雅砻江-安宁河并流段水沙及养分空间差异分析

为了解人类活动影响下的流域泥沙及养分分布情况,以雅砻江及其一级支流安宁河为研究对象,选择雅砻江—安宁河并流段为研究区,沿河流纵向选取6个断面,并对断面垂向与横向进行含沙量及氮磷浓度的监测,分析不同流域水沙沿程变化及养分空间分布特征。结果表明:(1)安宁河含沙量整体大于雅砻江并流段,2条河流中下游的含沙量均大于上游,总体沿程增加。在泥沙断面垂向分布上,雅砻江无明显分层现象;安宁河分层现象明显,表现出底层＞表层＞中层的规律。在泥沙断面横向分布上,除安宁河中下游为左侧分布外,安宁河上游及雅砻江并流段均表现为右侧分布。雅砻江并流段泥沙断面均匀性总体优于安宁河。(2)雅砻江TN、TP整体均显著小于安宁河流域,且雅砻江—安宁河并流段氮磷空间分布在断面垂向和断面横向上均存在显著差异。(3)雅砻江并流段TN、TP浓度与含沙量呈线性正相关,其中断面横向拟合度优于断面垂向,且TN与含沙量的相关性高于TP;而安宁河则是断面垂向拟合度大于断面横向,TP与含沙量的相关性高于TN。

Spatial Differences of Water, Sediment and Nutrients in the Parallel Section of Yalong-Anning River

In order to understand the spatial distribution of sediment and nutrient under the impact of human activities, taking Yalong River and its first tributary Anning River as the research object, selecting the parallel section of Yalong -Anning River as the research area, six across sections along the river were selected, and the sediment concentration, nitrogen and phosphorus concentration were monitored vertically and transversely. The variation of sediment and spatial distribution characteristics of nutrient in different basins along the way were analyzed. The results showed that:(1) The sediment concentration of the Anning River was greater than that of the Yalong River, and the sediment concentration of the middle and lower reaches of these two rivers was higher than that of the upper reaches, and increased along the river. In the vertical distribution of sediment sections, there was no obvious stratification in Yalong River, while the stratification phenomenon of Anning River was remarkable,and the sediment concentration followed the order of bottom>surface>middle layer. In the transverse distribution of sediment section, except the middle and lower reaches of Anning River, the Yalong River and the upper reaches of the Anning River showed the right edge distribution. Generally, sediment uniformity of the cross section of Yalong River was better than that of Anning River. (2) TN and TP of Yalong River were significantly less than those of Anning River basin, and there were significant differences in spatial distribution of TN and TP of the parallel section of Yalong-Anning River in both vertical and horizontal sections. (3) There was a positive linear correlation between the concentrations of TN and TP and sediment in the parallel section of Yalong River. The fitting degree of transverse section was better than that of vertical section, and the correlativity between TN concentration and sediment was higher than TP. While for Anning River, the fitting degree of vertical section was better than that of transverse section, and the correlativity between TP concentration and sediment was higher than that TN.