Study On The Spatial And Temporal Evolution Characteristics Of Urban Morphology-water System Relationship In Nanchang City And Its Affecting Factors

As the source of life,water systems have guided the formation and development of cities throughout the ages.Many ancient cities in China have formed a unique urban spatial pattern based on the unique shape of the water system.However,in the era of industrial civilization,along with the urbanization of the city,the disorderly expansion of urban areas destroyed the systemic and integrity of the water system,and also affected the spatial pattern of the landscape of the whole city,which led to the identical urban construction style and various “urban diseases”.In the era of ecological civilization,spatial planning of national land has been carried out in full swing all over China.Mountains,water,forests,fields,lakes and grasses are also regarded as important urban components,and cities should completely abandon the outdated development concept and establish a more natural city-water relationship.In the past two decades,there have been more and more studies on urban-water relationship,but most of them are limited to qualitative interpretation,and there is a lack of research on quantitative analysis using rational and scientific urban planning technology methods.Based on this,this thesis takes Nanchang,a typical Eastern Water City,as a sample,and applies GIS spatial analysis technology to scientifically analyze its evolution characteristics,providing a theoretical basis for the broad analysis of urban-water relationship.This thesis firstly uses GIS spatial overlay analysis method to vectorize the historical maps of Nanchang city in four years of 1927,1949,1977,and 2005 and the high-definition image map of Nanchang in 2020 with a pixel resolution of 1m to outline the built-up area of the central city of Nanchang.The correlation between urban morphology and water system was investigated based on the transfer of mass method and iso-sector analysis.Then,the water system contours is extracted from the 1963 Nanchang map and the 2020 Nanchang high-definition image map by using GIS surface and line elements respectively,and constructed the quantitative and structural characteristics indicators based on them to quantify the influence of Nanchang urban morphological development on the water system morphology.Secondly,the historical evolution process of Nanchang city-water relationship is sorted out,and the influence of water system morphology on its urban morphology and the influence of urban morphology on its water system morphology is summarized and analyzed;based on the above analysis,the evolution characteristics of Nanchang city-water relationship are summarized.Finally,the factors influencing the spatial and temporal evolution of urban-water relations in Nanchang are studied from geographical and cultural factors,policy and planning factors and economic and construction factors,and on this basis,it fully reveals the interrelationship and degree of influence between the various influencing factors,and then derives a refined comprehensive mechanism of action.