Remote Sensing Monitoring And Simulation Study Of Urban Built-up Area In Nanchang City

With the continuous progress of urbanization in China,the urbanization process brought about by the population growth,urban land rapid expansion,traffic congestion,environmental pollution and other urban diseases also come along with.The urban construction area can reflect the general situation of urban development,and the accurate extraction of the urban built-up area boundary is the key to the study of urban spatial pattern change,urban expansion and urban driving force analysis.It plays an important role in urban economic development,urban planning,land resource management and many other aspects.In order to put forward scientific countermeasures as soon as possible,take Nanchang city as an example,in this paper we would discuss Nanchang city built area development status,to identify existing problems and shortcomings more and in-depth.And it also played a very significant role to improve the City in the Yangtze River economic zoneThrough the study of the progress of the expansion of the built area,First of all,on the basis of the definition of the built-up area,select five administrative areas and four counties in NanChang as research area.Combined with ENVI4.7,ERDAS9.1 remote sensing image processing software and Arcgis10.1 geographic information system software to analyze NanChang city expansion.In this paper,the data source,which was come from five different periods' s Landsat TM/ETM+.The classification method used four methods,unsupervised classification,supervised classification,texture analysis,three-index synthesis.Based on the selection of remote sensing image classification method,then extracted the built area accurately.And then discussed the characteristics of spatial and temporal differences of the quantitative and morphological characteristics of Nanchang city.In this paper have used the method of calculating extended dynamic degree,quadrant orientation analysis,global trend analysis,spatial autocorrelation to analyze the temporal and spatial evolution characteristics of the expansion of the built area of Nanchang from 1995 to 2015.Based on the socio-economic statistics of Nanchang,combined the qualitative and quantitative methods,the principal component analysis method was used to explore the driving mechanism of the built-up area expansion.The CA model based on artificial neural network was used to simulate the change trend of built-up area in Nanchang.The results showed:(1)The K-Means unsupervised classification,the maximum likelihood method to supervise the classification,combined with the supervised classification of texture information,the three-index synthesis method in ENVI4.7 was used in this experiment,The non-supervised classification,supervised classification,texture analysis and three-index synthesis method were used to classify remote sensing and the data came from 1995,2000,2005,2010 and 2015.Taking the Landsat5 remote sensing image of Nanchang in 1995 as an example,the classification accuracy reached 65.89%,82.66%,43.93% and 88.53% respectively.Through the three-index synthesis method,the area of Nanchang built in 1995,2000,2005,2010 and 2015 was 97.61 km 2,115.17 km2,273.53 km2,346.24 km2,463.99 km2.(2)From 1995 to 2015,the area of Nanchang City was increased from 97.61 km 2 to 463.99 km 2,with a total growth of 366.38 km 2.Among them,the expansion of the Qingshan Lake area,Nanchang County and Xinjian County was relatively rapid,reaching scale of 151.19 km2,93.55 km2,54.59 km2.Each time in 2000-2005 growth of 158.36 km 2 was the fast in the whole serieses,2010-2015 followed by the expansion of the scale of 117.16 km2.From the point of view of expansion speed,the expansion rate was 18.32 km 2 / a in 1995-2015,and the expansion of Nanchang and Qingshan Lake area was 4.68 km2 / a,7.56 km2 / a.In the period of 1995-2015,the development of Nanchang City was 18.77%.The areas with more intense expansion were Xinjian County,Nanchang New Town,Qingshanhu District,Bay Area,etc.(3)1995-2015,Nanchang City built area expansion concentrated in the northwest,north direction.The overall trend shows that the distribution area of the built area is mainly located in Nanchang city and Nanchang county,and Jinxian County,Anyi County built area is relatively small.The Moran's I index of the built-up area were-0.3020?-0.0807.The areas with obvious clustering characteristics were located in the East Lake area,the West Lake area,the Qingyun Lake area,the Qingyun spectrum area and the xinjian county.(4)Terrain profoundly affected the expansion of Nanchang city built area.In the low terrain within the city with the development of Nanchang City built in this expansion of space will be gradually limited.Therefore,the expansion of the built-up area will shift to a higher terrain area,but the areas in those large terrain,such as multi-forest land,mountain area,due to land development costs and poor land use condition,the possibility of expansion will continue small.The expansion of the built area of Nanchang is mainly due to the increase of population and economy,the improvement of people's living standard,the acceleration of urbanization and industrialization.(5)Simulated the expansion of the built-up area in Nanchang in 2020 with CA model,which was based on artificial neural network.Compared with the current situation,it was found that the calculated area of the completed area had no big differernces with the existing area.Based on this,the construction of Nanchang City built in 2020,Nanchang City in 2020 built area reached 630.55 km 2,compared with 2015 expanded 166.56 km 2,the expansion rate of 33.31 km 2 / a,the dynamic degree of 5.28%.In the 2020,the expansion scale of Nanchang County,Xinjian County and Anyi County is 41.23 km2,80.89 km2 and 29.09 km2,respectively.The expansion of Qingyun spectrum area,Bay area and East Lake area is relatively slow,and the scale of expansion is only 0.00 km2,1.26 Km2,1.61 km2.If the administrative divisions are not adjusted,this expansion of the spatial differences will continue to maintain in NanChang.The overall pattern compared to the used situation was small.(6)The future development of Nanchang City built area should strengthen the intensive use of land,improve the government intervention mechanism to protect the ecological environment,promote the coordinated development of urban and rural areas.