水稻干旱监测评估模型研究及在川中丘陵区的应用

Rice Drought Monitoring and Assessment Model and its Application in the Hilly Area of Central Sichuan Basin

干旱是影响四川省水稻生产最突出的气象灾害,川中丘陵区为四川省常年干旱发生较重区域。为分析评价川中丘陵区水稻干旱的时空分布特征和发生规律,结合水稻干旱评估模型,利用四川省川中丘陵区水稻种植33个市县气象台站53年逐日气象资料及10个农业气象观测站近33年水稻生育期资料,采用新的水稻干旱评估指标计算川中丘陵区水稻干旱发生频率的时空变化特征,并选取不同区域典型站点分析需水关键期水稻干旱评估指数的年代际变化特征。结果表明：川中丘陵区水稻全生育期干旱频率在60.5%~94.3%,孕穗期发生中旱以上频率高达50.3%,重旱一般出现在水稻的分蘖-拔节期达25%;水稻从孕穗-抽穗期（7月下旬）川中丘陵区的北部及南部大部地方干旱发生频率〈60%,川中丘陵区的中部部分区域干旱频率〉70%;孕穗-抽穗期各代表站的水稻干旱评估指数（I）值变化：20世纪60年代末期,70年代中期,80年代初期,90年代初期到00年代初期干旱较重,近几年干旱有变轻的趋势。

Drought is one of the most severe meteorological disasters and causes great loss of rice production in Sichuan province,especially in the hilly area of central Sichuan basin. In this paper a rice drought assessment model was used to analyze the temporal and spatial distribution and the frequency of rice drought. The daily meteorological data at 33 meteorological stations during the recent 53 years（ 1960- 2012） and the rice phonological records at 10 agro-meteorological observation stations during the recent 33 years（ 1980- 2012） were used to analyze the temporal and spatial distribution characteristics of rice drought occurrences in the hilly area of central basin in terms of an innovative rice drought assessment index. Further,we chose typical stations from each rice growing regions to analyze the inter-annual and inter-decadal variations of rice drought assessment index during the critical period of water requirement. The results showed that the drought frequency was around 60. 5 %- 94. 3 % through the whole rice growth period in the hilly area of central basin. The values of rice drought frequency varied with rice growth stages. The rice drought was more severe at booting stage,and its frequency over moderate drought was 50. 3%. Severe drought occurred during tillering and jointing stages,and its frequency was 25%. During the booting and heading stages（ late July）,the drought frequency was less than60% in the north and south of the hilly central basin,and it was higher than 70% in the middle of the hilly central basin. The changes of rice drought assessment index during the booting and heading stages at the typical stations showed that the rice drought was severe in the late 1960 s,mid-1970 s,early 1980 s,early 1990 s and early 2000 s. And rice drought tended to be less severe in recent years.