Spatial Distribution of Non-point Source Pollution in Daninghe Watershed Based on SWAT Model
4
Citation
0
Reference
20
Related Paper
Citation Trend
Abstract:
SWAT model was used to calculate the agricultural non-point source pollution in Daninghe watershed.The runoff and the sediment data series from 2000 to 2004 were used to calibrate the parameters and validate the model.Results indicated that SWAT model was appropriate for Daninghe watershed.Then the calibrated model was used to calculate the spatial distribution of non-point source pollution.The calculated result indicated that the west part of the watershed was the serious soil erosion area,which is the same as the spatial distribution of organic nitrogen.In one word,the production of non-point source pollution in the west is more than that in the east,while in the south,more than that in the north.The measures for the prevention of non-point source pollution were presented according to the simulated results.Keywords:
SWAT model
Cite
The availability of freshwater is likely to decrease due to population growth, industrialization, land use and climate change; unfortunately demand for water increases across the world. Quantifying the water resources of a watershed is essential for providing the strategic information needed for long-term planning of water security. Thus this study was initiated with an objective to determine the surface water resources potential of Somodo watershed. GPS, GIS, SWAT, and SWAT-CUP software were the materials used. Secondary data namely DEM, land use/land cover map, soil map, stream flow and meteorological data were collected from responsible organizations. Sensitivity analysis, calibration and validation of the model were done to check performance of the model. The result reveals that Surface runoff and base flow were the most sensitive parameters of the stream flow in Somodo watershed. The statistical results for the model performance displayed satisfactory (R2 of 0.795 and NSE of 0.68) between the simulated and observed flow, respectively for calibration and there was also a very good agreement between the observed and simulated stream flow with R2 value of 0.821 and NSE value of 0.7 for validation. From total watershed area of 19860 ha, a total of 56.75MCM surface runoff was generated by the model from the catchment annually. Construction of water harvesting structures at the upstream of the watershed is useful to increase the water potential and to use the water during the dry period and is recommended from this study.The availability of freshwater is likely to decrease due to population growth, industrialization, land use and climate change; unfortunately demand for water increases across the world. Quantifying the water resources of a watershed is essential for providing the strategic information needed for long-term planning of water security. Thus this study was initiated with an objective to determine the surface water resources potential of Somodo watershed. GPS, GIS, SWAT, and SWAT-CUP software were the materials used. Secondary data namely DEM, land use/land cover map, soil map, stream flow and meteorological data were collected from responsible organizations. Sensitivity analysis, calibration and validation of the model were done to check performance of the model. The result reveals that Surface runoff and base flow were the most sensitive parameters of the stream flow in Somodo watershed. The statistical results for the model performance displayed satisfactory (R2 of 0.795 and NSE of 0.68) between the simulated and observed flow, respectively for calibration and there was also a very good agreement between the observed and simulated stream flow with R2 value of 0.821 and NSE value of 0.7 for validation. From total watershed area of 19860 ha, a total of 56.75MCM surface runoff was generated by the model from the catchment annually. Construction of water harvesting structures at the upstream of the watershed is useful to increase the water potential and to use the water during the dry period and is recommended from this study.
Base flow
SWAT model
Land Cover
Time of concentration
Watershed Management
Cite
Citations (1)
[Objective] The study aimed to simulate the producing and transporting process of flow,sediment and non-point source pollution in Xincai River basin based on SWAT model.[Method] On the basis of analyzing the principles of SWAT model,the correlative parameters of flow and water quality were calibrated,then the spatial and temporal distribution of flow,sediment and non-point source pollution in Xincai River basin were studied using the SWAT model.[Result] The results of calibration and validation showed that the SWAT model was reasonable and available,and it can be used to simulate the non-point source pollution of Xincai River basin.The simulated results revealed that the amount of sediment and various pollutants' load was the highest in the rainy year,followed by the normal year,while it was the minimum in the dry year,which indicated that the production and output of sediment and non-point source pollution were closely related to annual runoff.[Conclusion] The research could provide scientific references for the prevention of non-point source pollution in a basin.
SWAT model
Cite
Citations (0)
SWAT model
Cite
Citations (58)
Nutrient pollution
Cite
Citations (51)
Runoff loads of pollutant in agricultural watersheds were spatially analyzed by using geographic information system(GIS) technology. The topological relationship between pollution sources in the watershed was, first of all, identified by using the developed digital map of land use and then the pollutant loads generated from each source was estimated by applying a conventional unit loading factor on the obtained digital information of pollution sources. To evaluate the loads delivered from spatially distributed pollution sources to monitoring stations in down stream via surface of watershed, a renovated empirical model incorporated with the information of pollutant discharge path was developed through introducing a digital terrain model(DTM) technique. In this model, the function of degradation of pollution loads during delivery process was simplified so that each watershed could have a basin-wide self-purification capacity which would be considered to be possessed inherently in each watershed and could retard the discharge of pollutants from sources generated to stream water. Model credibility showed good consistency with comparing the simulated values with observed data. Monte Carlo optimizing technique made it possible to estimate the basin-wide self-purification coefficients.
