Abstract:

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 land-use 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.

Key words: landuse, soil erosion, man-made erosion, policy, Luochuan Tableland