Modification of SWAT model for simulation of organic matter in Korean watersheds

2012 ◽  
Vol 66 (11) ◽  
pp. 2355-2362 ◽  
Author(s):  
Jae-Ho Jang ◽  
Kwang-Wook Jung ◽  
Chun Gyeong Yoon
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Assessment Tool ◽  
Swat Model ◽  
Oxygen Demand ◽  
Water Quality Modeling ◽  
Efficiency Coefficient ◽  
Watershed Model ◽  
Maximum Daily Loads ◽  
Improved Model

The focus of water quality modeling of Korean streams needs to be shifted from dissolved oxygen to algae or organic matter. In particular, the structure of water quality models should be modified to simulate the biochemical oxygen demand (BOD), which is a key factor in calculating total maximum daily loads (TMDLs) in Korea, using 5-day BOD determined in the laboratory (Bottle BOD5). Considering the limitations in simulating organic matter under domestic conditions, we attempted to model total organic carbon (TOC) as well as BOD by using a watershed model. For this purpose, the Soil and Water Assessment Tool (SWAT) model was modified and extended to achieve better correspondence between the measured and simulated BOD and TOC concentrations. For simulated BOD in the period 2004–2008, the Nash-Sutcliffe model efficiency coefficient increased from a value of −2.54 to 0.61. Another indicator of organic matter, namely, the simulated TOC concentration showed that the modified SWAT adequately reflected the observed values. The improved model can be used to predict organic matter and hence, may be a potential decision-making tool for TMDLs. However, it needs further testing for longer simulation periods and other catchments.

Evaluation of BASINS/WinHSPF applicability for pollutant loading estimation for a Korean watershed

2006 ◽  
Vol 53 (1) ◽  
pp. 25-32 ◽  
Author(s):  
J.H. Jeon ◽  
C.G. Yoon ◽  
J.H. Ham ◽  
K.W. Jung
Keyword(s):  
Water Quality ◽  
Assessment Tool ◽  
Oxygen Demand ◽  
Water Quality Assessment ◽  
Control Measures ◽  
Effective Control ◽  
Watershed Model ◽  
Pollutant Loading ◽  
Model Efficiency

Applicability of a widely accepted watershed-based water quality assessment tool (BASINS) and its associated watershed model (WinHSPF) was evaluated on the Seamangeum watershed in Korea. The study site is the largest polder project area in Korea and its environmental quality has been debated for the last five years. BASINS was found to be a convenient and powerful tool for assessment of watershed characteristics, and provided various tools to delineate the watershed into land segments and river reaches, reclassify land use, and parameterize for WinHSPF simulation. Calibration results were satisfactory showing model efficiency over 0.80 for stream flow, temperature, and dissolved oxygen simulation, and model output for water quality constituents also reasonably matched the observed data. It was demonstrated that calibration with dry-day data for a relatively long period might be adequate to simulate hydrologic characteristics and water quality of the watershed with WinHSPF, and using parameters generated with BASINS for nonpoint source pollution simulation is suggested when enough wet-day monitoring data are not available. The unit-area load of biochemical oxygen demand, total nitrogen, and total phosphorus was 27.8, 48.2, and 4.3 kg/ha/yr, respectively. These values are within the expected range but on the high side of the reported values, which implies that effective control measures are required to protect water quality of the downstream reservoir. Overall, BASINS/WinHSPF was applicable and found to be a powerful tool in pollutant loading estimation from the watershed, and its use in Korea is recommended.

scholarly journals Water Quality Modeling of Mahabad Dam Watershed–Reservoir System under Climate Change Conditions, Using SWAT and System Dynamics

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 394 ◽  
Author(s):  
Mohammad Nazari-Sharabian ◽  
Masoud Taheriyoun ◽  
Sajjad Ahmad ◽  
Moses Karakouzian ◽  
Azadeh Ahmadi
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
System Dynamics ◽  
Water Conservation ◽  
Assessment Tool ◽  
Swat Model ◽  
Water Quality Modeling ◽  
Quality Data ◽  
Livestock Farming ◽  
Water Quality Data

