scholarly journals Response of shallow subterranean freshwater amphipods to habitat drying

2018 ◽  
Vol 28 ◽  
pp. 15-28 ◽  
Author(s):  
Heather Gilbert ◽  
Jenna Keany ◽  
David C. Culver
Keyword(s):  
Surface Water ◽  
Behavioral Changes ◽  
The Us ◽  
Freshwater Amphipods ◽  
Wetland Species ◽  
Dry Out ◽  
Subterranean Species ◽  
Habitat Drying

The ability of three amphipods that occupy shallow subterranean habitats in the lower Potomac Basin of the US (hypotelminorheic), which often dry out seasonally, to withstand desiccation by burrowing in clay was investigated. Both Crangonyxshoemakeri, a wetland species, and Stygobromustenuis, a subterranean species, burrowed in clay in the laboratory after surface water was removed. Gammarusminus, a spring species, did not. All three species exhibited behavioral changes as the habitat dried out.

scholarly journals Improved Automated Detection of Subpixel-Scale Inundation—Revised Dynamic Surface Water Extent (DSWE) Partial Surface Water Tests

2019 ◽  
Vol 11 (4) ◽  
pp. 374 ◽  
Author(s):  
John Jones
Keyword(s):  
Surface Water ◽  
Mixture Models ◽  
Model Development ◽  
Depth Estimation ◽  
High Temporal Resolution ◽  
Commission Error ◽  
Dynamic Surface ◽  
In Situ Data ◽  
The Us ◽  
Spectral Mixture

In order to produce useful hydrologic and aquatic habitat data from the Landsat system, the U.S. Geological Survey has developed the “Dynamic Surface Water Extent” (DSWE) Landsat Science Product. DSWE will provide long-term, high-temporal resolution data on variations in inundation extent. The model used to generate DSWE is composed of five decision-rule based tests that do not require scene-based training. To allow its general application, required inputs are limited to the Landsat at-surface reflectance product and a digital elevation model. Unlike other Landsat-based water products, DSWE includes pixels that are only partially covered by water to increase inundation dynamics information content. Previously published DSWE model development included one wetland-focused test developed through visual inspection of field-collected Everglades spectra. A comparison of that test’s output against Everglades Depth Estimation Network (EDEN) in situ data confirmed the expectation that omission errors were a prime source of inaccuracy in vegetated environments. Further evaluation exposed a tendency toward commission error in coniferous forests. Improvements to the subpixel level “partial surface water” (PSW) component of DSWE was the focus of this research. Spectral mixture models were created from a variety of laboratory and image-derived endmembers. Based on the mixture modeling, a more “aggressive” PSW rule improved accuracy in herbaceous wetlands and reduced errors of commission elsewhere, while a second “conservative” test provides an alternative when commission errors must be minimized. Replication of the EDEN-based experiments using the revised PSW tests yielded a statistically significant increase in mean overall agreement (4%, p = 0.01, n = 50) and a statistically significant decrease (11%, p = 0.009, n = 50) in mean errors of omission. Because the developed spectral mixture models included image-derived vegetation endmembers and laboratory spectra for soil groups found across the US, simulations suggest where the revised DSWE PSW tests perform as they do in the Everglades and where they may prove problematic. Visual comparison of DSWE outputs with an unusual variety of coincidently collected images for locations spread throughout the US support conclusions drawn from Everglades quantitative analyses and highlight DSWE PSW component strengths and weaknesses.

scholarly journals Contamination Level, Source Identification and Health Risk Assessment of Potentially Toxic Elements in Drinking Water Sources of Mining and Non-mining Areas of Khyber Pakhtunkhwa, Pakistan

2021 ◽  
Author(s):  
Zahid Imran Bhatti ◽  
Muhammad Ishtiaq ◽  
Said Akbbar Khan ◽  
javed nawab ◽  
Sardar Khan ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Drinking Water ◽  
Surface Water ◽  
Health Risk ◽  
Toxic Elements ◽  
Water Sources ◽  
Potentially Toxic Elements ◽  
Mining Areas ◽  
The Us ◽  
Us Epa

Abstract Accelerated mining activities have increased water contamination with potentially toxic elements (PTEs) and their associated human health risk in developing countries. The current study investigated the distribution of PTEs, their potential sources and health risk assessment in both ground and surface water sources in mining and non–mining areas of Khyber Pakhtunkhwa, Pakistan. Water samples (n=150) were taken from selected sites and were analyzed for six PTEs (Ni, Cr, Zn, Cu, Pb and Mn). Among PTEs, Cr showed high mean concentration (497) μg L–1, followed by Zn (414) μg L–1 in mining area, while Zn showed lowest mean value (4.44) μg L–1 in non-mining areas. Elevated concentrations of Ni, Cr and moderate level of Pb in ground and surface water of Mohmand District exceeded the permissible limits set by WHO (2017). Multivariate statistical analyses showed that pollution sources of PTEs were mainly from mafic-ultramafic rocks, acid mine drainage, open dumping of mine-wastes and mine tailings. The hazard quotient (HQ) was highest for children relatively to adults, but not higher than the US-EPA limits. The hazard index (HI) for ingestions of all selected PTEs were lower than the threshold value (HIing <1), except Mohmand District which showed (HI >1) in mining areas through ingestion. Moreover, the carcinogenic risk (CR) values exceeded the threshold limits for Ni and Cr set by the US-EPA (1.0E−04 to 1.0E−06). In order to protect the drinking water sources of the study areas from more contamination, the management techniques and policy for mining operations need to be implemented.

