稻田甲烷排放模型研究——模型的验证  

Modeling methane emission from rice paddies: Model validation

作　　者：张稳[1] 黄耀[1] 郑循华[2] 李晶[2] 于永强[2] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]中国科学院大气物理研究所,北京100029

出　　处：《生态学报》2004年第12期2679-2685,共7页Acta Ecologica Sinica

基　　金：中国科学院知识创新工程重大资助项目 ( KZCX1-SW-0 1-13 ) ;国家重点基础研究发展计划资助项目 ( G19990 1180 5 )~~

摘　　要：模型的有效性检验是模型应用于估计区域尺度稻田甲烷排放量的基本前提 ,尤其是针对多种不同的土壤、气候以及农业管理方式等可能影响稻田甲烷排放的环境条件下的模型检验。利用覆盖全国主要水稻产区的 94个甲烷排放观测案例对稻田甲烷排放模型 (CH4 MOD)进行了验证。这些观测区域分布范围北至北京 (4 0°30′N,116°2 5′E) ,南至广州 (2 3°0 8′N,113°2 0′E) ,东起杭州 (30°19′N,12 0°12′E) ,西到四川的土主 (2 9°4 0′N,10 3°5 0′E)。既有双季稻 ,也有单季稻 ,稻田灌溉及施肥方式也多种多样 ,对我国水稻生产具有较广泛的代表性。观测获得的稻田甲烷排放季节总量从 3.1kg C/hm2到 76 1.7kg C/hm2 ,平均值为199.4 (± 187.3) kg C/hm2 ;相应的模拟值分别为 13.9、82 4 .3和 2 2 4 .6 (± 187.0 ) kg C/hm2。模拟值与实测值的线性相关系数(r2 )为 0 .84 (n=94 ,p<0 .0 0 1)。CH4Several models have been developed over the past decade to estimate methane emission from rice paddies. However, few models have been validated against field measurements with various parameters of soil, climate and agricultural practice. Thus, reliability of the model's performance remains questionable particularly when extrapolating the model from site micro-scale to regional scale. The objective of this paper is to validate a model that is dedicated to simulating methane emission from rice paddies, and hence to evaluate the model performance.The model, named as CH4MOD, was validated against a total of 94 field observations conducted in China. These observations covered main rice cultivation regions from northern (Beijing, 40°30′N, 116°25′E) to southern China (Guangzhou, 23°08′N, 113°20′E), and from eastern (Hangzhou, 30°19′N, 120°12′E) to southwestern (Tuzu, 29°40′N, 103°50′E) China. Both single rice and double rice cultivations are distributed in these regions with different irrigation patterns and various types of organic matter incorporation. Model inputs include rice grain yield, soil sand percentage, amount of organic amendment, water management pattern, and daily air temperature. The validation indicated that model simulations generally agreed with the observations. The observed seasonal amount of methane emission ranged from 3.1 to 761.7 (kg C/hm^2) with an average of 199.4±187.3 kg C/hm^2. In consonance with the observations, model simulations resulted in an average value of 224.6±187.0 kg C/hm^2, ranging from 13.9 to 824.3 kg C/hm^2. Comparison between the computed and the observed total seasonal methane emission yielded a correlation coefficient r^2 of 0.84 with a slope of 0.92 and an intercept of 41.1 (n=94, p<0.001). Compared with the original model, the CH4MOD can well capture the signals of bubble fluxes and the effect of water regime on methane emission. Model simulation for 94 cases resulted in the bubble flux contribution of 5%～45% to the overall emissions, which is

关 键 词：CH4MOD 模型 甲烷排放 稻田 验证 

分 类 号：S153.6[农业科学—土壤学]