清至民国洛川塬土地利用演变及其对土壤侵蚀的影响

Evolution process of landuse and its impact on soil erosion in Luochuan Tableland from the Qing Dynasty to the Republic of China

依据史料和已有研究,恢复了洛川塬土地利用的演变过程及其对土壤侵蚀的影响。研究表明,清至民国时期是一个由土地垦殖的初步恢复到土地垦殖力度的增强、垦殖范围的扩大,再至战乱、自然灾害后期的重建以及民国时期土地垦殖发展的过程。地貌的复杂性、降水的不稳定性,对土地开垦造成客观限制;政策制度的推行对土地开垦起到主导作用;而人口因素是土地开垦的根本动力。土地开垦面积随不同时期的人口变化而呈现显著差异,即土地开垦面积和人口数量之间成正相关关系。洛川塬环境伴随着人口增长、土地利用强度增强而逐步恶化。这种恶化是地理环境系统自我调节能力减弱,继而引发土壤侵蚀加剧,并呈现为人为加速侵蚀和自然侵蚀交相混合的共同作用。

With increasingly serious global ecological environmental problems, the natural changes of human living environment and the evolutions of environmental changes under human activities were given more and more attention. The research of Land Use/Land Change（LUCC）, as one of the core topics about the study of global environmental changes, is also a multidisciplinary topic. Chinese Loess Plateau had the longest time and most complete paleo-climate record, simultaneously it is the residential land surface in the past and present. The regional environmental changes have become extremely strenuous since 10,000 years ago. The fact shows that human activities are the main cause of the environmental changes of the Loess Plateau. Which contributions did human activities make on the environmental changes in historical times？ How to express these contributions？ How to alleviate them？ Focuses of these problems are our research directions. The research objective is the relationship between population change and land use, and environmental change. This thesis has made full use of historical geography, geomorphology, demography, selected classical areas of the Loess Plateau and analyzed important human and natural events from the Qing Dynasty to the Republic of China period. Simultaneously the paper extracted historical information to study the quantitative expression of population data and land data. Finally this thesis searched for the relationship between land use and environmental changes. The forming process has been resumed according to historical materials and researched results. And the paper analyzed the influence of natural conditions, population pressure, war disasters and policies on landuse and soil erosion. Complex geomorphic conditions and unexpected precipitation were the restriction on reclamation land, the implementation of the policy was the leading function, and population pressure was the basic motive force. The reclamation land amount presented significant changes according to population in different periods. The environment began to deteriorate due to population increase and landuse intensity on Luochuan Tableland and surrounding area. In fact, the deterioration was a weakening of self-control of geographic environmental system, and it led to the aggregation of soil erosion, and presented the role of superposition in program development： the man-made erosion and natural erosion.