Data for: Influence of cryosphere outflow and land cover on stream water quality in Central Asia's glacierized catchments

Stream water pH, temperature, electrical conductivity, and nitrate and phosphate concentrations are provided for four catchments (485 – 13 500 km2), all with glaciers and major urban areas in Central Asia. The catchments are: Kaskelen (Kazakhstan), Ala-Archa (Kyrgyzstan), Chirchik (Uzbekistan) and the Kofarnihon (Tajikistan). Measurements were made in stream water, groundwater, reservoir and lake samples over a 22-month period at fortnightly intervals from 35 sites. The water samples were collected at fixed locations along the main channel from 10 – 20 km downstream of the periglacial headwaters to the lowlands, from large tributaries, and from three deep wells, two wells that were artesian, and from three further springs. Sample collection started between April and July 2019 and ended between October 2020 and January 2021 dependent on the country. In addition, data are provided for cryosphere samples. Snow and glacial melt water samples were collected during the summers of 2019, 2020 and 2021 at the Tuyuksu (KZ) glacier, in 2019 and 2020 at the Golubin (KG) glacier, and at the Barkrak and Tekesh glaciers (UZ) in 2020. The snow samples were collected from snow pits using plastic scoops, placed in plastic bags, melted at room temperature, and filtered and stored as the other water samples. The snow pit sampling was most extensive in KZ where, in 2019, samples were collected from 6 cm layers from the top to the bottom of the snow pit. In 2020, the snow pit was divided into three equal vertical layers of the overall depth of 162 cm and one sample was taken from each layer. In Kyrgyzstan, the cryosphere samples (snow, glacial ice and glacial melt) were collected in 2019 and 2020. In Uzbekistan, 13 samples were collected from the Tekesh and Barkrak glaciers in June and July 2020. In Kazakhstan, at least three water samples were collected in immediate proximity of the Tuyuksu glacier terminus. Water samples were also collected from the outflow of Gorodetskiy and Morennyi rock glaciers and the meltwater from the permafrost active layer in the Ulken and Kishi Almaty headwaters. In total, cryosphere samples were taken at 39 unique locations, and the pH, EC and water temperature were measured in situ except were samples required melting, and NO3--N and PO43--P was measured on return to the laboratory. Not all analytes could be measured in every sample. The sampling and analysis methods are described in the publication ‘Influence of cryosphere outflow and land cover