In ancient times, there was a waterwheel that could water houses. And fans and ice cubes. And it was not as hot in ancient times as it is now. Climate change in China's 5,000-year history has had a far-reaching impact on China's social economy and culture. This problem has aroused great interest of scholars. Man Zhimin studied the basic laws of climate change in historical period by using literature phenological data, and put forward some basic theories, such as the principle of uniformity of climate influence, the principle of limiting factors, the principle of synchronization, the principle and mode of difference of human influence, and the principle of asymmetry of biological response to climate change, which have high academic value. [22] In the historical period, the agricultural economy in northern China experienced a process from prosperity to decline. Ni believes that apart from social factors, climate change and the destruction of ecological balance are very important reasons for this change. [23] Henry Hui Wang used the new research results of paleopedology, the ancient documents in the pre-Qin period and the unearthed ancient writing materials to investigate the climate environment in the middle and lower reaches of the Yellow River at the end of Shang Dynasty, and thought that the dry climate and famine in the late Shang Dynasty were the direct fuses of Zhou Wuwang businessmen, which led to the change of dynasties in Shang and Zhou Dynasties. [24] Qin Dongmei believed that the Wei, Jin, Southern and Northern Dynasties were an abnormal period of climate in China's history, characterized by abnormal changes in cold and warm, dry and wet, and an increase in the number of natural disasters. This abnormal climate has caused huge losses and poor harvests in agricultural production, and indirectly affected the social stability. [25] Wang developed a large number of sporopollen samples in Shanghai.

It is found that since the Holocene, the climate changes in Shanghai and Hangzhou have experienced many fluctuations, showing five cold periods and four warm periods. [26]

China is a country with frequent floods, and the problems of water and ecological environment are bound to attract researchers' attention. Fan and Fang Yingkai wrote articles to discuss the water resources of Tarim River. Fan Wen pointed out that in the Tarim Basin, where the climate is extremely dry, the development and utilization of water resources by human beings has changed the consumption of water resources from natural ecology to artificial oasis ecology, thus changing the ecological environment. The law of change is as follows: desertification and oasis coexist and rise and fall with each other, "people enter the sand and retreat", "sand enters the sand and retreats", and sand enters the sand and retreats; With the increase of water diversion in the upstream irrigation area, the artificial oasis has been promoted from the delta which was mostly distributed in the downstream of the river to the piedmont plain, and its area has been continuously expanded, which has improved the ecological environment here. In the middle and lower reaches of rivers, the ecological environment is deteriorating due to the decrease of water volume, the extinction of ancient oases, the degradation of natural vegetation and the expansion of desertification. However, the transition zone between desert and oasis, which is composed of woodland, grassland and natural water, is shrinking and its protection function is weakening, forming a severe situation that desert threatens oasis. [27] The study summarized the experience and lessons of five diversions in the lower reaches of the Tarim River in history, which caused drastic changes in the downstream ecological environment and the decline of the green corridor, and put forward 18 measures to protect the green corridor in the lower reaches of the Tarim River. [28]

The Yellow River is the mother river of the Chinese nation and the disaster river of the descendants of the Chinese people. Scholars pay special attention to the Yellow River and its ecological problems. Wang Xingguang wrote an article to discuss the "Huang Heqing" phenomenon in the historical period. He pointed out that Huang Heqing is a natural phenomenon, but it can't happen under normal circumstances. This phenomenon will only occur when there are abnormal situations such as continuous drought and lack of rain, too cold winter and earthquake in the basin. Huang Heqing is a precursor to drought and the Yellow River cut off. At the same time, it is intertwined with social politics, culture and life, becoming a peculiar cultural and social phenomenon. [29] Wang Shangyi put forward a new view on the environmental consequences of floods in the lower reaches of the Yellow River and the land use between the estuary and Longmen in the middle reaches: the frequency of floods in the Eastern Han Dynasty was higher than that in the Western Han Dynasty, and the disaster situation was more serious; During the Eastern Han Dynasty, the farming population between Hekou Town and Longmen decreased by more than 90%. Like the whole middle reaches of the Yellow River, a large number of nomadic people moved into this area. Primitive nomadism greatly destroyed natural vegetation, which was the main reason for frequent floods in the lower reaches of the Yellow River in the Eastern Han Dynasty. [30] Some commentators have discussed the historical roots of man-made soil erosion in the Loess Plateau and its prevention and control countermeasures, which has strong practical significance. [3 1] Zhang Jianmin investigated the changes and causes of weir canal water conservancy in southern Shaanxi in the late Qing Dynasty by using the inscriptions in Hanzhong and Xing 'an, and analyzed the basic characteristics of natural disasters dominated by floods in this area in the late Qing Dynasty and their relationship with human activities. [32]

Wang Jiange discusses the governance of Daqing River in Qing Dynasty. The intensification of forest vegetation destruction in Taihang Mountain area leads to the intensification of soil erosion and the increase of sediment in Yongding River and Ziya River, which is the key reason for the flood in Daqing River. In order to reduce the flood, the Qing government focused on building the dam systems of Yongding River and Ziya River, which made the water clear and muddy, and its water control process highlighted the characteristics of autocratic dynasties from tight to loose. [33] Guo Shengbo discussed the utilization of land resources, soil erosion and the relationship between agricultural land reclamation and soil erosion in Sichuan (including Chongqing) in history, and thought that soil erosion was related to farming methods, and there was a function variable relationship between soil erosion degree and agricultural land reclamation area and reclamation index. [34] Zhang Fang wrote the article "Man-made Causes of Soil Erosion in Southern Mountainous Areas in Qing Dynasty and Its Prevention Measures", and proposed that the development of mountainous areas should take the road of coordinated and sustainable development of ecosystem, economic system and social system. [35] Xu Huailin also analyzed the floods and droughts in Jiangxi since modern times and their problems related to the ecological environment.