皖中沿江平原水稻田CH_4和N_2O排放估算及其影响因素分析

利用DNDC9.3模型对研究区域水稻田排放的CH4和N2O通量进行模拟和定量估算,并对其影响因素进行分析。研究选取皖中沿江平原内具有典型代表性的长丰县水稻田为实验地区,利用DNDC9.3模型对该县内12个试验样点2008年的CH4和N2O排放量进行估算分析,并对其做敏感性实验分析。结果表明:1)长丰县水稻田2008年CH4和N2O年排放量分别为C 1.82×10-2 Tg和N 3.03×10-4 Tg;2)由敏感性分析实验得:CH4排放水平和气温、土壤pH和SOC呈正相关关系;N2O排放水平和气温、雨水中氮含量呈正相关关系,对SOC、土壤pH变化也较为敏感。

Estimation of CH4 and N2O Emissions from the Paddy Fields in Wan-zhong-yan-jiang Plain and Analysis of Their Influence Factors

DNDC9.3 model was applied to simulate the amount of CH4 and N2O emissions from research region’s paddy fields and analyze its influence factors.Changfeng County,which was one of the typical sites of Wan-zhong-yan-jiang Plain,was selected for our study.Using the DNDC9.3 model,the emissions of CH4 and N2O from twelve test samples were estimated and analyzed.The results showed that:1) The average amount of CH4 and N2O emissions from Changfeng County’s paddy fields were 1.82 × 10-2 Tg C and 3.03 × 10-4 Tg N respectively in 2008;2) The sensitivity experiment of the DNDC9.3 model showed that SOC(Soil Organic Carbon) 、air temperature、soil pH and the amount of CH4 emissions were positively correlated.In addition,the nitrogen in the rainfall and the amount of N2O emissions were positively correlated,and so were air temperature and N2O.The amount of N2O emissions were also sensitive to the variations of SOC and soil pH.