Pub Date : 2021-06-28DOI: 10.4236/ojmh.2021.113004
N. Chilagane, J. Kashaigili, E. Mutayoba, P. Lyimo, P. Munishi, Christine Tam, N. Burgess
Little Ruaha River catchment (6370 Km2) in the Southern Agricultural Growth Corridor of Tanzania (SAGCOT), is one of the country’s most significant waterways due to its ecological composition and economic value. Regardless of its ecological and economical value, the regional hydrologic condition has been tremendously affected due to land uses alteration, influenced by different socio-economic factors. This study aimed to understand the associated impacts of the present Land Use Land Cover (LULC) change on the surface runoff and sediment yield in the Little Ruaha River Catchment. Hydrological modelling using Soil and Water Assessment Tool (SWAT Model) was done to quantify the impact of land use and land cover dynamics on catchment water balance and sediment loads. The calibration and validation of the SWAT model were performed using sequential uncertainty fitting (SUFI-2). The results showed that, for the given LULC change, the average annual surface runoff increased by 2.78 mm while average annual total sediment loading increased by 3.56 t/ha, the average annual base flow decreased by 2.68 mm, ground water shallow aquifer recharge decreased from 2.97 mm and a slight decrease in average annual ground water deep aquifer recharge by 0.14 mm. The model predicts that in the future, there will be a further increase in both surface runoff and sediment load. Such changes, increased runoff generation and sediment yield with decreased base flow have implications on the sustenance flow regimes particularly the observed reduced dry season river flow of the Little Ruaha River, which in turn cause adverse impacts to the biotic component of the ecosystem, reduced water storage and energy production at Mtera Hydroelectrical dam also increasing the chances of flooding at some times of the year. The study recommends land use planning at the village level, and conservation agricultural practices to ameliorate the current situation. Developing multidisciplinary approaches for integrated catchment management is the key to the sustainability of Little Ruaha River catchment.
{"title":"Impact of Land Use and Land Cover Changes on Surface Runoff and Sediment Yield in the Little Ruaha River Catchment","authors":"N. Chilagane, J. Kashaigili, E. Mutayoba, P. Lyimo, P. Munishi, Christine Tam, N. Burgess","doi":"10.4236/ojmh.2021.113004","DOIUrl":"https://doi.org/10.4236/ojmh.2021.113004","url":null,"abstract":"Little Ruaha River catchment \u0000(6370 Km2) in the Southern Agricultural Growth \u0000Corridor of Tanzania (SAGCOT), is one of the country’s most significant \u0000waterways due to its ecological composition and economic value. Regardless of \u0000its ecological and economical value, the regional hydrologic condition has been \u0000tremendously affected due to land uses alteration, influenced by different \u0000socio-economic factors. This study aimed to understand the associated impacts \u0000of the present Land Use Land Cover (LULC) change on the surface runoff and \u0000sediment yield in the Little Ruaha River Catchment. Hydrological modelling \u0000using Soil and Water Assessment Tool (SWAT Model) was done to quantify the \u0000impact of land use and land cover dynamics on catchment water balance and sediment loads. The calibration and \u0000validation of the SWAT model were performed using sequential uncertainty \u0000fitting (SUFI-2). The results showed that, for the given LULC change, the \u0000average annual surface runoff increased by 2.78 mm while average annual total \u0000sediment loading increased by 3.56 t/ha, the average annual base flow decreased \u0000by 2.68 mm, ground water shallow aquifer recharge decreased from 2.97 mm and a \u0000slight decrease in average annual ground water deep aquifer recharge by 0.14 \u0000mm. The model predicts that in the future, there will be a further increase in \u0000both surface runoff and sediment load. Such changes, increased runoff \u0000generation and sediment yield with decreased base flow have implications on the \u0000sustenance flow regimes particularly the observed reduced dry season river flow \u0000of the Little Ruaha River, which in turn cause adverse impacts to the biotic \u0000component of the ecosystem, reduced water storage and energy production at \u0000Mtera Hydroelectrical dam also increasing the chances of flooding at some times \u0000of the year. The study recommends land use planning at the village level, and \u0000conservation agricultural practices to ameliorate the current situation. \u0000Developing multidisciplinary approaches for integrated catchment management is \u0000the key to the sustainability of Little Ruaha River catchment.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42709993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-28DOI: 10.4236/ojmh.2021.113003
Benewende Anthelme Victor Sondo, S. Ndao, P. B. D. Thioune, E. B. Diaw
This study is a part of a global approach in which, the main purpose is to understand the reasons behind the upsurge of flood events in the peri-urban area of the city of Dakar. Hydrological and hydraulics simulations were carried out to assess the risks of overflowing of the Lake Warouwaye after a so-called exceptional rain. Data were collected through field surveys, as well as site observations of dwellings before and after rain episodes. The simulations were performed using EPA’s Storm Water Management Model (SWMM) software with input data obtained from sub-software and supervisory applications such as Google Earth, Excel, and Global Mapper. The simulation results show factors of natural and anthropogenic origin may contribute to dysfunction hydrological elements such as the watershed capacity to drain and store water. In light of the results of this study, institutional governance efforts are to be made and to be sustained in order to reverse the tendency to occupy rainwater natural flow channels. It will also be necessary to involve the first actors who are the potential victims of flooding caused by the recurrent overflow of reservoirs.
