely constructive waves and destructive waves. Constructive waves have a strong swash but a weak backwash, while destructive waves produce a weak swash but a strong backwash. Wave refraction occurs as waves approach a coast. Then, they change their direction. This increases wave height and erosion energy.
Main Branch 7: Cause of variation. The variation of coastal features and landforms from place to place is caused by coastal processes, involving coastal erosion, sediment transport and sediment deposition.
