The Sacred Mountain and Holy Lakes located in the grand Yarlung Tsanpo Valley in the southern part of Ali Region, Tibet, that have been listed in the Preparation List of World Heritage Sites of Natural and Cultural Heritage include the Mount Gang Rinpoche, the Lake Mapam Yutso, the Lake Lana Tso. The four rivers originated in the vicinity are the Senge Kabab (the lion river), the langchen Kabab (the elephant river), the Macha Kabab (the peacock river), and the Tsangpo Kabab (the horse river), all which are the source of several world-famous rivers, such as the Indus River, the Ganges River, the Yarlung Tsanpo River and the Brahmaputra River.

In the ancient tradition of China and India, the Gang Renboqi mountain and its surrounding lakes and rivers had extremely important symbolic meanings, and they were the geographical landmarks indicating the center of the cosmological world. In the historical period, there were four ancient divine worldviews being formed around the Sacred Mountain and Holy Lakes in Ali, Tibet.

The first one is recognized by the local Bon religion of Zhangzhung culture in Ali area; the second one is the cosmological world center of anavatapta, which is recognized by Buddhism; the third one is the cosmological world center of Kunlun Mountain and Yao-chi, which is recognized by the ancient Chinese Book of Mountains and Seas; and the fourth one is the cosmological world center of Kailash (Kailasa), which was recognized by Hinduism. The four cosmography systems originated independently, formed their own special cognitive systems, and communicated and merged with other systems in history.

The integration of the Kunlun Mountain cosmological world view and the Buddhist Anavatapta cosmological world view happened around 1 500 years ago, and the new world view had a wide range of impact on ancient Chinese cosmography. In 1720, this world view was projected on the surveyed map, and the ancient subjective cognition was finally located into the concrete geographical objects of the Sacred Mountains and Lakes.

The Lixia River Plain, consisting of a great number of small lakes and swamps, spread widely in the north of Jiangsu Province in history. After 1570, the flood of Huaihe River entering Lixia River Plain continued to increase, which caused great changes in the distribution of lakes and drainage pattern in the region. After 1596, the flood from the Jinghe River and the Ziyinggou River entered into the Guangyang Lake, and then flowed through the Sheyang Lake into the sea. The waters in the southeast of Gaoyou all converge in the Luyang Lake. After 1681, due to the southward shift of the Guihai Dams, floods converged in the middle of the Lixia River Plain and overflowed from the south to the north. As a result, the Dazong Lake and other lakes were connected and merged as a whole. Due to the decrease of flood, the Guangyang Lake was divided into several scattered lakes. Whether the Guihai Dams were opened or not, it would directly affect the hydrological environment of the Lixia River Plain, and thus form two completely different lake distribution and drainage patterns in the flood period and normal period.

During the confrontation between the Northern Song and the Liao dynasties, the song army attached great importance to the northern border defense system of Hedong Lu. The defense line runs for more than 400 miles, along which a defense system with Daizhou as the center, and Fanshi and Guxian as the East and West wing respectively, has been formed. It mainly consists of citadels and fortresses and the aim is to deter the southward attacks through the Xiagu road of the Liao army. The fortresses are surrounded by defensive facilities such as square fields, protective forests, stone walls, ditches, and beacon towers. Taken together, they form a defense system integrating the functions of monitoring, reconnaissance, counter-attacking, military information transmission and so on. Horizontally, the distances between fortresses in different regions ranged from eight to seventy miles, with the majority at around thirty. Vertically, they rely on hinterland counties and towns, thus forming a three-tier defense system, which played a key role in the border defense system of the Northern Song Dynasty.