{"title":"Risk Assessment of Rainwater Overflow from Lake Warouwaye in the Case of a Ten-Year Rainfall in Yeumbeul North, Senegal","authors":"Benewende Anthelme Victor Sondo, S. Ndao, P. B. D. Thioune, E. B. Diaw","doi":"10.4236/ojmh.2021.113003","DOIUrl":"https://doi.org/10.4236/ojmh.2021.113003","url":null,"abstract":"This study is a part of a global approach in which, \u0000the main purpose is to understand the reasons behind the upsurge of flood \u0000events in the peri-urban area of the city of Dakar. Hydrological and hydraulics simulations were carried out to assess the \u0000risks of overflowing of the Lake Warouwaye after a so-called exceptional rain. Data \u0000were collected through field surveys, as well as site observations of dwellings \u0000before and after rain episodes. The simulations were performed using EPA’s \u0000Storm Water Management Model (SWMM) software with input data obtained from \u0000sub-software and supervisory applications such as Google Earth, Excel, and \u0000Global Mapper. The simulation results show factors of natural and anthropogenic \u0000origin may contribute to dysfunction hydrological elements such as the \u0000watershed capacity to drain and store water. In light of the results of this \u0000study, institutional governance efforts are to be made and to be sustained in \u0000order to reverse the tendency to occupy rainwater natural flow channels. It \u0000will also be necessary to involve the first actors who are the potential \u0000victims of flooding caused by the recurrent overflow of reservoirs.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46960743","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-23DOI: 10.4236/ojmh.2021.112002
M. Kassab, A. Abbas, Iman Elgamal, Basem M. Shawky, Mahmoud F. Mubarak, R. Hosny
Water manufactured is the primary waste source in the oil and gas industry. Because of the rising amount of waste worldwide, the environmental effect of wastewater has become a primary environmental concern in recent years. The vast amounts involved have resulted in considerable costs to the industry for handling produced water. This research explains the wide variety of choices for water management. This research’s first phase was water minimization techniques, consisting of three different applications made in three different wells (Well 1, Well 2 and Well 3) and water recycling and reuse by two techniques. In Well 1, Mechanical shut-off technique was applied using through tubing bridge plug and 5 m cement dumped above it to isolate the watered out zone; as per water oil ration plot the water cut is decreased from 100% to 4% and the production is increased from 0 to 400 bcpd. In Well 2, Chemical shut-off technique using a polymer called Brightwater has been used to block channeling through high permeability intervals after PLT log detected it, and the result was brilliant, the water cut decreased from 60% to 25%, also the oil production increase from 500 to 3000 bopd. In Well 3, downhole separator installed in it using workover (unfortunately, this technique is not applied in middle east till the moment so this application is taken from an oil field in Canada)and the result was perfect, the water cut decreased from 70% to 28%, also the oil production increase from 44 to 100 bopd. This study tried to clarify and compare the most widely used water management techniques using one of the Western Desert (W.D.) (enhanced for oil recovery, constructed wetland).
