scholarly journals Study on the Staged Operation of a Multi-Purpose Reservoir in Flood Season and Its Effect Evaluation

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2563
Author(s):  
Chongxun Mo ◽  
Can Zhu ◽  
Yuli Ruan ◽  
Xingbi Lei ◽  
Zhenxiang Xing ◽  
...  
Keyword(s):  
Water Level ◽  
Fractal Theory ◽  
Daily Rainfall ◽  
Water Shortage ◽  
Risk Theory ◽  
Effect Evaluation ◽  
Maximum Rainfall ◽  
Flood Season ◽  
River Reservoir ◽  
Staged Operation

A reasonable analysis of flood season staging is significant to the management of floods and the alleviation of water shortage. For this paper, the case of the Chengbi River Reservoir in China was selected for study. Based on fractal theory, the flood season is divided into several sub-seasons by using four indexes (multi-year average daily rainfall, multi-year maximum rainfall, multi-year average daily runoff, and multi-year maximum daily runoff) in this study. Also the Benefit-Risk theory is applied to evaluate the effects of staged dispatching. The results show that the flood season of the Chengbi River basin should be divided into the pre-flood season (13 April–6 June), the main flood season (7 June–9 September) and the post-flood season (10 September–31 October). After adjusting the flood limit water level for sub-season and benefit assessment, the probability of exceedance after reservoir flood season operation increases by 0.13×10-5, the average annual expected risk is 0.2264 million RMB, and the average annual benefit increases by 0.88–1.62 million RMB. The benefits obtained far outweigh the risks, indicating the importance of staging the flood season.

scholarly journals Study on the Staged Operation of a Multi-Purpose Reservoir in Flood Season and its Effect Evaluation

2021 ◽  
Author(s):  
Chongxun Mo ◽  
Can Zhu ◽  
yuli ruan ◽  
Juan Deng ◽  
Juliang Jin
Keyword(s):  
Spline Interpolation ◽  
Fractal Theory ◽  
Daily Rainfall ◽  
Water Shortage ◽  
Water Levels ◽  
Maximum Rainfall ◽  
Flood Season ◽  
Benefit Evaluation ◽  
River Reservoir ◽  
Risk Rate

Abstract A reasonable analysis of flood season staging is significant to the utilization of flood and the alleviation of water shortage. For a case study of the Chengbi River reservoir in China. Based on fractal theory, the flood season is divided into several sub-seasons by using four indexes (multi-year average daily rainfall, multi-year maximum rainfall, multi-year average daily runoff, and multi-year maximum daily runoff) in this study. The Cubic spline interpolation function is then used to determine the flood limit water levels of each sub-season. And the Benefit-Risk theory is applied to evaluate the effects of staged dispatching. The results show that the flood season of Chengbi River basin should be divided into the pre-flood season (13 April-6 June), the main flood season (7 June-9 September) and the post-flood season (10 September-31 October). Adjustment of flood limit water level for sub-season and benefit evaluation. When the risk rate after reservoir flood season operation increases by 0.13×10 -5 , the average annual expected risk is 0.2264 million RMB, and the average annual benefit increases by 0.88-1.62 million RMB. The benefits obtained far outweigh the risks, indicating the importance of staging the flood season.

scholarly journals Optimal Operation of Floodwater Resources Utilization of Lakes in South-to-North Water Transfer Eastern Route Project

2021 ◽  
Vol 13 (9) ◽  
pp. 4857
Author(s):  
Zitong Yang ◽  
Xianfeng Huang ◽  
Jiao Liu ◽  
Guohua Fang
Keyword(s):  
Water Level ◽  
Resource Utilization ◽  
Flood Control ◽  
Optimal Operation ◽  
Water Transfer ◽  
Water Levels ◽  
Reservoir Storage ◽  
Flood Season ◽  
Hongze Lake ◽  
North Water

In order to meet the demand of emergency water supply in the northern region without affecting normal water transfer, considering the use of the existing South-to-North Water Transfer eastern route project to explore the potential of floodwater resource utilization in the flood season of Hongze Lake and Luoma Lake in Jiangsu Province, this paper carried out relevant optimal operating research. First, the hydraulic linkages between the lakes were generalized, then the water resources allocation mode and the scale of existing projects were clarified. After that, the actual available amount of flood resources in the lakes was evaluated. The average annual available floodwater resources in 2003–2017 was 1.49 billion m3, and the maximum available capacity was 30.84 billion m3. Then, using the floodwater resource utilization method of multi period flood limited water levels, the research period was divided into the main flood season (15 July to 15 August) and the later flood season (16 August to 10 September, 11 September to 30 September) by the Systematic Clustering Analysis method. After the flood control calculation, the limited water level of Hongze Lake in the later flood season can be raised from 12.5 m to 13.0 m, and the capacity of reservoir storage can increase to 696 million m3. The limited water level of Luoma Lake can be raised from 22.5 m to 23.0 m (16 August to 10 September), 23.5 m (11 September to 30 September), and the capacity of reservoir storage can increase from 150 to 300 million m3. Finally, establishing the floodwater resource optimization model of the lake group with the goals of maximizing the floodwater transfer amount and minimizing the flood control risk rate, the optimal water allocation scheme is obtained through the optimization algorithm.

