郑州市景观格局演变对地表径流的影响

Impact of Zhengzhou landscape pattern changes on surface runoff

【目的】揭示郑州市景观格局与径流过程的相互关系,实现区域景观格局的可持续发展。【方法】以郑州市2000—2020年土地利用数据为数据集,利用景观指数计算、SCS-CN模型模拟、皮尔逊相关性分析等多学科方法,探究景观格局变化对地表径流的影响。【结果】1)2000—2020年郑州市土地转移主要发生在耕地、建设用地和林地之间,下垫面扰动使得景观斑块破碎、形状复杂化,景观格局聚集度增加、邻接性减弱。2)经过修正的SCS-CN模型能够较为准确模拟郑州市地表径流变化特征。研究期间地表径流不断增加,但增幅减小,其中2000—2010年、2010—2020年地表径流深度分别增加1.42、1.31 mm;径流变化空间分布差异显著,呈现“城镇周边增加,城区降低;东部增加,西南降低”的特征,径流量和空间分布受多种因素的影响。3)径流变化与LSI变化间呈显著正相关关系,与LPI、COHESION呈负相关关系,而与PD、FRAC_AM的相关性呈波动变化,说明景观斑块破碎化程度越高、形状越复杂且各类型景观间的邻接性越低,径流量的增幅就越大,透水景观斑块之间越连通,越容易拦截径流。【结论】城市化造成的景观格局变化对地表径流影响显著,可以通过合理的景观格局配置,考虑增加绿地生态空间用地等措施提高透水景观对雨水下渗和径流拦截的效率,达到拦蓄削减径流的目的。

【Objective】This study was conducted to reveal the interaction between the landscape pattern and the runoff process in Zhengzhou,and realize the sustainable development of the regional landscape pattern.【Method】Taking the land use data of Zhengzhou City from 2000 to 2020 as the dataset,the impact of landscape pattern changes on surface runoff was studied using the methods of landscape index calculation,SCS-CN model simulation and Pearson correlation analysis.【Result】1)From 2000 to 2020,land transfer in Zhengzhou mainly occurred between cultivated land,construction land and forest land.The disturbance of the underlying surface caused the landscape patches fragmented and complex in shape,increasing the aggregation degree of the landscape pattern and weakening the adjacency.2)The revised SCS-CN model can accurately simulate the variation characteristics of surface runoff in Zhengzhou.During the study period,the surface runoff increased continuously,however,the increase showed a decreasing trend.Duing 2000-2010,and 2010-2020,the increment of runoff depth was 1.42 and 1.31 mm respectively.The spatial distribution of runoff changes is significantly different,showing the characteristics of“increasing around towns and decreasing in urban areas;increasing in the east and decreasing in the southwest”.The runoff and spatial distribution are affected by many factors.3)There was a signi-ficant positive correlation between runoff change and LSI change,a negative correlation with LPI and COHESION,and a fluctuating correlation with PD and FRAC_AM,indicating that the higher the fragmentation degree of landscape patches,the more complex the shape and the lower the adjacency between various types of landscapes,the greater the increase rate in runoff.The more connected the permeable landscape patches are,the easier it is to intercept runoff.【Conclusion】Landscape pattern changes caused by urbanization has a significant impact on surface runoff,and measures such as increasing the use of green ecological space can be considered to improve the efficiency of permeable landscape for rainwater infiltration and runoff interception through reasonable landscape pattern configuration,so as to achieve the purpose of interception and reduction of runoff.