TY - JOUR
T1 - Cryosphere and land cover influence on stream water quality in Central Asia's glacierized catchments
AU - Wade, Andrew J.
AU - Yapiyev, Vadim
AU - Shahgedanova, Maria
AU - Saidaliyeva, Zarina
AU - Madibekov, Azamat
AU - Kapitsa, Vassiliy
AU - Kasatkin, Nikolay
AU - Ismukhanova, Laura
AU - Kulbekova, Roza
AU - Sultanbekova, Botakoz
AU - Severskiy, Igor
AU - Esenaman, Mukhammed
AU - Kalashnikova, Olga
AU - Usubaliev, Ryskul
AU - Akbarov, Fakhriddin
AU - Umirzakov, Gulomjon
AU - Petrov, Maksim
AU - Rakhimov, Ilkhomiddin
AU - Kayumova, Dilorom
AU - Kayumov, Abdulhamid
N1 - Publisher Copyright:
© 2024
PY - 2024/8/20
Y1 - 2024/8/20
N2 - This work helps address recent calls for systematic water quality assessment in Central Asia and considers how nutrient and salinity sources, and transport, affect water quality along the continuum from the cryosphere to the lowland plains. Spatial and, for the first time, temporal variations in stream water pH, temperature, electrical conductivity, and nitrate and phosphate concentrations are presented for four catchments (485–13,500 km2), all with glaciers and major urban areas. The catchments studied were: Kaskelen (Kazakhstan), Ala-Archa (Kyrgyzstan), Chirchik (Uzbekistan) and the Kofarnihon (Tajikistan). Measurements were made in cryosphere, stream water, groundwater, reservoir and lake samples over a 22-month period at fortnightly intervals from 35 sites. The results highlight that glacier, permafrost and rock glacier outflows were primary and secondary nitrate sources (>1 mg N L−1) to the headwaters, and there were major increases in salinity and nitrate concentrations where rivers receive inputs from agriculture and settlements. Overall, the water quality complied with national and World Health Organization standards, however there were pollution hot-spots with shallow urban groundwaters contaminated with nitrate (>11 mg N L−1) and stream electrical conductivity above 800 μS cm−1 in some agricultural areas indicative of high salinity. Phosphate concentrations were generally low (<0.06 mg P L−1) throughout the catchments, though elevated (>0.2 mg P L−1) in urban areas due to effluent contamination. A melt water dilution effect along the main river channels was discernible, in the electrical conductivity and nitrate concentration seasonal dynamics, 100 s of km from the headwaters. Thus, the input of relatively clean water from the cryosphere is an important regulator of main channel water quality in the urban and farmed lowland plains adjacent to the Tien Shan and Pamir. Improved sewage treatment is needed in urban areas.
AB - This work helps address recent calls for systematic water quality assessment in Central Asia and considers how nutrient and salinity sources, and transport, affect water quality along the continuum from the cryosphere to the lowland plains. Spatial and, for the first time, temporal variations in stream water pH, temperature, electrical conductivity, and nitrate and phosphate concentrations are presented for four catchments (485–13,500 km2), all with glaciers and major urban areas. The catchments studied were: Kaskelen (Kazakhstan), Ala-Archa (Kyrgyzstan), Chirchik (Uzbekistan) and the Kofarnihon (Tajikistan). Measurements were made in cryosphere, stream water, groundwater, reservoir and lake samples over a 22-month period at fortnightly intervals from 35 sites. The results highlight that glacier, permafrost and rock glacier outflows were primary and secondary nitrate sources (>1 mg N L−1) to the headwaters, and there were major increases in salinity and nitrate concentrations where rivers receive inputs from agriculture and settlements. Overall, the water quality complied with national and World Health Organization standards, however there were pollution hot-spots with shallow urban groundwaters contaminated with nitrate (>11 mg N L−1) and stream electrical conductivity above 800 μS cm−1 in some agricultural areas indicative of high salinity. Phosphate concentrations were generally low (<0.06 mg P L−1) throughout the catchments, though elevated (>0.2 mg P L−1) in urban areas due to effluent contamination. A melt water dilution effect along the main river channels was discernible, in the electrical conductivity and nitrate concentration seasonal dynamics, 100 s of km from the headwaters. Thus, the input of relatively clean water from the cryosphere is an important regulator of main channel water quality in the urban and farmed lowland plains adjacent to the Tien Shan and Pamir. Improved sewage treatment is needed in urban areas.
KW - Endorheic basins
KW - Glacial retreat
KW - Mountains
KW - Nutrients
KW - Salinity
KW - Semi-arid
KW - Urban
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UR - http://www.scopus.com/inward/citedby.url?scp=85194943329&partnerID=8YFLogxK
U2 - 10.1016/j.scitotenv.2024.173525
DO - 10.1016/j.scitotenv.2024.173525
M3 - Article
C2 - 38810747
AN - SCOPUS:85194943329
SN - 0048-9697
VL - 939
JO - Science of the Total Environment
JF - Science of the Total Environment
M1 - 173525
ER -
