Sedimentary Geomorphology And Quality Rating Of Beaches In Rizhao City

Beach is precious natural resource which nature gives human beings, its attractive scenery can be used as recreation and tourism resource which generates economic benefits, its special geographical position can block the impact of waves on buildings, farmland and roads to protect human living space. Rizhao is a coastal city, beach tourism is an important part of its tourism industry, which plays an irreplaceable part, but there is widespread erosion on sandy coast at present, the reason of erosion is different so it’s particularly important to grasp the characteristics of beach sedimentary geomorphology and correctly understand beach sedimentary dynamic environment and its process and protect them scientifically. We made field survey on7beaches in Rizhao city, from April2010to December2011. Look up relevant information widely at the early stage, to master research progress of the study area, select representative profiles of each beach to measure and collect surface samples during field survey. To test samples by grain size experiment, and then analyze the data of grain size experiments and profile measurements, to master the characteristics of the sedimentary geomorphology of Rizhao city’s beaches systematically. To establish a beach quality rating system at last which is based on9sedimentary parameters, beach length, profile length, berm width, slope, mean grain size, sorting coefficient and so on, obtain the rating results, and combine with field surveys to analyze. Understand beach dynamic equilibrium adequately and put forward some suggestions on beach development and protection. To master the characteristics of beach sedimentary geomorphology more clearly, we select some beaches to measure and sample repeatedly. Combine the geomorphic characteristics of beaches, hydrodynamic force, shoreline morphology, the impact of human activities and other factors to analyze the change of characteristic parameters of sediment grain size and profile variation in different periods. By analyzing, mainly draw the following conclusions:(1) Most of the surveyed beaches in Rizhao city are headland-bay coast, most beaches’ mean grain size range in0.8～3Φ (0.125～0.5mm),57%beaches’ sorting is Ⅳ medium.(2) Variation analysis of the surface sediments in the First Bathing Beach, the Second Bathing Beach, the Third Bathing Beach and Shi Laoren Bathing Beach shows that there is significant change of beach sediments by different wind and wave functions in April and October. The grain size in October is generally thinner than in April, and most of the sorting is getting better.(3) The geomorphic characteristic of each investigated beach is obviously different. The average length of Huangdao coast’s beach profile is138m which is the longest, while Laoshan coast is106m which is the shortest. The average slope of Jiaonan coast is the biggest (5.4%),and it’s the smallest in Jimo coast (2.3%). Make quantitative analysis of6fixed profiles’ seasonal variations in Wanpingkou Bathing Beach, its profile shape is basically stable.(4) Among the score of rating for the7beaches, in100point scale, the beaches which get score higher than85(excellent) and lower than65(poor) are respectively12%and8%, which shows that general status of the investigated beaches is good.