Study On The Spatial And Temporal Evolution Of Rural Settlements In Ningxia And The Optimization Of Typical Zones

Ningxia is located in the middle and upper reaches of the Yellow River Basin,where resource and environmental constraints are tightening,and the spatially dispersed distribution of villages in the geographical area poses a threat to the fragile ecological background,reduces the quality of the human habitat and even evolves into an obstacle limiting regional development.The study examines the spatial and temporal evolution of rural settlements in different geographic zones of Ningxia(the Northern Diversion Irrigation Zone,the Central Arid Zone and the Southern Mountainous Zone)and the optimal layout of typical areas(Xiji County,Guyuan City)to provide a scientific basis for the spatial and territorial classification of different geographic zones and to achieve a "smart shrinkage" of rural settlements in typical areas of fragile habitats in Ningxia.The study selects resource,environmental and socio-economic data,and applies the landscape pattern index,the village ranking-scale rule and the geographic probe to compare and study the spatial structure,morphological characteristics,land use conversion and other evolutionary patterns and influencing factors of rural settlements in different geographical zones of Ningxia from 1990 to 2020.By using Multi-agent model,the study classifies rural settlements in terms of their livability and ecology.The main findings of the study are as follows:(1)The spatial structure of rural settlements evolves in different ways in different geographical zones.The spatial pattern of rural settlements in the northern Yellow River Irrigation Area has evolved into a high-density cluster-wide-banded-cluster pattern;the central arid zone has shifted from low-density dispersal to medium-density scattered distribution;and the southern mountainous area has been characterized by medium-density cluster-nested distribution.The land forms of rural settlements in different geographical zones have been integrated,with a reduction in fragmentation and a tendency towards spatial clustering.In the northern part of the Yellow Irrigation Area,the rural settlement patches gradually become more regular,while the central arid zone and the southern mountainous area tend to become more complex.In the early part of the study,the land conversion patterns of different geographical zones were the same,but in the later part,there were differences.From 1990 to 2005,the land use of rural settlements in different geographical zones was mainly new and expanding,seriously encroaching on agricultural production space and grassland ecological space;from 2005 to 2020,the northern Yellow Diversion Irrigation Area was mainly extinction and decline,and the southern From 2005 to 2020,the Yellow Diversion Irrigation Area in the north will mainly disappear and decline,the mountainous area in the south will both disappear and decline,and the arid zone in the central part will mainly renew and expand,all of which will tend to compensate for agricultural production space and ecological space.The main factors influencing the distribution of rural settlements in the Northern Diversion Irrigation Zone are the distance to roads above the township level,slope,population density and distance to the central city;in the Central Arid Zone,population density,climate and slope;and in the Southern Mountainous Zone,the built-up area per capita,topography and population density.(2)The comprehensive landscape ecological safety pattern in the typical area of Xiji County shows a distribution of "low in the north and high in the south,with the area of rural settlements located in lower and lower safety level areas accounting for 24.88%of the total;the centre of rural settlements shows a distribution of "low in the west and high in the east".The number of low-grade nodes(level 3 and 4)and the area of the corresponding settlements account for 59.8%and 63.23%respectively,so there is still much room for rural settlements to shrink in terms of quantity and space.Combining the ecological security pattern of the landscape and the centrality of rural settlements,rural settlements are classified into the categories of agglomeration and upgrading,improvement and renovation,urban annexation and relocation,with an area of 4010hm2,8063hm2,507hm2 and 1306hm2 respectively,accounting for 28.88%,58.07%,3.65%and 9.41%respectively.(3)After optimising the layout of the multi-intelligent body system,the area of village settlements in the typical region of Xiji County in the category of agglomeration and upgrading,remediation and improvement,urban annexation and relocation and evacuation are 4322hm2,7987hm2,427hm2 and Ohm2 respectively,accounting for 33.94%,62.71%,3.35%and 0%respectively.There was little change in the suitability of village settlements in Xiji County,and there was a more obvious trend for settlements to move to areas with medium to high levels of ecological safety.The area of village settlements decreased by 1250hm2,the number decreased by 308,the average patch size increased by 11.5%,the average shape index decreased by 3.9%,the compactness increased by 15.4%,and the overall utility value increased by 15.5%,the village settlements got "smart shrinkage",the sporadic distribution decreased,the degree of fragmentation The village settlement has been’smartly shrunk’,with less fragmentation,less fragmentation and a significant increase in compactness and overall utility compared to the previous one.