The change of winter wheat planting structure under the background of climate change in Gansu Province

At present, the Remote Sensing (RS) and Geographic Information System (GIS) are becoming an important technology in the research of climate change and risk assessment. In this paper, based on the remote sensing data (HJ-A/B remote sensing images), geographic information data (digital elevation model, the land use and soil type) and meteorological data (the average annual rainfall, temperature, sunshine day, annual extreme lowest temperature, ≥0°C accumulated temperature and the ten-day average temperature in the hottest month (July-August) from 1981 to 2010 in Gansu province and neighboring province, we established the applicable winter wheat climate suitability index by the analysis of winter wheat biological characteristics, growth conditions, key climate factors affected the winter wheat yield and so on. Firstly, according to the measured meteorological data in the site, using remote sensing and geographic information technology, we establish the relationship between precipitation, temperature and geographical location (longitude and latitude), terrain. Used the neural network (GANN, neural network based on genetic algorithm), multiple regression statistics method to establish the relationship between average rainfall and soil moisture. Used the reduced scale model to simulate higher accuracy of precipitation and temperature. Using spatial database based on geographic information system, and the data of climate change before and after 30 years, the planting distribution of winter wheat was done especially under the background of climate change. The result showed that winter wheat planting mainly distributed in Pingliang, Qingyang, Tianshui, Longnan, Zhouqu, LinXia, and YuZhong County in Gansu province. The winter wheat planting area has changed under climate change. With climate change, winter wheat planting line move toward south, especially south area clear in suitable and plantable planting region. The decrease of rainfall mainly lead to chang- of planting region, drought problem more and more prominent in Gansu province, winter wheat planting area gradually reduced since 1998 in Gansu province. Of course, and government decision-making is also one of the reason for planting area reduction in recent years in Gansu Province, for example, promoting turn farmland to grassland.