{"title":"Review on the Estimating the Effective Way for Managing the Produced Water: Case Study","authors":"M. Kassab, A. Abbas, Iman Elgamal, Basem M. Shawky, Mahmoud F. Mubarak, R. Hosny","doi":"10.4236/ojmh.2021.112002","DOIUrl":"https://doi.org/10.4236/ojmh.2021.112002","url":null,"abstract":"Water manufactured is the \u0000primary waste source in the oil and gas industry. Because of the rising amount \u0000of waste worldwide, the environmental effect of wastewater has become a primary \u0000environmental concern in recent years. The vast amounts involved have resulted \u0000in considerable costs to the industry for handling produced water. This \u0000research explains the wide variety of choices for water management. This \u0000research’s first phase was water minimization techniques, consisting of three \u0000different applications made in three different wells (Well 1, Well 2 and Well \u00003) and water recycling and reuse by two techniques. In Well 1, Mechanical \u0000shut-off technique was applied using through tubing bridge plug and 5 m cement \u0000dumped above it to isolate the watered out zone; as per water oil ration plot \u0000the water cut is decreased from 100% to 4% and the production is increased from \u00000 to 400 bcpd. In Well 2, Chemical shut-off technique using a polymer called \u0000Brightwater has been used to block channeling through high permeability \u0000intervals after PLT log detected it, and the result was brilliant, the water \u0000cut decreased from 60% to 25%, also the oil production increase from 500 to \u00003000 bopd. In Well 3, downhole separator installed in it using workover (unfortunately, \u0000this technique is not applied in middle east till the moment so this \u0000application is taken from an oil field in Canada)and the result was perfect, \u0000the water cut decreased from 70% to 28%, also the oil production increase from \u000044 to 100 bopd. This study tried to clarify and compare the most widely used \u0000water management techniques using one of the Western Desert (W.D.) (enhanced \u0000for oil recovery, constructed wetland).","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48658628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-29DOI: 10.4236/OJMH.2021.111001
M. Y. Otache, J. Musa, I. Kuti, Mustapha Mohammed, Lydia Ezekiel Pam
The choice of a particular Artificial Neural Network (ANN) structure is a seemingly difficult task; worthy of relevance is that there is no systematic way for establishing a suitable architecture. In view of this, the study looked at the effects of ANN structural complexity and data pre-processing regime on its forecast performance. To address this aim, two ANN structural configurations: 1) Single-hidden layer, and 2) Double-hidden layer feed-forward back propagation network were employed. Results obtained revealed generally that: a) ANN comprised of double hidden layers tends to be less robust and converges with less accuracy than its single-hidden layer counterpart under identical situations; b) for a univariate time series, phase-space reconstruction using embedding dimension which is based on dynamical systems theory is an effective way for determining the appropriate number of ANN input neurons, and c) data pre-processing via the scaling approach excessively limits the output range of the transfer function. In specific terms considering extreme flow prediction capability on the basis of effective correlation: Percent maximum and minimum correlation coefficient (Rmax% and Rmin%), on the average for one-day ahead forecast during the training and validation phases respectively for the adopted network structures: 8 7 5 (i.e., 8 input nodes, 7 nodes in the hidden layer, and 5 output nodes in the output layer), 8 5 2 5 (8 nodes in the input layer, 5 nodes in the first hidden layer, 2 nodes in the second hidden layer, and 5 nodes in the output layer), and 8 4 3 5 (8 nodes in the input layer, 4 nodes in the first hidden layer, 3 nodes in the second hidden layer, and 5 nodes in the output layer) gave: 101.2, 99.4; 100.2, 218.3; 93.7, 95.0 in all instances irrespective of the training algorithm (i.e., pooled). On the other hand, in terms of percent of correct event prediction, the respective performances of the models for both low and high flows during the training and validation phases, respectively were: 0.78, 0.96: 0.65, 0.87; 0.76, 0.93: 0.61, 0.83; and 0.79, 0.96: 0.65, 0.87. Thus, it suffices to note that on the basis of coherence or regularity of prediction consistency, the ANN model: 8 4 3 5 performed better. This implies that though the adoption of large hidden layers vis-a-vis corresponding large neuronal signatures could be counter-productive because of network over-fitting, however, it may provide additional representational power. Based on the findings, it is imperative to note that ANN model is by no means a substitute for conceptual watershed modelling, therefore, exogenous variables should be incorporated in streamflow modelling and forecasting exercise because of their hydrologic evolutions.
{"title":"Effects of Model Structural Complexity and Data Pre-Processing on Artificial Neural Network (ANN) Forecast Performance for Hydrological Process Modelling","authors":"M. Y. Otache, J. Musa, I. Kuti, Mustapha Mohammed, Lydia Ezekiel Pam","doi":"10.4236/OJMH.2021.111001","DOIUrl":"https://doi.org/10.4236/OJMH.2021.111001","url":null,"abstract":"The choice of a particular Artificial Neural Network (ANN) structure is a seemingly difficult task; worthy of relevance is that there is no systematic way for establishing a suitable architecture. In view of this, the study looked at the effects of ANN structural complexity and data pre-processing regime on its forecast performance. To address this aim, two ANN structural configurations: 1) Single-hidden layer, and 2) Double-hidden layer feed-forward back propagation network were employed. Results obtained revealed generally that: a) ANN comprised of double hidden layers tends to be less robust and converges with less accuracy than its single-hidden layer counterpart under identical situations; b) for a univariate time series, phase-space reconstruction using embedding dimension which is based on dynamical systems theory is an effective way for determining the appropriate number of ANN input neurons, and c) data pre-processing via the scaling approach excessively limits the output range of the transfer function. In specific terms considering extreme flow