Who can help me find the information about irrigated agriculture and ecological environment in Hexi Corridor?

Oasis is a landscape type associated with desert. It mainly refers to an efficient eco-geographical landscape area with stable water sources, lush plants, active organisms, a certain spatial scale and obviously higher than the surrounding environment in the arid desert. Oasis in China is mainly distributed in the arid area west of Helanshan-Wushaoling line, which is basically divided into three areas: the eastern Hetao plain oasis area, the northwest arid inland oasis area and the Qaidam Plateau oasis area. The development of oasis agriculture in China began in the Qin Dynasty. Reclamation plays the most important role in the development of oasis agriculture. The development of agriculture in past dynasties promoted the oasis to change from a single fragile nomadic economy to an economic structure where agriculture and animal husbandry coexist, expanded the agricultural area of China and made full use of natural resources. However, large-scale oasis agricultural development has not only expanded the cultivated land area and increased the carrying capacity of the environmental population, but also brought a series of ecological problems. I. Agricultural Development of Oasis in Historical Period The historical development of oasis agriculture in China is a process of gradual development in different geographical locations according to regions, and military and civilian villages are the main way to develop oasis agriculture. Reclamation and migration are organized, political, military and economic large-scale agricultural development by using agricultural technology in the Yellow River Basin. The introduction of advanced farm tools and farming techniques in mainland China has accelerated the breadth and depth of oasis agricultural development and promoted the evolution of social system. The development process of oasis agriculture is from east to west and then to north and south according to the geographical (agricultural) region, which also shows that the division of oasis agriculture in China is also related to the historical development process. (1) Agricultural Development in Oasis Area of Hetao Plain The Hetao area mainly includes Yinchuan Plain in the west, which is called Tao Xi; The fan-shaped plain between Bayangaole and Wulashan is called the back cover; The Hohhot Plain (Tumochuan) east of Wula Mountain is called Tao Qian (also known as Tao Dong); Ordos plateau is also called inner sleeve. During the Spring and Autumn Period and the Warring States Period, Huns occupied most areas of Hetao and lived a nomadic life of "wild grass migration". In the late Warring States period, Wei, Qin and Zhao successively occupied the southern edge of Hetao area and the plain area, and set up counties and garrisons on the border, which opened the prelude to agricultural development. During the Qin and Han Dynasties, the Hetao area was first developed on a large scale. In the thirty-second year of the first emperor (2 15 BC), "General Meng Tian sent 300,000 troops to attack the Xiongnu in the north and plunder the land of Henan". In the thirty-sixth year of the first emperor, "30,000 households immigrated to Beihe and Yuzhong", which started the reclamation of Hetao immigrants in Qin and Han Dynasties. However, at that time, wars were frequent, the scale of reclamation was very limited, and the reclamation areas were just dotted around. By the time of Emperor Wu of the Han Dynasty, in order to solve the supply problem of the army, in the second year of Yuanshuo (127), "100,000 people were raised to move to Shuofang" to settle the field. Since then, immigration activities have continued. According to Liang's book Statistics of Household Registration, Fields and Land Taxes in China in Past Dynasties, in the second year of Yuan Dynasty (AD 2j4UiUh), the population of Hetao area reached 6.5438+0.7 million, exceeding the population of subsequent dynasties. Immigrants also brought advanced farm tools and farming techniques, such as substitution tillage, which were extended to border counties and Juyan City during this period. The key points of reclamation in the Western Han Dynasty were mainly in the plain, Yinchuan, Hetao plain east of Xishanzui in Inner Mongolia and the eastern Ordos Plateau. After the Northern Wei Dynasty unified Hetao, the oasis agriculture here was slowly restored and developed, and the wasteland was mainly concentrated in Hebei (northern Hetao), Wuyuan, Guyangsai (northwest of Baotou) and Yinchuan Plain. In the Tang Dynasty, the Hetao area was developed on a large scale for the second time. In the early Tang Dynasty, the official army system was implemented, and agricultural development was carried out in the form of non-commissioned officers farming in Lingzhou and Ningxia Plain. Reclamation in the Tang Dynasty made the vast area between the Yellow River and Wu Jia in Inner Mongolia deeply developed. At the same time, with the excavation of Tanglai No.1 Canal, Tao Xi Irrigation District expanded northward to Yinchuan, becoming a land of plenty. However, the agricultural composition in Ordos Plateau is further reduced, and the boundary between agriculture and animal husbandry in the nest area is becoming more and more obvious. After the Tang Dynasty, Houtao, Tao Dong and Neitao were successively occupied by the Tangut, Qidan, Mongolian (ancient) and other ethnic groups, mainly animal husbandry, while agriculture in Tao Xi Plain has been developing. At the beginning of Yuan Dynasty, more than 1 10,000 hectares of farmland were irrigated in Ningxia Plain to restore agriculture, that is, a large-scale irrigation project to harness the Yellow River, and channels such as Tanglai and Han Yan were restored. At the beginning of the Ming Dynasty, Tao Xi began to emigrate and station troops on a large scale, and in the early years of Yongle, there was a scene of "the most wasteland in the world". In Qing Dynasty, Hetao area ushered in the third climax of agricultural development. The Qing government abolished the barracks and turned all the soldiers who settled the fields into yeomen, which improved the efficiency of agricultural development and played an important role in the recovery of agricultural production. In addition to dredging the old canal, three main canals, Daqing Canal, Huinong Canal and Changrun Canal, have been built, so that the northwest of Tao, which was originally sparsely populated, also benefited from the Yellow River irrigation. During the Jiaqing period, Tao Xi Plain irrigated 42 1000 hectares, and the population of Ningxia Prefecture was1400,000. During the Daoguang period, the "black land" and "white land" north of the Ordos Plateau and the Great Wall were also fully reclaimed.