scholarly journals Accuracy Analysis of IMERG Satellite Rainfall Data and Its Application in Long-term Runoff Simulation

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2177
Author(s):  
Chongxun Mo ◽  
Mingshan Zhang ◽  
Yuli Ruan ◽  
Junkai Qin ◽  
Yafang Wang ◽  
...  
Keyword(s):  
Swat Model ◽  
Probability Of Detection ◽  
Rainfall Data ◽  
Karst Area ◽  
Efficiency Coefficient ◽  
Accuracy Analysis ◽  
Runoff Simulation ◽  
Satellite Rainfall ◽  
Simulation Results

Frequent flood disasters have caused serious damage to karst areas with insufficient measured rainfall data, and the analysis of the applicability of satellite rainfall data in runoff simulation is helpful to the local water management. Therefore, the purpose of this study is to analyze the accuracy of IMERG satellite rainfall data and apply it to long-term runoff simulations in a karst area—the Xiajia River basin, China. First, R (correlation coefficient) and POD (probability of detection) are applied to analyze the accuracy of the IMERG data, and the SWAT model is used for runoff simulation. The results show that the accuracy of the original IMERG data is poor (R range from 0.412 to 0.884 and POD range from 47.33 to 100), and the simulation results are “Unsatisfactory” (NSE (Nash-Sutcliffe efficiency coefficient) ranged from 0.17 to 0.32 and RSR (root mean square standard deviation ratio) ranged from 0.81 to 0.92). Therefore, the GDA correction method is used to correct the original IMERG data, and then the accuracy analysis and runoff simulation are carried out. The results show that the accuracy of the corrected IMERG data is better than that of the original data (R range from 0.886 to 0.987 and POD range from 94.08 to 100), and the simulation results of the corrected IMERG data are “Satisfactory” (NSE is over 0.55 and RSR is approximately 0.65). Therefore, the corrected data have a certain applicability in long-term continuous runoff simulations.

scholarly journals Improvement of the SWAT model for event-based flood simulation on a sub-daily timescale

2018 ◽  
Vol 22 (9) ◽  
pp. 5001-5019 ◽  
Author(s):  
Dan Yu ◽  
Ping Xie ◽  
Xiaohua Dong ◽  
Xiaonong Hu ◽  
Ji Liu ◽  
...  
Keyword(s):  
Swat Model ◽  
Human Society ◽  
Flood Events ◽  
Flood Simulation ◽  
Calibration And Validation ◽  
Event Model ◽  
Flood Period ◽  
Simulation Results ◽  
Event Based

Abstract. Flooding represents one of the most severe natural disasters threatening the development of human society. A model that is capable of predicting the hydrological responses in watershed with management practices during flood period would be a crucial tool for pre-assessment of flood reduction measures. The Soil and Water Assessment Tool (SWAT) is a semi-distributed hydrological model that is well capable of runoff and water quality modeling under changed scenarios. The original SWAT model is a long-term yield model. However, a daily simulation time step and a continuous time marching limit the application of the SWAT model for detailed, event-based flood simulation. In addition, SWAT uses a basin level parameter that is fixed for the whole catchment to parameterize the unit hydrograph (UH), thereby ignoring the spatial heterogeneity among the sub-basins when adjusting the shape of the UHs. This paper developed a method to perform event-based flood simulation on a sub-daily timescale based on SWAT2005 and simultaneously improved the UH method used in the original SWAT model. First, model programs for surface runoff and water routing were modified to a sub-daily timescale. Subsequently, the entire loop structure was broken into discrete flood events in order to obtain a SWAT-EVENT model in which antecedent soil moisture and antecedent reach storage could be obtained from daily simulations of the original SWAT model. Finally, the original lumped UH parameter was refined into a set of distributed ones to reflect the spatial variability of the studied area. The modified SWAT-EVENT model was used in the Wangjiaba catchment located in the upper reaches of the Huaihe River in China. Daily calibration and validation procedures were first performed for the SWAT model with long-term flow data from 1990 to 2010, after which sub-daily (Δt=2 h) calibration and validation in the SWAT-EVENT model were conducted with 24 flood events originating primarily during the flood seasons within the same time span. Daily simulation results demonstrated that the SWAT model could yield very good performances in reproducing streamflow for both whole year and flood period. Event-based flood simulation results simulated by the sub-daily SWAT-EVENT model indicated reliable performances, with ENS values varying from 0.67 to 0.95. The SWAT-EVENT model, compared to the SWAT model, particularly improved the simulation accuracies of the flood peaks. Furthermore, the SWAT-EVENT model results of the two UH parameterization methods indicated that the use of the distributed parameters resulted in a more reasonable UH characterization and better model fit compared to the lumped UH parameter.

