scholarly journals COASTAL AND ESTUARY RESERVOIR: CASE STUDIES FOR JOHOR RIVER BASIN

2017 ◽  
Vol 8 (1) ◽  
pp. 25-40
Author(s):  
H. H. Heng ◽  
W. F. Pan ◽  
F. L. Siaw ◽  
C. P. Hii
Keyword(s):  
River Basin ◽  
Mass Conservation ◽  
Low Flow ◽  
Reservoir Storage ◽  
Storage Scheme ◽  
The Future ◽  
Storage Location ◽  
Alternative Water ◽  
Yield Calculation

This paper presents an alternative water storage concept at lower sea-river interface vis-à-vis the conventional dam/reservoir storage scheme in the upper headwater region of a river basin. Two (2) estuary or coastal reservoir schemes are proposed to meet the future water demand of Johor Bahru and its vicinity. The low flow yields of a 98% reliability (or design 1:50-year return period) for both river schemes are also presented. A hydrological assessment is carried out to correlate the hydrometric variables, i.e. rainfall and streamflow. A long term 54-year streamflow record is adopted as input to the yield calculation. The reliable yields of 98% reliability criteria are in turn estimated based on a water balance or mass conservation. This new paradigmatic shift of reservoir storage location from headwater region to lower estuary/coastal interface can harness sufficient yield to meet the future demand of Johor Bahru and vicinity.

scholarly journals EVALUATION OF POSSIBLE CHANGES IN THE RIVER LINE OF THE OKA BASIN FOR THE COMING PERIOD OF THE FIRST HALF OF THE XXI CENTURY

2020 ◽  
Vol 1 (5) ◽  
pp. 71-75
Author(s):  
G. Kh. Ismaiylov ◽  
◽  
N.V. Muraschenkova ◽  
Keyword(s):  
River Basin ◽  
21St Century ◽  
River Runoff ◽  
River Flow ◽  
Climatic Conditions ◽  
Global Changes ◽  
The Future ◽  
Seasonal Runoff ◽  
The City

A retrospective analysis and assessment of long-term changes in the annual and seasonal runoff of the Oka River basin over a long 131-year observation period (1881 / 1882–2011/2012) was performed. The changes in the annual distribution of the Oka river runoff over the seasons of the year (spring flood, summer-autumn and winter low water) from its annual value for the selected time periods (before and after 1976/1977) are considered. It has been noted that over the past decades, river runoff has been formed in new climatic conditions associated with global changes and, as a result, regional climate. The assessment of possible changes in the annual and seasonal runoff of the Oka River basin (to the final alignment – the city of Kaluga, with a basin area of 54,900 km2 ) in the first half of the 21st century is carried out. In assessing changes in the river flow of the Oka basin for the future period, the method of trends (trends) is used, based on the identification of cycles in fluctuations in hydrological characteristics and unidirectional trends (trends) inherent in individual phases (ups and downs) of these cycles, as well as to the establishment of functional (correlation) relationships between environmental factors (climatic, anthropogenic) and the nature of the response (river flow). In this case, the trend model serves as an alternative to the homogeneity hypothesis of long-term fluctuations in river flow. The change in the future values of the river flow of the Oka basin was estimated using averaged data of 30-year periods of time characterized by relative stationarity of climatic and hydrological conditions. The dynamics of the average 30-year values of the annual runoff in the upper reaches of the Oka River (the closure target is the city of Kaluga for the period 1881/1882–2011/2012) is considered. Possible forecasted mean annual values of the annual flow of the Oka River for the first half of the 21st century are obtained

scholarly journals Identifying the runoff variation in the Naryn River Basin under multiple climate and land-use change scenarios

2021 ◽  
Author(s):  
J. S. Wu ◽  
Y. P. Li ◽  
J. Sun ◽  
P. P. Gao ◽  
G. H. Huang ◽  
...  
Keyword(s):  
Climate Change ◽  
Land Use ◽  
River Basin ◽  
Land Use Changes ◽  
Arable Land ◽  
Low Flow ◽  
Ensemble Prediction ◽  
Runoff Variation ◽  
The Future ◽  
The Impact

Abstract A multiple scenario-based ensemble prediction (MSEP) method is developed for exploring the impacts of climate and land-use changes on runoff in the Naryn River Basin. MSEP incorporates multiple global climate models, Cellular Automata–Markov and Soil and Water Assessment Tool (SWAT) within a general framework. MSEP can simultaneously analyze the effects of climate and land-use changes on runoff, as well as provide multiple climate and land-use scenarios to reflect the associated uncertainties in runoff simulation and prediction. Totally 96 scenarios are considered to analyze the trend and range of future runoff. Ensemble prediction results reveal that (i) climate change plays a leading role in runoff variation; (ii) compared to the baseline values, peak flow would increase 36.6% and low flow would reduce 36.8% by the 2080s, which would result in flooding and drought risks in the future and (iii) every additional hectare of arable land would increase the water deficit by an average of 10.9 × 103 m3, implying that the arable land should be carefully expanded in the future. Results suggest that, to mitigate the impact of climate change, the rational control of arable land and the active promotion of irrigation efficiency are beneficial for water resources management and ecological environmental recovery.