Effects of the Belo Monte hydro-electric-dam complex on crocodilians in the Xingu River, Brazilian Amazonia

2021 ◽  
pp. 1-8
Author(s):  
Zilca Campos ◽  
Fábio Muniz ◽  
William E. Magnusson ◽  
Guilherme Mourão
Keyword(s):  
Water Level ◽  
Xingu River ◽  
Hydroelectric Dam ◽  
River Reservoir ◽  
Before And After ◽  
Collateral Effects ◽  
Generating Capacity ◽  
Reservoir Filling ◽  
Belo Monte

Abstract The Belo Monte hydroelectric dam on the Xingu River has the third largest generating capacity of any hydroelectric dam in the world. We conducted surveys of crocodilians (Caiman crocodilus, Paleosuchus trigonatus) by boat in the Xingu River at the site of the dam prior to (2013-2015), and after filling (2016-2017). While the number of C. crocodilus sighted decreased with increasing water level, there was no difference in numbers prior to, and after reservoir filling. The number of P. trigonatus was unaffected by both water level prior to and after reservoir filling. Reservoir filling had little effect on the number of crocodilians using the forest around the Xingu River reservoir. Most crocodilians seen in forest surveys were P. trigonatus, both before and after reservoir filling, but C. crocodilus was recorded occasionally in the forest. It seems that most Amazonian crocodilians are sufficiently generalist to adapt to the new conditions created by the construction of dams, at least in the short-term. However, there may be long-term collateral effects on crocodilian populations from dams, due to as deforestation and improved access for hunters.

scholarly journals ANALISIS TINGGI MUKA AIR BANJIR DAS BELAWAN DENGAN MENGGUNAKAN SOFTWARE HECRAS

2018 ◽  
Vol 7 (1) ◽  
pp. 26-29
Author(s):  
Asril Zevri
Keyword(s):  
Water Level ◽  
Cross Section ◽  
Return Period ◽  
Industrial Development ◽  
Daily Rainfall ◽  
Flood Water ◽  
Flood Discharge ◽  
Flood Level ◽  
Maximum Daily Rainfall ◽  
River Cross Section

Abstract: Belawan River Basin is one of the watershed, which currently change the land use because of the increasing population and industrial development. Rainfall with high intensity can cause rapid runoff, causing flood around the plains of the river cross section. The purpose of this research is to determine the flood water level of Belawan Watershed and flood discharge return period. Scope of activity in this research is analyzing daily rainfall Belawan watershed with the flood-discharge return period. Scope of activity in this research is analyzing maximum daily rainfall Belawan Watershed, and simulating flood water level with HECRAS. The result of the study shows that the potency of Belawan watershed flood water level is caused by flood discharge at 25 to 100 years especially in the middle to downstream of river cross section that is between 0.7 m and 3.3 m. Keywords: Flood Discharge, Flood Level, Belawan Watershed, Software HECRAS. Abstrak: Daerah Aliran Sungai Belawan adalah salah satu DAS yang pada saat ini mengalami perubahan tata guna lahan seiring bertambahnya jumlah penduduk dan perkembangan industri. Curah hujan yang tinggi dapat mengakibatkan limpasan sehingga menimbulkan tinggi muka air banjir di sekitar dataran penampang sungai. Tujuan dari penelitian ini adalah untuk mensimulasi tinggi muka air banjir DAS Belawan dengan debit banjir periode kala ulangnya. Lingkup kegiatan dalam penelitian ini yaitu menganalisa curah hujan harian maksimum rata-rata DAS Belawan dan menganalisa debit banjir kala ulang 2 sampai dengan 100 tahun, mensimulasi tinggi muka air banjir dengan HECRAS. Hasil studi menunjukan potensi tinggi muka air banjir DAS Belawan terjadi akibat debit banjir periode kala ulang 25 sampai dengan 100 tahun khususnya  di bagian tengah sampai hilir penampang sungai yaitu berkisar antara 0.7 m sampai dengan 3.3 m. Kata kunci: Debit banjir, Tinggi Banjir, DAS Belawan, Software HECRAS.