scholarly journals Projecting the impacts of end of century climate extremes on the hydrology in California

2021 ◽  
Author(s):  
Fadji Zaouna Maina ◽  
Alan Rhoades ◽  
Erica R. Siirila-Woodburn ◽  
Peter-James Dennedy-Frank
Keyword(s):  
Surface Water ◽  
Global Climate ◽  
Climate Extremes ◽  
Watershed Hydrology ◽  
Hydrologic Models ◽  
Surface Water And Groundwater ◽  
Resilient Communities ◽  
Rcp 8.5 ◽  
Dry Out ◽  
Precipitation Phase

Abstract. In California, it is essential to understand the evolution of water resources in response to a changing climate to sustain its economy and agriculture and build resilient communities. Although extreme conditions have characterized the historical hydroclimate of California, climate change will likely intensify hydroclimatic extremes by the End of Century (EoC). However, few studies have investigated the impacts of EoC extremes on watershed hydrology. We use cutting-edge global climate and integrated hydrologic models to simulate EoC extremes and their effects on the water-energy balance. We assess the impacts of projected driest, median, and wettest water years under a Representative Concentration Pathway (RCP) 8.5 on the hydrodynamics of the Cosumnes river basin. High temperatures (> 2.5 °C) and precipitation (> 38 %) will characterize the EoC extreme water years compared to their historical counterparts. Also, precipitation, mostly in the form of rain, is projected to fall earlier. This change reduces snowpack by more than 90 %, increases peak surface water and groundwater storages up to 75 % and 23 %, respectively, and makes these peak storages occur earlier in the year. Because EoC temperatures and soil moisture are high, both potential and actual evapotranspiration (ET) increase. The latter, along with the lack of snowmelt in the warm EoC, cause surface water and groundwater storages to significantly decrease in summer, with groundwater showing the highest rates of decrease. Besides, the changes in the precipitation phase lead the lower-order streams to dry out in EoC summer whereas the mainstream experiences an increase in storage.

Influence of morphometric parameters and meteorological conditions on ephemeral pool hydrology in the Canadian Shield forest 

2021 ◽  
Author(s):  
Marjolaine Roux ◽  
Marie Larocque ◽  
Philippe Nolet ◽  
Sylvain Gagné
Keyword(s):  
Surface Water ◽  
Water Level ◽  
Meteorological Conditions ◽  
Canadian Shield ◽  
Water Levels ◽  
Forest Biodiversity ◽  
Rainfall Events ◽  
Ephemeral Pools ◽  
Water Level Variations ◽  
Dry Out

&lt;p&gt;Ephemeral pools are geographically isolated wetlands commonly found in temperate forests of northeastern North America. These wetlands are usually hydrologically isolated from the surface water network but in some conditions can be connected to local groundwater flow. They fill at maximal capacity following spring snowmelt and dry out during summer. They contribute to forest biodiversity by providing breeding habitats for amphibians during their spring and early summer period of hydrological activity. However, ephemeral pools are poorly understood and rarely studied because of their small dimensions and temporary hydrology. This work presents the final results of a five-year study aimed to acquire new knowledge on ephemeral pool hydrology to go beyond the anecdotical pool and to understand the conditions and processes that driving their hydrology. A large number of pools (39) located in the Canadian Shield forest were instrumented to monitor hourly water level variations in the pool and in the neighboring and underlying fractured bedrock aquifer. They were also described in extensive details for their geomorphological features and water levels over a period from one to five years (April 2016 to July 2020). The first rather surprising result from this work is that, although the pools are all located in bedrock depressions, they cover a wide range of morphologies. Their maximum sizes vary from 29 to 1866 m&lt;sup&gt;2&lt;/sup&gt; and their maximal volumes vary from 4 to 654 m&lt;sup&gt;3&lt;/sup&gt;. Their maximum water depths are also highly contrasted, ranging from 0.14&amp;#160;m to 2.03&amp;#160;m. The pool depressions are overlain by mineral sediments (silt to fine sand with occurrences of coarse sand and gravel) of contrasted thicknesses (0&amp;#160;m to 1.70&amp;#160;m). An organic matter layer of highly varying thickness (0.12&amp;#160;m to 1.24&amp;#160;m) was observed at all sites above the mineral sediments. Despite these varied morphological conditions, all the pools have similar hydrological patterns throughout the year and these patterns are highly resilient to meteorological conditions. They dry out between the end of May and the end of July, rapid temporary refilling during important summer rainfall events, and partially refilling in autumn following more frequent rainfall events and lower evapotranspiration. The results show that surface water levels are maintained when the underlying sediments are saturated. Otherwise, the ephemeral pools lose water by infiltration to the underlying aquifer. Water level variations within the pools are positively and significantly correlated with net precipitation (P &amp;#8211; PET). Hydroperiods vary between 28 days (2020) and 86 days (2017), reflecting the year-to-year meteorological variability. The mean hydroperiod is significantly correlated to spring rainfall (April to June), but also to the volume of water stored in the pool, and to the pool surface area. This study provides a unique and original dataset that contribute to better understand the hydrodynamics and resilience to anthropogenic (forestry) and natural (climate change) impacts of a wetland type that is rarely studied but provide crucial habitats for forest biodiversity.&lt;/p&gt;

