基于CA-Markov模型的黄土塬区黑河流域土地利用变化

Land use change in Heihe catchment on loess tableland based on CA-Markov model

研究黄土高原的土地利用变化,可为其生态建设提供重要的决策依据。基于CA-Markov模型,分析了黄土高塬沟壑区黑河流域1985-2000年土地利用变化的趋势、速度、类型及其与地形的关系,并模拟了2015年土地利用情景。结果表明,黑河流域以耕地和中覆盖草地为主;1985-2000年林地和农地减少,草地和建设用地增加,其他类型变化很小;林地和草地相互转化与耕地转出是两大变化类型;土地利用变化主要发生在沟壑区。CA-Markov模型模拟的2000-2015年土地利用将保持1985-2000年的变化趋势,因此,需加强耕地保护措施,推进退耕还林草工程,促进区域可持续发展。

Studying the land use changes in the Loess Plateau can provide important information for decision-making of ecologic construction.Using CA-Markov（Celluar Automata）model,the trend,rate,type of land use change from 1985 to 2000 and their relations with terrain in the Heihe watershed in the tableland-gully region of the Loess Plateau were analyzed,and the land use scenario in 2015 was simulated.Results showed that farmland and medium density grassland were the dominant land use types.Forest and farmland decreased,grassland and construction land increased while other land use types changed little from 1985 to 2000.The major transformation types were mutual conversion between forest and grassland,and farmland conversion to other land use types.Land use changes mainly occurred in the gully regions.The simulated result by CA-Markov model indicated that each land use type from 2000 to 2015 would keep the change trend from 1985 to 2000.Therefore,it is urgent to protect farmland,impel the Grain for Green Project and promote regional sustainable development.