In ancient china Irrigation effected it because only 10% of the land could be used to plant rice so most of that land was used to plant rice leaving less land to live on. It positively effects China because watering crops was not needed.
2/27/2015 Terraced Agriculture Lanzhou, China 36.002645285°, 103.552504602° Snow-covered, terraced fields swirl on the mountains outside of Lanzhou, China. Used on steep terrain to farm crops that require irrigation (such as rice), the structure of the terraces decreases erosion and surface runoff.
The Honhe Hani Rice Terraces in #China run down the slopes of the Ailao Mountains to the banks of the Hong River. Over 1300 years the Hani people have developed complex irrigation system for agriculture. Spread out over 82 villages this group upholds traditional social and religious structure which is based on the spiritual relationship between man and nature.
Irrigation of Rice Fields in China: this postcard depicts three Chinese people standing on a harvesting tool amidst paddy fields of rice. Rice is the most important crop grown in China. A paddy field is a flooded section of arable land used to grow semi aquatic rice. Paddy fields are usually flooded during or just after planting the rice seeds. Farmers typically manipulate streams or rivers for irrigating their crops.