scholarly journals Spatial distribution of extreme precipitation in the Tibetan Plateau and effects of external forcing factors based on Generalized Pareto distribution

2020 ◽  
Author(s):  
Jiajia Gao ◽  
Jun Du ◽  
Xiaoqing Huang
Keyword(s):  
Spatial Distribution ◽  
Extreme Precipitation ◽  
Pareto Distribution ◽  
Daily Precipitation ◽  
Generalized Pareto Distribution ◽  
The Tibetan Plateau ◽  
External Forcing ◽  
Maximum Rainfall ◽  
Flood Season ◽  
Generalized Pareto

Abstract The daily precipitation data of the years 1955–2017 from May to September were retrieved; then a Generalized Pareto Distribution (GPD) and maximum likelihood methods were adopted to understand trends and calculate the reappearance period of heavy precipitation in the Tibetan Plateau (TP). The daily precipitation values at 22 stations in the TP were found to conform to the model, and theoretical and measured frequencies were consistent. According to the spatial distribution of the maximum precipitation value, the extreme values of Shigatse and Lhasa showed large fluctuations, and the probability of record-breaking precipitation events was low. In the western part of Nagqu, the probability of extreme precipitation was relatively low, and that of record-breaking precipitation was relatively high. The peak values of extreme precipitation in the flood season in the TP generally exhibited a decreasing trend from southeast to northwest, and the extreme value of the flood season that reappeared in the southeast region was approximatelytwice that of the northwest region. The maximum rainfall in most areas will exceed 20 mm in the next 5–10 years, and the maximum rainfall in Shigatse will reach 52.7 mm. After 15 years of recurrence in various regions, the peak rainfall in the flood season has become low. Most of the regions in the model have different responses to ENSO and Indian Ocean monsoon indices with external forcing factors.

Identification and Synoptic Analysis of the Highest Precipitation Linked to Ars in Iran

2021 ◽  
Vol 3 (2) ◽  
pp. 20-32
Author(s):  
Hassan Lashkari ◽  
Neda Esfandiari ◽  
Abbas Kashani
Keyword(s):  
Water Vapour ◽  
Heavy Rainfall ◽  
Daily Rainfall ◽  
Horn Of Africa ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Atmospheric Rivers ◽  
Factors Affecting ◽  
North West ◽  
Integral Data

Atmospheric rivers are long, narrow, concentrated structures of water vapour that are highly associated with rainfall and floods. To identify and introduce the highest rainfall occurring during the presence of atmospheric rivers from November to April (2007-2018) while showing the importance of this phenomenon in creating super heavy rainfall and introducing the areas affected by it, analyzed the synoptic factors affecting them slowly. In order to identify atmospheric rivers, vertical integral data of water vapour flow were used and thresholds were documented on them. The date of occurrence of each atmospheric river with their daily rainfall was examined and ten of the highest rainfall events Station (equivalent to the 95th percentile of maximum rainfall) related to atmospheric rivers was introduced and analyzed. It is found that the South Gram has been directly and indirectly the main source of atmospheric rivers associated with heavy rainfall. The source of most of these atmospheric rivers is at the peak of the Red Sea, the Gulf of Aden and the Horn of Africa. Synonymously, the origins of 7 cases from Atmospheric rivers have been of the Sudanese low pressure and in the remaining three cases have been integrated systems. In Sudanese systems, the predominant structure of the meridional inclination jet and in Integration systems has been oriented. Due to the dominance of a strong upstream current in the vicinity of the highest flux, moisture of heavy convective currents has caused super heavy rainfall and the station with the highest rainfall in the east and North West of the negative omega field or upstream streams.

scholarly journals Heavy rainfall equations for Santa Catarina, Brazil

2011 ◽  
Vol 35 (6) ◽  
pp. 2127-2134 ◽  
Author(s):  
Álvaro José Back ◽  
Alan Henn ◽  
José Luiz Rocha Oliveira
Keyword(s):  
Coastal Region ◽  
Daily Rainfall ◽  
Rain Gauge ◽  
Annual Maximum ◽  
Santa Catarina ◽  
Maximum Rainfall ◽  
Rainfall Events ◽  
Significance Level ◽  
Intensity Duration Frequency ◽  
Annual Maximum Rainfall

