Impact Of Climate Change And Assessment Of Catastrophe Damage On Major Crop Yields In Pujiang County

Climate change is a recognized fact.With the advance of global climate change research,climate change impact research has become one of the most active research fields in academia.In this paper,the MK mutation test,linear regression fitting,climate impact model and damage risk index evaluation were used to test climate change mutation in Pujiang County in the past 37 years(1980-2016)and five major crops(rice,wheat,corn,sweet potato,Study on the impact degree and damage risk assessment of rapeseed yield,and put forward corresponding countermeasures.The following main findings emerged from the study:(1)The M-K mutation test was used to test the temperature,precipitation,and sunshine hours in Pujiang County in the past 37 years.It was determined that the temperature in the county changed significantly,and the mutation point was 1995,and the warming trend was obvious.Precipitation and sunshine hours did not change significantly.(2)Using linear regression fitting,the climate yield of five major crops in Pujiang County has been calculated and analyzed in the past 37 years.The average climate yield of the five major crops in the county in the past 37 years has been ranked from large to small:corn(13.43 kg/hm~2)>rice(13.34 kg/hm~2)>sweet potato(2.12 kg/hm~2)>wheat(-7.31 kg/hm~2)>(-7.89 kg/hm~2).The climate yield of the five major crops changed significantly before and after the climate mutation.The order before the climate mutation was:sweet potato(96.33 kg/hm~2)>corn(30.05kg/hm~2)>rape(-15.56 kg/hm~2)>rice(-61.90 kg/hm~2)>wheat(-62.45 kg/hm~2);The order of climate mutations is:rice(50.85 kg/hm~2)>wheat(33.75 kg/hm~2)>corn(10.74kg/hm~2)>rapeseed(-80 kg/hm~2)>sweet potato(-22.31 kg/hm~2).Among them,the average climate yield of rice and wheat increased after the mutation;The average climate yield of corn,sweet potato and rapeseed decreased after mutation,especially the sweet potato decreased significantly.(3)Using the climate impact model,the impact of climate change on the output of five major crops in Pujiang County in the past 37 years was analyzed.The absolute value of the combined climate impact of the five crops in the county is:sweet potato(|-25%|)>wheat(|5%|)>rice(|4%|)>corn(|-1%|)=rape(|-1%|).It shows that climate change has a positive effect on the increase of rice and wheat.The effect of negative yield on maize,sweet potato and rapeseed.The absolute value of the comprehensive impact before the climate mutation is sorted as:rice(|1%|)>wheat(|0.9%|)>corn(|0.8%|)>rape(|-0.3%|)>sweet potato(|-0.2%|);The absolute value of the post-mutation synthesis is:sweet potato(|-3.9%|)>corn(|-2.7%|)>wheat(|1.7%|)>rape(|1.4%|)>rice(|1%|).It shows that the climate change in the county in the past 37 years is not conducive to the production of sweet potatoes and corn.The climate change in the county is conducive to the production of rape and wheat,and the climate change has a small impact on rice production.(4)Using the disaster loss risk evaluation method,the disaster loss risk assessment of five major crops in Pujiang County in the past 37 years was carried out.The ranking of the comprehensive disaster risk indicators is:sweet potato(29.25%)>wheat(21.86%)>corn(21.28%)>rice(15.30%)>rape(11.17%).Before the climate mutation,the county's main crop comprehensive risk indicators were:wheat(29.78%)>sweet potato(26.60%)>corn(24.64%)>rape(12.58%)>rice(10.32%).After the climate mutation,its main crops were ranked as:sweet potatoes(39.43%)>corn(23.86%)>rape(22.68%)>wheat(20.34%)>rice(14.24%).After the sudden climate change,the risk of disaster loss of sweet potato and rapeseed increased obviously,and the risk of rice disaster loss increased slightly.The risk of wheat damage decreased significantly,while the risk of corn damage decreased slightly.(5)In the future,in the process of agricultural production in Pujiang County,the following measures should be taken to adapt to climate change:adjusting the structure of agricultural cultivation and stabilizing crop production;Pay attention to water Conservancy projects and strengthen field management;Cultivate excellent varieties and improve farming practices.