scholarly journals Simulation of the Potential Impacts of Projected Climate Change on Streamflow in the Vakhsh River Basin in Central Asia under CMIP5 RCP Scenarios

Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1426
Author(s):  
Aminjon Gulakhmadov ◽  
Xi Chen ◽  
Nekruz Gulahmadov ◽  
Tie Liu ◽  
Muhammad Naveed Anjum ◽  
...  
Keyword(s):  
Climate Change ◽  
River Basin ◽  
Hydrological Model ◽  
Assessment Tool ◽  
Global Climate Models ◽  
Low Flow ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Annual Average ◽  
The Future

Millions of people in Uzbekistan, Turkmenistan, Tajikistan, and Kyrgyzstan are dependent on the freshwater supply of the Vakhsh River system. Sustainable management of the water resources of the Vakhsh River Basin (VRB) requires comprehensive assessment regarding future climate change and its implications for streamflow. In this study, we assessed the potential impacts of projected climate change scenarios on the streamflow in the VRB for two future periods (2022–2060 and 2061–2099). The probable changes in the regional climate system were assessed using the outputs of five global climate models (GCMs) under two representative concentration pathways (RCPs), RCP4.5 and RCP8.5. The probable streamflow was simulated using a semi-distributed hydrological model, namely the Soil and Water Assessment Tool (SWAT). Evidence of a significant increase in the annual average temperature by the end of the 21st century was found, ranging from 2.25 to 4.40 °C under RCP4.5 and from 4.40 to 6.60 °C under RCP8.5. The results of three GCMs indicated a decreasing tendency of annual average precipitation (from −1.7% to −16.0% under RCP4.5 and from −3.4% to −29.8% under RCP8.5). Under RCP8.5, two GCMs indicated an increase (from 2.3% to 5.3%) in the average annual precipitation by the end of 2099. The simulated results of the hydrological model reported an increasing tendency of average annual streamflow, from 17.5% to 52.3% under both RCPs, by the end of 2099. A shift in the peak flow month was also found, i.e., from July to June, under both RCPs. It is expected that in the future, median and high flows might increase, whereas low flow might decrease by the end of 2099. It is concluded that the future seasonal streamflow in the VRB are highly uncertain due to the probable alterations in temperature and precipitation. The findings of the present study could be useful for understanding the future hydrological behavior of the Vakhsh River, for the planning of sustainable regional irrigation systems in the downstream countries, i.e., Uzbekistan and Turkmenistan, and for the construction of hydropower plants in the upstream countries.

scholarly journals Increased drought severity tracks warming in the United States’ largest river basin

2020 ◽  
Vol 117 (21) ◽  
pp. 11328-11336 ◽  
Author(s):  
Justin T. Martin ◽  
Gregory T. Pederson ◽  
Connie A. Woodhouse ◽  
Edward R. Cook ◽  
Gregory J. McCabe ◽  
...  
Keyword(s):  
River Basin ◽  
Warm Season ◽  
The United States ◽  
Low Flow ◽  
Drought Severity ◽  
Late 20Th Century ◽  
Proxy Records ◽  
Regional Temperature ◽  
Future Warming

Across the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the “turn-of-the-century drought,” was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking. Here we examine 1,200 y of streamflow from a network of 17 new tree-ring–based reconstructions for gages across the upper Missouri basin and an independent reconstruction of warm-season regional temperature in order to place the recent drought in a long-term climate context. We find that temperature has increasingly influenced the severity of drought events by decreasing runoff efficiency in the basin since the late 20th century (1980s) onward. The occurrence of extreme heat, higher evapotranspiration, and associated low-flow conditions across the basin has increased substantially over the 20th and 21st centuries, and recent warming aligns with increasing drought severities that rival or exceed any estimated over the last 12 centuries. Future warming is anticipated to cause increasingly severe droughts by enhancing water deficits that could prove challenging for water management.

scholarly journals Evaluation of low-flow metrics as environmental instream flow standards during long-term average and 2016 drought conditions: Tombigbee River Basin, Alabama and Mississippi, USA

Water Policy ◽  
2018 ◽  
Vol 20 (6) ◽  
pp. 1240-1255 ◽  
Author(s):  
Sarah Praskievicz ◽  
Cehong Luo ◽  
Bennett Bearden ◽  
Andrew Ernest
Keyword(s):  
River Basin ◽  
Environmental Flow ◽  
Low Flow ◽  
Instream Flow ◽  
Management Actions ◽  
Instream Flows ◽  
Societal Needs ◽  
Drought Conditions ◽  
Historical Flow

