Hydrology Of Springs Research Articles

Effects of Hydrologic Pulsing and Vegetation on Invertebrate Communities in Wetlands

Constructed, mitigation wetlands in the midwestern United States are frequently dominated by a Typha spp. monoculture and their hydrologies are often determined by adjustable control structures. Wetlands provide habitat for multiple macroinvertebrate species, which in turn provide food for other organisms inhabiting the wetlands, such as waterfowl. This study examined the impacts of plant diversity and manipulated hydrology on macroinvertebrate communities. Forty 1-m2 wetland mesocosms were either planted with a monoculture of Typha spp. or with a more diverse plant community of Schoenoplectus tabernaemontani, Juncus effusus, and Sparganium eurycarpum. They were also assigned to one of four hydrologic regimes: steady state, pulsing, deep spring/shallow fall, and shallow spring/deep summer. After one year, macroinvertebrates were sampled in the mesocosms. Mesocosms with deep spring hydrologies were found to have greater taxon diversity than those with other hydrologies, but Chironomidae biomass was the lowest under the deep spring hydrology. Culicidae and Chironomidae were found in higher numbers in mixed vegetation than in Typha spp. Taxon richness and Chironomid biomass were significantly higher in mixed vegetation mesocosms than in Typha spp. monocultures. Results suggest vegetation diversity and hydrological regimes impact macroinvertebrate communities, with potential implications for constructed wetland design and management.

Impact Of Lithology and Regional Climate Variability on Spring Characteristics Between Uttarkashi and Harsil, Garhwal Himalaya, India

Spring characteristics are dependent upon the nature of lithology and precipitation in the region. The area is divided into two zones based on their lithological characters, viz: lesser Himalayan zone and Central Crystalline Zone for the hydrogeological study. Forty-five springs and four hot springs under different lithological controls were studied to understand spring discharges' response to regional climate variability. Four types of springs, fracture jointrelated springs, colluvial springs, Karst and seepages, and contact springs identified, which emanates from two geohydrological zones with in the study area. Colluvial springs yield are higher in comparison to the fracture jointrelated springs. The study revealed that the regional climatic pattern and precipitation pattern has a direct impact on spring hydrology.

Snowmelt control on spring hydrology declines as the vernal window lengthens

The vernal window, or the winter-to-spring transition, is a key period for seasonally snow-covered, forested ecosystems. The events that open and close the vernal window shape the unique characteristics of spring hydrology that, in turn, influence both terrestrial and aquatic ecosystem processes. Few studies have examined how climate change will alter the vernal window and thereby impact basic hydrology during this transitional period. We project that over the 21st century the vernal window will lengthen by +15 to +28 d in northeastern North America. Loss of snow cover under a high climate forcing scenario eliminates the vernal window across 59% of the study domain, removing snow’s influence on spring runoff in those areas. Spring runoff timing where the vernal window lengthens but does not disappear becomes similar to the southern, snow-free region where precipitation drives winter runoff, indicating a fundamental change in the hydrologic character of northeastern forests.

Study of how hydrological conditions affect the propagation of pseudorandom signals from the shelf in deep water

The paper examines how hydrological conditions affect manifestation of the acoustic “landslide” effect, which consists in focusing of acoustic energy in the near-bottom layer on the shelf and its transition to the axis of an underwater sound channel in deep water. We compare the results of experiments performed in the Sea of Japan in April 2014 and August 2006 on the same acoustic track, where the distance between corresponding points was more than 100 km. In April, the hydrological conditions in the shelf region of the track and in the upper layer of the deep-water part of the sea were characterized by the presence of a relatively weak (~0.35 s–1) negative vertical sound velocity gradient, whereas in August 2006, it was ~1.5 s–1. Experimental and numerical studies showed that the acoustic landslide effect also manifests itself under conditions of a weak negative sound velocity gradient, but the structure of the acoustic field trapped by the underwater sound channel has a more complex character with a time-expanded pulse characteristic. Nevertheless, its ordered, stable, and well-identified structure at all track points chosen for measurements make it possible to reliably create an efficient (with accuracies to hundredths of a percent) underwater navigation systems like GLONASS and GPS for the spring hydrology season.

