Impacts on River Discharge of Changes in Glacierized Components of Mountain Basins

1987 ◽  
Vol 22 (4) ◽  
pp. 518-529 ◽  
Author(s):  
Peter G. Johnson ◽  
Claude David

Abstract A reliable and predictable water supply is essential to any development in mountainous regions. Large glacierized components of basins can produce surplus or deficit conditions as climate changes from season to season and as the ice extent fluctuates through time. Shorter time frame glaciological changes can produce stream diversion, catastrophic floods or very Irregular flow regimes. The major impact on water quality is the high level of and variations in sediment load concentrations which occur with the regime fluctuations. Sediment concentration regimes occur both in phase and out of phase with flow regimes.

2015 ◽  
Vol 8 (1) ◽  
pp. 38-42
Author(s):  
Pengfei Si ◽  
Xiangyang Rong ◽  
Angui Li ◽  
Xiaodan Min ◽  
Zhengwu Yang ◽  
...  

As a realization of the energy cascade utilization, the regional energy system has the significant potential of energy saving. As a kind of renewable energy, river water source heat pump also can greatly reduce the energy consumption of refrigeration and heating system. Combining the regional energy and water source heat pump technology, to achieve cooling, heating and power supply for a plurality of block building is of great significance to reduce building energy consumption. This paper introduces a practical engineering case which combines the regional energy system of complex river water source heat pump, which provides a detailed analysis of the hydrology and water quality conditions of the river water source heat pump applications, and discusses the design methods of water intake and drainage system. The results show that the average temperature of cold season is about 23.5 °C, the heating season is about 13.2 °C; the abundant regional water flow can meet the water requirement of water source heat pump unit; the sediment concentration index cannot meet the requirement of river water source heat pump if the water enters the unit directly; the river water chemistry indicators (pH, Cl-, SO42-, total hardness, total iron) can meet the requirement of river water source heat pump, and it is not required to take special measures to solve the problem. However, the problem of sediment concentration of water must be solved.


Water ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 106
Author(s):  
Yuhan Yan ◽  
Dehai Song ◽  
Xianwen Bao ◽  
Nan Wang

The Ou River, a medium-sized river in the southeastern China, is examined to study the estuarine turbidity maximum (ETM) response to rapidly varied river discharge, i.e., peak river discharge (PRD). This study analyzes the difference in ETM and sediment transport mechanisms between low-discharge and PRD during neap and spring tides by using the Finite-Volume Community Ocean Model. The three-dimensional model is validated by in-situ measurements from 23 April to 22 May 2007. In the Ou River Estuary (ORE), ETM is generally induced by the convergence between river runoff and density-driven flow. The position of ETM for neap and spring tides is similar, but the suspended sediment concentration during spring tide is stronger than that during neap tide. The sediment source of ETM is mainly derived from the resuspension of the seabed. PRD, compared with low-discharge, can dilute the ETM, but cause more sediment to be resuspended from the seabed. The ETM is more seaward during PRD. After PRD, the larger the peak discharge, the longer the recovery time will be. Moreover, the river sediment supply helps shorten ETM recovery time. Mechanisms for this ETM during a PRD can contribute to studies of morphological evolution and pollutant flushing.


2009 ◽  
Vol 24 (5) ◽  
pp. 889-908 ◽  
Author(s):  
Yongyong Zhang ◽  
Jun Xia ◽  
Tao Liang ◽  
Quanxi Shao

Geology ◽  
2021 ◽  
Author(s):  
Joel S. Scheingross ◽  
Michael P. Lamb

Waterfall plunge pools experience cycles of sediment aggradation and scour that modulate bedrock erosion, habitat availability, and hazard potential. We calculate sediment flux divergence to evaluate the conditions under which pools deposit and scour sediment by comparing the sediment transport capacities of waterfall plunge pools (Qsc_pool) and their adjacent river reaches (Qsc_river). Results show that pools fill with sediment at low river discharge because the waterfall jet is not strong enough to transport the supplied sediment load out of the pool. As discharge increases, the waterfall jet strengthens, allowing pools to transport sediment at greater rates than in adjacent river reaches. This causes sediment scour from pools and bar building at the downstream pool boundary. While pools may be partially emptied of sediment at modest discharge, floods with recurrence intervals >10 yr are typically required for pools to scour to bedrock. These results allow new constraints on paleodischarge estimates made from sediment deposited in plunge pool bars and suggest that bedrock erosion at waterfalls with plunge pools occurs during larger floods than in river reaches lacking waterfalls.


2015 ◽  
Vol 15 (3) ◽  
pp. 291-304
Author(s):  
Jiří Šindelář

Abstract The paper deals with the accuracy of the real GDP growth forecasts produced by two Czech non-governmental institutions: the Czech-Moravian Confederation of Trade Unions (CMKOS) and the Czech Banking Association (CBA) in the years 2007-2014 and 2011-2014 respectively. Utilizing a research method composed of simple (AFE), scale-dependent (RMSE) as well as relative (MASE) error measures, we found out that (i) CMKOS predictions achieved a lower forecasting error on average, beginning with a notable overestimation in the first turnover point from growth to decline (2008-2009), yet followed by gradual improvement resulting in superior accuracy over set benchmarks (Ministry of Finance, Czech National Bank, OECD) in later years (2010-2014). The CBA predictions, on the other hand, exhibited (ii) a high level of interconnection with official bodies (MF, CNB), but with overall inferior forecasting accuracy, despite the shorter time frame (2011-2014). Overall, the study suggests that of the two surveyed non-governmental bodies, only CMKOS forecasts represent a viable alternative to the official predictions published by the Ministry of Finance or the Czech National Bank, as CBA forecasts were found to be a less accurate satellite of these bodies.


