黄土区矿-农-城复合区土地利用时空转换特征

黄土区矿一农一城复合区在工业化、城镇化、城乡一体化的背景下,区域的土地利用类型转换频繁,尤其受到生态退耕政策、城乡建设、露天采煤损毁的影响。该研究旨在揭示矿.农一城复合区近30年土地利用类型转换的过程、特征及影响土地利用类型转换的主要原因。该文利用研究区1986—1996年、1996—2000年、2000—2004年、2004—2009年、2009—2013年及1986—2013年土地利用类型转换图分析了各研究阶段主要转换类型的重要值、面积、空间分布,基于各研究阶段土地利用类型转换过程划分了土地利用类型转换分区,并开展土地利用类型转换原因的讨论。研究结果表明:1)不同研究阶段土地利用转换类型差异明显,总体上呈现转换类型增加,而转换重要值和降低的趋势。转换类型由早期农用地互转逐渐过渡到农用地互转、农用地转向建设用地、农用地转向损毁土地三者共存的状态。2)各种土地利用转换类型在地域分布上呈现趋同性与差异性,并依据趋同性与差异性划分了农用地转建设用地区,农用地转损毁土地区,农用地互转区。3)农用地减少主要以耕地减少为主,耕地减少主要受到生态退耕、建设用地占用、采煤损毁等活动的影响。建设用地增长一是受到保障城镇发展和空间拓展的影响;二是受到新农村建设、农民建新房改善居住环境及"抢盖抢建"的影响。损毁土地的增长主要与煤炭资源开采规模扩大紧密相关。该研究成果可为研究区土地可持续利用及生态环境保护提供参考。

Temporal-spatial transformation characteristics of land use types in composite area of ore-agriculture-urban in Loess Area

Abstract: The transformation of land use type occurs frequently in the composite area of ore-agriculture-urban driven by industrialization, urbanization and urban-rural integration. This transformation is especially affected by the government policy of returning marginal cultivated land to forest and grassland, and reclamation of urban and rural construction occupied land and opencast mining site. This study aimed at revealing the process, characteristics and major causes of land use type transformation in nearly 30 years in the composite area of ore-agriculture-urban in the Loess region. With transformation maps of land use types in the periods of 1986-1996, 1996-2000, 2000-2004, 2004-2009 and 2009-2013, the important values, areas and space distribution of main transformation types were analyzed. The zoning of land use type transformation during 1986-2013 was divided, and the causes of land use type transformation were discussed. The results showed that the differences of transformation types in different periods were obvious and the number of transformation types was increased. There were 17 transformation types in the period of 1986-2013 and the sum of important values of the dominate transformation types was 94.58%, and the other transformation types were 22 and the sum of important values were 5.42%. The sum of important values in different periods presented decreasing trend. The transformation types gradually presented from the state of transformation in farmland to the coexistence of transformation in farmland, transformation between farmland and construction land, transformation between farmland and damage land. The results also showed that all transformation types presented the trends of convergence and diversity in regional distribution. In Xiangyangbao county, Jingping town, Baitang county, transformation from cultivated land into construction land was significant. In the southeast of Jingping town, the northwest of Taocun county, and the middle part of Yuling county, a great amount of cultivated lands became damage lands. Transformation among cultivated land, forestland and grassland was noticeable in the east, the southeast and the north of the studied area. The study area has been divided into regions of farmland transformation to construction land, farmland transformation to damage land, and region of farmland transformation to farmland transformation. Meanwhile, the region of farmland transformation was divided into region of cultivated land transformation to forest land, region of cultivated land transformation to grassland. The areas were nearly balanced on cultivated land transformation to forest land and cultivated land transformation to grassland in the period of 2009-2013. In addition, the results showed farmland decrease was mainly due to the reduction of cultivated land. The cultivated land was the dominant land use type in the transformation by converting into forestland, grassland, rural residential and stripped land, impacted by returning cultivated land to forest land and grassland, occupied construction land and opencast mining damage. The area was 1.01?104 hm2 on cultivated land transformation to forest land and grassland in the period of 1986-2013. The increase of construction land was promoted by urban expansion and land demand for farmers building new houses for improving the living condition and illegal building houses for more land requisition compensation. The area was 0.24?104 hm2 on cultivated land transformation to construction land in the period of 1986-2013. Damage land growth was related to the scale enlargement of coal production. The area was 0.37?104 hm2 on cultivated land transformation to damage land in the period of 1986-2013. The findings can provide references for land sustainable use and protection of ecological environment to the research area.