基于CA-Markov和InVEST模型的土地利用格局与生境质量时空演变及预测——以江西省南昌市为例

Evolution and Prediction of Land Use Pattern and Habitat Quality Based on CA-Markov and InVEST Model-A Case Study of Nanchang City in Jiangxi Province

为揭示土地利用变化对区域生境质量时空演变的影响,促进土地资源的合理利用和生态规划体系的建立健全,以江西省南昌市为例,基于1995年、2005年和2015年的土地利用数据,应用CA-Markov和MCE模型并结合InVEST模型,评价和预测了土地利用演变角度下的生境演化特征。结果表明:(1)1995—2015年,草地、耕地及水域是南昌市的主要土地利用类别,占比超过90%;建设用地急剧扩张,20 a间涨幅高达96.44%,耕地和林地是流转为建设用地的重要地类。(2)研究区整体景观生境质量显著下降,大量高等级生境景观向低等级生境景观转化;城市附近和各个流域的生境退化比较显著;生境稀缺性高的用地类型大多是耕地和林地。(3)2015—2025年期间,区内景观格局和生境质量继续保持1995—2015年的演变趋势,建设用地等生境适宜度较低的地类高速扩张,进而侵扰林地、水域和草地等生境质量优质地区,致使威胁源规模和影响范畴急剧扩大,景观破碎度水平升高,稳定性降低,这将引起研究区生境质量的持续下降。1995—2025年研究区生境质量明显退化,城镇化扩张与生态用地缩减是其主要原因。

In order to reveal the impact of land use change on the temporal and spatial evolution of regional habitat quality and promote the rational use of land resources and the establishment of ecological planning system,taking Nanchang City of Jiangxi Province as an example,based on land use data from 1995,2005 and 2015,we applied CA-Markov and MCE models and combined with the InVEST model to evaluate and predict the habitat evolution characteristics under the perspective of land use evolution.The results showed that:(1)during 1995—2015,grassland,farmland and water body were the main land use types in Nanchang,accounting for more than 90%;construction land in the region had expanded significantly,with a growth rate of 96.44%over 20 years,mainly transformed from farmland and woodland;(2)the overall landscape habitat quality in the study area was significantly degraded,and a large number of high-grade habitat landscapes were converted to low-grade habitat landscapes;habitat degradation was more significant near cities and in various watersheds;most of the land types with high habitat scarcity were farmland and woodland;(3)during 2015—2025,the landscape pattern and habitat quality of Nanchang City continued to maintain the change trend during the period 1995—2015;land types with low habitat suitability such as construction land will expand rapidly,and then occupied the areas with high habitat quality such as forest land,water area and grassland,resulting in a dramatic expansion of the scale and impact of threat sources,an increase in the level of landscape fragmentation and a decrease in stability,which will cause a continuous decline in habitat quality in the study area.During the 30 years from 1995 to 2025,the habitat quality in the study area has deteriorated significantly.The main reasons are the expansion of urbanization and the reduction of ecological land.