Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations
Accurately quantifying the spatiotemporal nutrient loads from nonpoint sources (NPSs) is still difficult due to the high spatial heterogeneity and temporal variability in rainfall-runoff processes. The export coefficient model (ECM) is a widely used tool to estimate the NPS nutrient load on an annua...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-09-01
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| Series: | Ecological Indicators |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S1470160X22006604 |
| _version_ | 1811340343765893120 |
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| author | Pinzeng Rao Siru Wang Ai Wang Dawen Yang Lihua Tang |
| author_facet | Pinzeng Rao Siru Wang Ai Wang Dawen Yang Lihua Tang |
| author_sort | Pinzeng Rao |
| collection | DOAJ |
| description | Accurately quantifying the spatiotemporal nutrient loads from nonpoint sources (NPSs) is still difficult due to the high spatial heterogeneity and temporal variability in rainfall-runoff processes. The export coefficient model (ECM) is a widely used tool to estimate the NPS nutrient load on an annual time scale, but it hardly considers the spatiotemporal distribution of the export coefficient. To address this issue, the ECM is improved by incorporating a grid-based rainfall-runoff module together with land-use data and analysing the spatiotemporal characteristics of the NPS nutrient loads in Yancheng city located in eastern China. Moreover, the effect of NPS nutrient loads on river water quality is assessed using a conceptual model. The results indicate that the improved ECM can simulate reasonable spatiotemporal variation in NPS nutrient loads, and the relative error in the total phosphorus (TP) load is less than 17.14 %. Precipitation has a considerable influence on both the total nitrogen (TN) and TP loads, which varied greatly from 1990 to 2018, with average annual values of 30.57 × 103 tons and 2.44 × 103 tons, respectively. The spatial distributions of the TN and TP loads were greatly affected by land-use patterns, and bodies of water and rural land had relatively high load intensities. Both TN and TP concentrations in the river exceeded the national standard, but TP was significantly reduced in the past 10 years, while TN was still at high level. This study provides a reference for reducing the river pollution in Yancheng city, especially by identifying pollution sources requiring priority control. |
| first_indexed | 2024-04-13T18:40:36Z |
| format | Article |
| id | doaj.art-3681b90b135945c99d54973793822bda |
| institution | Directory Open Access Journal |
| issn | 1470-160X |
| language | English |
| last_indexed | 2024-04-13T18:40:36Z |
| publishDate | 2022-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Ecological Indicators |
| spelling | doaj.art-3681b90b135945c99d54973793822bda2022-12-22T02:34:44ZengElsevierEcological Indicators1470-160X2022-09-01142109188Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculationsPinzeng Rao0Siru Wang1Ai Wang2Dawen Yang3Lihua Tang4State Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China; State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin, China Institute of Water Resources and Hydropower Research, Beijing 100038, ChinaState Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, China; State Key Laboratory of Hydrology and Water Resources and Hydraulic Engineering Science, Nanjing Hydraulic Research Institute, Nanjing 210029, China; Corresponding author at: State Key Laboratory of Hydrology and Water Resources and Hydraulic Engineering Science, Nanjing Hydraulic Research Institute, Nanjing 210029, China.College of Water Conservancy Engineering, Tianjin Agricultural University, Tianjin 300392, ChinaState Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, ChinaState Key Laboratory of Hydroscience and Engineering, Department of Hydraulic Engineering, Tsinghua University, Beijing 100084, ChinaAccurately quantifying the spatiotemporal nutrient loads from nonpoint sources (NPSs) is still difficult due to the high spatial heterogeneity and temporal variability in rainfall-runoff processes. The export coefficient model (ECM) is a widely used tool to estimate the NPS nutrient load on an annual time scale, but it hardly considers the spatiotemporal distribution of the export coefficient. To address this issue, the ECM is improved by incorporating a grid-based rainfall-runoff module together with land-use data and analysing the spatiotemporal characteristics of the NPS nutrient loads in Yancheng city located in eastern China. Moreover, the effect of NPS nutrient loads on river water quality is assessed using a conceptual model. The results indicate that the improved ECM can simulate reasonable spatiotemporal variation in NPS nutrient loads, and the relative error in the total phosphorus (TP) load is less than 17.14 %. Precipitation has a considerable influence on both the total nitrogen (TN) and TP loads, which varied greatly from 1990 to 2018, with average annual values of 30.57 × 103 tons and 2.44 × 103 tons, respectively. The spatial distributions of the TN and TP loads were greatly affected by land-use patterns, and bodies of water and rural land had relatively high load intensities. Both TN and TP concentrations in the river exceeded the national standard, but TP was significantly reduced in the past 10 years, while TN was still at high level. This study provides a reference for reducing the river pollution in Yancheng city, especially by identifying pollution sources requiring priority control.http://www.sciencedirect.com/science/article/pii/S1470160X22006604Nonpoint sourceImproved export coefficient modelConceptual model of river water qualityYancheng city |
| spellingShingle | Pinzeng Rao Siru Wang Ai Wang Dawen Yang Lihua Tang Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations Ecological Indicators Nonpoint source Improved export coefficient model Conceptual model of river water quality Yancheng city |
| title | Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations |
| title_full | Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations |
| title_fullStr | Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations |
| title_full_unstemmed | Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations |
| title_short | Spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in Yancheng city, China, simulated by an improved export coefficient model coupled with grid-based runoff calculations |
| title_sort | spatiotemporal characteristics of nonpoint source nutrient loads and their impact on river water quality in yancheng city china simulated by an improved export coefficient model coupled with grid based runoff calculations |
| topic | Nonpoint source Improved export coefficient model Conceptual model of river water quality Yancheng city |
| url | http://www.sciencedirect.com/science/article/pii/S1470160X22006604 |
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