梯田景观的历史分布及典型国际案例分析

梯田是在大面积多山地形和较高人口密度条件下产生的山区土地高效利用方式,广泛分布于世界各地,并且在不同的地理气候条件下产生了不同的类型,具有重要的生态价值和文化价值.梯田作为陡坡耕作区古老的土壤保持措施,有利于农业集约化,一般而言,梯田建设的目的是为了保持水土,减少产流产沙,改善立地环境,便于农业生产.在当前社会经济发展的背景下,大面积的梯田遭到荒废,不仅浪费了土地资源,还易导致严重的土壤侵蚀、坡面坍塌和土地退化.本文综述全球不同地理区域和自然环境条件下梯田的起源、发展以及分布特征,主要选择亚洲、欧洲、美洲和非洲四大重点区域进行系统介绍,并针对每一大洲内的典型国家做了案例剖析.在此基础上,深入探讨梯田建设、利用和荒废过程与气候变化、国家政策、人口变迁等因素的关系,最后针对目前梯田区存在的水资源紧张和梯田荒废退化两个严重问题,提出了尚需开展的研究工作,以期为梯田的可持续利用与管理提供参考依据.

History and distribution of terraced landscapes and typical international cases analysis.

Terracing, developed in those large mountainous areas with high pressure of dense population, is believed as one of the most effective land use approaches. Based on the geographical and climatic differences, the various types of terraces are widely distributed and highly evaluated in terms of ecological and cultural values around the world. Since ancient times, humans have used terracing practices for intensive agricultural production. The main objective of terracing is for mitigating water erosion, stabilizing hill slopes, improving site conditions and crop productivity. During the last decades, agricultural land use in the world has changed considerably. Terraces in many regions were abandoned and had resulted in increasing soil erosion, slope collapse and land degradation along with the socioeconomic development. In this study, through summarizing the origin, history and distribution of terraces in different geographical regions and environmental conditions around the world, we discussed how the different historical and environmental contexts such as climate change, public policy, demographic migration and economic change affected the cycles of terracing construction, usage and abandonment. Aiming at maintaining the sustainable use and mana-gement of terraced fields, further studies regarding water management and terrace maintenance needed to be enhanced.