The tiers of prefectures and counties are important indicators that reflect their political status, population and economic importance. By using historical quantitative analysis and GIS analysis methods, this paper unpacks the spatiotemporal changes of 339 prefectures and 1 607 counties in Tang Dynasty. The results show that: (1) The number of prefecture tier Fu (府), Fu (辅), Xiong (雄) and county tier Chi (赤), Ji (畿), Ci-Chi (次赤) and Ci-Ji (次畿) was relatively stable in Tang Dynasty, while the number of Shang (上), Zhong (中), Xia (下) prefectures and counties changed drastically. In the late Tang Dynasty, the number of upgraded prefectures and counties was more than that of degraded prefectures and counties, with the most significant hierarchical change took place from Kaiyuan (713-741) to Yuanhe (806-820). (2) The spatio-temporal changes of prefectures and counties in Tang Dynasty was “high in the north and low in the south”. Guanzhong Plain was the highest area in the prefecture and county level. The temporal change was “falling in the north and rising in the south”. The Plain of Hubei and Hunan, Poyang Lake Plain and Taihu Plain in the middle and lower reaches of the Yangtze River rose most significantly. (3) The tiers of prefectures and counties in the vicinity of the capital of the Tang Dynasty were most affected by political factors, while the tiers of the frontier fortresses and traffic throats were most affected by military factors. Other prefectures’ and counties’ tiers were mainly affected by economic factors, especially population size. (4) The spatio-temporal changes of the tiers of prefectures and counties in Tang Dynasty reflected the eastward and southward movement of the national political, demographic, urban and economic centers after the An-Shi Rebellion in the middle of the Tang Dynasty.

Boundary and jurisdiction are important geographical elements of the administrative division. In Qing Dynasty, a total of 203 county-level administrative divisions were split, most of which resulted in creation of new counties, while a few produced Zhili Ting (Para-county under the direct jurisdiction of the central government). As the number of county-level administrative divisions increased, the cultural and geographical elements such as the gathering point or the wicker edge had become important basis for deciding boundaries. The areas with more intensive adjustment of county boundaries were Fengtian, southern Jiangsu, southern Shaanxi, eastern Sichuan, and the junction between Fujian and Guangdong. More county-level administrative divisions had been added in these regions, reflecting their regional development process in the Qing Dynasty. As an administrative means of balancing local governance, dividing the border operated and evolved under the factors such as rectifying upheavals, grass-roots governance and responding to the border crisis. The spatial form of the county boundary was generally formed according to the principles of natural features including mountains and rivers, shaping a reasonable jurisdiction area, and adjusting the distance from the administrative center.

Both the records of historical documents in the early Ming Dynasty, and the Plaque of the “Timasa Pacification Commission” found in Assam Pradesh, India, indicate that the Gula Chiefdoms set up in the southwest frontier region in the early Ming Dynasty were actually located in the Brahmaputra Valley. Since the Han and Tang Dynasties, the Brahmaputra Valley had been an important channel connecting China and the South Asia. After the reunification of Yunnan, the Ming dynasty actively managed the southwestern frontier. With the continuous expansion of the influence of the Ming China, the Gula tribes established political contact with the Ming Dynasty and the latter then set up chiefdoms in this area. Although the relationship between the Ming dynasty and the Gula chiefdoms did not last long, the re-opening of the land Silk Road to South Asia greatly expanded the geographical cognition of the ancient Chinese.

传统观点以为,汉初豫章郡属淮南国,在今赣南。仔细梳理西汉文献所记汉初史事,豫章郡应属吴国,在今皖南。豫章郡因治于故鄣县,又名“故鄣郡”。魏晋时期,讹“故鄣郡”为“鄣郡”。汉初豫章郡先后属楚王韩信、荆王刘贾、吴王刘濞。《史记》所记淮南王英布、长沙王吴芮领有豫章郡乃“虚封”。景帝三年,汉廷将豫章郡一分为二,北部并入江都国;南部与庐江郡合并,改称“庐江豫章郡”。传世汉代封泥“庐江豫守”,即“庐江豫章郡守”,而非以往认为的庐江国豫章郡守。景、武之际,江淮之间另立庐江郡,汉廷更庐江豫章郡为豫章郡。元封二年,武帝从豫章郡中分置丹阳郡,豫章郡从此仅辖赣江流域,遂有《汉书·地理志》之规模。

