USEPA EMAP Surface Waters Lake Database Northeast Lake Water Chemistry Data, 1991-1994

The primary function of the lake water chemistry samples, collected with a van Dorn
sampler, is to determine acid-base status, trophic state, and classification of water chemistry
type. Water chemistry in lakes is analyzed for two purposes. First, to understand the chemical
habitat within which biota must exist so that we can understand the biological potential of the
system and second, to evaluate the chemical quality of the water for the purposes of determine
the potential stresses to which the biota are exposed. Water chemistry parameters are reported
for one sample taken at the location of the deepest part of the lake by a van Dorn sampler from
a depth of 1.5 m. These include: aluminum, alkalinity, acid neutralizing capacity, calcium,
carbonate, color, specific conductance, dissolved inorganic carbon, dissolved organic carbon,
bicarbonate, potassium, magnesium, ammonium, sodium, nitrate, total nitrogen, pH, total
phosphorus, silica, total suspended solids, turbidity, and chlorophyll-a. Sampling was initiated
July 1991 and ended September 1994.

本数据集采用范多恩采水器（van Dorn sampler）采集湖水化学样本，其核心功能为测定水体的酸碱状态、营养状态以及水化学类型分类。湖水化学分析兼具两大目标：其一为明确生物群落赖以生存的化学栖息环境，以此解析该水生生态系统的生物潜能；其二为评估水体化学质量，以判断生物群落所面临的潜在胁迫因素。本次采集的单一样本均由范多恩采水器于湖泊最深点处1.5米水深位置获取，共记录以下化学参数：铝、碱度、酸中和容量、钙、碳酸盐、色度、比电导率、溶解无机碳、溶解有机碳、碳酸氢根、钾、镁、铵、钠、硝酸盐、总氮、pH值、总磷、二氧化硅、总悬浮颗粒物、浊度以及叶绿素a。本次采样工作始于1991年7月，终止于1994年9月。