| The Liaohe estuary nature wetland reserve is located in the northern part of Liaodong Bay.The reserve has a huge wetland ecosystem and is one of the world's wetlands with intact ecosystems.In recent years,mankind has been pursuing economic development.Excessive human disturbance has caused the problem of wetland ecological environment in the reserve to be aggravated.Therefore,it is necessary to use real-time monitoring and mapping methods to monitor wetland land use information in real time and analyze wetland change.The article selects the 1985 to 2016 Landsat series satellites as the basic data source.First of all,taking object-oriented multi-scale classification theory as the basic theory and taking the actual needs of wetland protected area monitoring as the starting point,combining multi-scale image segmentation and multi-feature fusion extraction and systematically studies several key aspects and corresponding key points of object-oriented classification for specific data sources problem,which provides assistance and reference for the extraction of land use information in Liaohe estuary Wetland Reserve.Secondly,based on the classification(LULC)result,analyzed the process of wetland transformation in the past 30 years by using mathematical statistics model and preliminary socio-economic factors,the result shows:1.The extraction result based on the object-oriented method is continuou and can avoid the"salt and pepper"phenomenon.That reduce the workload of subsequent manual changes greatly,and the classification accuracy and the reliability of the data are improved.According to the accuracy evaluation results,the average precision reaches 87%.This classification system can accurately extract the information of land use protection of Liaohe Nature Wetlands,and can extract information from different types of landforms at the optimum scale.At the same time,it has good classification accuracy for Landsat series satellite data and meets the accuracy requirements of subsequent data applications.The high-precision and nearly 30-year land use information obtained by this classification method can provide effective follow-up land-use change detection the basic data support.2.In the period 1985-2016,LUCC mainly reflected the conversion of natural wetlands to constructed wetlands and others,while the total area of wetlands decreased and the area of others increased.During the period,natural wetlands decreased by 199.85 km~2,accounting for an overall decrease of 27.67%.Artificial wetlands increased by 146.75 km~2,with an overall increase of 20.23%.Total wetlands are converted to others by 53.1 km~2.The changes of constructed wetlands are obvious,mainly reflected in the large-scale growth of ponds and paddy fields;the increase of non-wetland areas is mainly reflected in the increase of construction land.At the same time,according to the change of land cover and the change trend(Ps)in different periods of the study area,according to the condition of the wetland,it can be divided into 4phases:(1)Wetland expansion(from 1985 to 1990),(2)Artificial wetland intensive conversion(from 1990 to 2000),(3)Continuous and stable(from 2000 to 2010)and(4)Balance(from 2010to 2016),represently.3.Due to short research time in Liaohe esturay Wetland Reserve,natural factors have little effect on the change of land use and land cover on a large time scale.Therefore,these natural factors are indirect image factors of LUCC.Changes in protected areas,especially the increase of non-wetland area,are mainly due to social development and economic relations. |
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