Nitrate concentrations in Mississippi River Basin priority watersheds 2000-2015

This repository contains data for HUC 8 priority watersheds in the Mississippi River Basin core states (Arkansas, Illinois, Indiana, Iowa, Kentucky, Louisiana, Minnesota, Mississippi, Missouri, Ohio, Tennessee, Wisconsin). Nitrate monitoring data in receiving streams and rivers in each priority watershed from 2000-2015 was collected from Water Quality Portal. Watershed metadata are included in the PriorityWatershed_Metadata file. Results of time series analysis (Seasonal Mann-Kendall test) for watersheds with sufficient data are detailed in SMK_results, SMKmonth_results, and SMKmonth_Trend_results files. All analyses were conducted in R within the attached R script file.

本数据集仓库包含密西西比河流域核心州内的8位水文单元代码（Hydrologic Unit Code 8，HUC 8）优先流域相关数据，涉及的核心州包括阿肯色州、伊利诺伊州、印第安纳州、艾奥瓦州、肯塔基州、路易斯安那州、明尼苏达州、密西西比州、密苏里州、俄亥俄州、田纳西州及威斯康星州。本数据集从水质门户（Water Quality Portal）获取了2000年至2015年间各优先流域受纳溪流与河流中的硝酸盐监测数据。流域元数据已收录于PriorityWatershed_Metadata文件中。针对数据量充足的流域开展的时间序列分析（季节性曼-肯德尔检验，Seasonal Mann-Kendall test）结果已详细记载于SMK_results、SMKmonth_results及SMKmonth_Trend_results文件中。所有分析均依托附件中的R脚本文件，在R语言环境中完成。