Simulation Of Maize And Wheat Yield Influenced By Potential Drought In China During1961-2010

Extreme weathers are projected to increase with climate change, which pose enhanced damages oncrop production. Maize and wheat are two kinds of the most important staple crops in China, anddrought is the main climate disaster affecting their yield, particularly in northern parts of the country.The temporal and spatial changes of drought impacts under climate change on maize and wheat weretherefore received significant concerns. This study assessed the potential yield impacts of past droughtanomaly (1961－2010) on maize and wheat, by using a process-based crop model DSSAT. Therelationships between estimated yield impacts and recorded indices of atmosphere circulation wasexamined to understand the underlying mechanisms of past drought risks. Our results demonstrate:1) Overall, past climate change has caused decreased drought risks for summer maize and springwheat production in China. While the drought risk for winter wheat and spring maize has increased inpast50years. The summer maize grown in Shandong, Hebei, and Shanxi,spring maize grown inNortheast China and the Hetao Area, the winter wheat grown in the Loess Plain and the Hexi Corridor,the spring wheat grown in Hexi Corridor and Southwest China, have shown the fastest increase of thedrought risks. On the other hand, the summer maize grown in North China Plain, the spring wheatgrown in Northeast China and Inner Mongolia has shown the fastest decrease of the drought risks.2) The drought affecting center of summer maize, spring maize, winter wheat and spring wheatmoved individually north, northeast, northwest and southwest during the past50years. And the droughtaffecting centers has the most obvious changes in1960s－1970s.3) Stronger Subtropical high system before crops growing season associated with a west movingof the drought-affecting center for summer maize. Stronger Subtropical high system during cropsgrowing season associated with a southwest moving of the drought-affecting center for maize and awest moving of the drought-affecting center for wheat. Moreover, a stronger North Pole Vortex beforecrops growing season associated with a southwest moving of the drought-affecting center for maize, asouth moving of the drought-affecting center for winter wheat, and an east moving of thedrought-affecting center for spring wheat. Stronger North Pole Vortex during crops growing seasonassociated with a southwest moving of the drought-affecting center for summer maize, a south movingof the drought-affecting center for winter wheat, and a northeast moving of the drought-affecting centerfor spring wheat, vice versa.4) According to the comparing between the simulated results and the statistics, the potentialdrought identified by crop model was able to reflect the variation trend of recorded drought disasters.