scholarly journals Hydrologic and geochemical modeling of a karstic Mediterranean watershed

2012 ◽  
Vol 9 (1) ◽  
pp. 1-27 ◽  
Author(s):  
N. P. Nikolaidis ◽  
F. Bouraoui ◽  
G. Bidoglio
Keyword(s):  
Climate Change ◽  
Water Management ◽  
Swat Model ◽  
Livestock Grazing ◽  
High Rate ◽  
Karst Area ◽  
Water Volume ◽  
Climate Change Scenarios ◽  
Karst Water ◽  
Simulation Results

Abstract. The SWAT model was modified to simulate the hydrologic and chemical response of karstic systems and assess the impacts of land use management and climate change of an intensively managed Mediterranean watershed in Crete, Greece. A methodology was developed for the determination of the extended karst area contributing to the spring flow as well as the degree of dilution of nitrates due to permanent karst water volume. The modified SWAT model has been able to capture the temporal variability of both karst flow and surface runoff using high frequency monitoring data collected since 2004 in addition to long term flow time series collected since 1973. The overall hydrologic budget of the karst was estimated and its evaporative losses were calculated to be 28% suggesting a very high rate of karst infiltration. Nitrate chemistry of the karst was simulated by calibrating a dilution factor allowing for the estimation of the total karstic groundwater volume to approximately 500 million m3 of reserve water. The nitrate simulation results suggested a significant impact of livestock grazing on the karstic groundwater and on surface water quality. Finally, simulation results for a set of climate change scenarios suggested a 17% decrease in precipitation, 8% decrease in ET and 22% decrease in flow in 2030–2050 compared to 2010–2020. A validated tool for integrated water management of karst areas has been developed, providing policy makers an instrument for water management that could tackle the increasing water scarcity in the island.

scholarly journals Floods in Southern Thailand in December 2016 and January 2017

2018 ◽  
Vol 13 (4) ◽  
pp. 793-803
Author(s):  
Taichi Tebakari ◽  
Sanit Wongsa ◽  
Yoshiaki Hayashi ◽  
◽  
◽  
...  
Keyword(s):  
Large Scale ◽  
Field Survey ◽  
Rainfall Data ◽  
Precipitation Event ◽  
Rain Gauges ◽  
Southern Thailand ◽  
Satellite Rainfall ◽  
Precipitation Phenomena ◽  
Precipitation Events

A large scale flood disaster occurred in Southern Thailand in December, 2016 and January, 2017, resulting in 95 deaths. The majority of the 15 provinces in Southern Thailand suffered from the disaster and extensive, long-term damage was caused which distinguished this flood event from previous flood disasters. This paper reports the findings of a field survey conducted in February, 2017 and analyzes the precipitation phenomena by using ground rainfall data as well as satellite rainfall data because there were not enough ground rain gauges set in this region. Results revealed that this precipitation event had the highest intensity out of all precipitation events occurring over the last 11 years.

scholarly journals Assessment of Ecological and Hydro-Geomorphological Alterations under Climate Change Using SWAT and IAHRIS in the Eo River in Northern Spain

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1745
Author(s):  
Julio Pérez-Sánchez ◽  
Javier Senent-Aparicio ◽  
Carolina Martínez Santa-María ◽  
Adrián López-Ballesteros
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Assessment Tool ◽  
Swat Model ◽  
General Circulation Models ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Efficiency Coefficient ◽  
Northern Spain

