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在变暖的气候中,亚北极地区的永久冻土可能有明显的减少甚至可能最终消失。这将在不同尺度上影响人们,本地尺度上,建筑和道路会下沉;全球尺度上,永久冻土的融解极有可能增加效应巨大的温室气体甲烷的排放,从而进一步加剧全球变暖。为了预测永久冻土未来的变化,了解当前气候条件下究竟什么原因决定着永久冻土的存在或消失,评估哪里的永久冻土对气候变化尤其敏感,识别哪里已经在发生变化,是至关紧要的。瑞典北部亚北极景观的Tornetrsk地区是已经记录到永久冻土变化、永久冻土对未来气候变化尤其脆弱的地区。本文将综述当前气候条件下决定Tornetrsk地区永久冻土存在或消失的各种物理、生物与人类学参数,以便我们了解它当前的脆弱性及其对未来气候变化的潜在响应。在Tornetrsk地区发现的永久冻土斑块的分布并不是随机的,而是控制小气候、地表面与次表面温度的特定空间因子的结果。同样也是过去与现在各个过程的产物。在亚北极区域如瑞典北部,主要是物理参数,如地形、土壤类型、气候(尤其是雪厚),决定了永久冻土的分布。虽然在本区域内人类活动已存在了几个世纪,但他们对永久冻土的影响在集水区尺度上或多或少可以忽略不计。由于现行的气候变暖预计仍将继续,导致雪盖的增加,此区域内的永久冻土很可能将在几十年内消失,至少在低海拔地区是如此。
In warmer climates, the permafrost in the subarctic may have significantly reduced or may eventually disappear. This will affect people at different scales, with buildings and roads sinking on a local scale; melting of permafrost on a global scale is likely to increase emissions of methane, a huge greenhouse gas, and further aggravate global warming. In order to predict future changes in permafrost, it is crucial to understand what the current climatic conditions determine the existence or disappearance of permafrost, assess where permafrost is particularly sensitive to climate change, and identify where changes have occurred of. The Tornetrsk region of the sub-Arctic landscape in northern Sweden is an area where permafrost changes have been recorded and permafrost is particularly vulnerable to future climate change. This article reviews the various physical, biological and anthropological parameters that determine the presence or absence of permafrost in the Tornetrsk region under current climate conditions so that we can understand its current vulnerability and its potential response to future climate change. The distribution of permafrost patches found in the Tornetrsk area is not random but rather the result of controlling specific spatial factors of microclimate, surface and subsurface temperatures. It is also a product of past and present processes. In sub-Arctic regions such as northern Sweden, the main physical parameters, such as topography, soil type, climate (especially snow thickness), determine the distribution of permafrost. Although human activities have existed for centuries in the region, their impact on permafrost is more or less negligible on the catchment scale. As the current warming is expected to continue, leading to an increase in snow cover, the permafrost in the region is likely to disappear for decades, at least at low altitudes.