基于InVEST模型的海南岛三大流域生境质量时空演变

基于1980—2020年5期土地利用数据,采用InVEST模型,综合应用土地利用转移、生境质量变化率和空间统计分析等方法,探究海南岛三大流域(南渡江、昌化江、万泉河)生境质量变化及其空间分布特征。结果表明: 海南岛三大流域土地利用类型以林地为主,占总面积的70%以上。1980—2020年间,海南岛三大流域建设用地面积增加量最大,达169.09 km²,主要来自耕地和林地。研究区生境质量整体呈现出上游源头区高、中下游区域低的空间分布格局,研究期间生境质量指数总体表现为先略微升高后显著降低的变化特征。在三大流域中,万泉河流域生境质量最高,昌化江流域次之,南渡江流域最低,且南渡江流域生境质量波动较大,受人为干扰较强。1980—2020年间,三大流域生境质量变化率总体降低0.5%,且在2010—2020年间退化明显。1980—2020年间,研究区生境质量在空间分布上具有较强的自相关性和显著的聚集性。三大流域生境质量的热点区主要集中在流域上游源头区域;冷点区主要分布在三大流域的入海口区域以及南渡江的中下游地区。研究结果可为海南岛三大流域生物多样性保护和生态修复提供数据支撑及科学参考。

Spatiotemporal evolution of habitat quality in three basins of Hainan Island based on InVEST model

Based on land use data of five periods during 1980 to 2020, using the InVEST model and the methods of land use transfer, habitat quality change rate and spatial statistical analysis, we explored the changes of habitat quality and its spatial distribution characteristics in the three major basins of Hainan Island (Nandu River, Changhua River and Wanquan River). The results showed that woodlands were the main land use type in the three basins of Hainan Island, accounting for more than 70% of the total area. From 1980 to 2020, the area of construction land increased the most, reaching up to 169.09 km², mainly from cultivated land and woodland. The spatial distribution pattern of habitat quality in the study area was higher in the upstream and head water areas and lower in the mid and downstream regions. Overall, habitat quality index increased slightly for a short period and then decreased significantly during the study period. Among the three basins, habitat quality of Wanquan River Basin was the highest, followed by Changhua River Basin, and Nandu River Basin was the lowest. The habitat quality of Nandu River Basin fluctuated greatly and was strongly affected by human disturbance. From 1980 to 2020, the change rate of habitat quality in the three basins generally decreased by 0.5%, which was significantly degraded from 2010 to 2020. From 1980 to 2020, the spatial distribution of habitat quality in the study area displayed strong autocorrelation and significant aggregation. The hot spot area of habitat quality was mainly concentrated near the head water and upstream areas of the three basins, while the cold spot area was mainly distributed in the estuary area of the three basins, along with the mid and downstream areas of the Nandu River. These results would provide scientific reference for biodiversity conservation and ecological restoration efforts in the three basins of Hainan Island.