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eISSN: 2083-5906
ISSN: 1230-1485
ISSN: 1230-1485
ORIGINAL RESEARCH
Spatio-Temporal Dynamics and Source
Apportionment of Nutrient Loading
in a High-Altitude Fragile River: A Case Study
of the Niyang River, Qinghai-Tibet Plateau
1
Xizang Agriculture and Animal Husbandry University, Linzhi 860000, China
2
Milin City People’s Procuratorate, Milin 850500, China
3
China Institute of Water Resources and Hydropower Research, Beijing 100038, China
Submission date: 2026-02-08
Final revision date: 2026-03-16
Acceptance date: 2026-08-14
Online publication date: 2026-09-17
Corresponding author
KEYWORDS
high-altitude fragile ecosystemsource apportionmentmulti-dimensional diagnostic frameworkoutput coefficient modelnutrient stoichiometric coupling
TOPICS
ABSTRACT
This study addresses the critical knowledge gap in nutrient dynamics within high-altitude fragile
ecosystems by investigating the Niyang River, a primary tributary of the Yarlung Zangbo River. A multidimensional
diagnostic framework was developed by coupling the Comprehensive Pollution Index (CPI)
with a refined Output Coefficient Model (OCM) and stoichiometric correlation analysis, bridging the
gap between ambient concentration-based risk profiling and land-use-driven pollution flux calculation.
Through systematic monitoring of nine representative sections during contrasting hydrological seasons,
the spatio-temporal evolution of Chemical Oxygen Demand (COD), Total Phosphorus (TP), Total
Nitrogen (TN), and Ammonia Nitrogen (NH₃-N) was quantified. The integrated modeling approach
reveals a distinct spatial purification gradient from the headwaters to the downstream confluence,
with the dry season identified as the critical window for pollution management due to reduced dilution
capacity. By synthesizing the CPI-based risk ranking with OCM-derived load estimation, this study
identifies a synchronous transport-source mechanism: specifically, the strong stoichiometric coupling
between organic matter and nutrients (COD-TP and TN-NH₃-N) validates that large-scale pastoral
waste and agricultural runoff are not merely parallel but functionally integrated pollution drivers. COD
was prioritized as the primary risk indicator within this coupled framework. These findings demonstrate
that the synergistic application of concentration-load modeling offers a more robust precision-targeting
tool for water quality management in the Third Pole region than traditional single-model assessments,
providing a scientific template for ecological preservation in similar alpine basins.
CONFLICT OF INTEREST
The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
REFERENCES (40)
1.
VÖRÖSMARTY C.J., MCINTYRE P.B., GESSNER M.O., DUDGEON D., PRUSEVICH A., GREEN P., GLIDDEN S., BUNN S.E., SULLIVAN C.A., LIERMANN C.R., DAVIES P.M. Global threats to human water security and river biodiversity. Nature, 467, 555, 2010.
2.
KRISHNAN S.R., NALLAKARUPPAN M.K., CHENGODEN R., KOPPU S., IYAPPARAJA M., SADHASIVAM J., SETHURAMAN S. Smart Water Resource Management Using Artificial Intelligence-A Review. Sustainability, 14 (20), 13384, 2022.
3.
EJIOHUO O., ONYEAKA H., AKINSEMOLU A., NWABOR O.F., SIYANBOLA K.F., TAMASIGA P., AL-SHARIFY Z.T. Ensuring water purity: Mitigating environmental risks and safeguarding human health. Water Biology and Security, 4 (2), 100341, 2025.
4.
POINTET T. The United Nations World Water Development Report 2022 on groundwater, a synthesis. LHB-Hydroscience Journal, 108 (1), 2090867, 2022.
5.
ZHENG Z.Q., DING H., WENG Z., WANG L.X. Research on a multiparameter water quality prediction method based on a hybrid model. Ecological Informatics, 76, 102125, 2023.
6.
MOHAPATRA S.S., ARORA M., WU W.Y., TIWARI M.K. A Review of IUWM Approach to Address Urban Water Challenges Faced by a Developing Country. Water Resources Management, 39 (6), 2443, 2025.
7.
SHEN D.J. Climate change and water resources: evidence and estimate in China. Current Science, 98 (8), 1063, 2010.
8.
YANG Y.H., YAN B.X., SHEN W.B. Assessment of Point and Nonpoint Sources Pollution in Songhua River Basin, Northeast China by Using Revised Water Quality Model. Chinese Geographical Science, 20 (1), 30, 2010.
9.
