Remote Sensing Monitoring And Analysis Of The Impact Of Hainan Artificial Island On Nearshore Environment

In response to the major strategy of “International Tourism Island” and the economic development of coastal cities,Hainan Province has successively carried out a series of reclamation projects including offshore artificial islands in its roundabout area.Reclamation will inevitably change the original ecological environment of the surrounding land and sea,which may cause various ecological problems.This paper monitors the construction process of artificial islands based on high-resolution series(GF)satellite imagery and Landsat series satellite imagery,and evaluates the impact of artificial island construction process on nearshore land and marine ecological environment.The main methods and conclusions are as follows:(1)Based on the 23 rd high score(GF)satellite imagery and the 10 th Landsat series satellite imagery,through the object-oriented classification method,the artificial sea island of Nanhai Pearl Island,Haikou Bay Lighthouse Hotel,Ruyi Island,and Coconut Grove Bay Leisure Resort Center The actual reclamation area of the 11 artificial islands of the island,the South China Sea resort artificial island,the Tanmen fishing port artificial island,the Riyuewan artificial island,the Phoenix Island,the Yazhou fishing port artificial island,the Haihua Island and the Millennium Hotel artificial island The length of the artificial shoreline is monitored to dynamically monitor the construction process of the artificial island.The results show that the actual sea area of the 11 artificial islands is consistent with the planned sea area.The actual reclamation area is 1810.41 ha,and a total of 120.97 km of new artificial shoreline is formed.(2)Based on the 21 st Landsat satellite imagery and the 9th high score(GF)image,using the combination of object-oriented classification and band ratio,respectively,the artificial island of the Coconut Grove Bay Leisure Resort Center,Riyuewan Island,Tan The changes in the sandy shoreline near the artificial fishing port,the Phoenix Island and the Pearl River Island in the South China Sea were monitored,and the sedimentation was obtained through the change of the sandy shoreline.Through the analysis of the erosion and siltation conditions of several representative artificial islands,it is concluded that the artificial island will be in the coastal land when only the appropriate island width and offshore distance ratio,sufficient hydrodynamic conditions and sediment source are available.The inter-island area forms a relatively obvious sedimentation.(3)Based on the 36 th Landsat 8 satellite image and the chlorophyll a concentration in Sanya Bay,an inversion model for the concentration of chlorophyll a in the coastal waters of Hainan was constructed,focusing on the second phase of the Phoenix Island and the sea that began construction after 2013.The temporal and spatial variation of chlorophyll a concentration in the waters around Huadao,Nanhai Pearl Island II and Riyuewan artificial islands was analyzed.From the time point of view,after the construction of the artificial island began,the concentration of chlorophyll a in the water near the artificial island area increased,and the upward trend of the reclamation project will gradually flatten after completion.According to the spatial angle analysis,the concentration of chlorophyll a in the water near the artificial island is higher than that in the artificial island.During the reclamation of the artificial island,the trend of chlorophyll a concentration in the surrounding water body and the change trend away from the artificial island water body are different during the construction of the artificial island.The increase of chlorophyll a concentration in water has a limited range.After a certain distance from artificial island,the change of chlorophyll a concentration in water is consistent with the change of chlorophyll a concentration in ocean water.This conclusion reflects that during the construction process of the artificial island,the concentration of chlorophyll a in the surrounding waters will increase,but the scope of impact is small,and it does not expand away from the artificial island area,but only affects the coastal ecological environment.In summary,the reclamation process of artificial islands will have an impact on the surrounding land and sea ecosystem.The shape design,distribution location,surrounding hydrodynamic conditions of the artificial island and the change of the area of the sandy beach near it are closely related.The artificial island construction also affects the stability of the marine ecological environment.Therefore,before the construction of the coastal zone project,the prediction of the ecological environment impact of the coastal zone should be fully prepared,and the advantages and disadvantages between ecological health and economic development should be weighed.