Magnitude and temporal variability of streamflow is essential for natural biodiversity and the stability of aquatic environments. In this study, a comparative analysis between historical data (1971–2013) and future climate change scenarios (2010–2039, 2040–2069 and 2070–2099) of the hydrological regime in the Eo river, in the north of Spain, is carried out in order to assess the ecological and hydro-geomorphological risks over the short-, medium- and long-term. The Soil and Water Assessment Tool (SWAT) model was applied on a daily basis to assess climate-induced hydrological changes in the river under five general circulation models and two representative concentration pathways. Statistical results, both in calibration (Nash-Sutcliffe efficiency coefficient (NSE): 0.73, percent bias (PBIAS): 3.52, R2: 0.74) and validation (NSE: 0.62, PBIAS: 6.62, R2: 0.65), are indicative of the SWAT model’s good performance. The ten climate scenarios pointed out a reduction in rainfall (up to −22%) and an increase in temperatures, both maximum (from +1 to +7 °C) and minimum ones (from +1 to +4 °C). Predicted flow rates resulted in an incrementally greater decrease the longer the term is, varying between −5% (in short-term) and −53% (in long-term). The free software IAHRIS (Indicators of Hydrologic Alteration in Rivers) determined that alteration for usual values remains between excellent and good status and from good to moderate in drought values, but flood values showed a deficient regime in most scenarios, which implies an instability of river morphology, a progressive reduction in the section of the river and an advance of aging of riparian habitat, endangering the renewal of the species.

Investigating Error Metrics for Satellite Rainfall Data at Hydrologically Relevant Scales

2008 ◽  
Vol 9 (3) ◽  
pp. 563-575 ◽  
Author(s):  
Faisal Hossain ◽  
George J. Huffman
Keyword(s):  
High Resolution ◽  
Spatial Scales ◽  
The United States ◽  
Space Time ◽  
Probability Of Detection ◽  
Rainfall Data ◽  
True Value ◽  
Error Metrics ◽  
Satellite Rainfall ◽  
New Generation

Abstract This paper addresses the following open question: What set of error metrics for satellite rainfall data can advance the hydrologic application of new-generation, high-resolution rainfall products over land? The authors’ primary aim is to initiate a framework for building metrics that are mutually interpretable by hydrologists (users) and algorithm developers (data producers) and to provide more insightful information on the quality of the satellite estimates. In addition, hydrologists can use the framework to develop a space–time error model for simulating stochastic realizations of satellite estimates for quantification of the implication on hydrologic simulation uncertainty. First, the authors conceptualize the error metrics in three general dimensions: 1) spatial (how does the error vary in space?); 2) retrieval (how “off” is each rainfall estimate from the true value over rainy areas?); and 3) temporal (how does the error vary in time?). They suggest formulations for error metrics specific to each dimension, in addition to ones that are already widely used by the community. They then investigate the behavior of these metrics as a function of spatial scale ranging from 0.04° to 1.0° for the Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks (PERSIANN) geostationary infrared-based algorithm. It is observed that moving to finer space–time scales for satellite rainfall estimation requires explicitly probabilistic measures that are mathematically amenable to space–time stochastic simulation of satellite rainfall data. The probability of detection of rain as a function of ground validation rainfall magnitude is found to be most sensitive to scale followed by the correlation length for detection of rain. Conventional metrics such as the correlation coefficient, frequency bias, false alarm ratio, and equitable threat score are found to be modestly sensitive to scales smaller than 0.24° latitude/longitude. Error metrics that account for an algorithm’s ability to capture rainfall intermittency as a function of space appear useful in identifying the useful spatial scales of application for the hydrologist. It is shown that metrics evolving from the proposed conceptual framework can identify seasonal and regional differences in reliability of four global satellite rainfall products over the United States more clearly than conventional metrics. The proposed framework for building such error metrics can lay a foundation for better interaction between the data-producing community and hydrologists in shaping the new generation of satellite-based, high-resolution rainfall products, including those being developed for the planned Global Precipitation Measurement (GPM) mission.

scholarly journals Improvement of the SWAT model for event-based flood forecasting on a sub-daily time scale

2017 ◽  
Author(s):  
Dan Yu ◽  
Ping Xie ◽  
Xiaohua Dong ◽  
Xiaonong Hu ◽  
Ji Liu ◽  
...  
Keyword(s):  
Time Scale ◽  
Swat Model ◽  
Flood Forecasting ◽  
Flood Events ◽  
Calibration And Validation ◽  
Event Model ◽  
Simulation Results ◽  
Event Based ◽  
Daily Time

