scholarly journals Influence of periglacial conditions on river chemistry in active mountain belts insights from the Zayu River catchment from SE Tibet

2021 ◽  
Author(s):  
Xiaobai Ruan ◽  
Albert Galy
Keyword(s):  
River Catchment ◽  
River Chemistry ◽  
Mountain Belts ◽  
Se Tibet

Oxygen and deuterium isotope characteristics of Teesta river catchment from Sikkim Himalaya, India: Implications of different moisture sources

2020 ◽  
Vol 54 (5) ◽  
pp. 327-336
Author(s):  
Sheikh Nawaz Ali ◽  
Anupam Sharma ◽  
Shailesh Agrawal ◽  
M. G. Yadava ◽  
R. A. Jani ◽  
...  
Keyword(s):  
Sikkim Himalaya ◽  
River Catchment ◽  
Moisture Sources

SIMULATION AND CONTROL OF FLOODS IN A WATER NETWORK. CASE STUDY OF JIJIA RIVER CATCHMENT

2017 ◽  
Vol 16 (3) ◽  
pp. 587-595
Author(s):  
Vasile Mircea Cristea ◽  
Ph.m Thai Hoa ◽  
Mihai Mogos-Kirner ◽  
Csavdari Alexandra ◽  
Paul Serban Agachi
Keyword(s):  
Water Network ◽  
River Catchment ◽  
Simulation And Control ◽  
And Control

Sedelnikovaea baicalensis (Lecanoraceae) — new lichen genus and species for Europe

2018 ◽  
Vol 52 (2) ◽  
pp. 407-416
Author(s):  
T. V. Makryi
Keyword(s):  
Central Asia ◽  
Lichen Species ◽  
Significant Part ◽  
The Urals ◽  
Southern Siberia ◽  
Central Asian ◽  
Northeastern Siberia ◽  
Mountain Belts ◽  
First Time ◽  
Vast Range

Sedelnikovaea baicalensis, the Siberian-Central Asian lichen species, is recorded for the first time for Europe. Based on all the known localities, including those first-time reported from Baikal Siberia, the peculiarities of the ecology and distribution of this species are discussed, the map of its distribution is provided. It is concluded that the species was erroneously considered earlier as a Central Asian endemic. The center of the present range of this lichen is the steppes of Southern Siberia and Mongolia. Assumptions are made that S. baicalensis is relatively young (Paleogene-Neogene) species otherwise it would have a vast range extending beyond Asia, and also that the Yakut locations of this species indicate that in the Pleistocene its range was wider and covered a significant part of the Northeastern Siberia but later underwent regression. Based on the fact that in the mountains of Central Asia the species is found only in the upper mountain belts, it is proposed to characterize it as «cryo-arid xerophyte» in contrast to «arid xerophytes». A conclusion is made that the presence of extensive disjunctions of S. baicalensis range between the Southern Pre-Urals and the Altai-Sayan Mountains or the Mountains of Central Asia is unlikely; the lichen is most likely to occur in the Urals and most of Kazakhstan.

scholarly journals Effects of Soil and Water Conservation Measures on Soil Quality Indicators: The Case of Geshy Subcatchment, Gojeb River Catchment, Ethiopia

2020 ◽  
Vol 2020 ◽  
pp. 1-16 ◽  
Author(s):  
Melku Dagnachew ◽  
Awdenegest Moges ◽  
Asfaw Kebede ◽  
Adane Abebe
Keyword(s):  
Soil Quality ◽  
Quality Indicators ◽  
Water Conservation ◽  
Soil And Water Conservation ◽  
Land Resources ◽  
Soil Quality Indicators ◽  
Volumetric Soil Water Content ◽  
River Catchment ◽  
The Status ◽  
Soil And Water

Land degradation is a global negative environmental process that causes the decline in the productivity of land resources’ capacity to perform their functions. Though soil and water conservation (SWC) technologies have been adopted in Geshy subcatchment, their effects on soil quality were limitedly studied. The study was conducted to evaluate the effects SWC measures on soil quality indicators in Geshy subcatchment, Gojeb River Catchment, Ethiopia. A total of 54 soil samples (two treatments–farmlands with and without SWC measures ∗ three slope classes ∗ three terrace positions ∗ three replications) were collected at a depth of 20 cm. Statistical differences in soil quality indicators were analyzed using multivariate analysis of variance (ANOVA) following the general linear model procedure of SPSS Version 20.0 for Windows. Means that exhibited significant differences were compared using Tukey’s honest significance difference at 5% probability level. The studied soils are characterized by low bulk density, slightly acidic with clay and clay loam texture. The results revealed that farmlands with SWC measures had significantly improved soil physical (silt and clay fractions, and volumetric soil water content (VSWC)) and chemical (pH, SOC, TN, C : N ratio, and Av. phosphorus) quality indicators as compared with farmlands without SWC measures. The significantly higher VSWC, clay, SOC, TN, C : N ratio, and Av. P at the bottom slope classes and terrace positions could be attributed to the erosion reduction and deposition effects of SWC measures. Generally, the status of the studied soils is low in SOC contents, TN, C : N ratio, and Av. P (deficient). Thus, integral use of both physical and biological SWC options and agronomic interventions would have paramount importance in improving soil quality for better agricultural production and productivity.

