Temporal and Spatial Evolution of Agricultural Facilities in Heihe River Basin Since Han Dynasty

In this paper, geography, history, and geographic information methods were comprehensively used to analyze the spatial and temporal changes of agricultural land, irrigation canals, water sources, and water conservancy facilities since the Han Dynasty in China based on remote sensing images, historical atlases, and word record materials.The results showed that agricultural land was mainly distributed in the upper reaches of the river basin and the southeast region.It rapidly increased from 614.32 km 2 to 6396.54 km 2 from the beginning of the Yuan Dynasty to the People's Republic of China, while the length of irrigation canals increased from 2051.78km to 3267.69km in this period.The total length of the water source remained unchanged from the Han Dynasty to the Republic of China, but increased from 2350km in the Qing Dynasty to 2514km in the People's Republic of China.Moreover, there were 12 water conservancy facility points in the Qing Dynasty, but only 3 facility points in the Tang, Song, and Yuan dynasties.We found that agricultural facilities in the Heihe River basin were mainly comprehensively influenced by natural and social economic factors.Temperature, precipitation, and water resources were the natural background elements of agricultural development and played a key role, while policy, military war, and population migration were important factors effecting the changes in agricultural facilities.