历史时期敦煌、酒泉绿洲典型渠系复原及相关方法论研究

In exploring the natural and humanistic issues with respect to the development of water resources in China’s arid regions of the historical period, it is of fundamental importance to conduct the study of the restoration of canal systems within a specific time and region. The consistent improvement of the science and accuracy involved in such restoration is methodologically valuable to the study of historical-geography and the history of water conservancy. This study aims at selecting irrigation farmland zones from the two well-known arid regions of Dunhuang and Jiuquan oases as research subjects, using previous findings from textual sources on the history of water conservancy in this area, especially through systematic collection and organization of various types of regional hydrographic maps and modern survey maps, from which 6 regional historical maps will be produced with the quintessential canal systems depicted for Tang, Ming, Qing, and the Republican periods. From this, social and technological elements produced out of specific canal system structures, as well as the mutual relationship between canal systems and waterways, will be discussed. The study of pertinent methodological issues regarding this type of research will focus on the accurate drawing of large scale maps of historical canal systems as well as the compatibility of applying historical-geographical studies in the theories of hydrology and water resources. The former includes methods for which various schematic hydrographic maps and measured survey maps could be merged to determine the accurate positioning of modern canal systems, and how this could be used as the foundation to depict the changing canal systems through historical time and space. The latter involves the application of reverse deduction in hydrological models and the evaluation of the usage of water resources.

在探讨历史时期中国干旱区水资源开发活动中的相关自然、人文问题时，对特定时空范围内渠系状况的复原研究具有重要的基础意义；不断提升这种复原工作的科学性与准确性，对历史地理学、水利史相关研究亦有方法论价值。本研究选取敦煌、酒泉绿洲两个干旱区著名灌溉农业区为研究对象，依托前期成果中对该区域水利史文献、特别是各类区域河渠图以及近代实测地图进行的系统搜集与整理，以绘制6幅区域历史地图的方式分别展现其在唐、明、清、民国等历史时期典型渠系的分布状况，并对影响特定渠系结构形成的社会、技术要素以及“渠系—水系”互动关系进行讨论。探讨相关方法论的尝试贯穿始终，重点为较大比例尺历史渠系图的精确绘制方法与水文水资源学理论引入历史地理研究的适应性问题；前者包括如何将各类示意性河渠图与实测地图结合以精确定位近代渠系、如何以此为基础建立渠系时空变迁的完整证据链，后者主要为水资源利用率评价方法与水文模型反演的应用问题

在探讨历史时期中国干旱区水资源开发活动中的相关自然、人文问题时，细致研究特定时空范围内的渠系变化具有重要的基础意义。本项目依托前期成果中对相关水利史文献的系统搜集与整理，完成对敦煌绿洲唐后期、清中期与民国时期干渠系统以及酒泉绿洲明后期、清中期与民国时期干渠系统的复原，总结其演化规律并着重从技术、社会两个方面对其演变原因进行了探讨，尝试运用WEAP、MODFLOW模型与清华大学对于相关区域的当代水文研究成果，分别模拟计算了清代敦煌绿洲渠系变迁对哈拉淖尔湖水量的影响过程、清代民国酒泉绿洲渠系变迁对其北部地下水涌出带的影响过程。本项目在为期一年的研究时间中，完成论文7篇（其中发表4篇、投稿审查中3篇）、专著1部（书稿正在科学出版社专家审读中），其中被《新华文摘》全文转载1篇。本项目的重要结论在于：其一，历史时期酒泉、敦煌绿洲主要渠系形态的基本演化过程是从叶脉状渐变为放射状，水源结构从“河水—泉水”分离渐变为“河水—泉水”混合式；其次，渠系演化并不意味着水资源利用率的提升，河西走廊屯田区域特殊的“国家—社会”关系以及干旱区传统水利技术的内在特点是渠系演化的最重要决定力量，“公平”而非“效率”是这两块绿洲渠系变迁的首要目标；其三，绿洲渠系演化与敦煌绿洲西北部最大湖泊哈拉淖尔湖的盈缩以及酒泉绿洲北部泉水涌出带变迁之间存在明显的因果联系。本项目获得的主要科学数据为两组时间数据：其一，哈拉淖尔湖的形成年代不早于公元1715年，其最大水域面积出现于1734—1758年之间，其后逐渐缩减；其二，估算出清代酒泉绿洲北部泉水带地下水最高水位出现在1768—1788年之间。本项目主要科学意义，在于揭示出历史时期敦煌绿洲与酒泉绿洲的演化规律及其原因，同时进行了水利史料的量化与结合现代水文学工具的方法论探索，还原了历史时期干旱区传统水利技术的细节，进而揭示出边疆地区水利社会某些未被前人所发现的基本特点。