prediction capability on the basis of effective correlation: Percent maximum and minimum correlation coefficient (Rmax% and Rmin%), on the average for one-day ahead forecast during the training and validation phases respectively for the adopted network structures: 8 7 5 (i.e., 8 input nodes, 7 nodes in the hidden layer, and 5 output nodes in the output layer), 8 5 2 5 (8 nodes in the input layer, 5 nodes in the first hidden layer, 2 nodes in the second hidden layer, and 5 nodes in the output layer), and 8 4 3 5 (8 nodes in the input layer, 4 nodes in the first hidden layer, 3 nodes in the second hidden layer, and 5 nodes in the output layer) gave: 101.2, 99.4; 100.2, 218.3; 93.7, 95.0 in all instances irrespective of the training algorithm (i.e., pooled). On the other hand, in terms of percent of correct event prediction, the respective performances of the models for both low and high flows during the training and validation phases, respectively were: 0.78, 0.96: 0.65, 0.87; 0.76, 0.93: 0.61, 0.83; and 0.79, 0.96: 0.65, 0.87. Thus, it suffices to note that on the basis of coherence or regularity of prediction consistency, the ANN model: 8 4 3 5 performed better. This implies that though the adoption of large hidden layers vis-a-vis corresponding large neuronal signatures could be counter-productive because of network over-fitting, however, it may provide additional representational power. Based on the findings, it is imperative to note that ANN model is by no means a substitute for conceptual watershed modelling, therefore, exogenous variables should be incorporated in streamflow modelling and forecasting exercise because of their hydrologic evolutions.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46384972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4236/ojmh.2021.114005
A. Yao, K. Anoh, Loukou Alexis Brou, Menouan Wilfried Goli, L. K. Kouassi
In recent years, the Cavally River has been subject to multiple activities, including the construction of diversion channels and a bridge that makes it vulnerable to flooding. In order to assess the impact of these hydraulic structures on the river hydrodynamic functioning, a 1D-2D model was realized. The implementation of the 1D-2D model consisted of first running the 1D model, then the 2D model, and finally in coupling them. The 1D-2D model was designed with the 1988 flood hydrograph, a Manning’s coefficient of 0.052 m 1/3 /s for the minor bed and 0.06 m 1/3 /s for the major bed. The results of the hydraulic model show that the velocities are almost identical to those of the Cavally in natural operation. The values of the velocities are included between 0.4 m/s and 1.3 m/s at the level of the minor bed of the river and between 0.06 m/s and 0.71 m/s at the level of the floodplains. The average water level for flood propagation is 262.37 ± 0.44 m before construction of the structures and 262.23 ± 0.85 m after construction of the structures. The 0.41 m reduction in water level due to the diversion canal and bridge is negligible compared to the total fluctuations of the Cavally River, which vary from 6 to 7 m over the year.
近年来，卡瓦利河受到多种活动的影响，包括建设导流渠道和一座桥梁，使其容易受到洪水的影响。为了评估这些水工建筑物对河流水动力功能的影响，实现了一个1D-2D模型。3d -2D模型的实现包括先运行1D模型，然后运行2D模型，最后将两者耦合。采用1988年洪水线设计一维-二维模型，小河床的曼宁系数为0.052 m 1/3 /s，大河床的曼宁系数为0.06 m 1/3 /s。水力模型计算结果表明，水流速度与自然运行时的速度基本一致。在小河床上的速度值在0.4 ~ 1.3 m/s之间，在洪泛平原上的速度值在0.06 ~ 0.71 m/s之间。构筑物施工前洪水传播平均水位为262.37±0.44 m，构筑物施工后平均水位为262.23±0.85 m。由于引水渠和桥梁造成的0.41米的水位下降与卡沃利河全年6 - 7米的总波动相比微不足道。
{"title":"Simulation of the Hydrodynamic Functioning of the Cavally River Using a Coupled 1D-2D Model in the Ity Area (Zouan-Hounien in Côte d’Ivoire)","authors":"A. Yao, K. Anoh, Loukou Alexis Brou, Menouan Wilfried Goli, L. K. Kouassi","doi":"10.4236/ojmh.2021.114005","DOIUrl":"https://doi.org/10.4236/ojmh.2021.114005","url":null,"abstract":"In recent years, the Cavally River has been subject to multiple activities, including the construction of diversion channels and a bridge that makes it vulnerable to flooding. In order to assess the impact of these hydraulic structures on the river hydrodynamic functioning, a 1D-2D model was realized. The implementation of the 1D-2D model consisted of first running the 1D model, then the 2D model, and finally in coupling them. The 1D-2D model was designed with the 1988 flood hydrograph, a Manning’s coefficient of 0.052 m 1/3 /s for the minor bed and 0.06 m 1/3 /s for the major bed. The results of the hydraulic model show that the velocities are almost identical to those of the Cavally in natural operation. The values of the velocities are included between 0.4 m/s and 1.3 m/s at the level of the minor bed of the river and between 0.06 m/s and 0.71 m/s at the level of the floodplains. The average water level for flood propagation is 262.37 ± 0.44 m before construction of the structures and 262.23 ± 0.85 m after construction of the structures. The 0.41 m reduction in water level due to the diversion canal and bridge is negligible compared to the total fluctuations of the Cavally River, which vary from 6 to 7 m over the year.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70316022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-27DOI: 10.4236/ojmh.2020.104007
Mohammedreshid A. Aliye, Alemu O. Aga, Teshale Tadesse, P. Yohannes
A number of physically-based and distributed watershed models have been developed to model the hydrology of the watershed. For a specific watershed, selecting the most suitable hydrological model is necessary to obtain good simulated results. In this study, two hydrologic models, Soil and Water Assessment Tool (SWAT) and Hydrological Engineering Centre-The Hydrologic Modeling System (HEC-HMS), were applied to predict streamflow in Katar River basin, Ethiopia. The performances of these two models were compared in order to select the right model for the study basin. Both models were calibrated and validated with stream flow data of 11 years (1990-2000) and 7 years (2001-2007) respectively. Nash-Sutcliffe Error (NSE) and Coefficient of Determination (R2) were used to evaluate efficiency of the models. The results of calibration and validation indicated that, for river basin Katar, both models could simulate fairly well the streamflow. SWAT gave the model performance with the R2 > 0.78 and NSE > 0.67; and the HEC-HMS model provided the model performance with the R2 > 0.87 and NSE > 0.73. Hence, the simulated streamflow given by the HEC-HMS model is more satisfactory than that provided by the SWAT model.
