Weinan Crops Fitness Evaluation Under Climate Change

Studies have shown that over the past century the global and China is experiencing a climate change process that the main features are warming. The IPCC2007Fourth Assessment Report pointed out that the linear increasing trend of the average global temperature in the past100years was0.74℃. In recent years, the study of global climate change has been a change from the initial forecast, slowing the development to a generally accepted adaptation for the current. Adaptation has been a worldwide issue, especially in the developing countries. The trends of climate change of most parts of China are basically the same that showing a significant of warming. Guanzhong region appears a significant warming phenomenon in the1980s. As one of the most sensitive to climate change sectors, agriculture is directly affected by the change of temperature, precipitation, sunshine, and CO2concentration. Weinan City, Shaanxi Province is an important agricultural base of goods; it is worth studying in the ability of crop to adapt to tackle climate change. It was used in10sites in Weinan from1961to2010in this paper on the monthly temperature、 precipitation and sunshine hours, as well as the1961-2010wheat yields and1978-2009years of cotton yield data. This paper analyzed the temporal and spatial variation of the various elements of the climate of Weinan City, and use the yield of crop production on the climate to calculate the degree of adaption of temperature, precipitation and sunshine hours of winter wheat and cotton in Weinan, eventually combined with the gray relational analysis method and the AHP decision analysis method to calculate the climate adaptation of winter wheat and cotton. The main conclusions are as follows:(1)The characteristics of climate change. Recent50years the average temperature of Weinan was13.05℃, the city and counties were becoming significantly warmer and occured a significant mutation in1997. The spatial distributions of average temperature of50years in Weinan were higher in the south and lower in the north. It had formed a high and low temperature center in Linwei and Baishui. However, the temperature of Pucheng County which located in the northeast was slightly higher than the other northern counties. The average precipitation was553.32mm and the change was not obvious. The spatial distribution of average precipitation of50years of Weinan was lower in the middle and higher in the south and highest in the north. It had formed a dry and wet center in Dali、Fuping and Tongguan、Huaxian. The spatial distribution of average sunshine hours of recent49years of Weinan was higher in the north and lower in the south. It had formed a high and low center in Chengcheng and Huaxian.(2) The adaption degree of winter wheat. Overall the50years the adaption degree of winter wheat was high, and the mean of the adaption degree of temperature、 precipitation and sunshine hours were0.865、0.852and0.948. The three climate elements of adaption degree were waving near the mean and there was a weak growth trend. The climate adaption degree of winter wheat was ladder-like rising before the1980s and it got an average of0.914which was the biggest in the50years. The adaptation was more stable in the1980s and1990s, and the mean of1990s took a weak decrease. There was a small reduction in the late20th century and early21th Century.(3) The adaption degree of cotton. Overall the32years the adaption degree of cotton was high, and the adaption degree precipitation was0.892which was the highest and the other two elements were little lower than it. The three climate elements of adaption degree increased slightly and did not pass the significance test.The climate adaption degree dumped from late1870s to1980s.The mean degree of1978and1979was0.801, while the mean of adaption degree occured a sudden drop in1980s, reaching0.755. During the1980s, the1990s to the early nine years in21st century the climate adaption degree of precipitation showed a ladder-like rebound and the maximum in the first nine years of the21st century.(4) It could be found that when climate elements appeard extremely or unsuitable temperture、precipitation and sunshine and impacted on crop yield, the adaption degree cut down. Some countermeasures are proposed related to the sustainable development of agriculture. For example, improve agricultural education and technology promotion,breeding new varieties, regulate of the farming season timely and develop water-saving agriculture, take specific measures to strengthen agricultural disasters, weather forecasting and defense can be useful in improving crop adaptation degree to climate change.