The total phosphorus (TP) concentration, as the primary limiting eutrophication factor in the Mahabad Dam reservoir in Iran, was studied, considering the combined impacts of climate change, as well as the scenarios on changes in upstream TP loadings and downstream dam water allocations. Downscaled daily projected climate data were obtained from the Beijing Normal University Earth System Model (BNU-ESM) under moderate (RCP4.5) and extreme (RCP8.5) scenarios. These data were used as inputs of a calibrated Soil and Water Assessment Tool (SWAT) model of the watershed in order to determine the effects of climate change on runoff yields in the watershed from 2020 to 2050. The SWAT model was calibrated/validated using the SUFI-2 algorithm in the SWAT Calibration Uncertainties Program (SWAT-CUP). Moreover, to model TP concentration in the reservoir and to investigate the effects of upstream/downstream scenarios, along with forecasted climate-induced changes in streamflow and evaporation rates, the System Dynamics (SD) model was implemented. The scenarios covered a combination of changes in population, agricultural and livestock farming activities, industrialization, water conservation, and pollution control. Relative to the year 2011 in which the water quality data were available, the SD results showed the highest TP concentrations in the reservoir under scenarios in which the inflow to the reservoir had decreased, while the upstream TP loadings and downstream dam water allocations had increased (+29.9%). On the other hand, the lowest TP concentration was observed under scenarios in which upstream TP loadings and dam water allocations had decreased (−18.5%).

scholarly journals Comparative Analysis of Bioenergy Crop Impacts on Water Quality Using Static and Dynamic Land Use Change Modeling Approach

Water ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 410 ◽  
Author(s):  
Eeshan Kumar ◽  
Dharmendra Saraswat ◽  
Gurdeep Singh
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Land Use Change ◽  
Assessment Tool ◽  
Swat Model ◽  
State Agency ◽  
Bioenergy Crops ◽  
Marginal Land ◽  
Cache River ◽  
Land Area

Researchers and federal and state agency officials have long been interested in evaluating location-specific impact of bioenergy energy crops on water quality for developing policy interventions. This modeling study examines long-term impact of giant miscanthus and switchgrass on water quality in the Cache River Watershed (CRW) in Arkansas, United States. The bioenergy crops were simulated on marginal lands using two variants of a Soil and Watershed Assessment Tool (SWAT) model. The first SWAT variant was developed using a static (single) land-use layer (regular-SWAT) and for the second, a dynamic land-use change feature was used with multiple land use layers (location-SWAT). Results indicated that the regular-SWAT predicted larger losses for sediment, total phosphorus and total nitrogen when compared to location-SWAT at the watershed outlet. The lower predicted losses from location-SWAT were attributed to its ability to vary marginal land area between 3% and 11% during the 20-year modeling period as opposed to the regular-SWAT that used a fixed percentage of marginal land area (8%) throughout the same period. Overall, this study demonstrates that environmental impacts of bioenergy crops were better assessed using the dynamic land-use representation approach, which would eliminate any unintended prediction bias in the model due to the use of a single land use layer.

scholarly journals A New Physically-Based Spatially-Distributed Groundwater Flow Module for SWAT+

Hydrology ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 75
Author(s):  
Ryan T. Bailey ◽  
Katrin Bieger ◽  
Jeffrey G. Arnold ◽  
David D. Bosch
Keyword(s):  
Water Balance ◽  
Groundwater Flow ◽  
Land Surface ◽  
Assessment Tool ◽  
Swat Model ◽  
Watershed Model ◽  
Groundwater Head ◽  
Physically Based ◽  
Spatially Distributed ◽  
Modeling Code

Watershed models are used worldwide to assist with water and nutrient management under conditions of changing climate, land use, and population. Of these models, the Soil and Water Assessment Tool (SWAT) and SWAT+ are the most widely used, although their performance in groundwater-driven watersheds can sometimes be poor due to a simplistic representation of groundwater processes. The purpose of this paper is to introduce a new physically-based spatially-distributed groundwater flow module called gwflow for the SWAT+ watershed model. The module is embedded in the SWAT+ modeling code and is intended to replace the current SWAT+ aquifer module. The model accounts for recharge from SWAT+ Hydrologic Response Units (HRUs), lateral flow within the aquifer, Evapotranspiration (ET) from shallow groundwater, groundwater pumping, groundwater–surface water interactions through the streambed, and saturation excess flow. Groundwater head and groundwater storage are solved throughout the watershed domain using a water balance equation for each grid cell. The modified SWAT+ modeling code is applied to the Little River Experimental Watershed (LREW) (327 km2) in southern Georgia, USA for demonstration purposes. Using the gwflow module for the LREW increased run-time by 20% compared to the original SWAT+ modeling code. Results from an uncalibrated model are compared against streamflow discharge and groundwater head time series. Although further calibration is required if the LREW model is to be used for scenario analysis, results highlight the capabilities of the new SWAT+ code to simulate both land surface and subsurface hydrological processes and represent the watershed-wide water balance. Using the modified SWAT+ model can provide physically realistic groundwater flow gradients, fluxes, and interactions with streams for modeling studies that assess water supply and conservation practices. This paper also serves as a tutorial on modeling groundwater flow for general watershed modelers.