{"title":"Evaluating the Performance of HEC-HMS and SWAT Hydrological Models in Simulating the Rainfall-Runoff Process for Data Scarce Region of Ethiopian Rift Valley Lake Basin","authors":"Mohammedreshid A. Aliye, Alemu O. Aga, Teshale Tadesse, P. Yohannes","doi":"10.4236/ojmh.2020.104007","DOIUrl":"https://doi.org/10.4236/ojmh.2020.104007","url":null,"abstract":"A number of physically-based and distributed \u0000watershed models have been developed to model the hydrology of the watershed. \u0000For a specific watershed, selecting the most suitable hydrological model is \u0000necessary to obtain good simulated results. In this study, two hydrologic \u0000models, Soil and Water Assessment Tool (SWAT) and Hydrological Engineering \u0000Centre-The Hydrologic Modeling System (HEC-HMS), \u0000were applied to predict streamflow in Katar River basin, Ethiopia. The \u0000performances of these two models were compared in order to select the right \u0000model for the study basin. Both models were calibrated and validated with \u0000stream flow data of 11 years (1990-2000) and 7 years (2001-2007) respectively. \u0000Nash-Sutcliffe Error (NSE) and Coefficient of Determination (R2) \u0000were used to evaluate efficiency of the models. The results of calibration and \u0000validation indicated that, for river basin Katar, both models could simulate \u0000fairly well the streamflow. SWAT gave the model performance with the R2 > 0.78 and NSE > 0.67; and the HEC-HMS model provided the model \u0000performance with the R2 > 0.87 and NSE > 0.73. Hence, the \u0000simulated streamflow given by the HEC-HMS model is more satisfactory than that \u0000provided by the SWAT model.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44159834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-10-27DOI: 10.4236/ojmh.2020.104006
Moussé Landing Sane, S. Sambou, Issa Lèye, D. Ndione, S. Diatta, I. Ndiaye, M. Badji, Seïdou Kane
Management of reservoir water resources requires the knowledge of flow inputs in this reservoir. Hydrological rainfall-runoff model is used for this purpose. There are several types of hydrological model according the description of the hydrological processes: black-box models, conceptual models, deterministic physical based model. SWAT is a semi-distributed hydrological model designed for water quality and quantity. This versatile tool has been used all around the world to assess and manage water resources. The main objective of the paper is to calibrate and validate the SWAT model on the watershed of Bafing located between 10°30' and 12°30' north latitude and between 12°30' and 9°30' west longitude to assess climate change on this river flows. A DEM with a resolution of 12.5 m × 12.5 m, the daily average flows and the daily observed precipitations on the period 1979-1986 (long period) are used as inputs for the calibration, while precipitations for the period 1988-1994 are used for the validation. The sensitivity analysis was done to detect the most determining coefficients during the calibration step. It shows that 19 parameters are required. Then, the effect of the period on the parameters calibration is checked for using first the whole period of study and then each year of the period of study. The Nash criterion was used to compare the calculated and the observed hygrographs in each case. The results showed that the longer is the period of calibration, the more accurate is the Nash criterion. The calibration per year gave a best Nash criterion except for a single year. During the validation, the parameters calculated on the long period lead to the best Nash criterion. The values of the Nash criterion calibration and validation are very suitable. These results of calibration can be used to study the long-term evolution of flow at Senegal River on Bafing Makana.