In Ming Dynasty, the ranking system of the administrative division of prefectures and counties were initially accorded to the amount of taxes and levied grain, hence the different grades of officials. In the fourteenth year of Hongwu, taxation and location were also used in determining the social and natural quality of the divisions, namely Fan or Jian, as well as the assessment methods of officials. Yang Yunsheng proposed to divide the administrative hierarchy into three levels according to administrative workload, geographic location and transportation during the Jiajing years. Consequently, the Ministry of Personnel unified the administrative divisions into three levels in the first year of Longqing. According to the statistics recorded in the Da ming guan zhi, the places with important roads, heavy workload, dire taxation were mostly concentrated in the Southern Zhili, Northern Zhili, and Jiangxi provinces, among which the places along the canals were particularly typical. Officials were selected to fill in the positions of Fan or Jian in the late Ming dynasty, but the ranking system was not continued after the implementation of the method of drawing lots. The ranking system in the Ming Dynasty had a great influence on the Qing Dynasty, and the spatial distribution of the administrative divisions in the Ming and Qing Dynasties also had certain similarities.

The flow direction of the mainstream shifted from southwards to northwards in the Chang-Xi-Cheng District, northwest of the Taihu Lake Basin, from pre-Han Dynasty to today. The turning point was approximately between the Tang and Song Dynasties. This was driven by the long-term external factors such as the advance and retreat of coastlines, the variation of tidal power and the water storage and drainage situations in the Taihu Lake Basin over historical periods. Influenced by the variation of mainstream flow directions, the reclamation process of Furong Lake can be divided into three stages. Before the Tang Dynasty, the reclamation attempts in the Furong Lake Area were mainly conducted in the east of Wuxi and the south of the primitive Grand Canal in Wuxi section to adapt to southward characteristics of the mainstream flow in this time. Such projects changed the original form of the south edge of the Furong lake, and shaped the boundary-con-bank between the Furong lake, primitive canal and Taihu Lake. In mid-Tang Dynasty, the south edge of the the Furong Lake retreated by nine li (traditional Chinese length units, one li equals 500 meters approximately) north of the Wuxi section of the Grand Canal. The overall hydrological pattern in the Song Dynasty made it hard for the long-lasting success of reclamations of the Furong lake. All the attempts in this time such as the dredging of river channels and the construction of weir and gate system were soon proved unsustainable. The variation of hydrological patterns in not only the Chang-Xi-Cheng District but also the entire Taihu Lake Basin since the Yuan and Ming Dynasties was the fundamental factor for the complete and final reclamation success of the Furong lake. The dynamic variation of water flows was not only affected the reclamation process of the Furong Lake, but also recorded in the writings of relevant historical material.

In the Luoyang Basin during the Han, Wei, Sui, and Tang dynasties, the flow patterns of the Yi, Luo, Chan, and Jian rivers were closely related to their geological setting. The orientations of these rivers are predominantly determined by the underlying geological fault lines of the basin. The orientations of the Yi and Luo rivers are mainly determined by east-west and northeast-oriented fault lines, with the flow path of the Luo River primarily influenced by the Matun-Yanshi fault and the Yi River influenced by the Yiyang-Yanshi fault. Jian and Chan Rivers share simultaneous spatial similarities and transient transformation similarities, both following city site migrations, turning from being sectioned eastward during Han and Wei dynasties to falling back to the natural southward flow during Sui and Tang dynasties. Luo River exhibited a trend of continual northward transformation during Han, Wei, Sui, and Tang dynasties, while Yi River constantly extends eastward and southward. Over historical periods, the Yi and Luo rivers gradually separated north and south, with their confluence point shifting eastward. Unequal north-south subsidence and a northward tilt of the sedimentary center caused Luo River to migrate northward, while a central bulge and ‘two cut first base’complex fault depression caused Yi River to extend eastward and southward.

