The Impact Assessment Of Climate Change On Agriculture Water Demand In Henan Province

The Production of Chinese agriculture has been effected in recent years as the changing of Global climate.The agricultural irrigation water would increase by 6% ~10% when the temperature rising every 1? instead of considering the of increasing of CO2 concentration in the showing of some data.Therefore,the spatial and temporal distribution of irrigation water requirement under climate changing is become more and more important for the formulation of scientific irrigation quota and response.Based on the mechanism of impact of agricultural irrigation water requirement under the climate changing,we have analyzed the characteristics of Henan province meteorological elements under the historical conditions,screened the weights of the related influence factors,forecasted irrigation water requirement under the future change of Henan province.The main contents and results are as follows:(1)The characteristics of various meteorological elements in Henan province is analyzed based on Mann-Kendll analysis.Results show that the speed of wind and the time of sunshine have a weakening trend,and the average temperature has a rising trend;The relative humidity change trend is not obvious;The internal factors influence weight of reference evapotranspiration quantity is to be identified based on partial correlation analysis,and the results show that the average temperature and wind speed,sunshine time of ET0 ate contribute for positive correlation,relative humidity contributes negative correlation;And the partial correlation coefficient of Wind speed?the average temperature and average sunshine time are 0.92?0.69 and0.93,and the average correlation coefficient of relative humidity is 0.75;(2)The calculation of ET0 for 50 years of Henan province is analyzing by using the Penman-Monteith formula.Results show that,the overall declines with the statistic Z value of 2.99 within the scope of Henan province,and the mutations in1965;The high value appears in the north-central region by using IDW method with the daily reference evapotranspiration volume of 3.53 mm;(3)The irrigation water requirement in Henan province is forecasted in future climate scenarios.ETc and I in the north-central region of Henan province is higher,and Pe in the south-central region of Henan province is higher;ETc and I appear as the high value in the north-central region of Henan province in 2030 s and 2050s;ETc andI in the climate model of RCP8.5 showed higher;And I of Henan province in 2050 is higher than which in 2030.