Area Change Of Wetlands In Laizhou Bay And Its Evolution Mechanism In Recent Years

The development of wetlands directly influences the evolution of the coastalareas of ecological environment, economic development and social progress, and itplays an important role to the local economy and the change of the social environment,and the wetland has great significance in maintaining regional ecological balancesystem. Laizhou bay wetland is under intense development and serious damage, andthe contradiction of development and protection of the wetland is growing.It has important significance for wetland protection and rational utilization of thewetland and it provides a scientific basis for scientific planning and management ofwetland of the distribution characteristics and the use of the status quo of the wetlandresources, the Laizhou bay analysis of variation characteristics and evolutionmechanism of wetland for many years and the scientific evaluation of laizhou baywetland functions.In this paper, we use related image processing software such as ENVI4.8,ERDAS9.2, ArcGIS9.3, MAPINFO9.5, Surfer8to do research in Laizhou bay area in1983,1992,2000,1992Landsat image data and in pretreatmention, interpretion andclassification of1986,2005,2009, Laizhou bay chart.It is described in detail that thechanges in Laizhou bay coast, water depth, change of wetland landscape area.Results show that the total length of shoreline are454.70km,527.90km,588.70km,623.50km in1983、1992、2000、2012, the transformation of each coast shorelinetype is mainly from the natural coastline to artificial coast. From2012to1983, thecoastline is totally forward1241.4km~2, at the speed of42.8km~2/a and totallyretreat11.6km~2, at the speed of0.4km~2/a.The isobath near the Yellow River delta forward tremendously for about490km~2, forwarding15km on the average.This ismainly caused by the Yellow River delta sediment transport.The wetland total area of Laizhou bay sea area within each year are4475.24km~2,4603.91km~2,4729.33km~2,4399.18km~2, and the transformation of various wetlandtypes are mainly from natural wetland to artificial coast. Transition probability matrixto the area of wetland type shows that it grow larger that the human factor controlculture zones of ponds and salt pan, and the natural wetland reduce into artificialwetland.The reason of change mechanism to the Laizhou bay wetland is the combinationof the natural environment, human activities and decisive factors of intervention.Natural actors is mainly embodied in the natural environment such as climate, stormtide, coastal erosion, sea level rise, seawater intrusion, etc. Human factors mainly arethe influence of artificial constructions such as port, wharf and breakwater seawall,aquiculture area, salt pan and ponds and the factor of human activities in thewater-sediment regulation of rivers that affects the sediment sources and transport andindirectly affect the natural coastline and wetlands.