气象因子对洪湖有机氯农药大气沉降的影响

Influence of Meteorological Factor on Atmospheric Deposition of Organochlorine Pesticides in Honghu

对洪湖进行了为期一年(2005年2月-2006年2月)的大气沉降采样,采用被动大气采样方法对大气沉降中的有机氯农药进行了分析,得到该年通过大气沉降向洪湖输入有机氯农药9.77 kg,其中大气颗粒态沉降量为2.74 kg,湿沉降量为7.03kg。大气沉降中六六六(HCHs)和滴滴涕(DDTs)的沉降量最大。将所获气象数据和各季度有机氯农药大气沉降量进行了相关性分析,结果表明:①气象因子对湿沉降的相关性较大气颗粒态沉降的明显,其中降雨量、平均温度、平均风速与湿沉降量的相关系数最高;②风速、温度、日照对有机氯农药在气相溶解态和大气颗粒态分配影响强烈,而温度是决定有机氯农药在大气中以何种形式沉降的主要因素;③由于降雨的前锋时段具备有效的强沉降能力,使得连续性降雨频次对大气沉降影响强烈。

Atmospheric deposition of organochlorine pesticides （OCPs） was sampled and measured in Honghu for a whole year. The result showed Honghu gained OCPs 9.77 kg due to the atmospheric deposition, including 2.74 kg from the gas phase and 7.03 kg from the particle phase. HCHs and DDTs were both found predominantly in the atmospheric deposition. Analysis of relativity between meteorological factor and deposition in gas phase and particle phase showed that, （1） relativity between meteorological factor and deposition in gas phase was higher than that of particle phase, and rainfall, even humidity, even wind speed had highest relativity coefficient with deposition in gas phase; （2） wind speed, temperature and sunlight had strong influence on the distribution of OCPs in gas phase and particle phase, and temperature was the main factor to influence the form of OCPs to deposition in the atmosphere; and （3） due to the vanguard of rainfall had strong faculty on atmospheric deposition, frequency of rainfall had strong influence on atmospheric deposition.