Abstract Environmental instream flows are a common tool for maintaining river flows that are required to sustain both ecosystem and societal needs. Many of the most widely adopted environmental flow standards are based on historical flow, mainly because of the relative simplicity of these methods. Few previous studies, however, have examined the ability of historical flow standards to protect low flows. Here, the low-flow protective ability of five different historical flow methods, using 35 gaging stations in the Tombigbee River Basin of Alabama and Mississippi, was analyzed. The minimum environmental flow thresholds were calculated using the five indices, and the number of times in a recent 32-year period flows fell below each threshold was determined. The Tennant-based threshold was reached most frequently, followed by the modified Tennant. Although other low-flow metrics, such as 7Q10, were triggered infrequently (9% of the time) over the whole period, triggering rates increased to 46% for 7Q10 during the drought of 2016, suggesting that even minimal low-flow standards may provide some benefit during drought. Analyzing historical flow methods to see how often they would result in management actions if implemented is a useful way of developing guidance on the adoption of minimum environmental instream flow standards.

scholarly journals Using the Markov Chain to Analyze Precipitation and Groundwater Drought Characteristics and Linkage with Atmospheric Circulation

2019 ◽  
Vol 11 (6) ◽  
pp. 1817 ◽  
Author(s):  
Hsin-Fu Yeh ◽  
Hsin-Li Hsu
Keyword(s):  
Markov Chain ◽  
Steady State ◽  
Atmospheric Circulation ◽  
River Basin ◽  
Drought Characteristics ◽  
Groundwater Drought ◽  
The Future ◽  
Southern Taiwan ◽  
The Mean

In recent years, Taiwan has been facing water shortages due to the impact of climate change, which has resulted in many serious drought events, especially in southern Taiwan. Long-term records from 25 rainfall stations and 17 groundwater stations in the southern Taiwan basin were used in this study. We used the Standardized Precipitation Index (SPI) and the Standardized Groundwater Level Index (SGI) and employed the first-order Markov chain model and wavelet transform to determine the drought characteristics and propagation, including the steady-state probabilities of drought events and the mean duration for each station. The Drought Index (DI) was also used to investigate the effects of rainfall on groundwater drought. The results show that the steady-state probability of the meteorological drought in the Yanshui River basin in southern Taiwan is higher than that in other basins. The area with the longer mean duration is located in the Yanshui River basin and the Erren River basin, and overall, the mean duration ranges from 3 to 7 months. In addition, the results from the drought proneness analysis indicated that when rainfall causes a longer drought duration, there will be a higher degree of proneness to groundwater drought in the future. Finally, the results show that the mean duration of groundwater droughts are longer than those of meteorological droughts. The results of the wavelet analysis revealed a positive correlation at long-term scales, which may be related to large-scale atmospheric circulation. The information from this research could be used as a reference for water resource management in the future.

scholarly journals A Probabilistic Approach for Assessment of Future Drought in Bagmati River Basin, Nepal

2018 ◽  
Vol 2 ◽  
pp. 75-88
Author(s):  
Rajendra Man Shrestha ◽  
Azaya Bikram Sthapit ◽  
Srijan Lal Shrestha
Keyword(s):  
River Basin ◽  
Probabilistic Approach ◽  
Standardized Precipitation Index ◽  
Severe Drought ◽  
Summer Drought ◽  
The Future ◽  
Moderate Drought ◽  
Extreme Distribution ◽  
Bagmati River

Background: The Bagmati River is the rain-fed river in the basin of Nepal. The climate change in rainfall patterns may lead to drought or flashflood in this basin. Drought is a silent and pervasive hazard due to the deficit of water availability. It may have adverse impact on society leading to impact on environment, culture, political and other functions of the region.Objective: This study aims to assess the future drought in the Bagmati River Basin, Nepal.Materials and Methods: Providing Regional Climates for Impact Studies precipitation data was obtained from Department of Hydrology and Meteorology, Kathmandu. The Generalized Extreme Distribution was fitted to respective total precipitations in 3 time-scales using EasyFit software. Standardized Precipitation Index (SPI) method was used to derive SPI for winter drought, SPI for summer drought and SPI for long-term (annual) drought.Results: The results of data analysis showed that winter moderate drought episodes may occur in years 2035, 2042, 2048, 2049, 2051 and 2053. Likewise, summer severe drought episode may occur in 2046. The year 2046 also indicated long-term extreme drought. Moreover, 2030, 2031, 2035, 3040 and 2053 may be long-term moderate drought episodes years in future.Conclusion: There may be winter moderate drought, summer severe drought and a long-term extreme as well as moderate drought during the future period 2030-2060.Nepalese Journal of Statistics, Vol. 2, 75-88

951: “Experience in the Treatment of Low Flow Priapism”; A Novel, Easy and Effective Technique: A Long-Term, Binational, Multi-Institutional Study in 18 Patients Over 8 Years

2007 ◽  
Vol 177 (4S) ◽  
pp. 314-315
Author(s):  
Jose A. Medina Machuca ◽  
Jose A. Medina Coello ◽  
Hugo Manzanilla ◽  
Francisco A. Gutierrez
Keyword(s):  
Low Flow ◽  
Effective Technique
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