Optimization for Crop on the Coupling Relations of Regional Precipitation and Crop Water Requirements: A Case Study of Taihang Mountain Piedmount Region and Heilonggang Region in Hebei Province

Using methods of Penman and subsection interpolation, the study calculates water requirements of familiar crops in growth period of Qian district in Taihang Mountain and Heilong district, comparing coupling of precipitation of crop in growth period, the study found that precipitation and crop water requirements has no coordination during crop growth stages in areas. Due to water adaptability, winter wheat is adapted to Qian district in Taihang mountain, while summer corn has advantage in Heilong district, basing on winter wheat -- summer corn composite model, water ecological adaptation of Qian district in Taihang mountain was higher. Cotton has weak advantag in Heilong distric. Oil plants and beans are more adapted toHeilong distric. vegetables, fruit and potato have no difference in two areas.