Qing Dynasty officials organized several expeditions to explore the source of the Yellow River. In the late Qing Dynasty, Westerners also did a lot of explorations. The results of the source explorations reflected the understanding of the very question in the Qing Dynasty. Constrainted by surveying and mapping conditions, the water system of the source area of the Yellow River was not fully understood. Therefore, the conclusion drawn from current textual researches on the basis of the source of the Yellow River as explored in the Qing Dynasty might be problematic. Similarly, the historical maps compiled and drawn on the same basisare also worth examing. In this paper I argue that it is appropriate to take a fuzzy approach to the labeling of the river sources in Qing Dynasty.

The Qing government achived effective governance of the whole of Guizhou province by altering the native chieftain system into governmental appointed officials, establishing garrisons, county-level administrations and pioneering new frontiers, ending up the situation that all were wild beyond the settled line. This also rendered great changes in the patterns of military geography. The Qing government transformed the linear defense military mode of the Ming dynasty into a more ambitious “two-governor” system: one in Anshun to control the hinderland of Guizhou, and the other in Guiyang to manage the soldiers from the newly subdivided land. Both of the governors could mobilize the troops around the province. In addition, a generalship was set up in Zhenyuan to safeguard the eastern courier route and gain special control of the new land of Songtao, Taigong and Qingjiang. Generals of Weining, Guzhou and Anyi were also set up to manage the northwest, southeast and southwest, respectively. The new governance penetrated into countryside and achieved the goal of controlling the province as a whole.

During the Tang Dynasty, there are two Shaoyang yards within the Daming Palace city and both are located in the vicinity of the inner court where the emperors reside. The West Shaoyang Yard is not in line with the tradition of the location of the crown prince’s palace, which prioritize the East, but it can receive the attention from emperor, empress and eunuchs because of its better location. In the period of the Late Tang, the eunuchs find it easier to control the West Shaoyang Yard, hence the emperor and crown prince, because it is close to Neishibiesheng and the barracks of the imperial guards just outside the Jiuxian Gate. The East Shaoyang Yard not only includes the eastern part of the Menxiasheng, but also a quarter inside the Chongming Gate, and the later is the real abode for the crown prince. The Eastern location and the fact that most of the successions of the throne are not from father to son contribute to ascending status of the East Shaoyang Yard as an important ritual space for the crown prince before taking up the throne.

Based on Qing dynasty Shilu and historical accounts, as well as reports, photographs and maps from Chinese and foreign expeditions, this paper marks the first successful search in a century for the site of the Qianlong Westernmost Ji Gong Stele, which was located far beyond current borders, by pinpointing it and presenting the results promptly for repetitive examination by academics and society in the ‘Silk Road GIS’, and will also be included in the Qing Dynasty Atlas. This monument stands as an important symbol of the formation of the Qing Dynasty’s territory at its peak.

In the late Qing Dynasty and the Period of Republic of China, the provincial government of Xinjiang actively promoted the reform of administrative divisions and created a large number of new county-level administrative districts, in order to meet the needs of frontier management. It’s worth an in-depth study on the characteristics of these new counties, and the similarities and differences between them and the counties in the hinterland. By restoring the process of Horgos County’s establishment and reconstructing its boundaries in 1914 using archives and maps, this study reveals the political considerations of the provincial government of Xinjiang including strengthening the military defense, diplomacy, management of foreign trade and domestic affairs, when establishing new counties along the border area between China and Russia. At the same time, this case also shows that in the process of delineating the boundaries of administration districts in the modern frontier areas, in addition to concerns over traditional principle of following mountains and rivers, domestic and foreign political relations such as disputes over national boundaries, economic distribution, and the local warlords’ own benefits also affect the delimitation.

The Army Map Service (AMS) was a professional military mapping agency established by the U.S. military during World War II. The 1:250 000 China topographic map is a medium-scale topographic map series compiled by the AMS in the 1950s. This set of maps primarily reflects the geographical situation of China from the end of the Comprehensive Anti-Japanese War to the period just before 1949. The accuracy of the topographic maps is contingent upon whether the U.S. military conducted actual surveys in the area and the quality of the data sources. The data sources primarily consist of American, Japanese, and Chinese maps, as well as aerial photography, making them the most accurate medium-scale topographic maps reflecting modern standards at the time. The versioning and compilation cycles of the topographic maps are tied to the operational needs of the U.S. military, with faster updating and publication speeds for maps near theaters of war. Overall, this map series represents an organic integration of numerous modern cartographic achievements and stands as the most accurate medium-scale topographic map reflecting contemporary surface features. Furthermore, the standardized processing of these maps also offers new opportunities for cross-regional historical geography research.