CHEN S.J., WANG J.Y. An integrative analytical framework and evaluation system of water environment security in the context of agricultural non-point source perspective. Environmental Research Communications, 5 (1), 015009, 2023.
10.
KIM M.G., BARTOS M. A digital twin model for contaminant fate and transport in urban and natural drainage networks with online state estimation. Environmental Modelling & Software, 171, 105868, 2024.
11.
LIU J.J., GUO H.C. Hydrochemical Characteristics and Ion Source Analysis of the Yarlung Tsangpo River Basin. Water, 15 (3), 537, 2023.
12.
QU B., ZHANG Y.L., KANG S.C., SILLANPÄÄ M. Water chemistry of the southern Tibetan Plateau: an assessment of the Yarlung Tsangpo river basin. Environmental Earth Sciences, 76 (2), 74, 2017.
13.
LI H.A., TIAN S.M., SHANG F.D., SHI X.Y., ZHANG Y., CAO Y.T. Impacts of oxbow lake evolution on sediment microbial community structure in the Yellow River source region. Environmental Research, 252 (3), 119042, 2024.
14.
LIAO N., JIANG L., LI J., ZHANG L.L., ZHANG J., ZHANG Z.Y. Effects of freeze-thaw cycles on phosphorus from sediments in the middle reaches of the Yarlung Zangbo River. International Journal of Environmental Research and Public Health, 16 (19), 3783, 2019.
15.
WU J., ZHAO Z.Q., MENG J.L., ZHOU T. Analysis on water quality of the tibetan plateau based on the major ions and trace elements in the Niyang River Basin. Applied Ecology and Environmental Research, 18 (2), 3729, 2020.
16.
ADYARI B., LIAO X., YAN X.H., QIU Y.X., GROSSART H.P., LI L.Y., YU T., MAO G.N., LIU K.S., SU J., LIU Y., HU A. Anthropogenic gene dissemination in Tibetan Plateau rivers: sewage-driven spread, environmental selection, and microeukaryotic inter-trophic driving factors. Water Research, 284, 123887, 2025.
17.
WANG J.X., CAI Y.H., GAO X.D., ZHOU Y.Q., WU P.T., ZHAO X.N. Modeling the dynamics of evapotranspiration of wolfberry (Lycium barbarum L.) under different cultivation methods on the Tibetan Plateau. Journal of Hydrology, 639, 131537, 2024.
18.
ZHAO Y.M., DONG N.P., MA C., WANG H. Runoff simulation based on granular computing by introducing terrain factors to construct climate characteristic index. Journal of Hydrology, 661, 133614, 2025.
19.
WANG P.X., ZHOU Z.H., LIU J.J., XU C.Y., WANG K., LIU Y.L., LI J., LI Y.Q., JIA Y.W., WANG H. Application of an improved distributed hydrological model based on the soil-gravel structure in the Niyang River basin, QinghaiTibet Plateau. Hydrology and Earth System Sciences, 27 (14), 2681, 2023.
20.
FU S.Y., MENG F.L., FENG S.J., YAO C.X., LIU J.J., LIU X.J., XU W. Hotspots of nitrogen losses from anthropogenic sources in the Huang-Huai-Hai Basin, China. Environmental Pollution, 367, 125597, 2025. PMid:39732281.
21.
DÖNDÜ M., ÖZDEMIR N., DEMIRAK A., DOGAN H.M., DINCER N.G., KESKIN F. Seasonal assessment of the impact of fresh waters feeding the Bay of Gokova with water quality index (WQI) and comprehensive pollution index (CPI). Environmental Forensics, 25 (1-2), 68, 2024.
22.
DU H.Q., WANG T., XUE X., LI S. Estimation of soil organic carbon, nitrogen, and phosphorus losses induced by wind erosion in Northern China. Land Degradation & Development, 30 (8), 1006, 2019.
23.
DUAN Y.H., SHAN X., FEI L., TANG J.L., GONG L.Y., LIU X.Y., WEN T.X., WANG H.R. GIS-based assessment of spatial and temporal disparities of urban health index in Shenzhen, China. Frontiers in Public Health, 12, 1429143, 2024.
24.
LI N., WANG D. Quantifying Time-Lag and TimeAccumulation Effects of Climate Change and Human Activities on Vegetation Dynamics in the Yarlung Zangbo River Basin of the Tibetan Plateau. Remote Sensing, 17 (1), 160, 2025.
25.