scholarly journals Spatial Variation of Water Chemistry in Aries River Catchment Western Romania

2021 ◽  
Vol 11 (14) ◽  
pp. 6592
Author(s):  
Ana Moldovan ◽  
Maria-Alexandra Hoaghia ◽  
Anamaria Iulia Török ◽  
Marius Roman ◽  
Ionut Cornel Mirea ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Water Quality ◽  
Water Chemistry ◽  
Water Samples ◽  
Mine Drainage ◽  
Pollution Indices ◽  
Mining Activities ◽  
River Catchment ◽  
High Concentrations ◽  
The Impact

This study aims to investigate the quality and vulnerability of surface water (Aries River catchment) in order to identify the impact of past mining activities. For this purpose, the pollution and water quality indices, Piper and Durov plots, as well vulnerability modeling maps were used. The obtained results indicate that the water samples were contaminated with As, Fe, Mn, Pb and have relatively high concentrations of SO42−, HCO3−, TDS, Ca, K, Mg and high values for the electrical conductivity. Possible sources of the high content of chemicals could be the natural processes or the inputs of the mine drainage. Generally, according to the pollution indices, which were correlated to high concentrations of heavy metals, especially with Pb, Fe and Mn, the water samples were characterized by heavy metals pollution. The water quality index classified the studied water samples into five different classes of quality, namely: unsuitable for drinking, poor, medium, good and excellent quality. Similarly, medium, high and very high vulnerability classes were observed. The Durov and Piper plots classified the waters into Mg-HCO3− and Ca-Cl− types. The past and present mining activities clearly change the water chemistry and alter the quality of the Aries River, with the water requiring specific treatments before use.

scholarly journals Rainfall-Runoff Modeling Using the HEC-HMS Model for the Al-Adhaim River Catchment, Northern Iraq

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 58
Author(s):  
Ahmed Naseh Ahmed Hamdan ◽  
Suhad Almuktar ◽  
Miklas Scholz
Keyword(s):  
Geographical Information Systems ◽  
Hydrological Model ◽  
Daily Rainfall ◽  
Curve Number ◽  
Geographical Information ◽  
Coefficient Of Determination ◽  
Rainfall Runoff ◽  
Time Step ◽  
River Catchment ◽  
Northern Iraq

It has become necessary to estimate the quantities of runoff by knowing the amount of rainfall to calculate the required quantities of water storage in reservoirs and to determine the likelihood of flooding. The present study deals with the development of a hydrological model named Hydrologic Engineering Center (HEC-HMS), which uses Digital Elevation Models (DEM). This hydrological model was used by means of the Geospatial Hydrologic Modeling Extension (HEC-GeoHMS) and Geographical Information Systems (GIS) to identify the discharge of the Al-Adhaim River catchment and embankment dam in Iraq by simulated rainfall-runoff processes. The meteorological models were developed within the HEC-HMS from the recorded daily rainfall data for the hydrological years 2015 to 2018. The control specifications were defined for the specified period and one day time step. The Soil Conservation Service-Curve number (SCS-CN), SCS Unit Hydrograph and Muskingum methods were used for loss, transformation and routing calculations, respectively. The model was simulated for two years for calibration and one year for verification of the daily rainfall values. The results showed that both observed and simulated hydrographs were highly correlated. The model’s performance was evaluated by using a coefficient of determination of 90% for calibration and verification. The dam’s discharge for the considered period was successfully simulated but slightly overestimated. The results indicated that the model is suitable for hydrological simulations in the Al-Adhaim river catchment.

scholarly journals Trans-lithospheric diapirism explains the presence of ultra-high pressure rocks in the European Variscides

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Petra Maierová ◽  
Karel Schulmann ◽  
Pavla Štípská ◽  
Taras Gerya ◽  
Ondrej Lexa
Keyword(s):  
High Pressure ◽  
Numerical Models ◽  
Classical Concept ◽  
Plate Interface ◽  
Ultra High Pressure ◽  
Common Process ◽  
Mountain Belts ◽  
Collisional Orogens ◽  
Rock Association ◽  
European Variscides

AbstractThe classical concept of collisional orogens suggests that mountain belts form as a crustal wedge between the downgoing and overriding plates. However, this orogenic style is not compatible with the presence of (ultra-)high pressure crustal and mantle rocks far from the plate interface in the Bohemian Massif of Central Europe. Here we use a comparison between geological observations and thermo-mechanical numerical models to explain their formation. We suggest that continental crust was first deeply subducted, then flowed laterally underneath the lithosphere and eventually rose in the form of large partially molten trans-lithospheric diapirs. We further show that trans-lithospheric diapirism produces a specific rock association of (ultra-)high pressure crustal and mantle rocks and ultra-potassic magmas that alternates with the less metamorphosed rocks of the upper plate. Similar rock associations have been described in other convergent zones, both modern and ancient. We speculate that trans-lithospheric diapirism could be a common process.

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