| With global warming,land underlying surface process that one of important factors making climatic change has been subject to people’s common concems.Agricultural economy in industrial structure has a very important position in ShiJiaZhuang area.As an environmental unit,it is in montanic and blair trasition belt with complicated landform.Uder such specific landform conditions spatio temporal evolution of surface temperature and its impacting on agriculture are worth doing a deep research after a quick urbanization stage.Based on the daily ground temperature during1961～2010,shallow layer ground temperature during1981～2010, grass land temperature during2008～2010and per unit area yield of staple crops during1985～2010of5stations in Shijiazhuang area, spatio temporal evolution of ground temperature by means of anomaly,variability and variation tendency,such as climate sudden change and change cycle by means of Mann-Kendall-adjusted and Morlet wavelet transform respectively were analyzed.By analyzing the correlation between air temperature,precipitation,wind speed,sunshine duration,total cloud amount and land surface temperature,as well as the correlation between precipitation,frozen earth and shallow layer ground temperature,response of ground temperature to climate and its impacting on staple crops were investigated initially. The main results are as follows:In recent50years,annual mean fluctuation range of land surface temperature was minimal,and fluctuation range of of land surface temperature’s daily range was maximal.Annual mean land surface temperature had a weak warming trend with summer having a obvious drop and winter having a obvious rise.The maximum mean land surface temperature had a significant downtrend with summer ocurring the strongest one,and the minimum mean land surface temperature had a signicant warming trend with winnter ocurring the strongest one,and daily range of land surface temperature had a significant reduce trend with winter ocurring the strongest one. Fluctuation range of daytime in one day was the maximum,and nighttime,morning and nightfall had a obvious warming trend,as well as daytime having a obvious downtrend.A obvious cooling being in the beginning of21st century was a sudden change.Mean land surface temperature had a around20lows and a6～8high frequency oscillation period,which was shorter than air temperature’s lows(about23) and had a sensitive impact on climate probably.The positive correlation between air temperature and land surface temperature was the strongest one in years and seasons with the positive correlation between sunshine duration and land surface temperature being stronger in spring and summer as well as wind speed being stronger in summer. The negative correlation between precipitation and land surface temperature was stronger in spring,summer and autumn with total cloud amount being stronger in spring and summer and wind speed and sunshine duration being stronger in winter.In recent30years, annual mean fluctuation range of shallow layer ground temperature was large,the larger one of which was being in spring and summer,and it had a warming trend,the obvious one of which was being in winter.Daily mean fluctuation range of shallow layer ground temperature was large,the minimum of which was being at morning.The significance of5cm and10cm deep ground temperature was stronger at nighttime when the soil layer got deeper,and the warming trend of shallow layer ground temperature at morning was from strong to weak, and the warming trend of it was weak at daytime,and the weak trend of it at nightfall was from a cooling one to a warming one.Annual mean shallow layer ground temperature had not a sudden change while had a9～10lows and a4～6high frequency oscillation period,which had a sensitive impact on climate compared to air temperature’s (about23lows and5-8high frequency oscillation period).The relevance between precipitation,maximual frozen earth deepth,a period of freezing weather and shallow layer ground temperature had a negative correlation,the stronger one of which precipitation was in spring,summer and autumn while the stronger one of which maximual frozen earth deepth,a period of freezing weather were also in winter.Monthly grass land temperature got warming from2to7in one year while the rest of hours got cooling,hourly grass land temperature got warming from6to13in one day while the rest of hours was adverse.The warming extent of it during first half year was smaller while the cooling extent of it during the second half was larger. Variability of annual mean grass land temperature had three peaks with two ocurring in spring with one ocurring in autumn.Variational relation between air temperature,Iand surface temperature,shallow layer ground temperature and grass land temperature existed in all seasons and various weather. Quarterly mean sheer difference between air temperature,ground temperature and grass land temperature was larger in spring and summer and was smaller in autumn and winter.In recent26years, fluctuation range of vegetables’per unit area yield was strongest while cotton’s was weakest.A large proportion of staple crops had a obvious increase trend in output such as vegetables,wheat and peanut.Corn and cotton’s per unit area yield had a sudden change. Staple crops had a10-14lows oscillation period which extended around5years next to lows oscillation period of shallow layer ground temperature.Impacting of mean5cm and10cm deep ground temperature on wheat’s pass safely in winter was larger.Mean shallow layer ground temperature had a larger effect on wheat’s growth and cotton and peanut’s seeding in spring.The variation trend of mean shallow layer ground temperature did good to corn’s and cotton’s growth while it did harm to soybean’s and peanut’s growth in summer. |
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