巢湖流域不同空间尺度土地利用对河流水体碳氮磷及其化学计量特征的影响  

The Influence of Land Use at Different Spatial Scales on Carbon,Nitrogen,Phosphorus and Their Stoichiometry in River Water of Chaohu Lake Catchment

作　　者：李小雪 赵德华[1] 李雅静 安树青[1] LI Xiao-xue;ZHAO De-hua;LI Ya-jing;AN Shu-qing(School of Life Sciences,Nanjing University,Nanjing 210023,Jiangsu,China)

机构地区：[1]南京大学生命科学学院,江苏 南京 210023

出　　处：《湿地科学与管理》2024年第4期2-8,14,共8页Wetland Science & Management

基　　金：山水林田湖草沙一体化保护和修复工程生态修复成效评估模型构建研究(H3002)。

摘　　要：为更好地理解土地利用对水质和化学计量比的影响,本研究采用相关分析和冗余分析,定量探讨了2022年巢湖流域丰水期和平水期多个尺度土地利用与河流水体中总氮(TN)、总磷(TP)、化学需氧量(COD)浓度及C、N、P元素摩尔比的关系。结果表明:巢湖流域河流水体中的主要污染物是TN,与巢湖及全球尺度地表水平均值相比,其氮磷比(N︰P)偏高。在大部分研究尺度,TN、TP与建设用地占比呈显著(P<0.05)或极显著(P<0.01)正相关,与耕地占比无显著相关性,表明建设用地是TN、TP的重要来源。在子流域尺度,N︰P与建设用地占比呈极显著正相关(P<0.01),与耕地占比呈极显著负相关(P<0.01),表明建设用地占比的提升会加剧氮磷不平衡,而耕地占比的提升会缓解这一现象。土地利用对所有指标变异的总解释率在子流域尺度最高,各研究尺度土地利用的总解释率在丰水期更高。本研究结果可为巢湖流域的水质管理和土地利用规划提供理论指导。To better understand the influence of land use on water quality and stoichiometry,correlation and redundancy analyses were employed in this study,to quantitatively investigate the relationships between land use at different spatial scales and the concentrations of total nitrogen(TN),total phosphorus(TP),chemical oxygen demand(COD),and the mole ratios of carbon,nitrogen and phosphorus in rivers of the Chaohu lake catchment during both high and low water periods in 2022.Results indicated that TN is the main pollutant in the rivers,with a higher N︰P ratio compared to the average of surface water at catchment and global scales.At most research scales,TN and TP exhibit a significant(P<0.05)or highly significant(P<0.01)positive correlation with the proportion of construction land,but no significant correlation with the proportion of cropland,suggesting construction land serves as an important source of TN and TP.At the sub-catchment scale,N︰P ratio exhibits a highly significant positive correlation with the construction land proportion(P<0.01),and a highly significant negative correlation with the cropland proportion(P<0.01),indicating an increase in the proportion of construction land exacerbates nitrogen-phosphorus imbalance,while an increase in cropland proportion alleviates it.Land use exhibits the highest overall explanatory power for the variation in all indicators at the sub-catchment scale.At all scales studied,the overall explanatory power of land use is higher during the water season.These findings offer a theoretical guidance for water quality management and land use planning in the Chaohu lake catchment.

关 键 词：土地利用 化学计量比 多尺度 巢湖流域 总氮 总磷 化学需氧量 

分 类 号：X522[环境科学与工程—环境工程]