2018 ◽  
pp. 70-79 ◽  
Author(s):  
Le Viet Thang ◽  
Dao Nguyen Khoi ◽  
Ho Long Phi

In this study, we investigated the impact of climate change on streamflow and water quality (TSS, T-N, and T-P loads) in the upper Dong Nai River Basin using the Soil and Water Assessment Tool (SWAT) hydrological model. The calibration and validation results indicated that the SWAT model is a reasonable tool for simulating streamflow and water quality for this basin. Based on the well-calibrated SWAT model, the responses of streamflow, sediment load, and nutrient load to climate change were simulated. Climate change scenarios (RCP 4.5 and RCP 8.5) were developed from five GCM simulations (CanESM2, CNRM-CM5, HadGEM2-AO, IPSL-CM5A-LR, and MPI-ESM-MR) using the delta change method. The results indicated that climate in the study area would become warmer and wetter in the future. Climate change leads to increases in streamflow, sediment load, T-N load, and T-P load. Besides that, the impacts of climate change would exacerbate serious problems related to water shortage in the dry season and soil erosion and degradation in the wet season. In addition, it is indicated that changes in sediment yield and nutrient load due to climate change are larger than the corresponding changes in streamflow.


2018 ◽  
Vol 3 (2) ◽  
pp. 50
Author(s):  
Muarofah Ghofur ◽  
Muhammad Sugihartono ◽  
Husna Daya Aulia

Temperature is one of the most dominant water quality parameters on the survival of fish, and almost every living organism has the optimum temperature for its life. One of the obstacles in the cultivation activity is the high level of death in the most critical phase of the larvae so that the handling and carrying capacity of optimal environmental conditions can minimize the death of the larvae as well as the extreme temperature changes will also cause higher death rates of larvae. In the maintenance effort, the quality and quantity of the resulting larva becomes an important factor, as the success of production support to reach the next phase. Therefore, to find out the larval synthesis is done research about the optimum temperature with treatment temperature 240C, 260C, 280C and 300C to the survival of maintenance of botia larvae (Chromobotia macrachantus). The water quality parameters of CO2, NH3, DO, and pH are carried out at the beginning and end of the study for 28 days. The results showed that the highest survival rate at temperature treatment 240C and 260C with a value of 100%.Keywords : Botia Larvae, Temperature, Survival Rate AbstrakSuhu merupakan salah satu parameter kualitas air yang sangat dominan terhadap kelangsungan hidup ikan, dan hampir setiap organisme yang hidup didalamnya memiliki suhu optimum untuk kehidupannya. Salah satu kendala dalam kegiatan budidaya adalah tingginya tingkat kematian pada fase paling kritis yaitu larva sehingga penanganan dan daya dukung kondisi lingkungan yang optimal dapat meminimalisir kematian larva demikian pula dengan perubahan suhu yang ekstrim juga akan menyebabkan tingkat kematian larva semakin tinggi. Dalam upaya pemeliharaan, kualitas dan kuantitas larva yang dihasilkan menjadi faktor penting, sebagai penunjang keberhasilan produksi  hingga mencapai fase selanjutnya. Oleh karena itu, untuk mengetahui sintasan larva dilakukan penelitian mengenai suhu optimal dengan suhu perlakuan 240C, 260C, 280C dan 300C terhadap kelangsungan hidup pemeliharaan larva ikan botia (Chromobotia macrachantus). Parameter kualitas air yitu CO2, NH3, DO, dan pH dilakukan pada awal dan akhir penelitian yang dilakukan selama 28 hari. Hasil penelitian menunjukkan bahwa tingkat kelangsungan hidup tertinggi pada perlakuan suhu 240C dan 260C dengan nilai sebesar 100%.Kata Kunci : Larva Botia, Suhu,Tingkat Kelangsungan Hidup


2018 ◽  
Vol 11 (3) ◽  
pp. 49-60 ◽  
Author(s):  
Le Hung Trinh ◽  
V. R. Zablotskii ◽  
Thi Giang Le ◽  
Thi Thu Hien Dinh ◽  
Thi Trinh Le ◽  
...  

The traditional methods for measuring water quality variables are timeconsuming and do not give a synoptic view of a water body or, more significantly, a synoptic view of different water bodies across the landscape. However, remote sensing technology with advantages such as wide area coverage and short revisit interval have been effectively used for environmental pollution applications, such as for monitoring water quality parameters. Many studies around the world show that optical satellite imagery can be used effectively in evaluating suspended sediment concentration. This article presents results of monitoring suspended sediment concentration in Red River, Hanoi, Vietnam through ground truth measurements and VNREDSat-1A multispectral data. The results obtained in the study can be used to serve the management, monitoring and evaluation of surface water quality.


Author(s):  
Irina GRIGORE ◽  
Severin CAZANESCU ◽  
Raluca Alexandra CAZANESCU

In our days, communities have to face high level of water and food consumption based on uncertain supplies and growing demands. Thus, they work to prevent floods, soil erosion, to supply fresh water for population, industry and irrigation and to redirect streams and rivers in order to increase the food production. On the other hand, climate changes increased the frequency of extreme events like droughts and floods, and water management became a matter of great concern, in order to protect and preserve fertile land and drinkable water resources. Powerful software are needed to help environmental specialists to develop reliable projects for sustainable land development, in a short time. In the present paper, we will briefly present AutoCAD Civil 3D 2010, the most powerful software application released by Autodesk Inc., a short time ago. Using AutoCAD Civil 3D 2010 components together with new set of extensions, named Hydraflow Extension, land development specialists can deal with a large variety of hydrologic and hydraulic aspects, such as delineating watersheds and drainage areas and computing time of concentration and other rainfall-runoff relationship for the designated basins.


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