基于多模型的县域土地利用/土地覆盖模拟

County-scale land use/land cover simulation based on multiple models

土地利用/土地覆盖(land use/land cover,LULC)模拟是土地变化研究的重要一环。基于谷歌地球引擎(Google Earth Engine,GEE)平台提取禄劝县1991—2021年高精度的LULC信息,分析其时空演变特征;利用随机森林模型探究LULC变化的驱动因素;对比元胞自动机-马尔科夫模型(cellular automata-Markov,CA-Markov)、土地变化模型(land change modeler,LCM)、未来土地利用模拟模型(future land use simulation,FLUS)和斑块生成土地利用模拟模型(patch-generating land use simulation,PLUS)4种模型在禄劝县的模拟效果;根据模拟效果最好的模型预测禄劝县2027年的LULC状况。结果表明:①1991—2021年,禄劝县LULC空间格局以林地、草地和耕地为主;耕地和水体分别波动增加89.26 km^(2)和27.72 km^(2),林地、建设用地和裸地面积分别持续增加724.25 km^(2),21.08 km^(2)和13.67 km^(2),草地面积以年均29.20 km^(2)的速度波动减少。②禄劝县LULC变化主要受到地形条件(高程和坡度)的影响。③4种LULC模型的模拟效果排行为PLUS>FLUS>CA-Markov>LCM,其Kappa系数分别为0.63,0.58,0.46和0.35,总体精度分别为0.78,0.75,0.66和0.58。④禄劝县2027年的LULC空间格局与2021年相似,2021—2027年,耕地、草地和水体的面积分别以40.21 km^(2)/a,4.51 km^(2)/a和0.70 km^(2)/a的速率减少,而林地、建设用地和裸地分别向外扩张265.52 km^(2),4.85 km^(2)和2.08 km^(2)。

Land use/land cover(LULC)simulation is essential for research on changes in land use.Based on the Google Earth Engine(GEE)platform,this study extracted the high-precision LULC information of Luquan County from 1991 to 2021 and analyzed the spatio-temporal evolution pattern.Then,this study analyzed the factors driving LULC changes using a random forest model and compared the simulation results of Luquan County obtained using the cellular automata-Markov(CA-Markov),land change modeler(LCM),future land use simulation(FLUS),and patch-generating land use simulation(PLUS).Finally,this study forecast the LULC change scenario in Luquan County in 2027 using the optimal model.The results show that:①From 1991 to 2021,the spatial LULC pattern of Luquan County was dominated by forestland,grassland,and farmland.The areas of farmland and waterbodies increased by 89.26 km^(2) and 27.72 km^(2),respectively,the areas of forestland,construction land,and bare land increased continuously by 724.25 km^(2),21.08 km^(2),and 13.67 km^(2),respectively,and the grassland decreased at an annual average rate of 29.20 km^(2);②The LULC in Luquan County was primarily influenced by topographic conditions(elevation and slope);③The simulation effects of the four LULC models were in the order of PLUS>FLUS>CA-Markov>LCM,with Kappa coefficient of 0.63,0.58,0.46 and 0.35,respectively and the overall accuracy of 0.78,0.75,0.66 and 0.58,respectively;④The spatial LULC pattern in Luquan County in 2027 will share similarities with that in 2021.From^(2)021 to 2027,the areas of farmland land,grassland,and water bodies will decrease at a rate of 40.21 km^(2)/a,4.51 km^(2)/a,and 0.70 km^(2)/a,respectively,while the forestland,construction land,and bare land will expand by 265.52 km^(2),4.85 km^(2),and 2.08 km^(2),respectively.