地理生态学的干燥度指数及其应用评述

ARIDITY INDEX AND ITS APPLICATIONS IN GEO-ECOLOGICAL STUDY

干燥度指数 (Aridityindex ,AI,该文特指气候干燥度 )是表征一个地区干湿程度的指标 ,在地理学和生态学研究中长期应用 ,近来成为全球变化研究中经常涉及到的气候指标之一 ,尤其是气候变化和干旱化、荒漠化等研究。该文列举了国内外目前存在的 2 2种干燥度指数 ,并对目前常用的 8种指数进行了详细描述和分析 ,包括各自的原理、计算方法和在生态学与地理学研究中的应用等。结合其应用和中国的实际状况 ,分析了各自的优缺点 ,认为修改后的谢氏干燥度、deMartonne干燥度和Holdridge可能蒸散率 (等同于某种意义上的干燥度 )计算方法简单实用 ,有着明确的物理学和生态学意义 ,与我国的实际情况对应性较强 ,适合于中国气候变化及其相关的干旱化、荒漠化等方面的研究。

The aridity Index (AI, here defined as the climatic aridity) is an index tha t de scribes the dry and wet conditions of a site. Historically, the AI has been ofte n used in long-term studies of geography and ecology. Recently it has became one of the most frequently used climatic factors in studies of global change, espec ially in studies of climate change, ariditification and desertification. A total of 22 AIs used worldwide were briefly introduced in this paper, and of thes e ei ght of the more commonly used AIs were evaluated. We discussed their princip les, c alculation methods, their applications in ecological and geographical studies, a nd the advantages and shortcomings of each indice were analyzed based on their a pplications and practice in China. Our analyses indicated that three AIs, th e mo dified Selianinov AI, the de Martonne AI and the Holdridge potential eva potranspiration ratio (another AI to some extent) have clear applicability and significa nce for physics and ecology. These AIs are suitable for characterizing the phys ical environment of China and can be used in future studies of climate change, a ridification and desertification in China.