scholarly journals Impacts of River Engineering on Multi-Decadal Water Discharge of the Mega-Changjiang River

2020 ◽  
Vol 12 (19) ◽  
pp. 8060
Author(s):  
Binbin Ma ◽  
Wenhong Pang ◽  
Yaying Lou ◽  
Xuefei Mei ◽  
Jie Wang ◽  
...  
Keyword(s):  
Salt Water ◽  
Water Discharge ◽  
Water Diversion ◽  
Water Withdrawal ◽  
Salt Water Intrusion ◽  
Human Consumption ◽  
River Engineering ◽  
The Changjiang Estuary ◽  
Discharge Data ◽  
Gezhouba Dam

Knowledge of river engineering impacts on water discharge is significant to flow guidelines and sustainable water resource managements for balancing human consumption and the natural environment. In this study, based on the collected multi-decadal discharge data at Yichang, Hankou, and Datong stations, we determined that in October, Three Gorges Dam contributed 34.4%, 24.5%, and 18.7% to the discharge decrease in the upper, middle, and lower reach, respectively, while Gezhouba Dam contributed 14.5%, 10.7%, and 10%. Danjiangkou Reservoir caused the discharge ratio of Hanjiang to Changjiang to decline from 7.2% during 1954–1973 to 6.3% during 1973–2014. Owing to growing water withdrawal and consumption, we suggest that the distribution of water diversion and consumption should be regulated to prevent the probable occurrence of the severe issue of salt water intrusion in the Changjiang Estuary in 2028.

scholarly journals Salt intrusion in the Pungue estuary, Mozambique: effect of sand banks as a natural temporary salt intrusion barrier

2008 ◽  
Vol 5 (4) ◽  
pp. 2523-2542 ◽  
Author(s):  
S. Graas ◽  
H. H. G. Savenije
Keyword(s):  
Water Supply ◽  
Water Intake ◽  
Salt Water ◽  
Water Discharge ◽  
Dry Season ◽  
Salt Water Intrusion ◽  
Salt Intrusion ◽  
Water Intrusion ◽  
Salinity Levels ◽  
Monthly Discharge

Abstract. This paper presents a salt intrusion model for the Pungue estuary with the aim to determine the minimum discharge required to prevent the salt intrusion from reaching the water intake situated 82 km from the estuary mouth. The Pungue river is shared between Zimbabwe and Mozambique and has a large variation in precipitation and runoff. The mean monthly discharge can be as low as 8 m3/s and as high as 893 m3/s. The second largest city of Mozambique, Beira, relies on the Pungue for its water supply. In the dry season it frequently occurs that the water intake has to be ceased because the salinity of the Pungue is too high. The salt intrusion model used in this paper is based on a fully analytical and predictive theory which is confronted with measurements of salt intrusion and estuary topography. The paper presents the collection of estuary characteristics and the salt water intrusion measurements that were obtained by field measurements in 1993 and 2002. Using these data the salt intrusion model has successfully been applied. During salinity intrusion measurements in the dry season of 1993 it was observed that sand banks in the middle zone of the estuary prevented the salt water from intruding further upstream, resulting in lower salinity levels upstream than the theoretical salt water intrusion model predicts. This effect occurs during ebb of neap and average tides and can reduce the salt water intrusion by 10 km. The model indicates that in a natural situation a minimum monthly discharge of 12 m3/s is required to maintain acceptable salinity levels during high water and spring tide near the water intake. The actual water discharge upstream of the water intake has to be higher, since this minimum discharge does not take into account the water abstracted for irrigation and/or urban water supply. Current water abstractions lead to salt water intrusion near the water intake at approximately 10% of the time. The model indicates that an additional water abstraction of 5 m3/s will lead to an increase in salt water reaching the intake at 10% of the time. During neap tide the sand banks act as a temporary natural salt intrusion barrier reducing the chance of salt water reaching the water intake.

Hydrochemistry of springs in the bambui-sabga volcanic area (north west region, Cameroon volcanic line)

2015 ◽  
Vol 3 (2) ◽  
pp. 42
Author(s):  
Wotchoko Pierre ◽  
Tita Margaret Awah ◽  
Kouankap Nono Gus Djibril ◽  
Alice Magha ◽  
Fosap Lawrence Mbitegemboh ◽  
...  
Keyword(s):  
Salt Water ◽  
Thermal Spring ◽  
Salt Water Intrusion ◽  
Human Consumption ◽  
Volcanic Area ◽  
North West ◽  
Chemical Enrichment ◽  
Average Temperature ◽  
West Region ◽  
Area North