During the period of the Qing Dynasty and the Republic of China, Suiyuan, which was located in the western part of the Northern Agricultural Pastoral Ecotone, underwent diversified changes in its industrial structure in response to changes in the situation at home and abroad. Diversification became a prominent feature of local economic geography. By the 1930s, it was mainly reflected in the non-local primary industries of agriculture, industry, commerce and transportation, which infiltrated, superimposed and transformed with the local native nomadic economy into a modernity and diversified regional economic system. Before that, it could only be called piecemeal changes, rather than full scale changes. Thereafter, Suiyuan had evolved from a nomadic landscape of cattle and sheep throughout the territory in the early Qing Dynasty, to a new pattern of diversified industries in the late Republic of China, which was characterized by pastoral farming, numerous industrial enterprises, prosperous domestic and foreign trade, and interlaced roads and railways. It had become a common home for Mongolian and Han peoples with a prosperous regional economic and harmonious inter-ethnicity relations.

The Zhendi Circuit of Xinjiang during the Qing Dynasty was formed on the basis of both the Anxi circuit and the Liangwu Circuit of Urumqi. During the relatively peaceful era before the Tongzhi period, the Zhendi Circuit functioned in the capacity of provincial governor and surveillance commissioner. There were formal and hierarchical administrative districts and sub-official defence posts that also functioned as administrative district under its jurisdiction. It was administered by the Viceroy of Shaanxi and Gansu, and at the same time jointly liaised to the Urumqi Dutong, while Urumqi Dutong was a subordinate to the Yili General before the Tongzhi period. However, the Governor of Shaanxi and Gansu not being based at Urumqi meant that its administration was to a large extent remote, and the Yili General’s control over the Urumqi Dutong was nominal, which made Urumqi Dutong’s administration to Zhendi Circuit rather uninterrupted. As such, the Circuit Intendant took the mandate of provincial governor and surveillance commissioner, and that of Dutong was comparable to Viceroy. The district formed was a special type of quasi-provincial jurisdiction: the Urumqi Dutong, which was relatively independent. This special administration system was imitated in other districts that were facing similar situation for reference purpose.

Putianze (圃田泽), an ancient lake in the Yellow River Basin, serves as an ideal subject for exploring the evolutionary patterns of lakes and swamps on the alluvial plains of the Yellow River’s lower reaches. Based on the historical geographical reconstruction methods, this study delineates the process of Putianze’s silting and disappearance during the Ming and Qing dynasties and analyzes the driving factors behind the background. According to the study, it reveals that the rapid disappearance of Putianze was the result of the long-term cumulative effects of sediment deposition and lake water drainage. This process is characterized by ‘lake silting and human encroachment’, ultimately leading to its transformation into land between the Qianlong and Tongzhi reigns of Qing Dynasty. The direct cause of Putianze’s disappearance was sediment deposition following Yellow River breaches, while long-term human intervention accelerated this process.

Foreign owned trading companies were an essential institution between China and western countries in modern times. Its spatial evolution and strategy represent imperialism’s destructive and reconstructive influences on Chinese cities. This paper takes Tianjin as a case study, and analyzes the important role that foreign companies played in urban development through a visual analysis of its spatial evolution process using HGIS. The result shows that Tianjin, as a trading center in northern China attracted a large number of foreign companies, which formed a unique spatial system. These foreign companies had a complex impact on the formation and transformation of the urban spatial structure of modern Tianjin, as they did on other treaty port cities.

