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用Peman公式计算了华南广东12个气象站1971~2010年潜在蒸散值,并分析了其时空变化特征。潜在蒸散值随纬度的升高减少,变化范围为680~1800 mm a-1;潜在蒸散的大小主要受温度和降水支配,20世纪80年代最小,90年代以后,随气候变暖,潜在蒸散值增加明显,本世纪00年代达到最高值,突变年为2004年。中亚热带夏季最高,南亚热带及北热带春季最高,各地冬季均最小。一年当中,地表湿润指数最高的时段为5月及6月,最低时段为冬季及秋季11月,最高的季节为春季,其次为夏季和秋季,最低为冬季。湿润度指数随纬度的降低下降明显,春季和冬季最为突出,湿润程度最好的时期为20世纪80年代,最差为21世纪的00年代,以春季下降最多。广东各地不同季节出现不同程度的土壤水分亏缺,作物生长所需水分未及最适宜状态,造成不同程度的季节性干旱,主要为各地的秋旱、南部地区的春旱和中南部的冬旱,南部地区春旱重于秋旱,北部地区秋旱重于春旱。针对不同地域不同旱灾,采取有效防旱抗旱措施成为保障当地农业产业持续发展的有效途径之一。
Pent formula was used to calculate the potential evapotranspiration values from 1971 to 2010 in 12 meteorological stations in Guangdong in southern China, and its temporal and spatial variation characteristics were analyzed. The potential evapotranspiration decreases with the increase of latitude, ranging from 680 to 1800 mm a-1. The size of potential evapotranspiration is dominated by temperature and precipitation, the smallest in the 1980s. After the 1990s, with the warming potential and potential evapotranspiration Increase significantly, this century reached the highest value of 00, the mutation year 2004. The highest in the subtropics in summer, the highest in the south and the tropical in the tropics and the smallest in the winter. During the year, the highest wetting index of the surface was in May and June, the lowest in winter and autumn in November, the highest in spring, the next in summer and autumn, and the lowest in winter. The wettability index decreased obviously with the decrease of latitude. The spring and winter were the most prominent ones. The wetting degree was the best in 1980s and the worst in the 00s of the 21st century, with the highest decrease in spring. In different seasons in Guangdong, soil moisture deficit occurred in different degrees, and the water needed for crop growth did not reach the optimum state, resulting in seasonal drought in different degrees, mainly including autumn droughts in various areas, spring droughts in southern areas and winter droughts in central and southern China In the south, the spring drought was heavier than the autumn drought, and the northern region was heavier in autumn than in the spring drought. For different types of droughts in different regions, taking effective measures to combat drought and resist drought has become one of the effective ways to ensure the sustainable development of local agricultural industries.