Abstract. Flooding represents one of the most severe natural disasters threatening the development of human society. Flood forecasting systems imbedded with hydrological models are some of the most important non-engineering measures for flood defense. The Soil and Water Assessment Tool (SWAT) is a well-designed hydrological model that is widely applied for runoff and water quality modeling. The original SWAT model is a long-term yield model. However, a daily simulation time step and continuous time marching limit the use of the SWAT model for detailed, event-based flood forecasting. In addition, SWAT uses a uniform parameter set to parameterize the Unit Hydrograph (UH) for all sub-basins, thereby ignoring the heterogeneity among the sub-basins. This paper developed a method to perform event-based flood forecasting on a sub-daily time scale based on SWAT2005. First, model programs for surface runoff and water routing were modified for a sub-daily time scale. Subsequently, the entire loop structure was broken into discrete flood events in order to obtain a SWAT-EVENT model in which antecedent soil moisture and antecedent reach storage could be obtained from daily simulations of the original SWAT model. Finally, the original lumped UH parameters were refined into distributed parameters to reflect the spatial variability of the studied area. The modified SWAT-EVENT model was used in the Wangjiaba catchment located in the upper reaches of the Huaihe River in China. Daily calibration and validation procedures were first performed for the SWAT model with long-term flow data from 1990 to 2010, after which sub-daily (Δt = 2 h) calibration and validation in the SWAT-EVENT model were conducted with 24 flood events originating primarily during the flood seasons within the same time span. Daily simulation results demonstrated acceptable model performances with Nash-Sutcliffe efficiency coefficient (ENS) values of 0.77 and 0.78 for the calibration and the validation, respectively. Event-based flood simulation results indicated reliable performances, with ENS values varying from 0.66 to 0.95. The SWAT-EVENT model, compared to the SWAT model, also improved the simulation accuracies of the flood peaks. The application of distributed UH parameters within the SWAT-EVENT model can more effectively depict the spatial variability within the study area, resulting in higher qualification ratios of the relative peak discharge error (ERP), relative peak time error (ERPT) and relative runoff volume error (ERR) relative to the application of lumped parameters.

The Flow Simulation Based on SWAT Model in Wohushan Reservoir Basin

2013 ◽  
Vol 353-356 ◽  
pp. 2637-2640
Author(s):  
Shan Shan Yang ◽  
Zheng He Xu ◽  
Ke Kong
Keyword(s):  
Swat Model ◽  
Flow Simulation ◽  
Simulated Data ◽  
Measured Data ◽  
Efficiency Coefficient ◽  
Runoff Simulation ◽  
Entire Study ◽  
Simulation Based ◽  
Monthly Runoff ◽  
Reservoir Basin

In order to study the applicability of SWAT model in small and medium-sized basin, the author established SWAT model to simulate monthly runoff in Wohushan Reservoir basin. According to a lot of basic data, the spatial database and the attribute database were constructed. The entire study area was divided into 51 catchments including 126 hydrological response units. The parameters were validated by the measured data from 2007 to 2009 and calibrated from 2010 to 2011. The correlation coefficient and the Nash efficiency coefficient of monthly runoff simulation are higher than 0.70, and the relative error is lower than 15%. Considering some potential errors between the measured data and the simulated data, SWAT model can simulate the runoff process of Wohushan Reservoir basin well.

scholarly journals Long-Term Simulation of Daily Streamflow Using Radar Rainfall and the SWAT Model: A Case Study of the Gamcheon Basin of the Nakdong River, Korea

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Huiseong Noh ◽  
Jongso Lee ◽  
Narae Kang ◽  
Dongryul Lee ◽  
Hung Soo Kim ◽  
...  
Keyword(s):  
Swat Model ◽  
Rainfall Data ◽  
Nakdong River ◽  
Runoff Simulation ◽  
Spatiotemporal Resolution ◽  
Radar Rainfall ◽  
Daily Streamflow ◽  
The Nakdong River ◽  
Rain Radar ◽  
Better Than

In recent years, with the increasing need for improving the accuracy of hydrometeorological data, interests in rain-radar are also increasing. Accordingly, with high spatiotemporal resolution of rain-radar rainfall data and increasing accumulated data, the application scope of rain-radar rainfall data into hydrological fields is expanding. To evaluate the hydrological applicability of rain-radar rainfall data depending on the characteristics of hydrological model, this study appliedRgaugeandRradarto a SWAT model in the Gamcheon stream basin of the Nakdong River and analyzed the effect of rainfall data on daily streamflow simulation. The daily rainfall data forRgauge,RZ, andRKDPwere utilized as input data for the SWAT model. As a result of the daily runoff simulation for analysis periods usingRZ(P)andRKDP(P), the simulation which utilizedRgaugereflected the rainfall-runoff characteristics better than the simulations which appliedRZ(P)orRKDP(P). However, in the rainy or wet season, the simulations which utilizedRZ(P)orRKDP(P)were similar to or better than the simulation that appliedRgauge. This study reveals that analysis results and degree of accuracy depend significantly on rainfall characteristics (rainy season and dry season) and QPE algorithms when conducting a runoff simulation with radar.