Super typhoons are one of the most severe natural disasters affecting China’s coastal areas. Relying on modern research results of typhoons, this paper uses historical local gazettes, archives, newspapers and other materials to deduct six indicators, including the wind scales, death toll, house damage, crop loss, official and public relief policy, and typhoon impact range, to develop a method for identifying super typhoons in the historical period. It is applied to reconstructing the super typhoon affecting Jiangsu-Zhejiang-Shanghai area from 1640-1949, and the results are in turn statistically tested against the records of super typhoons from 1950-2019. This study shows that this method is robust in identifying the super typhoon events in the historical period. The reconstructed sequence shows that an average of 2.3 super typhoons occurs every 10 years, and there are obvious fluctuations in its frequency, which are different from that of general typhoons.

The delimitation of sea defense zones forms the basis of the spatial deployment of sea defense. During the Ming and Qing dynasties, the military defense area boundaries of the Zhoushan Islands were divided into three main levels: the boundaries of the Wei(卫) and Zhen(镇), the boundaries of the inland and outer seas, and the boundaries of the Suo(所) and Ying(营). The northern boundary of the Wei or Zhen corresponded with the provincial boundary, which was delineated by Chenqian(陈钱)to Bixia(壁下) in Ming Dynasty and by Yang Mountain(羊山) to Maji(马迹) in Qing Dynasty. The southern boundary was marked by Nantian(南田), Jiantiao(健跳), and Niutou Mountain(牛头山) in Ming Dynasty, and by the Tianhou Palace(天后宫) at the southern end of Shipu Town(石浦镇) in Qing Dynasty. The western boundary, which extended far inland during the Ming Dynasty, was divided along the coast of Zhenhai(镇海) and Xiangshan(象山) in Qing Dynasty. The boundaries between the inland and outer seas were indicated by a line that included Wuyu Mountain(五屿山), Liangtou Cave(两头洞), Changtu(长涂), Luojia Mountain(洛泇山), Taohua Mountain(桃花山), Jiancang(尖仓), Jiushan(韭山), and Tantou(檀头). There were distinct boundaries between the five garrisons of the Ming Dynasty and the five green standard armies of the Qing Dynasty. These defense boundaries often crossed district political boundaries but never crossed prefectural or provincial boundaries. The boundaries of the inland and outer seas, as well as those of the garrisons and the Suo and Ying, were determined based on defense tasks and the natural maritime environment.

The Tang Dynasty Chinese cliff carvings discovered in the Dil mountain of Ulziit in the central Gobi Province of Mongolia indicate that this area was an important node on the grassland transportation line at that time. The route through the desert to capital of the Uyghur Empire, as recorded in the New Book of Tang passed through this area as the ‘Eastern Uyghur Road’, also known as the ‘the road of having an audience with Tengri Khan’. The inscriptions were carved during the rule of restraint period of the Tang Dynasty in the second year of Linde, which confirmed the historical event that Emperor Gaozong of the Tang Dynasty offered sacrifices to heaven and earth in Mount Tai and invited the leaders of Tiele tribes in the Boreal desert to come, which reflected the communications between the Tang Dynasty and the northern nomads and the control of the Tang government over the vassal prefectures in the Boreal desert.

Due to the lack of altitude gradient of sewers and scouring capacity of rivers, the old sewerage system in the Shanghai International Settlement was not fully capable of handling domestic waste. In the 1910s, in order to cope with the challenge brought by water-closets, the Municipal Council decided to build an underground separate sewerage system to accomplish the transformation of sewage treatment method from combined sewers to separate sewers. From 1921 to 1934, on the basis of combining the experience of Anglo- American municipal engineering and the geographical situation of Shanghai, the Council gradually constructed a brand-new sewer network with three levels including the main, the subsidiary and house sewers. Through the spatial competition and functional linkage between the sewers and other municipal pipelines, the upgrading of the sewerage system had brought about the integration of urban subterranean space.