水库水资源的管理需要了解该水库的流量输入。为此，采用了水文降雨径流模型。根据水文过程的描述，水文模型有几种类型:黑箱模型、概念模型、确定性物理模型。SWAT是针对水质和水量设计的半分布式水文模型。这一多功能工具已在世界各地用于评估和管理水资源。本文的主要目的是在北纬10°30′~ 12°30′、西经12°30′~ 9°30′之间的八滨流域对SWAT模型进行标定和验证，以评估该河流流量的气候变化。采用分辨率为12.5 m × 12.5 m的DEM、1979-1986年(长周期)的日平均流量和日观测降水作为定标输入，1988-1994年的降水用于验证。进行灵敏度分析以检测校准步骤中最重要的决定系数。显示需要19个参数。然后，首先使用整个研究期间，然后使用研究期间的每一年，检查周期对参数校准的影响。采用纳什判据来比较每种情况下的计算值和观测值。结果表明，标定周期越长，Nash准则的精度越高。每年的校准给出了最佳纳什标准，除了单一年份。在验证过程中，通过长周期的参数计算得到最佳纳什准则。纳什准则的校正和验证值是非常合适的。这些校正结果可用于研究巴冰马卡纳塞内加尔河流量的长期演变。
{"title":"Calibration and Validation of the SWAT Model on the Watershed of Bafing River, Main Upstream Tributary of Senegal River: Checking for the Influence of the Period of Study","authors":"Moussé Landing Sane, S. Sambou, Issa Lèye, D. Ndione, S. Diatta, I. Ndiaye, M. Badji, Seïdou Kane","doi":"10.4236/ojmh.2020.104006","DOIUrl":"https://doi.org/10.4236/ojmh.2020.104006","url":null,"abstract":"Management of reservoir water resources requires the \u0000knowledge of flow inputs in this reservoir. Hydrological rainfall-runoff model \u0000is used for this purpose. There are several types of hydrological model \u0000according the description of the hydrological processes: black-box models, \u0000conceptual models, deterministic physical based model. SWAT is a semi-distributed \u0000hydrological model designed for water quality and quantity. This versatile tool \u0000has been used all around the world to assess and manage water resources. The \u0000main objective of the paper is to calibrate and validate the SWAT model on the \u0000watershed of Bafing located between 10°30' and 12°30' \u0000north latitude and between 12°30' and 9°30' west longitude to assess climate change \u0000on this river flows. A DEM with a resolution of 12.5 m × 12.5 m, the daily average flows and the \u0000daily observed precipitations on the period 1979-1986 (long period) are used as \u0000inputs for the calibration, while precipitations for the period 1988-1994 are \u0000used for the validation. The sensitivity analysis was done to detect the most \u0000determining coefficients during the calibration step. It shows that 19 \u0000parameters are required. Then, the effect of the period on the parameters \u0000calibration is checked for using first the whole period of study and then each \u0000year of the period of study. The Nash criterion was used to compare the \u0000calculated and the observed hygrographs in each case. The results showed that \u0000the longer is the period of calibration, the more accurate is the Nash \u0000criterion. The calibration per year gave a best Nash criterion except for a \u0000single year. During the validation, the parameters calculated on the long \u0000period lead to the best Nash criterion. The values of the Nash criterion \u0000calibration and validation are very suitable. These results of calibration can \u0000be used to study the long-term evolution of flow at Senegal River on Bafing \u0000Makana.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42374257","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-03DOI: 10.4236/ojmh.2020.103005
M. Y. Otache, O. D. Jimoh, J. Musa, Abdullahi Danmagaji
Hydrological drought is usually characterised by water loss over time from both underground and surface supplies. Thus for this study, the assessment of hydrological drought was carried out by employing Cumulative Rainfall/Streamflow Anomaly as preliminary tools for the presence of drought signatures while detailed characterisation was via Streamflow Drought Index (SDI). The results revealed that hydrological drought was observed in all the stations; however, though in general, the stations could be classified as experiencing near normal drought conditions with mild drought signatures. The findings also revealed that the average streamflow deficit volume and durations of the hydrological drought severity were 1.780 Mm3 and 192 months, 1.444 Mm3 and 252 months, 3.148 Mm3 and 252 months, and 0.159 Mm3 and 372 months for Bakolori, Goronyo (pre dam construction era), Goronyo (post dam construction era) and Zobe stations, respectively. The results also revealed the relevance of flow duration curve and analysis of frequency of drought state transition for the development of scenario-based basin water resources management protocol. The coefficient of determination (R2) statistic of the developed regression models indicate that 73.3% and 86.5% variation in streamflow dynamics across the Basin can be explained by climate change variables. However, for sustainable management of water resources in the Basin, it is imperative that characterisation of hydrological drought and monitoring should employ robust indices which use improved monthly precipitation estimates under global warming scenario in addition to ensuring that there is a shift from reactive to proactive approach in order to combat hydrological risk. Hence, a robust framework that finds application both for planning mitigation actions which embody strategic, tactical and emergency components should be designed; to this end, analysis of persistence and recurrence of drought in time and determination of possible recurrent patterns are necessary.
