关键词: 温室气体, DNDC 模型, 水稻田, 排放通量, 遥感图像

Abstract: Abstract: 【Objective】This study used the DNDC model which is based on the ecological process to simulate the flux of Greenhouse Gas emits from rice paddy field under various management practice scenario and estimate quantitatively. Give one way in accessing the impact of agricultural ecosystem on climate and environment. 【Method】The Landsat TM and CBRES remote sensing images required in 1988 and 2005 were utilized to classify the Land Use/Cover covers Dawa county, Liaoning province. The aim is to extract the temporal-spatial distribution of rice paddy field and calculate its area. The DNDC model was applied to simulate the flux of Gas (Carbon dioxide, Nitrous oxide, Methane) emits from rice paddy field in different period of time, and analyzed the spatial-temporal dynamics of Greenhouse Gas emits from rice paddy field in Liaodong coastal region.【Result】Comparison of the area of rice paddy field in 2005 with that of 1988, there were 7,066.2 hectares increment in amount. The total emission of three GHG (CO2、N2O、CH4) in 1988 and 2005 were-12.02 Pg C, 2.57 Tg N, 0.14 Pg C and 7.22 Pg C, 2.69 Tg N, 0.17Pg C, respectively. The spatial distribution of them were, flux rate of CO2 high region in the east and south of study site, low in the north, N2O high in the mid-east and northwest, low in the north, CH4 high in the mid-east and southwest, low in the north and southeast, respectively. For the net Global Warming Potential (GWP), the spatial difference in 2005 were smaller than in 1988.【Conclusion】Socio-economical impact is the key factor of diving area change of rice paddy field. The rice paddy field is one sink of CO2, source of N2O and CH4. In addition to climate factors, different soil type make significant impact on the flux magnitude of Greenhouse Gas emits from rice paddy field, so does the farm management practice scenario.

Key words: Greenhouse gas, DNDC Model, Rice paddy field, Flux of emission, Remote sensing