南疆地区极端气候变化及其对农业生产的影响——基于百分位阈值法探讨

Effects of Extreme Climate Change on Agriculture Production in the Southern Xinjiang——Based on the Percentile Threshold Method

选取南疆地区18个代表站点1961-2011年气温与降水量原始数据,用百分位阈值法分析了近51年南疆地区极高、低温和极端降水量变化趋势及其对农业生产的影响。结果表明,南疆地区近51年极高、低温和极端降雨量均呈上升趋势,增幅分别为1.7℃、4.6℃和3.7 mm,极高温增幅显著低于极低温增幅,所以温度年较差呈降低趋势(-2.8℃/51年)。南疆地区极高温发生天数增加幅度为0.8 d/51年;而极低温发生天数减少幅度为2.0 d/51年;极端降水天数增加幅度为3.8 d/51年。极端气候对南疆地区农业生产存在双重影响。极高温和极高温天数的升高导致农作物遭遇热害,生育期缩短,加剧南疆地区干旱情况;极低温的升高和极低温天数的减少有利于农作物顺利过冬和种植界限的扩展,但也会造成干旱、盐渍化的加剧及病虫草害的发生;极端降雨量和降雨天数的提高有利于缓解干旱,但农作物花期和成熟期降雨会导致坐果率和果实品质的下降。

The changes of extreme temperature and extreme precipitation were analyzed based on the percentile threshold method from the recorded daily data of temperature and precipitation at 18 typical stations in the Southern Xinjiang from 1961-2011. Effects of extreme climate change on the agriculture production were studied. In the period of 51 years, the extreme high temperature, low temperature and precipitation was increased 1.7 ℃, 4.6 ℃ and 3.7 mm, respectively. The annual temperature difference was increased -2.8℃∕51 years because absolute increase of extreme low temperature was higher than that of the extreme high temperature. In 51 years, the days of extreme high temperature increased 0.8 d, while the days of extreme low temperature were decreased 2.0 d and the days of extreme precipitation were increased 3.8 d. The occurrence of extreme climate had both advantages and disadvantages on the agriculture production in southern Xinjiang. The increase of extreme high temperature and the days of extreme high temperature caused hot damage on crops and fruits, by shorting growth stage and intensifying drought. The increase of extreme low temperature and the decrease of the days of extreme low temperature reduced freeze injury on crops and fruits by benefitting winter and expanding the crop and fruit boundaries to the high latitude. However, the increase of extreme low temperature and the decrease of the days of extreme low temperature would also increase the disease, insect pest and weeds in the next growth season and intensify the drought and salinization. The increase of extreme precipitation and days of extreme precipitation would ease the drought in southern Xinjiang and promote the nutrition uptake by crops and fruits, while the rainfall at flowering stage or near maturity would reduce fruit setting rate and the quality.