山东省建设用地扩张对耕地占用的时空分析
Spatio-Temporal Dynamics of Built-Up Land Expansion and Cropland Loss in Shandong Province

自20世纪80年代以来，在经济快速增长的背景下，山东省建设用地和耕地的总面积与空间格局均有较大变化，山东省是我国的农业大省，耕地的减少对粮食安全造成很大影响。本文以山东省1980s至2015年每隔5年共7期土地利用数据为空间数据源，对不同时期山东省建设用地和耕地的变化趋势进行了定量分析。主要结论如下：1) 山东省1985~2015年间建设用地面积呈持续增长趋势，由1985年的16,925 km²增长到2015年的22,765km²，而耕地面积总体呈减少趋势，由1985年的104,738 km²增长到2015年的101,280 km²。2) 1985~2015年间，减少的耕地向林地、草地、水体、建设用地、未利用地转移的面积分别为53 km²、15 km²、527 km²、4453 km²、16 km²，即87.9%的耕地缩减面积转变建设用地，因此耕地的减少主要是由建设用地扩张所导致。3) 在空间分布上，建设用地对耕地的占用主要集中发生在与原有建设用地相邻的耕地区域。
Since the 1980s, the quantity and quality of built-up land and cropland of Shandong Province have changed greatly under the background of rapid economic growth. The shrink of cropland has caused the decline of grain production and brought stress to food security. In this study, land use data from 1985 to 2015 derived from remote sensing imagery were used to analyze the spa-tio-temporal dynamics of built-up and cropland quantitatively. The main spatial characteristics of change in built-up land and cropland included: 1) The built-up land area of Shandong Province in-creased continuously during 1985 and 2015, from 16,925 km² in 1985 to 101,280 km² in 2015; 2) During 1985 and 2015, the area converted from cropland to forest, grassland, water area, built-up land and unused land are 53 km², 15 km², 527 km², 4453 km², 16 km² respectively. Thus 87.9% of reduced cropland was converted to built-up land. Therefore, the loss of cropland was mainly caused by the expansion built-up land; 3) The conversion from cropland to built-up land occurred mainly in the neighbor of existed built-up land. We suggest that the cropland protection should be strengthened in the future in Shandong Province. Strict cropland protection policies should be im-plemented and the exploration of reserved cultivated land resources should be launched.