Reconstruction And Evolutionary History Of Communication Route On The Qinghai-Tibet Plateau During The Palaeolithic To Historical Time Period

Prehistorical material dissemination in the Eurasian Mainland and the east-west cultural communication are the frontiers of the scientific issues that are internationally concerned,especially after the propose of the "Belt and Road" initiative,study of inter-regional exchanging routes become significantly important.The Qinghai-Tibet Plateau is important as it is an intersection of the Eurasian civilization and the core area of the "Belt and Road ".It is also of great significance to study the evolutionary history of early communication routes to understand the adaptability and changing patterns of human beings in extreme environments.However,at present,the researches about early exchanging routes on the Qinghai-Tibet Plateau are mostly conceptualized on archaeological evidence and literature,limited in refinement and concretization.Consequently,the understanding of the detailed evolutionary process of the early human history on the plateau is very limited.With this perspective,this study took graph as a research tool,used natural factors including elevation,gradient,vegetation,river as cost data,form the data source with site during the paleolithic to historical time period,abstracted the simulation of the early communication route on the Tibetan Plateau into a path search problem on the weighted map(network),based on the principle of minimum cost,the optimal path is used to simulate the early communication route on the Tibetan Plateau.For the specific performance,use local Python geographic processing tool in the Arc GIS(ESRI)software to perform the script calculation,use random point,and flow accumulation model under the single cost control,reconstruct the Paleolithic route;use archaeological sites,settlement points,integrated cost control node weighted connection model,reconstructed the Neolithic-Bronze-historical routes.Finally,interpolate the paleo-climate and the archaeological evidence and literature records,analyze the evolutionary process and the driving factors from the perspective of human adaptability.Mainly concluded the following points:(1)Reconstructed route during the Paleolithic age is about 100,000 km.The routes expand from the edge to the hinterland,low altitude to high altitude,with a continuous long route entered the high altitude range of the plateau,and the trace of activity covered the whole plateau.The total length of the Neolithic route is 16,900 km,consisted of 15 routes,mainly along the Hehuang-Lancang River,Yangtze River Valleys-Yarlung Zangbo River valleys,was characterized with totally marginalized-corridor type.During the Bronze Age,the total route length was 16300 km,with 18 major routes.On the basis of the Neolithic formation route,the northeast and southwest routes extended to the high altitude area as a whole,showing the characteristics of edge-hinterland type.During the historical period,the total route length was 39700 km,with 28 routes.Northeast and Eastern regions have developed networks deep into the hinterland.The emergence of hinterland route and the strengthening of northwest route dictated to form a complex-road network on the plateau.The result of this simulation is highly accordant with the archaeologically testified ancient routes including “colored pottery road” and millet propagation path,“jade stone road”,crop-domesticated sheep,horse-bronze propagation path,and relation of the northeast and southwest to the “silk road” which was documented,as well as “Qiang middle road”,“Ancient Tang-Tibet Road”,indicating the reliability of this simulation.(2)Generally,the routes during the Palaeolithic to historical time period exhibit an evolution of random-dispersal type,edge-corridor type,edge-hinterland type,to complex-road net type.The extreme climate during the last de-glaciation has promoted innovation of technology on the plateau.The prevalence of fine stone technology places hunter and gatherers on the plateau.The simulation route demonstrates characteristics of random,dispersion and unstable,which exactly accords with this behavioral characteristics.The spreading of agricultural planting technology in the Yangshao culture during the Neolithic period was an important factor for the formation of the edge-corridor route.The transcontinental expansion of wheat crops,domesticated sheep and horses to the high altitude regions during the Bronze Age has resulted in the the extension of simulated routes to high altitude areas.During the historical time,the diversification of agricultural products,improvement of production technology formed stable settlements,and boosted the population,this was concomitant with the complex political,economic and cultural interactions among the settlements,thus the simulation route exhibits complex network.(3)The simulation route presents the complex interactive communication from the Paleolithic to historical time on the Qinghai Tibet Plateau,since communiction is the base for road formation.Synchronously,it reflects the process of human to adapt the gradually rising elevation and control the cost of walking,early humans chose valleys as channels.The valleys are relatively low in slope,altitude,good with vegetation,the rivers support sufficient supply and relatively high oxygen content,which is the biological adaptive behavior made by humans to adapt to the natural environment of the plateau itself.In order to adapt the rising altitude and control walking cost,prehistoric humans chose areas with low slope and relatively high oxygen content,which is the adaptive behavior of humans to adapt to the natural geographical environment of the plateau.From the aspect of production technology,the subsistence model has experienced the hunting and gathering economy during the Paleolithic Age,the coexisting economy of agriculture and hunting gathering during the Neolithic Age,the overall developing of the economy of agriculture and grazing in the Bronze Age,and the in depth development of pastoral and agricultural economy,commerce,politics and wars in the historical time.This pattern corresponds with the pattern of the simple request for plateau resources in the Paleolithic Age,the active occupation of plateau agricultural areas in the Neolithic Age,the development of high altitude areas in the Bronze Age,and the active,comprehensive development and utilization of the plateau in the historical time.The mode of subsistence and cultural exchange directly influenced the pattern of route formation,which led to the formation of a stable route,in the agricultural settlement area during the Neolithic Age;in the junction of agricultural and grazing area during the Bronze period;and between the developed settlements during the historical time.From the aspect of cultural exchange intensity,the Neolithic cultural exchange during the Neolithic Age is mainly between the Yangshao culture and the Central Asia and the South Asia through the southern edge of the plateau.In Bronze Age,the cultural interaction along the northern plateau through Xinjiang to Hoxi Corridor has strengthened.During the historical time,the cultural communication between the south and north margin has continually strengthened.With the comprehensive development of high plateau,and expansion to the plateau's hinterland,this place has become the transit station and distribution center of Chinese and foreigner culture communication,and provided the foundation for the plateau to form a unique civilization,and the bridge to assimilate into the Chinese culture.