Evolution Of Rural Settlement Form And Influencing Factors In Typical Areas Of The Lower Reaches Of The Yellow River

The Yellow River Basin,one of the birthplaces of human civilization,has a long history of settlement,its unique style and heritage are formed here.Changyuan section of the Yellow River is a typical wandering section,which is the "bean curd waist" of the Yellow River.The safety and economic prosperity of the placanticline are affected by the migration of the river.Changyuan——the pilot county of National Rural Revitalization Strategy,is carrying out rural planning and construction all over the country.Menggang Town,with profound cultural heritage,has formed a representative form of settlement space in the long historical development and evolution process.Settlement form is affected by regional geographical environment and economic environment.The study on the evolution and mechanism of rural settlement space form has an important reference significance for the protection of the traditional features of the river basin and the implementation of the strategy of Rural Revitalization.GIS spatial analysis method is used to analyze the scale,spatial pattern,distribution density and evolution characteristics of rural settlements in menggang town.Historical data and on-site investigation are used to further analyze the evolution of residential space.The method of plane figure quantification is used to divide the types of village forms in menggang town and select typical villages.The method of space syntax and kernel density analysis is used to analyze the typical village forms in detail and deeply to explore the characteristics of the typical village plane forms in the meso dimension.The results show that:First,the expansion of rural settlements in menggang town is obvious,and the spatial form of settlements is increasingly complicated.From 1990 to 2018,the total area of settlement patches in menggang town increased from 402.86 hm2 to 869.93 hectares,among which,in 2008,the area of settlement patches increased from 644.19 hm2 to 869.93 hectares in 2018,with an area growth rate of 35.04%.The total number of patches decreased,and the expansion of villages was the most obvious during this period.From 1990 to 2018,the proportion of patches whose compactness index belongs to the third level in menggang town is decreasing,which indicates that the settlement form is increasingly complex.The Cv values of Voronoi diagram in 1990,2000,2008 and 2018 are 50.8,45.36,39.01 and 41.48 respectively.In the study of settlement distribution pattern,it shows that the settlement of menggang town is a random distribution pattern,which basically conforms to the distribution characteristics of settlement in plain area.Secondly,the building area in the courtyard gradually increases,people's demand for the courtyard decreases,and the appearance of the building changes greatly.Since 1990,it has been 30 years of rapid change and development in rural areas.The living environment and conditions of menggang town people have changed dramatically.In 1990,the depth of the main house was 4-5meters long,and in 2000,it was 6-8meters long.After 2008,the depth of the newly built house reached 10-14 meters long.The building area increased,and the building color became richer.The architectural details experienced complex——simple——complex changes.Thirdly,The external enclosure elements of typical villages are various,and the internal spatial form features are obvious.rich forms of internal space node space,and the high efficiency of street space utilization are clustered settlements and banded clusters.One or several high-density centers of buildings are formed in the settlements,with the building inclination mainly from northeast to southwest.Fourth,the natural factors,mainly soil and hydrological conditions,have a great influence on the settlement production mode,which is the basis of the settlement formation and evolution in menggang town.The growth of regional population and the increase of settlement scale with the opening of rural economy and the development of industry.With the improvement of residents' income level,people pursue a better living environment and transform the residential space.The convenience of transportation strengthens regional cooperation and plays a leading role in settlement development.The influence of traditional culture on settlement form has been reduced with the opening of people's thoughts.