Characteristics Of Climate Change And Its Impact On The Yield Of Main Crops In Zhangjiakou City In Recent 20 Years

It is of great scientific significance to research the impact of climate change on the growth and yield of main food crops in Zhangjiakou area.It can ensure the safety of food production and explore the agricultural production mode to adapt to climate change.In zhangjiakou main crop planting area eight representative cities were selected and divided into the north and the south,according to the geographical location.Based on the meteorological observation data,yield and area data of maize and naked oats in recent 20 years(2000-2019),the relationship between climate factors(sunshine hours,temperature,precipitation,and accumulated temperature)and yield per unit area of maize and naked oats in Zhangjiakou was analyzed by mathematical statistics.Based on the analysis of the disaster area,no harvest area,drought area,flood area,hail area and frost area in Zhangjiakou to explore the change trend and characteristics of main meteorological disasters in Zhangjiakou.The main research results were as follows:(1)In recent 20 years,the sunshine hours in Zhangjiakou area showed a fluctuating upward trend,and the increase of sunshine hours in the northern area was greater than that in the southern area.The annual average temperature showed a fluctuating upward trend.The northern area and southern area parts were in the same trend.The m-k test of temperature showed that there were mutation points in the average annual temperature of the northern area,while only Huaian area had mutation points.The active accumulated temperature at 10? showed a slight decreasing trend.Through the m-k test of precipitation,it was found that there were mutation points in the precipitation in the north and the south.The fluctuation of precipitation was more frequent and showed a rising trend,and the increase rate in the south was greater than that in the north.The annual precipitation during the growth period showed an upward trend,and the precipitation in the northern area was higher than that in the southern area.(2)The climate potential productivity in the north and south of Zhangjiakou were fluctuated greatly,but there was no obvious increasing or decreasing trend.The planting area of naked oats in the northern region was increasing.The planting area of Maize in the south was increasing.The correlation coefficient between annual average temperature and climate productivity was very small.There was a positive correlation between the average temperature and maize yield per unit area in most areas.In most areas,sunshine hours were positively correlated with naked oats yield per unit area,while active accumulated temperature was negatively correlated with maize yield per unit area.(3)The main meteorological disasters in Zhangjiakou were drought,flood,hail and frost,among them,drought and hail were the main meteorological disasters affecting crops in Zhangjiakou,followed by frost and flood.From the change trend of the affected area of crops caused by the main meteorological disasters,the affected area of drought and hail showed a downward trend,while the flood and frost disasters increased slightly.The grey correlation analysis method was used to get the conclusion the correlation degree between grain yield and four meteorological disasters was frost disaster>flood disaster>hail disaster>drought disaster.The correlation degree of maize and naked oats with the four meteorological disasters was frost>flood>hail>drought.