XU L.Y., JIANG J., LU M.Y., DU J.G. Spatial-Temporal Evolution Characteristics of Agricultural Intensive Management and Its Influence on Agricultural Non-Point Source Pollution in China. Sustainability, 15 (1), 371, 2023.
26.
WU L.F., GUO X.R., CHEN Y. Grey Relational Entropy Calculation and Fractional Prediction of Water and Economy in the Beijing-Tianjin-Hebei Region. Journal of Mathematics, 2021, 4418260, 2021.
27.
ZHANG Y.D., YANG W.S., PENG L., FU H., CHEN M.J. Natural and anthropogenically driven change of organic carbon burial rate in two alpine lakes from the southeastern margin of the Tibetan Plateau. Catena, 247, 108490, 2024.
28.
YANG S.Y., TAYLOR D., YANG D., HE M.J., LIU X.M., XU J.M. A synthesis framework using machine learning and spatial bivariate analysis to identify drivers and hotspots of heavy metal pollution of agricultural soils. Environmental Pollution, 287, 117611, 2021.
29.
ZHANG J., JIANG Y.E., ZHANG H.Y., FENG D., BU H.L., LI L.L., LU S.Y. A critical review of characteristics of domestic wastewater and key treatment techniques in Chinese villages. Science of the Total Environment, 927, 172155, 2024.
30.
DENG Y., OU Y., PANG S.J., YAN B.X., ZHU H., YAN L.M., CUI Q. Multi-objective optimization of best management practices at watershed scale: A case study of drinking water source watersheds in northeast black soil region of China. Agricultural Water Management, 318, 109736, 2025.
31.
WU W.C., ZHAO L., PEI Y.D., DING W.H., YANG H., XU Y.P. Variability of tetraether lipids in Yellow Riverdominated continental margin during the past eight decades: Implications for organic matter sources and river channel shifts. Organic Geochemistry, 60, 33, 2013.
32.
YU J.N., ZHANG H.C., WANG P.X., WANG J.Z., LU F. Sequence analysis of local indicators of spatio-temporal association for evolutionary pattern discovery. GIScience & Remote Sensing, 62 (1), 2487292, 2025.
33.
LI D.S., CUI B.L., ZHAO Y.D. Effects of the hydrologic process and geochemistry on dissolved carbon in shallow groundwater surrounding Qinghai Lake. Journal of Great Lakes Research, 50 (3), 102349, 2024.
34.
WANG X.Y., YANG Y.Q., WAN J., CHEN Z., WANG N., GUO Y.Q., WANG Y.G. Water quality variation and driving factors quantitatively evaluation of urban lakes during quick socioeconomic development. Journal of Environmental Management, 344, 118615, 2023.
35.
XU T, WENG B.S., YAN D.H., WANG K., LI X.N., BI W.X., LI M., CHENG X.J., LIU Y.X. Wetlands of International Importance: Status, Threats, and Future Protection. International Journal of Environmental Research and Public Health, 16 (10), 1818, 2019.
36.
LI H.D., SHEN W.S., ZOU C.X., JIANG J., FU L.N., SHE G.H. Spatio-temporal variability of soil moisture and its effect on vegetation in a desertified aeolian riparian ecotone on the Tibetan Plateau, China. Journal of Hydrology, 479, 215, 2013.
37.
BO Y., WEN W. Treatment and technology of domestic sewage for improvement of rural environment in China. Journal of King Saud University Science, 34 (7), 102181, 2022.
38.
XU C.Y., LIU D., WANG X.Y., WANG T. Shifting from a thermal-constrained to water-constrained ecosystem over the Tibetan Plateau. Frontiers in Plant Science, 14, 1125288, 2023.
39.
DEVKOTA K.P., PASUQUIN E., ELMIDOMABILANGAN A., DIKITANAN R., SINGLETON G.R., STUART A.M., VITHOONJIT D., VIDIYANGKURA L., PUSTIKA A.B., AFRIANI R., LISTYOWATI C.L., KEERTHISENA R.S.K., KIEU N.T., MALABAYABAS A.J., HU R., PAN J., BEEBOUT S.E.J. Economic and environmental indicators of sustainable rice cultivation: A comparison across intensive irrigated rice cropping systems in six Asian countries. Ecological Indicators, 105, 199, 2019.
40.
DE MELLO N.G.R., GULINCK H., VAN DEN BROECK P., PARRA C. Social-ecological sustainability of non-timber forest products: A review and theoretical considerations for future research. Forest Policy and Economics, 112, 102109, 2020.
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| eISSN: | 2083-5906 |
| ISSN: | 1230-1485 |
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