河势特征分界下的黄河滩区周边城镇生境质量与景观格局演变

在黄河流域生态保护和高质量发展战略背景下，加强对黄河滩区生境质量及其驱动机制研究对区域生物多样性保护和生态韧性提升具有重要意义。以黄河滩区沿河城镇为研究区，依据河势特征将其划分为4个河段和14个子研究区，并基于InVEST模型与3类景观格局指数分析论证不同河势特征分界下生境质量与景观格局的时空演变规律。结果表明：（1）生境质量方面，2000-2020年研究区生境质量整体呈下降趋势，各河段生境质量平均值由大到小依次为河口段、弯曲段、游荡段、过渡段；（2）景观格局方面，各河段之间景观破碎度指数波动最小，并随城镇化发展破碎化程度逐渐减弱，连接度与复杂度波动明显，且因河势特征存在差异性变化；（3）生境质量与景观格局相关性方面，多数土地景观格局指数与生境质量显著相关，但关联程度有所下降。相同地类景观格局指数在不同河段内表现出不同甚至反向的互动关系。研究表明，河势特征是黄河滩区生境质量的全局性支撑或限制因素，其作用主要体现为对黄河滩区周边城镇土地空间发展的差异化影响，该影响直接作用于紧邻黄河地带的城镇组团，并间接影响其他区域，在一定程度上左右了城镇发展主向以及土地转化、空间格局的演变规律，最终影响区域生境质量的分布格局。研究结果对黄河滩区重要生态功能区的生境保护与生态系统功能调控具有一定的理论与实践价值。

Evolution of habitat quality and landscape pattern in the towns along the Yellow River floodplain under the boundary of river regime

Under the background of ecological protection and high-quality development strategy in the Yellow River Basin, strengthening the research on the habitat quality and driving mechanism of the Yellow River floodplain is of great significance for regional biodiversity conservation and ecological resilience improvement. The towns along the Yellow River floodplain, as the research area, are divided into 4 river sections and 14 sub-study areas according to the characteristics of the river regime. Based on the InVEST model and three types of landscape pattern indices, the temporal and spatial evolution of habitat quality and landscape pattern under the boundary of different river regime characteristics is analyzed and demonstrated. The results show that:(1) In terms of habitat quality, from 2000 to 2020, the overall habitat quality of the study area showed a downward trend. The average value of habitat quality of each river section was river section of delta, meandering river section, turbulent river section, and transitional river section in descending order. (2) In terms of landscape pattern, the fragmentation index among 4 river sections had the smallest fluctuation, and the degree of fragmentation gradually decreased with the development of urbanization. The connectivity index and complexity index fluctuated significantly among 4 river sections, and the changes were different due to river regime characteristics. (3) In terms of the correlation between quality and landscape pattern, most of the land landscape pattern indices were significantly correlated with habitat quality, but the correlations were gradually weakened with the acceleration of urbanization. The same landscape pattern index showed different or even reverse interaction relationship in different river sections. The study shows that the river regime is an overall supporting or limiting factor for the habitat quality of the Yellow River floodplain, and its effect is mainly reflected in the differential effect on the land spatial development of the towns along the Yellow River floodplain. This influence directly affected the evolution of urban built-up or green space adjacent to the Yellow River floodplain, and indirectly affected other district of the study area. To a certain extent, it has a profound influence on the main direction of urban development, the master regulation of the evolution of land cover and spatial pattern, and finally affects the distribution pattern of habitat quality in the towns along the Yellow River floodplain. The study results have certain theoretical and practical values for the habitat protection and ecosystem function regulation of important ecological function areas in the Yellow River floodplain.