雷州半岛农作物水分供需关系与农业旱灾

Crops Water Supply and Agro-drought Disaster in Leizhou Peninsula

雷州半岛是中国东部沿海农业旱灾最为严重地区之一。通过分析积分湿度指数I值变化,探讨雷州半岛农作物水分供需关系及其对农业旱灾的影响。结果表明:农作物水分供应不足是雷州半岛农业旱灾最主要原因。从时间上看,1962～2007年46a间,有31a的I值小于0.6,中旱和重旱频率高达67.4%。I值也有明显的季节差异,冬旱最为严重,46a中有44a为重旱,出现频率为95.65%。从空间上看,南部和北部农业旱灾尤为严重。徐闻和湛江中等以上农业旱灾频率达71%以上,廉江、雷州和吴川为66%左右,遂溪最低,也达57%。

The agro-drought disaster takes place frequently and is very serious in Leizhou Peninsula. Inadequate water supply of crops is one of the most important factors. Integral humidity index I is used to analyze crop water supply. The results reveal the agro-drought regulations of spatial and temporal distribution in the Peninsula. From 1962 to 2007, the frequency of agro-drought disasters over middle level （I 0.6） reached 67.40% and they were particularly obvious in the northern and southern parts. The highest frequency was in Xuwen County, the lower in Zhanjiang City; it was as high as 95.65% in winter and causes very serious disaster from winter to spring.