Economics Analysis On The Agronomic Modeling Of Food Production With ENSO Impacts In The Mid-Eastern China

As a result of human activities and greenhouse gas emissions,global warming and climate anomalies have attracted more and more attention around the world(IPCC 2007).Represented by El Ni(?)o and the Southern Oscillation(Southern Oscillation),the imbalance between the atmosphere and ocean is one of the important reasons for world climate anomalies."El Ni(?)o" phenomenon is defined as the abnormal warming of sea water near the equator(about 4 degrees north latitude and 4 degrees south latitude,150 degrees west longitude to 90 degrees) with a range of thousands of kilometers.Now it is being used to specifically refer to the continuing large-scale abnormal sea surface temperature warming phenomenon in eastern and central equatorial Pacific and its impact on both global climate change phenomenon the potential impact of human affairs.Started in the 1970s,El Ni(?)o is now becoming more and more frequent which brings even more serious impact worldwide.The influence that El Ni(?)o has on global climate varies from place to place.Extreme weathers like droughts,storms and floods happen in different area around the world because of El Ni(?)o.According to IPCC 2007,during 1997 and 1998 the lost that caused by El Ni(?)o in the world is about 20 billion U.S.dollars.Agricultural production is a social activity that carries on natural body which is greatly influenced by climate change.China's major grain-producing area locates in the world's largest monsoon region - the East Asian monsoon area.The climate type is a mixture with continental climate and oceanic climate.During summer,the warm ocean currents bring a large amount of precipitation that forms a maritime climate with high temperature, humid and rainy.In winter time,dry and cold air currents from the continent forms the continental climate which is cold and dry.As a Monsoon climate type,it is humid and rainy in summer,dry and has little rain in winter.Rain bands move upwards with time advancing from southeast to northwest.Precipitation and rainfall are concentrated but very unstable with a big annual anomaly.However,monsoon climate type has the advantage of high temperature and wet periods in the same time period which is very favorable to the development of agriculture.A sufficient supply of rain ensures the crop growth.Bigger temperature spans is favorite to agriculture too.Low temperatures in winter can reduce pests and diseases.However,due to the seasonal variation of precipitation and inter-annual variation,floods and droughts frequently happen,which have bad influence in agricultural production.Therefore,China's agriculture,especially grain-growing industry is vulnerable and has high dependency on climate.Climate change on agriculture and food security of China's impact is particularly important.In addition,China has more than 1.3 billion population,is the world's largest food exporting and importing country.Agriculture is an important part of national security.Research on the influence of climate change on China's agriculture,especially the grain-growing industry is important.In this thesis,44 ground stations which locate in the mid and eastern part of China are chosen.The data of daily minimum temperature,daily maximum temperature and precipitation information is collected.Anomaly values are used to remove the seasonal trends,highlight the inter-annual changes in analysis.Changes in inter annual seasonal mean minimum temperature;maximum temperature and precipitation are significant. Empirical Orthogonal Function is used to establish the first EOF time series modal field. Combined with Southern Oscillation Index SOl correlation analysis,the economic model of food production is built and is used in food production evaluation,from the statistical point of view,the contribution of monthly data's first pattern time series to the variance is relatively small(30%) no matter the time series is present ones or lagging ones which draws a conclusion that monthly data' s relevant correlation with SOI is not obvious.Likewise,seasonal(spring,summer) minimum temperature,maximum temperature and precipitation anomaly EOF analysis is made.Result shows that their contribution to the first mode variance is quite big,more than 50%,which better reflects the main features of the inter-annual change.In the confidence level of 95%,January,March, April,June,September and October's SOI are selected.Combined with the total power of agricultural machinery and other factors,evaluation model of mid and eastern China crop yield with SOI index is built. According to SOI oscillations' own characteristics,trigonometric function is introduced in the model rather than a linear function.Overall,the model is well fitted with R~2=0.990253.Looking through the established model,it is obvious that the agricultural machinery and electricity in rural areas,followed by the fertilizer application rate and the state financial expenditure items of expenditure in the agriculture as well as rural relief have significant influence on the food production.However,SOI reflects the non-human effects,and is the most uncontrollable factor in food production that can not be overlooked.Finally,SOI of last January,September and October,as well as present March data are used which is comparative ahead of the annual grain harvest period,It brings a certain reference value for national food policy formulation and adjustment.