Reconstruction Of Population Spatial Pattern In Northeast Qinghai-tibet Plateau During Ming And Qing Dynasties

People are at the center of the relationship between man and land,and the change of population quantity has an important impact on global climate,land use/land cover,water resources and so on.Therefore,the spatial study of population has been widely concerned.However,the traditional population spatialization takes the administrative unit as the statistical scope,which has low resolution and cannot reflect the actual distribution characteristics of the population in the study area.Therefore,through the population spatialization model,using natural environment,socio-economic,land use and other data,the population is accurately presented to the space,and a high-precision population spatial distribution map is obtained,which provides key basic data for disaster risk assessment,environmental protection,climate change and so on.The research on population spatialization in historical period is the core of exploring the long-time scale environment,socio-economic development and changes,and the foundation of high-precision land use reconstruction in historical period,which provides reference for modern and future response to global changes.However,due to the limited availability of historical data,the research on historical population spatialization is seldom carried out.Qinghai-Tibet Plateau,as a sensitive and fragile area of global climate change,is extremely vulnerable to population changes.This paper chooses Hehuang Valley in the northeast of Qinghai-Tibet Plateau as the research object,collects a large amount of historical data,fully excavates relevant data information,reasonably estimates the population based on historical facts,selects factors affecting population distribution,constructs a spatial model of population in plateau valley area in historical period,and tests the reliability of the model.Finally,it analyzes the driving mechanism of population changes.The following conclusions are drawn:(1)By consulting relevant local chronicles,history books and other materials,the population information was collected,and reasonable speculation and estimation were made according to historical facts,and the population of Hehuang Valley in the Ming and Qing Dynasties was reconstructed.Analysis shows that the population of Ming Dynasty is generally low.After the establishment of the Ming Dynasty,in order to solve the problem of military pay,the government implemented military camps,built castles and villages,immigrated to consolidate the development of border areas,and the population grew.Although it kept growing continuously,the growth rate was slow.The Qing government still paid close attention to the development of Hehuang Valley,continued to build more castles and villages,and the population increased rapidly,reaching the highest value in the late Qing Dynasty,and the population showed a downward trend in the late Qing Dynasty.(2)The spatial scope of population distribution is affected by the natural conditions and socio-economic activities in the study area.Due to the limitation of natural conditions,the space suitable for population distribution in Hehuang Valley is very limited,and there are few grids with population distribution in the region,mainly distributed along the main tributaries of rivers,and concentrated in areas with small slope and low altitude.Coupled with the role of social and economic activities,the population grid of Huangshui River Valley is denser than that of Yellow River Valley.In addition,with the increase of population,the spatial scope of population distribution expands,the altitude of distribution rises,and the proportion of population grid in high altitude areas increases.(3)From Ming Dynasty to Qing Dynasty,the population density in the region showed an overall upward trend.From the early Ming Dynasty to the middle Ming Dynasty,the population density of Hehuang Valley was small,and most of them were sparsely populated areas;From the late Ming Dynasty to the middle Qing Dynasty,the population density increased,and most areas were medium population areas;In the late Qing Dynasty,the population density reached a high value,and the densely populated areas accounted for more than half;At the end of Qing Dynasty,the population density decreased obviously,and the middle population area in the region accounted for a large proportion.(4)Comparing the data of climate,natural disasters,wars,policies and population migration in Ming and Qing Dynasties to explore the driving mechanism of population change,it is found that the warm and cold climate has great influence on population development,and natural disasters interact with population growth.Immigrants have brought a large number of people to Hehuang Valley,including spontaneous immigration and policy-based immigration.The immigration type in Ming Dynasty is more focused on government-led policy-based immigration,while in Qing Dynasty it is mainly spontaneous immigration.Immigrants who migrated here in various ways promoted the population growth in the region,but the war caused the population to drop sharply.