Spatiotemporal variability in stable isotopes of the Ganga River and factors affecting their distributions

CATENA ◽  
2021 ◽  
Vol 204 ◽  
pp. 105360
Author(s):  
Shive Prakash Rai ◽  
Jacob Noble ◽  
Dharmaveer Singh ◽  
Yadhvir Singh Rawat ◽  
Bhishm Kumar
Keyword(s):  
Stable Isotopes ◽  
Ganga River ◽  
Spatiotemporal Variability ◽  
Factors Affecting

scholarly journals Assessment of Spatiotemporal Variability of Evapotranspiration and Its Governing Factors in a Mountainous Watershed

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 243 ◽  
Author(s):  
Anh Tran ◽  
Joseph Rungee ◽  
Boris Faybishenko ◽  
Baptiste Dafflon ◽  
Susan Hubbard
Keyword(s):  
Water Balance ◽  
Temporal Variations ◽  
Spatiotemporal Variability ◽  
Spatiotemporal Resolution ◽  
Factors Affecting ◽  
Community Land Model ◽  
East River ◽  
Coarse Texture ◽  
Spatio Temporal ◽  
High Elevations

Evapotranspiration (ET) is a key component of the water balance, which influences hydrometeorology, water resources, carbon and other biogeochemical cycles, and ecosystem diversity. This study aims to investigate the spatio-temporal variations of ET at the East River watershed in Colorado and analyze the factors that control these variations. ET was acquired using the community land model (CLM) simulations and was compared with the values estimated using Fu’s equation and a watershed-scale water balance equation. The simulation results showed that 55% of annual precipitation in the East River is lost to ET, in which 75% of the ET comes from the summer months (May to September). We also found that the contribution of transpiration to the total ET was ~50%, which is much larger than that of soil evaporation (32%) and canopy evaporation (18%). Spatial analysis indicated that the ET is greater at elevations of 2950–3200 m and lower along the river valley (<2750 m) and at the high elevations (>3900 m). A correlation analysis of factors affecting ET showed that the land elevation, air temperature, and vegetation are closely correlated and together they govern the ET spatial variability. The results also suggested that ET in areas with more finely textured soil is slightly larger than regions with coarse-texture soil. This study presents a promising approach to the assessment of ET with a high spatiotemporal resolution over watershed scales and investigates factors controlling ET spatiotemporal variations.

scholarly journals Anthropogenic Factors Affecting the Vegetation Dynamics in the Arid Middle East

2020 ◽  
Author(s):  
Iman Rousta ◽  
Haraldur Olafsson ◽  
Hao Zhang ◽  
Md Moniruzzaman ◽  
Jaromir Krzyszczak ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Middle East ◽  
Vegetation Index ◽  
Spatiotemporal Variability ◽  
Vegetation Coverage ◽  
Anthropogenic Factors ◽  
Strong Increase ◽  
P Value ◽  
Positive Trend ◽  
Factors Affecting

The spatiotemporal variability of vegetation in the Middle East was investigated for the period 2001&ndash;2019 using the Moderate Resolution Imaging Spectroradiometer (MODIS) 16-day/500 m composites of the Normalized Difference Vegetation Index (NDVI; MOD13A1). The results reveal a strong increase in the NDVI coverage in the Middle East during the study period (R = 0.75, p-value = 0.05). In Egypt, the annual coverage exhibits the strongest positive trend (R = 0.99, p-value = 0.05). In Turkey, both the vegetation coverage and density increased from 2001 to 2019, which can be attributed to the construction of some of the biggest dams in the Middle East, such as the Atat&uuml;rk and Ilisu dams. Significant increases in the annual coverage and maximum and average NDVI in Saudi Arabia are due to farming in the northern part of the country for which groundwater and desalinated seawater are used. The results of this study suggest that the main factors affecting the vegetation coverage in the Middle East are governmental policies. These policies can have a positive effect on the vegetation coverage in some countries such as Egypt, Saudi Arabia, Qatar, Kuwait, Iran, and Turkey.

scholarly journals Insights from mercury stable isotopes into factors affecting the internal body burden of methylmercury in frequent fish consumers

Elem Sci Anth ◽  
2016 ◽  
Vol 4 ◽  
pp. 000103 ◽  
Author(s):  
Miling Li ◽  
Katherine von Stackelberg ◽  
Christoph M. Rheinberger ◽  
James K. Hammitt ◽  
David P. Krabbenhoft ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Body Burden ◽  
Factors Affecting ◽  
Mercury Stable Isotopes ◽  
Internal Body

Determination of spatiotemporal variability of tree water uptake using stable isotopes (δ18O, δ2H) in an alluvial system supplied by a high-altitude watershed, Pfyn forest, Switzerland

Ecohydrology ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. 319-333 ◽  
Author(s):  
Guillaume Bertrand ◽  
Jean Masini ◽  
Nico Goldscheider ◽  
Jessica Meeks ◽  
Véronique Lavastre ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
High Altitude ◽  
Water Uptake ◽  
Spatiotemporal Variability

scholarly journals Dynamic Analysis Of Soil Erosion-Based Watershed Health

2019 ◽  
Vol 12 (3) ◽  
pp. 43-59 ◽  
Author(s):  
Zeinab Hazbavi ◽  
Seyed Hamidreza Sadeghi ◽  
Mehdi Gholamalifard
Keyword(s):  
Soil Erosion ◽  
Change Detection ◽  
Geometric Mean ◽  
Risk Indicators ◽  
Spatiotemporal Variability ◽  
Health Index ◽  
Environmental Pressures ◽  
Factors Affecting ◽  
Detection Analysis ◽  
Watershed Health

