Multi-source Remote Sensing Monitoring Of The Impact Of Port Construction On The Maritime Silk Road

Port is a key strategic infrastructure in the maritime silk road transport corridor.It undertakes the responsibility and mission of the maritime silk road construction and can attract many resource elements.Port is to promote the country to open to the outside world,strengthen the economic and trade between countries important node.This paper sorted out the port projects built by China in the maritime silk road.So far,101 overseas port projects have been counted as under construction or completed,and 4 key ports are selected as cases to study.Remote sensing technology can not only carry out spatio-temporal dynamic monitoring and integral research on the project,but also save manpower and material resources.Therefore,this paper uses multi-source remote sensing technology to monitor Colombo port in Sri Lanka,Dohalley port in Djibouti,Kuantan port in Malaysia,Walvis bay port in Namibia.Landsat images were used to analyze the impact of port construction on the ecological environment of the study area,and High-definition images and night light remote sensing images were used to analyze the changes of port construction on the local economic development.As a natural economic complex,land is not only an important part of human and land systems,but also the main space support for ecological environment construction.Vegetation coverage is an important index to measure the state of surface vegetation,and also an important index to evaluate the ecological environment quality in this area.In this paper,Landsat images were used to monitor the land use/land cover change and vegetation coverage change of the port and analyze the impact of project construction on the ecological environment of the area.Firstly,according to the actual situation of the port,the land use types are mainly divided into five categories: construction land,forest land,grassland,water area and unused land.Then,the maximum natural law is used to supervise and classify the remote sensing images before and after the project construction.Through the analysis of land use transfer matrix,it can be seen that the port construction mainly occupies unused land and water,and had relatively little impact on other features.Based on the analysis of vegetation coverage,the vegetation coverage of the four ports did not change much in the range of 0.6～1.As the port of Dohalley in Djibouti and Walvis bay in Namibia have tropical desert and tropical arid climate respectively,the overall vegetation cover is very rare,so the vegetation coverage is very low.The vegetation coverage in Kuantan port in Malaysia and Colombo port of Sri Lanka is in good condition.The vegetation coverage in the range of0.6-1 is stable at about 50%,and the overall vegetation coverage is relatively high.The vegetation coverage of the four study areas remained basically unchanged before and after the port project construction,indicating that the port construction had little impact on the environment of the region.The road is an important infrastructure that affects the development of regional economy.The light index can reflect the development level of regional economy.A large number of studies show that the brightness of a region’s light at night is in direct proportion to its GDP.This paper selects two indexes of road and light brightness to monitor the influence of port construction on social economy.The distribution of roads was extracted with 1-meter High-definition images,and it can be seen that the roads in the four ports all increased with different growth ranges.Among them,the port of Dohalley in Djibouti has the most obvious growth rate,from 24 693 meters before construction to 55 161 meters,an increase of 123.39%.Based on the monitoring and analysis of the remote sensing image of the 40 km light around the port,the increase of the light brightness of the port position is very obvious,and the light brightness of the area near the port also increases greatly,while the increase range of the inland area is small,indicating that the port plays a radiating role in the economy of the surrounding area.From 2014 to 2019,the port with the largest increase in light brightness value is the port of Dohalley in Djibouti,with the average light brightness rising from the original 10.96 to 29.92,and its lighting growth rate of 172.99% in five years.After the completion of the port project,the lights in the port of Dohalley in Djibouti can be seen increasing significantly,reflecting the substantial economic growth in the region.Through the analysis of the ecological environment of the four port areas,it can be seen that the port construction on the maritime silk road will change the land use structure of an area.However,in the process of project construction,the construction side adopted a series of environmental protection measures,so the environmental impact on a region is small.Through the monitoring and analysis of the economic development status,it can be seen that the port construction has a great promoting effect on the economy of a region,which leads to the increase of roads,the expansion of building area and the increase of population.Especially for the least developed countries,port construction can greatly boost the economic growth of the country.In the future port development process,the sustainable development of the port area cannot be achieved without the protection of the ecological environment,so it is necessary to strengthen the environmental supervision and protection of the port in the daily transportation.