Knowledge of intensity-duration-frequency (IDF) relationships of rainfall events is extremely important to determine the dimensions of surface drainage structures and soil erosion control. The purpose of this study was to obtain IDF equations of 13 rain gauge stations in the state of Santa Catarina in Brazil: Chapecó, Urussanga, Campos Novos, Florianópolis, Lages, Caçador, Itajaí, Itá, Ponte Serrada, Porto União, Videira, Laguna and São Joaquim. The daily rainfall data charts of each station were digitized and then the annual maximum rainfall series were determined for durations ranging from 5 to 1440 min. Based on these, with the Gumbel-Chow distribution, the maximum rainfall was estimated for durations ranging from 5 min to 24 h, considering return periods of 2, 5, 10, 20, 25, 50, and 100 years,. Data agreement with the Gumbel-Chow model was verified by the Kolmogorov-Smirnov test, at 5 % significance level. For each rain gauge station, two IDF equations of rainfall events were adjusted, one for durations from 5 to 120 min and the other from 120 to 1440 min. The results show a high variability in maximum intensity of rainfall events among the studied stations. Highest values of coefficients of variation in the annual maximum series of rainfall were observed for durations of over 600 min at the stations of the coastal region of Santa Catarina.

scholarly journals Variation of the Water Level in the Yangtze River in Response to Natural and Anthropogenic Changes

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2594 ◽  
Author(s):  
Jinxin Liu ◽  
Jinyun Deng ◽  
Yuanfang Chai ◽  
Yunping Yang ◽  
Boyuan Zhu ◽  
...  
Keyword(s):  
Water Level ◽  
Yangtze River ◽  
Dry Season ◽  
Climate Variation ◽  
Dominant Factor ◽  
The Yangtze River ◽  
Flood Season ◽  
Dam Operation ◽  
Adjustment Mechanisms ◽  
Measured Water

The water level in the Yangtze River has significantly changed due to the effects of varied precipitation and dam operations, which have exerted significant effects on irrigation, navigation, and ecosystems. Based on the measured data and the proposed calculation method, we analyzed the adjustment mechanisms of the seasonal water level in the whole Yangtze River. The results were as follows. During the dry season, the rising precipitation and dam operation both increased the water level in the upper reaches and in the reaches from the Jianli to Datong stations during 1981–2014. Moreover, dam operations were the dominant factor (except at Datong station). In the reaches from the Yichang to Shashi stations, dam operations are the reason for the reduction of the measured water level in the dry season, while the rising precipitation had an opposite influence. During the flood season, dam operations helped to reduce the water level from the upper reaches to the estuary during 1981–2014, while climate variation stresses adversely affected the entire river basin. In the reaches between the Luoshan and Jianli stations, climate variation is the dominant factor for the increased water level during the flood season, while dam operation is the reason for the reduced water level at the other six hydrological stations.

scholarly journals A quantitative model for danger degree evaluation of staged operation of earth dam reservoir in flood season and its application

2018 ◽  
Vol 11 (1) ◽  
pp. 81-87 ◽  
Author(s):  
Chong-xun Mo ◽  
Gui-yan Mo ◽  
Qing Yang ◽  
Yu-li Ruan ◽  
Qing-ling Jiang ◽  
...  
Keyword(s):  
Quantitative Model ◽  
Earth Dam ◽  
Dam Reservoir ◽  
Flood Season ◽  
Staged Operation

scholarly journals Analysis of the Behavior of Daily Maximum Rainfall within the Department of Atlántico, Colombia

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2453
Author(s):  
Orlando M. Viloria-Marimón ◽  
Álvaro González-Álvarez ◽  
Javier A. Mouthón-Bello
Keyword(s):  
Time Series ◽  
Daily Rainfall ◽  
Information Criterion ◽  
Rain Gauge ◽  
Caribbean Region ◽  
Daily Maximum ◽  
Maximum Rainfall ◽  
Rain Gauges ◽  
Stationary Conditions ◽  
Areal Rainfall

In the Colombian Caribbean region, there are few studies that evaluated the behavior of one of the most commonly used variables in hydrological analyses: the maximum daily rainfall (Pmax-24h). In this study, multiannual Pmax-24h time series from 19 rain gauges, located within the department of Atlántico, were analyzed to (a) determine possible increasing/decreasing trends over time, (b) identify regions with homogeneous behavior of Pmax-24h, (c) assess whether the time series are better suited under either a stationary or non-stationary frequency analysis, (d) generate isohyetal maps under stationary, non-stationary, and mixed conditions, and (e) evaluate the isohyetal maps by means of the calculation of areal rainfall (Pareal) in nine watersheds. In spite of the presence of both increasing and decreasing trends, only the Puerto Giraldo rain gauge showed a significant decreasing trend. Also, three regions (east, central, and west) with similar Pmax-24h behavior were identified. According to the Akaike information criterion test, 79% of the rain gauges showed better fit under stationary conditions. Finally, statistical analysis revealed that, under stationary conditions, the errors in the calculation of Pareal were more frequent, while the magnitude of the errors was larger under non-stationary conditions, especially in the central–south region.

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