The Minzhou Zongguanfu (General Administration Office) was the product of the deteriorating of the relationship between Tang and Tuyuhun which was moving from cooperation to conflict. During the Wude period, the jurisdiction of the governor’s government expanded from north to south, reflecting the Tang defense strategy in the face of the aggressions from the Tuyuhun. By expanding the jurisdiction of the Minzhou General Administration Office, the Tang Dynasty first established a linkage between the prefectures in the Taoshui and Qiangshui basin with Minzhou as the pivot to protect the Weihe Valley passage from Chang’an to the Western Regions. Subsequently, a Wuzhou node was established to connect theprefectures in the Qiangshui and Baishui basins to protect the Sanguan Road from Yizhou to Chang’an. During the Zhenguan period, its jurisdiction shrank from south to north and east to west in accordance with Tang’s military advances. By reducing the area under the jurisdiction of the Minzhou Dudufu (succeeding the Zongguanfu) and the division of territory with the Songzhou Dudufu, the Tang could focus on pacifyng the Tangut and regime change of the Tuyuhun. Behind this expansion and shrinkage of jurisdiction hides the irreconcilable conflict between Tang and Tuyuhun over border security, which proved to be the norm rather than the temporary cooperation.

In the middle and late Yuan Dynasty, the Yuan government restored a number of prefectures and counties in Sichuan Province. By comparing the historical records and data of schools, ancestral temples and famous officials, we can summarize that from Dade to Zhizheng, the restored administrative districts included three prefectures, namely Rong, Zi, and long, and nine counties of Jingyan, Neijiang, Anyue, Changning, Dazu, Lechang, Jiangyou, Baoning and Tongjiang. Another Shiyang county was newly established. The main reasons for the restoration were the growth of population. These administrative districts shared three characteristics: most of them were established on the basis of the inspection department (xunjiansi), insufficient population and low efficiency.

Analysis on the spatio-temporal changes and types of 229 Paleolithic sites in Northeast China shows that, the early sites were distributed sparsely in the foothills of Qianshan Mountain and the eastern Songnen Plain, with about 57.1% of them located at less than 200 meters above the sea level. The ruins type was predominatly mountain and hillock platform type. In the middle period, the sites were mainly distributed on both banks of rivers and streams in the eastern mountains. About 58.8% of the sites were in the area between 200-400 meters above the sea level, and the type of the sites was mainly river valley terrace type. The distribution of the late sites basically extended to as far as half of the Northeast, especially in the middle and lower reaches of Nenjiang River, the lower reaches of Liaohe River, the foothills of Qianshan Mountain,the lower reaches of Mudan River, the upper reaches of Muling River, Buerhatong River basin, Suifenhe River basin and other regions. About 49.4% of ruins were located in the area between 200-400 meters above the sea level, and the type of ruins was mainly valley terrace type. A few were hillock platform type or mountain hilly type. The spatial distribution of the ruins gradually expanded from the southeast to the northwest and from low altitude to high altitude. This change may be the result of diversified strategies such as improving stone tools technology, maintaining high mobility, changing hunting methods, and strengthening resource utilization so as to adapt to climate and environmental changes.

In the early Qing Dynasty, the official strategy for managing the Yellow and Huai River floods largely adhered to the Ming Dynasty’s water management philosophy, prioritizing ‘restraint’ over ‘dredging’. During Emperor Kangxi’s reign, the policy of ‘opening the sea outlets’ was effectively implemented with imperial intervention, fundamentally aimed at achieving ‘diversion to the sea’ by deepening the drainage channels and expanding the sea outlets along the coastal counties of the Xiahe Area. As the water conditions of the Yellow River, Huai River, the Grand Canal, and Hongze Lake evolved, the deepening of river channels alone could no longer effectively direct waters from the central lowlands to the coastal accumulation zones, resulting in frequent overflows and disasters. Therefore, during Emperor Qianlong’s reign, embankments were constructed along the sides of the returning-to-sea rivers to confine the waters. Concurrently, the construction of polder fields began, linking with river embankments to establish a polder system in the coastal counties of the Xiahe Area. Influenced by the eastward flow of water and the impact of the ocean, the water environment and the construction of embankments in these coastal counties exhibited characteristics of complex and dynamic changes.