广州地区稻田甲烷排放通量研究

Study on Methane Emission Flux from Paddy Rice Fields in Guangzhou

１９９３～１９９４年连续２ａ在广州东郊采用自动采样和气相色谱分析系统测量了稻田甲烷的排放率，首次获得了华南地区赤红壤类型稻田甲烷排放特征和排放通量。结果表明：广州地区稻田甲烷排放率的日变化和季节变化随气温、灌溉状态及水稻不同生长期而变化，早稻甲烷平均排放量为１６ｍｇ／（ｍ２·ｈ）；晚稻为１２５ｍｇ／（ｍ２·ｈ），排放率较国内其他观测点低。在当地常规干湿灌溉方式下，估算得到广东和广西两省稻田甲烷排放总量约为０２６Ｔｇ／ａ。

Methane emission rates have been continuously measured in the eastern suburb of Guangzhou from 1993 to 1994 by using an automatic sampling and gas chromatographic analyzing system, and the methane emission characteristics and fluxes for red soil paddy fields in south China were obtained for the first time. results show that the diurnal and seasonal variations of methane emission rates in Guangzhou changes with the soil temperature, irrigating conditions and different grown up phase of rice; average methane emission flux for the early rice is 1.60 mg/(m 2·h) and that for the late rice is 1.25 mg/(m 2·h), and the data are lower than those in other domestic regions; under the normal conditions of local dry moisture irrigating methods, the estimated total methane emission flux from paddy rice fields in both Guangdong Province and Guangxi Province is about 0.26 Tg/a.