Hydrological and water quality modeling in a medium-sized basin using the Soil and Water Assessment Tool (SWAT)

Desalination ◽  
2010 ◽  
Vol 250 (1) ◽  
pp. 274-286 ◽  
Author(s):  
Vassilios Pisinaras ◽  
Christos Petalas ◽  
Georgios D. Gikas ◽  
Alexandra Gemitzi ◽  
Vassilios A. Tsihrintzis
Keyword(s):  
Water Quality ◽  
Assessment Tool ◽  
Water Quality Modeling ◽  
Quality Modeling ◽  
Water Assessment ◽  
Soil And Water

Discharge Assessment by Using Integrated Hydrologic Model for Environmental Technology Development

2014 ◽  
Vol 911 ◽  
pp. 378-382 ◽  
Author(s):  
Mohd Fozi Ali ◽  
Nor Faiza A. Rahman ◽  
Khairi Khalid
Keyword(s):  
Water Quality ◽  
River Water ◽  
River Discharge ◽  
Technology Development ◽  
Swat Model ◽  
Hydrologic Model ◽  
Water Quality Modeling ◽  
River Water Quality ◽  
Environmental Technology ◽  
Current State

River water quality degradation is one of the most significant environmental challenges. Over the years, many models have been used to investigate the current state of Malaysian rivers and its effects to the environment. River discharge is an important factor in water quality investigation. An integrative computational model, GIS coupled with SWAT model was being used to predict river discharge of this research. The simulation results in the period 1999 to 2010 represented fluctuation of discharge relatively well with both R2and NSI values were above 0.6. The results proved that the development of integrative GIS technology coupled with SWAT model is a good tool for environmental technology development in terms of investigating the current state of Langat river water quality as well as the capability of simulating the river discharge in the river basin. This shows that GIS-SWAT interface can be a reliable tool for water quality modeling in Malaysia in the future and further development on the software technology is a benefit for the water resources and environmental studies.

Post-validation of SWAT model in a coastal watershed for predicting land use/cover change impacts

2015 ◽  
Vol 46 (6) ◽  
pp. 837-853 ◽  
Author(s):  
Harsh Vardhan Singh ◽  
Latif Kalin ◽  
Andrew Morrison ◽  
Puneet Srivastava ◽  
Graeme Lockaby ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Suspended Solids ◽  
Assessment Tool ◽  
Organic Phosphorus ◽  
Swat Model ◽  
Coastal Watershed ◽  
Water Quality And Quantity ◽  
Water Assessment ◽  
Total P

Watershed models are typically calibrated and validated with the same land use and land cover (LULC) dataset and later used in assessing impacts of changing LULC, such as urbanization, on hydrology and/or water quality. However, their performance in predicting water quality/quantity in response to changing LULC is rarely assessed. The main objective of this paper was to explore the performance of the soil and water assessment tool (SWAT) in predicting water quality and quantity in response to changing LULC in a coastal watershed in Alabama, USA. Using the 1992 LULC as the input, the model was calibrated and validated for flow for the period 1990–1998, and for total suspended solids (TSS), nitrate (NO3−), and organic phosphorus for the period 1994–1998 at several sites within the watershed. The model was then driven with the 2008 LULC data and its performance in predicting flow and TSS, NO3−, and total-P loads during the period 2008–2010 was evaluated (post-validation). SWAT showed good performance in predicting changes in flow and water quality during the post-validation period. The study also highlighted the importance of using the most up-to-date LULC data for effectively predicting the impacts of LULC changes on water quality.

scholarly journals Use of the swat model for hydro-sedimentologic simulation in a small rural watershed

2012 ◽  
Vol 36 (2) ◽  
pp. 557-565 ◽  
Author(s):  
Talita Uzeika ◽  
Gustavo H Merten ◽  
Jean P.G Minella ◽  
Michele Moro
Keyword(s):  
Land Use Planning ◽  
Cover Crops ◽  
Assessment Tool ◽  
Swat Model ◽  
Conservation Agriculture ◽  
The United States ◽  
Daily Basis ◽  
Efficiency Coefficient ◽  
Monthly Basis ◽  
Sediment Yields

