Evaluating the risk of phosphorus loss with a distributed watershed model featuring zero-order mobilization and first-order delivery.
In: Science of the Total Environment, Jg. 609 (2017-12-31), S. 563-576
academicJournal
Zugriff:
Many semi-distributed models that simulate pollutants' losses from watersheds do not handle well detailed spatially distributed and temporal data with which to identify accurate and cost-effective strategies for controlling pollutants issuing from non-point sources. Such models commonly overlook the flow pathways of pollutants across the landscape. This work aims at closing such knowledge gap by developing a Spatially and Temporally Distributed Empirical model for Phosphorus Management (STEM-P) that simulates the daily phosphorus loss from source areas to receiving waters on a spatially-distributed grid-cell basis. STEM-P bypasses the use of complex mechanistic algorithms by representing the phosphorus mobilization and delivery processes with zero-order mobilization and first-order delivery, respectively. STEM-P was applied to a 217 km 2 watershed with mixed forest and agricultural land uses situated in southwestern China. The STEM-P simulation of phosphorus concentration at the watershed outlet approximated the observed data closely: the percent bias (P bias ) was − 7.1%, with a Nash-Sutcliffe coefficient (E NS ) of 0.80 on a monthly scale for the calibration period. The P bias was 18.1%, with a monthly E NS equal to 0.72 for validation. The simulation results showed that 76% of the phosphorus load was transported with surface runoff, 25.2% of which came from 3.4% of the watershed area (classified as standard A critical source areas), and 55.3% of which originated from 17.1% of the watershed area (classified as standard B critical source areas). The standard A critical source areas were composed of 51% residences, 27% orchards, 18% dry fields, and 4% paddy fields. The standard B critical source areas were mainly paddy fields (81%). The calculated spatial and temporal patterns of phosphorus loss and recorded flow pathways identified with the STEM-P simulations revealed the field-scale critical source areas and guides the design and placement of effective practices for non-point source pollution control and water quality conservation. [ABSTRACT FROM AUTHOR]
Titel: |
Evaluating the risk of phosphorus loss with a distributed watershed model featuring zero-order mobilization and first-order delivery.
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Autor/in / Beteiligte Person: | Li, Sisi ; Zhang, Liang ; Liu, Hongbin ; Loáiciga, Hugo A. ; Zhai, Limei ; Zhuang, Yanhua ; Lei, Qiuliang ; Hu, Wanli ; Li, Wenchao ; Feng, Qi ; Du, Yun |
Zeitschrift: | Science of the Total Environment, Jg. 609 (2017-12-31), S. 563-576 |
Veröffentlichung: | 2017 |
Medientyp: | academicJournal |
ISSN: | 0048-9697 (print) |
DOI: | 10.1016/j.scitotenv.2017.07.173 |
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