Biochemistry of water-logged soils: Part II. The presence of a deaminase in water-logged soils and its rôle in the production of ammonia

1927 ◽  
Vol 17 (4) ◽  
pp. 449-467 ◽  
Author(s):  
V. Subrahmanyan
Keyword(s):  
Aqueous Solution ◽  
Amino Acids ◽  
Surface Water ◽  
Aspartic Acid ◽  
Biological Action ◽  
Plant Food ◽  
Soil Sediment ◽  
Dry Out ◽  
Active Preparation ◽  
Production Of Ammonia

(1) The ammonia formed in water-logged soils was present mostly in the soil sediment. The surface water contained only a very small portion of the total amount produced.(2) Added ammonia was in a similar manner retained mostly in the soil itself. It could not be leached out by extraction with water nor volatilised with increase of temperature. There is evidence to show that the ammonia exists in the soil as an exchangeable base.(3) On allowing the soils to dry out the ammonia disappeared rapidly and corresponding amounts of nitrates were formed. Very little ammonia was lost by volatilisation.(4) The production of ammonia took place even in presence of volatile antiseptics. The reaction was shown to be brought about by a deaminase.(5) Studies with a number of proteins and ammo acids showed that only very simple amino compounds (glycine aspartic acid and asparagine) were deaminised. Witte's peptone, which contains amino acids, was also attacked.(6) An active preparation of enzyme was extracted from the soil with an aqueous solution of glycerin saturated with toluene.(7) Significant deaminising action was shown by the enzymes from cultures of the mixed microflora of the soils.(8) By acting on amino bodies that are otherwise resistant to biological action the deaminase probably helps to release readily available plant food. Its action should be of great importance in tropical swamp soils.

Surface Water Information Collection

2017 ◽  
pp. 285-301
Author(s):  
Mark Gillingham
Keyword(s):  
Surface Water ◽  
Environmental Protection Agency ◽  
The United States ◽  
Clean Water ◽  
National Strategy ◽  
Earth Observations ◽  
Quality Of Water ◽  
The Us ◽  
Private Citizens

This chapter's starting premise is that for decades the United States Environmental Protection Agency region subsuming most of the Great Lakes watershed has been partially monitored by private citizens, but collected data have been underutilized by water managers, scientists, and policymakers. Today, citizens with only a smartphone can dramatically increase our understanding of surface water, help managers and policymakers, and educate the general public about the quality of water. The US Clean Water Act and National Strategy for Civil Earth Observations have helped to coordinate citizen scientists and direct funds to surface-water monitoring. And more contributors are being solicited and trained to help with the enormous task of monitoring lakes and streams. At the same time, technology allows citizens with a smartphone to accomplish what previously required experts in a lab: to act for clean water!

scholarly journals Distribution and sources of polycyclic aromatic hydrocarbons in the aquatic environment: a multivariate analysis

2010 ◽  
Vol 63 (2) ◽  
pp. 211-218 ◽  
Author(s):  
Joil José Celino ◽  
Henry Xavier Corseuil ◽  
Marilda Fernandes ◽  
Karina Santos Garcia
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Surface Water ◽  
Aromatic Hydrocarbons ◽  
Principal Component ◽  
Mean Value ◽  
Gas Chromatography Mass Spectrometry ◽  
The Us ◽  
Polycyclic Aromatic ◽  
Sewage Contamination ◽  
Almost All

Fourteen polycyclic aromatic hydrocarbons (PAHs) included in the US Environmental Protection Agency's (EPA) priority pollutant list were analyzed using gas chromatography-mass spectrometry (GC--MS). Surface water sampling was undertaken in the Paraguaçu Estuary (Bahia), northern Brazil. Total PAH concentrations varied from 0.0029 to 0.1079 ng/L in the surface waters (main rivers, tributaries) with a mean value of 0.0344 ng/L. Such concentrations can be taken as background values for the studied region. The PAH profiles were dominated by low molecular weight PAHs (two- and three-ring components) in surface water samples. It indicated that PAHs in surface water may have its origin from oil or sewage contamination (petrogenic input). The collected data showed that petrogenic input was predominant at almost all the stations investigated. To discriminate pattern differences and similarities among the samples, a principal component analysis (PCA) was performed using a correlation matrix. PCA revealed the latent relationships among all the surface water from the investigated stations.

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