Cite
Citations (8)
In order to select the right model for the watershed of purple soil,and provide scientific basis for controlling the export of non-point source pollutant from the hilly area of purple soil and establish the monitoring model for Three Gorge Reservoir Area fur-ther,the research applied two water quality models:AnnAGNPS and SWAT to typical watershed of purple soil under different land using,and simulated surface runoff and non-point source pollutant export.Results showed that the effect that simulated surface runoff by two models was best,and the average relative error were -7.5% and 2.9%;the effect that simulated sediment was not ideal,error was rather big;the result simulating nutrient transport was that AnnAGNPS model was better than SWAT model,and the average error was about 10%.So AnnAGNPS was more suitable for applying to typical watershed of purple soil,and could gain higher reliability about simulated results.
SWAT model
Cite
Citations (2)
Non-point source agricultural pollution has become the focus of water pollution control in the source areas of the Liaohe River. Although AnnAGNPS model is applicable in simulating agricultural non-point source pollution, the accuracy of model results depends on the reliability of the model parameters. In this paper the watershed of the source areas of Liaohe River was taken as a case study. As the sub-division number of a watershed is closely related to the spatial distribution of non-point pollution sources, the CSA (critical source area) and MSCL (the minimum channel length) were iteratively employed to determine the number of sub-division of watershed and it was captured when a variety of non-point source pollution loads were stabilized. As the soil texture system in the Chinese Soil Survey is different from that used in AnnAGNPS,the soil erodibility factor was calculated by using EPIC model after the soil textures were adapted to AnnAGNPS model by interpolation method, with an assumption that the soil cumulative sizes follow the lognormal cumulative. The methods of determining the parameters were proved feasible by comparing the simulated results with the field survey data.
Soil texture
Cite
Citations (0)
Taking Hunhe Basin for an example,SWAT model is used to simulate the non-point source pollution load.And then the yearly and monthly variation tendency is analyzed and the load distribution in 4 major districts is estimated.The result shows that the SWAT model has good applicability;non-point source is the main pollution load;annual average load has obvious variation with the precipitation changing;spring and summer are effective seasons for control of pollution.
SWAT model
Cite
Citations (0)
The SWAT model was used to simulate the effects of parameter spatial distribution on flow and nutrients loadings in the Daning river watershed. It was first calibrated and validated using the measured data for the period of 2000 - 2004. Then the model was used to simulate the effects of watershed delineation scenarios on flow and nutrients loadings, using six watershed delineations, each with a different number of sub-watersheds. The max relative error is 19.6% for the annual mean flow under different watershed delineation scenarios. The flow increase first and then decrease with the number of sub-watersheds. The efficiencies coefficient is 0.52 - 0.82 for annual mean flow and 0.80 - 0.83 for monthly mean flow under six delineation scenarios. Outlet nutrients simulations are slightly affected by changes in watershed delineation scenarios. The relative errors of organic nitrogen and organic phosphorous are 16.2% and 7.7% respectively and no explicit trend is observed.
SWAT model
System Dynamics Model
Cite
Citations (2)
A validation study has been performed using the Soil and Water Assessment Tool (SWAT) model with data collected for the Upper Maquoketa River Watershed (UMRW), which drains over 16,000 ha in northeast Iowa. This validation assessment builds on a previous study with nested modeling for the UMRW that required both the Agricultural Policy EXtender (APEX) model and SWAT. In the nested modeling approach, edge-of-field flows and pollutant load estimates were generated for manure application fields with APEX and were then subsequently routed to the watershed outlet in SWAT, along with flows and pollutant loadings estimated for the rest of the watershed routed to the watershed outlet. In the current study, the entire UMRW cropland area was simulated in SWAT, which required translating the APEX subareas into SWAT hydrologic response units (HRUs). Calibration and validation of the SWAT output was performed by comparing predicted flow and NO3-N loadings with corresponding in-stream measurements at the watershed outlet from 1999 to 2001. Annual stream flows measured at the watershed outlet were greatly under-predicted when precipitation data collected within the watershed during the 1999-2001 period were used to drive SWAT. Selection of alternative climate data resulted in greatly improved average annual stream predictions, and also relatively strong r2 values of 0.73 and 0.72 for the predicted average monthly flows and NO3-N loads, respectively. The impact of alternative precipitation data shows that as average annual precipitation increases 19%, the relative change in average annual streamflow is about 55%. In summary, the results of this study show that SWAT can replicate measured trends for this watershed and that climate inputs are very important for validating SWAT and other water quality models.
SWAT model
Cite
Citations (0)