渠江流域水稻热量垂直特征分析

Analysis of Rice Thermal Vertical Characteristics in Qujiang River Basin

利用1981—2018年渠江流域及周边20个站点的气象资料,基于水稻生理界限温度指标,建立界限温度、积温和初终日期等热量因子的数理模型,计算分析各热量因子的垂直变化特征,各海拔高度的旬气温,水稻潜在生育期、播种、齐穗等界限温度的季节变化以及高温和低温情况。结果表明:渠江流域水稻生长期各旬的气温垂直递减率有较大差异,在0.45~0.81℃/100 m之间变化,最大值出现在9月下旬,最小值出现在6月中旬。随着海拔由低到高变化,通过各界限气温的时间依次后延,终期提前,潜在安全生育期缩短。海拔1100 m左右山区的12~23℃潜在安全生育期不足100 d,只适合种植耐寒性较强的早熟粳稻。海拔1200 m以上山区热量条件明显不足,不适合种植水稻。渠江流域日最高气温≥35℃平均日数的垂直递减率约为4 d/100 m,海拔800 m以上无高温影响;日最高气温30~35℃之间的日数,海拔800 m以下为58~59 d。高温强度较适宜的水稻种植海拔高度范围为500~700 m,生产上海拔400 m以下平坝浅丘区的水稻安全齐穗期应安排在7月中旬。

Using the meteorological datas of 20 stations in and around the Qujiang River Basin from 1981 to 2018,based on the physiological threshold temperature index of rice,mathematical model of heat factors such as boundary temperature,accumulated temperature and beginning and end date was established,the vertical variation characteristics of each heat factor,the ten-day air temperature at each elevation,the seasonal variation of the boundary temperature such as rice potential growth period,sowing,full heading and high and low temperature were calculated and analyzed.The results showed that there was a great difference in the temperature lapse rate in each ten days during rice growing period in the Qujiang River Basin,ranging from 0.45℃/100 m to 0.81℃/100 m,with the maximum value in late September and the minimum value in mid-June.With the increase of altitude,the time of passing through each boundary temperature was delayed successively,the final stage was advanced,and the potential safe growth period was shortened.The potential safe growth period of 12-23℃was less than 100 d in mountainous areas with an altitude of 1100 m,which was only suitable for early maturing japonica rice with strong cold resistance.The thermal condition of the mountainous area above altitude 1200 m was obviously insufficient,which was not suitable for planting rice.The lapse rate of the daily maximum temperature≥35℃in the Qujiang River Basin was about 4 d/100 m,and the altitude above 800 m had no high temperature effect.The number of days with the highest daily temperature of 30-35℃below 800 m was 58-59 days.The altitude is 500-700 m where the high temperature intensity is suitable for rice planting,and the safe heading period for rice production in shallow hilly area of plateau dam below altitude 400 m should be arranged in mid-July.