Accelerated soil erosion is one of the most important detrimental factors affecting the quality of the watershed health. Due to different environmental pressures and drivers, the effort is needed for ecological health and resilience assessment in regards to erosion changeability. However, this important subject has not been adequately studied yet. Towards this, in the present research, an innovative approach was developed for conceptualizing the watershed health dynamics in viewpoint of soil erosion. A risk-based study was conducted to quantitatively characterize the spatiotemporal variability of erosion-based health in an industrialized watershed i.e., the Shazand Watershed using the conceptual reliability, resilience and vulnerability (RelResVul) framework for four node years of 1986, 1998, 2008 and 2014. To this end, the soil erosion was estimated at monthly scale in 24 sub-watersheds by applying the Revised Universal Soil Loss Equation (RUSLE). The RelResVul indicators were then computed according to the threshold defined for the study watershed. A geometric mean was used to combine the three risk indicators and the erosion-based watershed health index was ultimately calculated for each study sub-watershed. Additionally, the change detection analysis was conducted over the years of 1986 to 2014. According to the results of erosion-based the RelResVul indices, very healthy, healthy, moderately healthy, unhealthy and very un-healthy conditions in the Shazand Watershed were respectively distributed over some 67, 25, zero, zero and eight percent for 1986; 50, 13, eight, zero and 29 % for 1998; 71, eight, 83, zero, zero and eight percent for 2008 and finally 71, zero, 17, zero and 12 % for 2014. The results of change detection revealed an oscillating trend of erosion-based watershed health index during the whole study period (1986 -2014). So that, during periods of 1986-1998, 1986-2008 and 1986-2014, the watershed health decreased at tune of 23, 13 and six percent, respectively. Whilst, the watershed health improved during study periods of 1998-2008 (13 %), 2008-2014 (eight percent) and 1998-2014 (22 %). The results also identified ‘hot spots’ of the most important index of land degradation and ‘bright spots’ of land improvement in the Shazand Watershed.The proposed approach would provide a sustainable framework supporting decision makers to comprehend health-related soil erosion targets according to the integrated watershed management plans.

scholarly journals Anthropogenic Factors Affecting the Vegetation Dynamics in the Arid Middle East

2020 ◽  
Author(s):  
Iman Rousta ◽  
Haraldur Olafsson ◽  
Hao Zhang ◽  
Md Moniruzzaman ◽  
Jaromir Krzyszczak ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Middle East ◽  
Vegetation Index ◽  
Spatiotemporal Variability ◽  
Vegetation Coverage ◽  
Anthropogenic Factors ◽  
Strong Increase ◽  
P Value ◽  
Positive Trend ◽  
Factors Affecting

The spatiotemporal variability of vegetation in the Middle East was investigated for the period 2001&ndash;2019 using the Moderate Resolution Imaging Spectroradiometer (MODIS) 16-day/500 m composites of the Normalized Difference Vegetation Index (NDVI; MOD13A1). The results reveal a strong increase in the NDVI coverage in the Middle East during the study period (R = 0.75, p-value = 0.05). In Egypt, the annual coverage exhibits the strongest positive trend (R = 0.99, p-value = 0.05). In Turkey, both the vegetation coverage and density increased from 2001 to 2019, which can be attributed to the construction of some of the biggest dams in the Middle East, such as the Atat&uuml;rk and Ilisu dams. Significant increases in the annual coverage and maximum and average NDVI in Saudi Arabia are due to farming in the northern part of the country for which groundwater and desalinated seawater are used. The results of this study suggest that the main factors affecting the vegetation coverage in the Middle East are governmental policies. These policies can have a positive effect on the vegetation coverage in some countries such as Egypt, Saudi Arabia, Qatar, Kuwait, Iran, and Turkey.

scholarly journals A New Look at the Summer Arctic Frontal Zone

2015 ◽  
Vol 28 (2) ◽  
pp. 737-754 ◽  
Author(s):  
Alex Crawford ◽  
Mark Serreze
Keyword(s):  
Arctic Ocean ◽  
Frontal Zone ◽  
Surface Wind ◽  
Past Research ◽  
Spatiotemporal Variability ◽  
The Arctic ◽  
Factors Affecting ◽  
Atmospheric Heating ◽  
Seasonal Characteristics ◽  
The Arctic Ocean

Abstract A notable characteristic of the summertime Arctic is the existence of a narrow band of strong horizontal temperature gradients spanning the coastlines of Siberia, Alaska, and western Canada that extends through a considerable depth of the troposphere. Past research has associated this summer Arctic Frontal Zone (AFZ) with contrasts in atmospheric heating between the Arctic Ocean and snow-free land, with its regional strength strongly influenced by topography; however, little is known about its variability. In this study, output from the latest generation of global atmospheric reanalyses is used to better constrain and define the summer AFZ, including its spatial and seasonal characteristics. The relative importance of different factors linked to its variability is then evaluated. The AFZ is best expressed in July and is manifested aloft as a separate Arctic jet feature at about 250 hPa. It is clearly associated with differential atmospheric heating, as evidenced by the sharp difference in surface energy balance terms between the Arctic Ocean and land. Furthermore, the AFZ is strongest over the coastline whether observed near the surface or throughout the troposphere. Interannual variations in peak strength of the AFZ are spatially heterogeneous and systematic near the surface (the 2-m level). Spatiotemporal variability is primarily dependent on factors affecting temperature over land, especially variability in cloud cover, surface wind direction, and the timing of the annual snow cover retreat. Local variability in the timing of annual sea ice retreat is also important through its control on temperatures over coastal seas.

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