城市湿地气候调节功能遥感监测评估

湿地是地球上最为重要而独特的生态系统类型,在缓解全球气候变化和调节区域气候特征方面具有重要作用。以北京湿地为研究案例,在分析湿地气候调节作用过程机理的基础上,综合运用遥感数据和常规气象站点监测资料,利用CASA模型和植被指数累积模型分别定量反演获得北京湿地年地上生物量和年蒸散量,基于价值量方法定量评估了北京城市湿地气候调节能力。结果表明:①北京湿地地上生物量吸收固定二氧化碳和释放氧气分别约为1.42×10⁸kg和1.03×10⁸kg,价值量分别约为2.83亿元和0.42亿元;②北京湿地蒸散发量约为4.16亿m³,价值量约为1.14亿元。③北京湿地通过固碳释氧和地表蒸散发等过程所形成的气候调节功能总价值约为4.39亿元。

Monitoring and evaluation for climate regulation service of urban wetlands with remote sensing

Wetland is one of the most important and extraordinary ecosystems.It plays a key role in decelerating the climatic change trend and regulating the regional climatic feature, which is closely related to the human well-being.Based on the satellite images and meteorological data of ground observation stations,Beijing taken as the study region, biological mass and evapotranspiration intensity of wetlands are respectively estimated with CASA(Carnegie-Ames-Stanford Approach)model and NDVI(Normal Difference Vegetation Index)cumulative model,then regulation valuation implemented by carbon sequestration, oxygen release and evapotranspiration are evaluated with carbon tax method,shadow project method and results reference method.The results show that:(1)The quality of carbon dioxide sequestration and oxygen release by wetlands in Beijing is about 1.42×10⁸ kg and 1.03×10⁸ kg respectively,which are about 283 million yuan and 42 million yuan in turns in 2007.(2) The capacity of water vapor evapotranspired from wetlands is about 416 million m³,which is about 114 million yuan in 2007.In general,the total valuation of climatic regulation of wetlands is about 439 million yuan in 2007.