55年来黄土高原边缘地区耕地动态变化的多尺度分析

本文对地处干旱、半干旱黄土高原生态脆弱地带的大同市耕地现状和1949—2003年间耕地总量变化进行分析,同时采用Morlet小波变换方法,对大同市耕地面积变化进行了多时间尺度和相应的周期变化特征分析,得出55年来大同市耕地面积变化具有2—3年和6年左右的年际尺度周期变化,并预测未来大同市耕地面积变化趋势;运用主成分分析方法分析得出耕地动态变化的驱动机制为人口因素、农业现代化水平、经济发展水平三个方面,所得结论有利于在科学的指导下采取措施稳定耕地面积,为干旱半干旱地区耕地的可持续利用提供科学依据,对相关省市农业可持续发展具有重要意义。

Multiple Time Scales Analysis of the Dynamic Change of Cultivated Land in the Marginal Zone of the Loess Plateau for Recent 55a——A Case Study on Datong City of Shanxi

The current situation of cultivated land and the dynamic change process of cultivated land in Datong City which lied in the Loess plateau district with fragile ecological environment were analyzed.The wavelet analysis was used to analyze the area change of cultivated land.The results showed:the area of cultivated land had 2—3 years,6 years cycles from the figures of the wavelet coefficents.The area of cultivated land seemed to be decreasing in the recent 6—7 years,and be increasing after the decreasing peroid;As the economic factors were more effective than the natural factors in current dynamic change process of cultivated land,so through the Principal Component Analysis,we summarized the economic driving forces factors as three: population growth、agricultural modernization level and economic development level.In the end specific countermeasures were given according to various driving forces of the cultivated lands to offer the scientific basis for sustainable utilization of cultivated land in arid & sem-arid areas,and offered the basis for sustainable agricultural development in the related cities and provinces.