{"title":"Characterisation of Hydrological Drought and Implications for Sustainable Water Resources Management in the Sokoto-Rima River Basin (SRRB), Nigeria","authors":"M. Y. Otache, O. D. Jimoh, J. Musa, Abdullahi Danmagaji","doi":"10.4236/ojmh.2020.103005","DOIUrl":"https://doi.org/10.4236/ojmh.2020.103005","url":null,"abstract":"Hydrological drought is \u0000usually characterised by water loss over time from both underground and surface \u0000supplies. Thus for this study, the assessment of hydrological drought was \u0000carried out by employing Cumulative Rainfall/Streamflow Anomaly as preliminary tools for the presence of drought signatures while \u0000detailed characterisation was via Streamflow Drought Index (SDI). The results \u0000revealed that hydrological drought was observed in all the stations; however, \u0000though in general, the stations could be classified as experiencing near normal \u0000drought conditions with mild drought signatures. The findings also revealed \u0000that the average streamflow deficit volume and durations of the hydrological \u0000drought severity were 1.780 Mm3 and 192 months, 1.444 Mm3 and 252 months, 3.148 Mm3 and 252 months, and 0.159 Mm3 and 372 months for Bakolori, Goronyo (pre dam construction era), Goronyo (post \u0000dam construction era) and Zobe stations, respectively. The results also \u0000revealed the relevance of flow duration curve and analysis of frequency of \u0000drought state transition for the development of scenario-based basin water \u0000resources management protocol. The coefficient of determination (R2) \u0000statistic of the developed regression models indicate that 73.3% and 86.5% \u0000variation in streamflow dynamics across the Basin can be explained by climate \u0000change variables. However, for sustainable management of water resources in the \u0000Basin, it is imperative that characterisation of hydrological drought and \u0000monitoring should employ robust indices which use improved monthly \u0000precipitation estimates under global warming scenario in addition to ensuring \u0000that there is a shift from reactive to proactive approach in order to combat \u0000hydrological risk. Hence, a robust framework that finds application both for \u0000planning mitigation actions which embody strategic, tactical and emergency \u0000components should be designed; to this end, analysis of persistence and \u0000recurrence of drought in time and determination of possible recurrent patterns \u0000are necessary.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-06-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46418340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-08DOI: 10.4236/ojmh.2020.102002
M. Gophen
Regional Climate Change studied during 1950-2019 aimed at enhancement of aridity was indicated recently in the Lake Kinneret (Israel) watershed. Climate change was indicated by: Higher periodical frequency of negative SPI Values (Standard Precipitation Index), decline of Precipitation regime and River flow inputs that was followed by decline of Lake Kinneret WL and Elevation of ET regime. Nevertheless aridity enhanced the opposite, decline of ET capacities. Underground flows indicated outputs enhancement. The temporal decline of air temperature during 1940-1980 probably due to the change of ALBEDO Factor was twisted later into regional temperature elevation. During the 1950s, old lake Hula and surrounding wetlands were drained and water cover surface was converted to plant cover, which enhanced sunlight energy reflection. Followed eventual climate change, management legislations were a reduction of water allocation for agricultural irrigation. A recent public dispute has indicated contradicted conclusions as causation for WL decline in Lake Kinneret: 1) Enhancement of Agricultural water consumption in the Upper Jordan Watershed and 2) Climate change-aridity enhancement. This paper confirms the second conclusion.
