环渤海地区县域耕地景观细碎化时空变异分析——以昌黎县为例

目的]耕地细碎化使耕地的生态系统完整性受到威胁,不利于耕地的规模化经营。因此,探讨县域耕地景观细碎化状况,分析其时空变化态势,对维护耕地生态系统稳定、推进耕地规模利用具有重要意义。方法]文章以村为单位,从斑块面积、斑块形状和斑块分布状况3方面构建昌黎县耕地景观细碎化评价指标体系,在确定各耕地景观细碎化指数分级标准和权重基础上,采用综合指数模型计算各村域耕地景观细碎化度,分析了昌黎县1996~2014年耕地景观细碎化的时空动态变化。结果]1996年、2006年和2014年,耕地景观达到轻度细碎化的行政村数量占比分别为57.33%、41.78%和34.44%,达到中度细碎化的行政村数量占比分别为40.89%、54.67%和62.22%。达到轻度细碎化程度的行政村数量逐渐减少,中度细碎化行政村数量逐渐增多;空间分布上,昌黎县北部的十里铺乡、两山乡细碎化严重,北部的昌黎镇和西北部的朱各庄镇次之,昌黎县各行政村耕地景观细碎化程度不一。结论]针对不同区域,昌黎县需采取预防或综合整治措施,防止细碎化程度的加强。

ANALYSIS ON THE TEMPORAL AND SPATIAL CHANGE OF CULTIVATED LAND LANDSCAPE FRAGMENTATION IN BOHAI RIM——A CASE STUDY OF CHANGLI COUNTY

The fragmentation of cultivated land threatens the integrity of cultivated land and large-scale manage-ment. Therefore, exploring the condition of cultivated land fragmentation and analyzing the temporal and spatial variation situation in county range are of great significance for cultivated ecosystem stability as well as promoting the large-scale using of cultivated land. The paper built an evaluation index system of cultivated land landscape frag-mentation of Changli county from three respects, i. e. , patch area, patch shape and patch distribution. Based on the determination of classification standards and weights of farmland landscape fragmentation index, the cultivated land landscape fragmentation degree of each village was calculated by the comprehensive index model. Then the temporal and spatial dynamic change of cultivated land landscape fragmentation in 1996-2014 was analyzed. The results were as follows: the percentages of the villages in slight fragmentation were 57. 33%, 41. 78% and 34. 44%, and the percentages of the villages in moderate fragmentation are 40 . 89%, 54 . 67% and 62 . 22% in the year of 1996, 2006 and 2014. The number of villages in slight fragmentation gradually reduced, while that in mod-erate fragmentation increased gradually in 1996 -2014. The fragmentation in Shilipu, Liangshan were more seri-ous, followed by the northern and northwest part of Changli. It should take preventive or comprehensive improve-ment measures to prevent the fragmentation degree.