Walker Branch Watershed Atmospheric Deposition Data

This data set provides atmospheric deposition data for Walker Branch Watershed. The data were collected during the period 1980 - 2000 as part of the National Atmospheric Deposition Program /National Trends Network. The National Atmospheric Deposition Program/National Trends Network (NADP/NTN) is a nationwide network of precipitation monitoring sites. The network is a cooperative effort between many different groups, including the State Agricultural Experiment Stations, U.S. Geological Survey, U.S. Department of Agriculture, and numerous other governmental and private entities. The purpose of the network is to collect data on the chemistry of precipitation for monitoring of geographical and temporal long-term trends. The precipitation at each station is collected weekly according to strict clean-handling procedures. It is then sent to the Central Analytical Laboratory where it is analyzed for hydrogen (acidity as pH), sulfate, nitrate, ammonium, chloride, and base cations (such as calcium, magnesium, potassium and sodium).本数据集提供沃克分支流域（Walker Branch Watershed）的大气沉降数据。相关数据采集于1980年至2000年间，作为国家大气沉降项目/国家趋势网络（National Atmospheric Deposition Program /National Trends Network，简称NADP/NTN）的一部分完成采集。 国家大气沉降项目/国家趋势网络（NADP/NTN）是覆盖全美的降水监测站点网络。该网络由多方主体协作共建，涵盖各州农业试验站、美国地质调查局、美国农业部，以及众多其他政府与私营机构。 该网络的建设目的是采集降水化学组分数据，以监测降水化学特征在地理与时间维度上的长期变化趋势。各监测站点将按照严格的洁净采样操作规范，每周收集降水样本。随后样本将被送往中央分析实验室，针对氢离子（以pH值表征的酸度）、硫酸盐、硝酸盐、铵盐、氯化物以及碱金属阳离子（包括钙、镁、钾、钠）开展分析检测。