<p>This study was carried out in the Bambui-Sabga volcanic area in Tubah Sub-Division, North West Region, Cameroon. This research was aimed at carrying out a hydrochemical characterization of springs in the area. Chemical analysis were done using a DR 2010 Hach Spectrophotometer. The analysed spring samples were close to neutral (pH 6.9-7.6) with a high electrical conductivity ranging from 1,400 - 11,400 µS/cm and TDS from 750 - 7,960 mg/l. The FS01 spring recorded the highest average temperature of 34oC, yellowish-brown in colour and rusty odour, while the FS02 spring had a salty taste and soapy feel. The FS02 spring recorded the highest Na+ concentration of 128 mg/l. The analyzed springs can be classified into: thermal spring (FS01), salt spring (FS02) and normal (mineral) spring (FS03). The spring waters showed a (Na+K)-Cl (SO4) facies and are stable with Na-montmorillonite and zeolites, with their mineralisation from evaporation, salt water intrusion and leaching. Physical parameter were enriched in the dry season except for pH, and deficient in cations and anions except NO3- in FS02. In the rainy season, chemical enrichment was higher. The spring waters were not suitable for drinking and should be treated before human consumption.</p>

Approximation for Salt-Water Intrusion in Unconfined Coastal Aquifer

Ground Water ◽  
1980 ◽  
Vol 18 (2) ◽  
pp. 147-151 ◽  
Author(s):  
B. K. Panigrahi ◽  
A. Das Gupta ◽  
A. Arbhabhirama
Keyword(s):  
Coastal Aquifer ◽  
Salt Water ◽  
Salt Water Intrusion ◽  
Water Intrusion

Linking rivers to the rock record: Channel patterns and paleocurrent circular variance

Geology ◽  
2021 ◽  
Author(s):  
C.P. Galeazzi ◽  
R.P. Almeida ◽  
A.H. do Prado
Keyword(s):  
Water Discharge ◽  
Global Scale ◽  
Sedimentary Record ◽  
Discharge Data ◽  
Alluvial Rivers ◽  
Channel Pattern ◽  
Fluvial Deposits ◽  
Circular Variance ◽  
Rock Record ◽  
Channel Patterns

Alluvial rivers are the most important agents of sediment transport in continental basins, whose fluvial deposits enclose information related to the time when rivers were active. In order to extract the most information from fluvial deposits in the sedimentary record, it is imperative to quantify the natural variability of channel patterns at the global scale, explore what controls may influence their development, and investigate whether channel pattern information is preserved in the alluvial plains in order to develop tools for recognizing them in the sedimentary record. By surveying 361 reaches of modern alluvial rivers with available water discharge data at a global scale, we present a quantitative channel pattern classification based on sinuosity and channel count index applicable to the recognition in the rock record. A continuum of channel patterns ranging from high-sinuosity single channel to lowsinuosity multichannels is documented, along with the proportion of depositional elements in their alluvial plains and their conditions of occurrence. Preserved barforms in the alluvial plains of these rivers are used to infer and quantify paleoflow directions at the channel-belt scale and result in ranges of paleocurrent circular variance that may lead to channel pattern identification in the rock record. Data from this work indicate that the recognition of channel patterns may be used to predict paleogeographic features such as the scale of drainage basin area and discharge, slope, and annual discharge regimes.

scholarly journals GIS analysis of effects of future Baltic Sea level rise on the island of Gotland, Sweden

2016 ◽  
Author(s):  
Karin Ebert ◽  
Karin Ekstedt ◽  
Jerker Jarsjö
Keyword(s):  
Baltic Sea ◽  
Sea Level Rise ◽  
Sea Level ◽  
Coastal Aquifers ◽  
Salt Water ◽  
Global Perspective ◽  
Salt Water Intrusion ◽  
The Baltic Sea ◽  
Water Intrusion ◽  
The Baltic

Abstract. Future sea level rise as a consequence of global warming will affect the world's coastal regions. Even though the pace of sea level rise is not clear, the consequences will be severe and global. Commonly the effects of future sea level rise are investigated for relatively vulnerable development countries; however, a whole range of varying regions need to be considered in order to improve the understanding of global consequences. In this paper we investigate consequences of future sea level rise along the coast of the Baltic Sea island of Gotland, Sweden, with the aim to fill knowledge gaps regarding comparatively well-suited areas in non-development countries. We study both the quantity of loss of infrastructure, cultural and natural values for the case of a two metre sea level rise of the Baltic Sea, and the effects of climate change on seawater intrusion in coastal aquifers, causing the indirect effect of salt water intrusion in wells. We conduct a multi-criteria risk analysis by using Lidar data on land elevation and GIS-vulnerability mapping, which gives formerly unimaginable precision in the application of distance and elevation parameters. We find that in case of a 2 m sea level rise, 3 % of the land area of Gotland, corresponding to 99 km2, will be inundated. The features most strongly affected are items of touristic or nature values, including camping places, shore meadows, sea stack areas, and endangered plants and species habitats. In total, 231 out of 7354 wells will be directly inundated, and the number of wells in the high-risk zone for saltwater intrusion in wells will increase considerably. Some values will be irreversibly lost due to e.g. inundation of sea stacks and the passing of tipping points for sea water intrusion into coastal aquifers; others might simply be moved further inland, but this requires considerable economic means and prioritization. With nature tourism being one of the main income sources of Gotland, monitoring and planning is required to meet the changes. Seeing Gotland in a global perspective, this island shows that holistic multi-feature studies of future consequences of sea level rise are required, to identify overall consequences for individual regions.

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