摘要
土地利用和土地覆盖变化(LUCC或LULCC)不仅对人类赖以生存的地球环境有重要影响,同时与人类福祉密切联系。人类活动对气候的强迫不仅包括温室气体排放导致的气候变暖,还通过直接改变地表物理性状以及间接改变其他生物地球物理过程和生物地球化学过程等对气候系统产生深刻影响。作者在此认识的基础上回顾了LUCC对气候系统影响的研究历史,结合新近的研究结果归纳了诸如森林砍伐、城市化、修坝等LUCC活动在区域和全球尺度的气候效应。LUCC具有高度的空间异质性,因此气候系统对它的反馈也具有明显的空间差异。由于全球平均后变化幅度相对区域上的小,LUCC对区域气候影响显著,而对全球气候影响不明显。它对区域气候的影响取决于反照率、蒸散发效率和地表粗糙率等变化的综合效应:在热带地区LUCC主要引起温度升高,在高纬度地区使温度下降。在全球尺度上LUCC导致气候的变暖主要通过减少蒸散发和潜热通量引起陆表水循环的改变,其次通过改变地表反照率导致辐射强迫改变。最后指出目前LUCC在气候变化学科中的研究所存在的问题。在此基础上提出了未来的研究首先需要评估的3个气候指标,并提倡多学科间的相互合作。
Land Use and Land Cover Change (LUCC or LULCC) has a significant influence on the environment on which mankind's survival depends, and it is closely related to human being's social- economical activities. The role of humans within the climate system involves much more than global warming due to greenhouse gases. By changing the natural land surface directly and other biogeophysical or biogeochemical processes indirectly, LUCC represents a first-order human climate forcing. This manuscript reviews the history of the study of LUCC and its correlation to climate system briefly. Forcing due to LUCC has significant spatial heterogeneity, leading to spatial variability in the associated climate response. Summarizing recent peer-reviewed papers, the authors conclude that the impact of LUCC such as deforestation, urbanization, damming, etc on regional climate is robust while it does not have strong effects at global level, because the variability of LUCC has regional magnitudes much greater than its global ave- rage. The net biogeophysical impact of LUCC results from the competition between the effects of variation of albe- do, evapotranspiration efficiency, and surface roughness. LUCC leads to warming in tropical and subtropical regions and cooling in temperate and boreal zones. Current global warming owing to LUCC is predominantly driven by chan- ges in surface hydrology through reduced evapotranspiration and latent heat flux, with the radiative forcing playing a secondary role. Finally existing issues in current study of the influence of LUCC on climate system are pointed out. The authors recommend that three climate metric should be assessed as a start and interdisciplinary cooperation is essential in future research.
出处
《气候与环境研究》
CSCD
北大核心
2012年第1期103-111,共9页
Climatic and Environmental Research
基金
"十一五"国家高技术研究发展计划重点项目2009AA122100
中国科学院知识创新工程重要方向项目群KZCX2-YW-219