Mathematical models have great potential to support land use planning, with the goal of improving water and land quality. Before using a model, however, the model must demonstrate that it can correctly simulate the hydrological and erosive processes of a given site. The SWAT model (Soil and Water Assessment Tool) was developed in the United States to evaluate the effects of conservation agriculture on hydrological processes and water quality at the watershed scale. This model was initially proposed for use without calibration, which would eliminate the need for measured hydro-sedimentologic data. In this study, the SWAT model was evaluated in a small rural watershed (1.19 km²) located on the basalt slopes of the state of Rio Grande do Sul in southern Brazil, where farmers have been using cover crops associated with minimum tillage to control soil erosion. Values simulated by the model were compared with measured hydro-sedimentological data. Results for surface and total runoff on a daily basis were considered unsatisfactory (Nash-Sutcliffe efficiency coefficient - NSE < 0.5). However simulation results on monthly and annual scales were significantly better. With regard to the erosion process, the simulated sediment yields for all years of the study were unsatisfactory in comparison with the observed values on a daily and monthly basis (NSE values < -6), and overestimated the annual sediment yield by more than 100 %.

scholarly journals ANALISIS TOTAL BAKTERI COLIFORM DI SUNGAI BANJIR KANAL BARAT DAN SILANDAK, SEMARANG Analysis of Total Coliform Bacteria in Banjir Kanal Barat and Silandak Rivers, Semarang

2020 ◽  
Vol 8 (4) ◽  
pp. 309-315
Author(s):  
Dilia Puspita Asih ◽  
Churun Ain ◽  
Niniek Widyorini
Keyword(s):  
Water Quality ◽  
Organic Matter ◽  
Dissolved Oxygen ◽  
Pearson Correlation ◽  
Oxygen Demand ◽  
Total Coliform ◽  
Biological Oxygen Demand ◽  
Coliform Bacteria ◽  
Survey Method ◽  
The Relationship

Sungai Banjir Kanal Barat dan Silandak merupakan sungai besar yang berada di Kota Semarang. Terdapat berbagai aktivitas di sepanjang aliran sungai tersebut, diantaranya aktivitas domestik dan industri dimana buangan limbah masuk ke dalam badan sungai sehingga menyebabkan penurunan kualitas perairan. Salah satu mikroorganisme yang terkandung dalam limbah domestik yang berperan sebagai indikator pencemaran yaitu bakteri coliform sehingga perlu dilakukan perhitungan total coliform guna mengetahui adanya pencemaran di Sungai Banjir Kanal Barat dan Silandak. Tujuan dari penelitian ini adalah untuk mengetahui kelimpahan total coliform, status mutu air berdasarkan PP Nomor 82 Tahun 2001 kelas II dan hubungan antara total coliform dengan bahan organik dan BOD (Biological Oxygen Demand) di Sungai Banjir Kanal Barat dan Silandak. Metode yang digunakan dalam penelitian ini yaitu metode survei. Pengambilan sampel terdiri dari 2 stasiun (A dan B) yang masing-masing terdapat 5 titik dan 2 kali pengulangan (P1 dan P2). Variabel utama yang dianalisis yaitu total coliform, bahan organik dan BOD, variabel pendukung yang diukur yaitu temperatur, salinitas, DO (Dissolved Oxygen ) dan pH. Berdasarkan hasil penelitian, jumlah total coliform pada stasiun A berkisar antara 240-16000 MPN/100 mldan 23-5400 MPN/100 ml pada stasiun B. Nilai total coliform pada titik A2 dan B2 pada P1 serta A5 P2telah melebihi bakumutu. Hubungan antara total coliform dengan bahan organik yaitu sangat lemah (nilaiPearson Correlation = 0,15). Hubungan antara total coliform denganBOD yaitu lemah (nilaiPearson Correlation= 0,378). Banjir Kanal Barat and Silandak Rivers are large rivers in Semarang. There are various activities along the river flow, including domestic activities and industries where waste effluents enter the river bodies causing a decrease in water quality. One of the microorganisms contained in domestic waste that as an indicator of pollution is coliform bacteria, so it is necessary to calculate the total coliform in order to find out the pollution in the Banjir Kanal Barat and Silandak Rivers. This study aims to determine abundance of total Coliform, water quality status based on PP No. 82 of 2001 class II and relationship between the total coliform with organic matter and BOD (Biological Oxygen Demand) in the Banjir Kanal Barat and Silandak Rivers. The method used in this study is survey method. Sampling consisted of 2 stations (A and B), each of which had 5  points and 2 repetitions (P1 and P2). The main variables analyzed were total coliform, organic matter and BOD, the supporting variable analiyzed were temperature, salinity, DO (Dissolved Oxygen ) and pH. Based on the results of the study, the total number of coliform at station A ranged from 240-16000 MPN/100 ml and 23-5400MPN/100 ml at station B. The total value of coliform at points A2 and B2 at P1 and A5 P2 has exceeded the standard. The relationship between total coliform and organic matter is very weak (Pearson Correlation value = 0.15). The relationship between total coliform and BOD is weak (Pearson Correlation value = 0.378). 

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