土地利用变化碳排放效应研究——以重庆市为例

The Effects of Land Use Changes on Carbon Emission C:Take Chongqing as an Example

土地利用方式是影响碳排放的主要原因,低碳排放已成为土地利用调控的新课题。为了分析不同土地利用方式的碳排放效应,本文以重庆市为例,分析直辖以来重庆市主要土地利用方式的碳排放,并对重庆市的碳排放进行预测。结果表明,1997-2008年,由于土地利用的变化,重庆市碳排放从1 158.29万t增加到2 892.75万t,其中建设用地和耕地是主要碳源,建设用地年碳排放达1 214.92～2 987.29万t,排放强度为2.49～5.04 kg/(m2a),耕地年碳排放从126.3万t降为111.13万t;林地为主要的碳汇,由于林地面积持续扩大,林地的年碳吸收量由182.43万t增加到205.17万t。对重庆市2020年土地利用规划下的碳排放预测结果显示,2020年重庆市单位GDP碳排放比2005年减少43.99%,但碳排放总量显著增加,为10 381.19万t,因此面临的减碳任务非常严峻。

Land use is one of the most mainly factors affecting the carbon emission, and the low-earbon emission has become an important land use management issue. In order 1o investigale varialions in carbon emission in response to land use changes, this paper analyzed Ihe quatllilative and the sh＇uehwal evolutions of earbon emissions influenced by land use patterns of Chongqing since 1997, and estimated the prospective earbon emission of Chongqing 2020 based on the plan for land use. The resuhs showed thai, owing to land use change, the carbon emission has grown from 11.58 million t to 28.93 million t. Carbon emissions were significantly diverse according to different land use categories, in which the construction land and cultivated land were the two main earl）on sources with annual carbon emission of 12. 15-29.87 million t and 1. 11-1.26nlillion t separately, at/d forest land was the main carbon sink with absorbed 1. 82.43-2.05 million t（C） per year. Aecording tl） the forecasts of carbon emission influenced by land use changes, ahhough compared with 2005, in 2020 lhe carbon emission will reduce by 43.99% , the carbon emission will increase significantly with annual carbon emission of 103.81 million t in 2020, whieh indicated that it is severe to reduce the earbon emission in Chongqing.