{"title":"Climate and Water Balance Changes in the Kinneret Watershed: A Review","authors":"M. Gophen","doi":"10.4236/ojmh.2020.102002","DOIUrl":"https://doi.org/10.4236/ojmh.2020.102002","url":null,"abstract":"Regional Climate Change studied during 1950-2019 \u0000aimed at enhancement of aridity was indicated recently in the Lake Kinneret \u0000(Israel) watershed. Climate change was indicated by: Higher periodical \u0000frequency of negative SPI Values (Standard Precipitation Index), decline of \u0000Precipitation regime and River flow inputs that was followed by decline of Lake \u0000Kinneret WL and Elevation of ET regime. Nevertheless aridity enhanced the \u0000opposite, decline of ET capacities. Underground flows indicated outputs \u0000enhancement. The temporal decline of air \u0000temperature during 1940-1980 probably due to the change of ALBEDO Factor \u0000was twisted later into regional temperature elevation. During the 1950s, old lake Hula and surrounding wetlands were \u0000drained and water cover surface was converted to plant cover, which \u0000enhanced sunlight energy reflection. Followed eventual climate change, \u0000management legislations were a reduction of water allocation for agricultural \u0000irrigation. A recent public dispute has indicated contradicted conclusions as \u0000causation for WL decline in Lake Kinneret: 1) Enhancement of Agricultural water \u0000consumption in the Upper Jordan Watershed and 2) Climate change-aridity enhancement. This \u0000paper confirms the \u0000second conclusion.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45822258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-07DOI: 10.4236/ojmh.2020.102003
Kassa Issifou Mounou Sambieni, F. P. Codo
Floods and flows data are useful for dimensioning of dikes and dams which often include evacuation devices that regulate flows to ensure the volumes of water. The objective of this study is to estimate the available water resource in the village of Gbedji-Kotovi, located in the watershed of Couffo river in Benin by using sequentially, the HBV (Hydrologiska Byrans Vattenbalansavdelning) and GR4J (Rural Engineering model with 4 daily parameters) climate models. Hydrographs of water levels are simulated according to the calibration period (1994-1999) different from the validation one (1982-1988). Considering the Nash-Sutcliffe model Efficiency coefficient (NSE), the performance of GR4J model during calibration is slightly higher than the performance of the HBV model, while during the validation, the contrary is noticed. The annual rainfall average simulated is 1117.7 mm/year while the average observed is 1104.6 mm/year over the period 1981-2005. By 2050, on one hand, the annual flow rate values will vary from -19.2 to -11.9%, while the actual evapotranspiration will vary between 0.5 and -5.8; on another hand, the potential evapotranspiration and the annual precipitation remain constant. An average flow of 187 millions m3/year for annual average water depth of 1094 mm is obtained at Lanta rain station, which covers an area of 1664.47 km2, while this flow enabled an average flow of 327.5 millons m3/year to be obtained at the virtual station of our study area of 2908.15 km2. The flow rates corresponding to the return periods of 10, 25 and 50 years vary from 5.51 to 12.67 m3/s at the outlet of the virtual station; while those at the outlet of Lanta station vary from 3.6 to 6.6 m3/s. However, the simulated water quantiles cannot be fully mobilized; because of the uses, they undergo upstream and downstream. Thus, Gbedji-Kotovi locality requires the implementation of an integrated water resource management strategy that includes the construction of dikes and dams.
{"title":"Modelling Estimation of the Available Rainwater Resource in Gbédji-Kotovi Clay Area for Supplying Dikes and Dams","authors":"Kassa Issifou Mounou Sambieni, F. P. Codo","doi":"10.4236/ojmh.2020.102003","DOIUrl":"https://doi.org/10.4236/ojmh.2020.102003","url":null,"abstract":"Floods and flows data are \u0000useful for dimensioning of dikes and dams which often include evacuation \u0000devices that regulate flows to ensure the volumes of water. The objective of \u0000this study is to estimate the available water resource in the village of \u0000Gbedji-Kotovi, located in the watershed of Couffo river in Benin by using \u0000sequentially, the HBV (Hydrologiska Byrans Vattenbalansavdelning) and GR4J \u0000(Rural Engineering model with 4 daily parameters) climate models. \u0000Hydrographs of water levels are simulated according to the calibration period \u0000(1994-1999) different from the validation one (1982-1988). Considering the Nash-Sutcliffe model Efficiency coefficient (NSE), \u0000the performance of GR4J model during calibration is slightly higher than the \u0000performance of the HBV model, while during the validation, the contrary is \u0000noticed. The annual rainfall average simulated is 1117.7 mm/year while the average observed is 1104.6 mm/year over the period 1981-2005. By 2050, on \u0000one hand, the annual flow rate \u0000values will vary from -19.2 to -11.9%, while the actual \u0000evapotranspiration will \u0000vary between 0.5 and -5.8; on another hand, the \u0000potential evapotranspiration and the annual precipitation remain constant. An \u0000average flow of 187 millions m3/year for \u0000annual average water depth of 1094 mm is obtained at Lanta rain station, which \u0000covers an area of 1664.47 km2, while this flow enabled an average \u0000flow of 327.5 millons m3/year to be obtained at the \u0000virtual station of our study area of 2908.15 km2. The flow rates corresponding to \u0000the return periods of 10, 25 and 50 years vary from 5.51 to 12.67 m3/s \u0000at the outlet of the virtual station; while those at the outlet \u0000of Lanta station vary from 3.6 to 6.6 m3/s. However, the simulated \u0000water quantiles cannot be fully mobilized; because \u0000of the uses, they undergo upstream and downstream. Thus, Gbedji-Kotovi locality \u0000requires the implementation of an integrated water resource management strategy \u0000that includes the construction of dikes and dams.","PeriodicalId":70695,"journal":{"name":"现代水文学期刊(英文)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47774934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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