2026-10-14T14:11:26Z https://www.scidb.cn/oai

10.57760/sciencedb.j00266.0000e 2026-09-09T15:21:47Z

2026-09-09 Water quality monitoring results of the Tanglangchuan - Pudu River doi:10.57760/sciencedb.j00266.0000e en This dataset consists of 655 sampling records. Each row corresponds to one observation and contains 14 variables. The first column identifies the name of the monitoring cross‑section. The second column indicates the sampling location within the section, coded as 1 for the left bank, 2 for the mid‑channel, and 3 for the right bank. Columns three through five provide the sampling date, recorded separately as year, month, and day. The next six columns are water quality parameters: total nitrogen (TN), dissolved total nitrogen (DTN), nitrate nitrogen (NO₃⁻‑N), total phosphorus (TP), dissolved total phosphorus (DTP), and orthophosphate (PO₄³⁻‑P), all expressed in mg/L. The twelfth column gives chlorophyll‑a concentration, measured in μg/L. The final two columns contain the geographic coordinates of the sampling section, namely longitude (east) and latitude (north), in decimal degrees. All nutrient concentrations are reported in mg/L, with the exception of chlorophyll‑a, which is in μg/L. The coordinate system is assumed to be WGS‑84 or an equivalent reference frame, unless otherwise specified. Sampling campaigns were carried out in August and November 2018; March, April, July, and October 2019; January 2020; and May 2023. Sampling followed the Technical Guidance for Water Quality Sampling (HJ 494-2009). Triplicate samples (left bank, right bank, center) were collected where river width permitted, stored in amber polyethylene bottles, kept cool and protected from light, and transported under refrigeration to the laboratory. Missing data exist in this dataset, primarily because the sampling and laboratory analyses were conducted over a period of five years, and certain indicators were not measured in some batches. Tanglangchuan - Pudu River; Lake Dian; water quality Hucai Zhang RESTRICTED dataset http://www.doi.org/10.1016/j.ecofro.2026.05.014 Science Data Bank