scholarly journals Merging Satellite and Gauge Rainfalls for Flood Forecasting of Two Catchments Under Different Climate Conditions

Water ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 802
Author(s):  
Xinyi Min ◽  
Chuanguo Yang ◽  
Ningpeng Dong
Keyword(s):  
Correlation Coefficient ◽  
River Basin ◽  
Flood Forecasting ◽  
Rainfall Data ◽  
Good Prospect ◽  
Efficiency Coefficient ◽  
Climate Conditions ◽  
Spatial Coverage ◽  
Monitoring Accuracy ◽  
Satellite Rainfall

As satellite rainfall data has the advantages of wide spatial coverage and high spatial and temporal resolution, it is an important means to solve the problem of flood forecasting in ungauged basins (PUB). In this paper, two catchments under different conditions, Xin’an River Basin and Wuding River Basin, were selected as the representatives of humid and arid regions, respectively, and four kinds of satellite rainfall data of TRMM 3B42RT, TRMM 3B42V7, GPM IMERG Early, and GPM IMERG Late were selected to evaluate the monitoring accuracy of rainfall processes in the two catchments on hourly scale. Then, these satellite rainfall data were respectively integrated with the gauged data. HEC-HMS (The Hydrologic Engineering Center's-Hydrologic Modeling System) model was calibrated and validated to simulate flood events in the two catchments. Then, improvement effect of the rainfall merging on flood forecasting was evaluated. According to the research results, in most cases, the Nash–Sutcliffe efficiency coefficients of the simulated streamflow from initial TRMM (Tropical Rainfall Measuring Mission) and GPM (Global Precipitation Measurement) satellite rainfall data were negative at the two catchments. By merging gauge and TRMM rainfall, the Nash–Sutcliffe efficiency coefficient is mostly around 0.7, and the correlation coefficient is as high as 0.9 for streamflow simulation in the Xin'an River basin. For the streamflow simulated by merging gauge and GPM rainfall in Wuding River basin, the Nash–Sutcliffe efficiency coefficient is about 0.8, and the correlation coefficient is more than 0.9, which indicate good flood forecasting accuracy. Generally, higher performance statistics were obtained in the Xin'an River Basin than the Wuding River Basin. Compared with the streamflow simulated by the initial satellite rainfalls, significant improvement was obtained by the merged rainfall data, which indicates a good prospect for application of satellite rainfall in hydrological forecasting. In the future, it is necessary to further improve the monitoring accuracy of satellite rainfall products and to develop the method of merging multi-source rainfall data, so as to better applications in PUB and other hydrological researches.

scholarly journals Evaluation of the effect of land use change on runoff using supervised classified satellite data

2019 ◽  
Keyword(s):  
Land Use ◽  
Land Use Change ◽  
Surface Runoff ◽  
Agricultural Land ◽  
Swat Model ◽  
Model Parameters ◽  
Time Interval ◽  
Efficiency Coefficient ◽  
Runoff Simulation ◽  
Maximum Probability

<p>The main objective of this study was to determine the effect of land use change on runoff in Chenar Rahdar watershed. Land use map of the studied basin was determined using Landsat satellite imagery for 2004 and 2015 using ENVI software. After applying the necessary corrections to the images and field surveys to take the educational points, supervised classification technique and maximum probability algorithm were applied to mapping land use change in the study area. According to results, 6 classes of land use were investigated (bare land, rain fed land, forest land, water agriculture land, rangelands and urban lands). In this study, 21 model parameters were calibrated with monthly runoff using 2004-2012 data and validated using 2012-2015 data. The efficiency coefficient for calibration and validation were between 0.88 and 0.94, respectively. The land use changes trend within the time interval showed that the highest percentage of incremental changes is related to urban lands with 108.45%, whereas, the highest decline was observed for agricultural land with 12.46%. In order to investigate the effect of land use change on surface runoff, different land use maps were applied to SWAT model, supposing constant condition for other parameters of the model. The results show that surface runoff increased by 11%, in 2015 compared to 2004. Comprehensive water management can reduce surface runoff in the watershed. The results showed that if all uncertainties were minimized, the calibrated SWAT model can give acceptable runoff simulation results regarding the land use change. These results can be useful for water and environmental resource managers.</p>

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