Environmental and depositional controls on laminated freshwater carbonates: An example from the Roman aqueduct of Patara, Turkey

Carbonate deposits in aqueducts are a new high-resolution data source for environmental changes during the time of the Roman Empire, notably in the fields of palaeoclimate and spring hydrology. In order to distinguish environmental effects from those related to depositional setting, laminated carbonate deposits were compared along the entire length of an ancient aqueduct channel at Patara, Turkey. The carbonate deposits, up to 80mm in thickness, are composed of lamina couplets up to 1mm thick of alternating porous microspar and dense, columnar sparite. The former formed in the dry, warm season and the latter in the wet, cool season. The presence of biofilms seems to play a role in the development of the porous laminae. The relative importance of both lamina types depends also on the location within the aqueduct: dense, coarse-crystalline laminae dominate in steep sections of the aqueduct, while porous, fine-crystalline laminae are mostly found on gentle slopes. This is attributed to the flow velocity of the water, since fast flow on steep slopes hampers the development of biofilms. Carbonate microstructures can vary considerably down the line of a specific aqueduct; hence multiple sampling is needed along the channel in order to collect specimens suitable for detailed research. δ18O profiles show oscillations with increasing amplitude downstream reflecting rising water temperatures in the channel, while evaporation plays a minor, damping role on these oscillations. The periodicity of the δ18O values can be used to recognise annual layering in order to establish the number of years an aqueduct was operating. δ13C values are higher in open masonry channel sections than in ceramic pipes, probably due to stronger degassing of CO2 in the open channel. Carbonate deposits in Roman aqueducts hold high promises as seasonally resolved archives of hydrology and climate and, possibly, of earthquakes.

Vegetation and hydrogeology along the distribution range of Centaurium somedanum, an endemic plant of mountain calcareous springs

Calcareous springs support bryophyte-dominated habitats relevant to biodiversity and conservation, but not much is known about the ecology of vascular plants restricted to these environments. Here, we investigate vegetation and hydrogeological patterns within the distribution of Centaurium somedanum, a threatened vascular plant endemic to mountain calcareous springs in the Cantabrian range (Spain). We studied the hydrogeological characteristics of the spring systems where this species occurs and identified three types of springs: (a) springs with active travertine deposition in small valleys, (b) springs in rock fall avalanches and (c) springs fed by calcareous water close to geological faults. Vascular plants and bryophytes co-occurring with the study species were sampled in 1-m2 plots to identify major vegetation types and to assess the relationships between species composition and topography. The presence of C. somedanum was associated with vegetation of calcareous spring fens (Caricion davallianae) in geological faults, tufa concretions (Adiantion) in active travertines, and another vegetation type of calcareous flushes (Pinguiculion) that was found in all of the spring types. C. somedanum shows a wider ecological range than other vascular plants of calcareous springs, occupying micro-habitats with similar cover of bryophytes but different from the cover of vascular plants. Although these plant communities are primarily dependent on the hydrology of springs, the variation in species composition is also correlated to the slope and solar radiation at the micro-scale. Our study demonstrates how a vascular plant with a calciphilic character may adapt to tufa-forming niches along the spring-flush-fen gradient, thus allowing it to occupy a wide range of habitats at different altitudes and geohydrological conditions.

Determining Informational Entropy of KARST Spring Hydrology Based on Wavelet Transform

Wavelet transform by DB4 method can be applied to determine informational entropy of KARST spring hydrology conveniently. The complexity of KARST spring hydrology was described by entropy. Compared with the runoff of surface water, it concludes that KARST spring hydrology has higher complexity than the runoff of surface water.

Evaluation of CANWET model for hydrologic simulations for upper Canagagigue Creek watershed in southern Ontario

This paper discusses the uncertainty associated with the dominant hydrologic processes for watershed-scale water budget calculations in a rural southern Ontario watershed. Very little field data is available that would help in direct calculation of spatial and temporal variation of some of the key components of the water budget, including evapotranspiration and groundwater recharge on a watershed scale. Therefore, the Ontario Ministry of the Environment has recommended the use of a suite of hydrologic models for water budget calculations. The methodologies behind these models vary in procedural complexities and spatial and temporal resolutions. In the current study CANWET (Canadian Nutrient and Water Evaluation Tool) model, which uses relatively simplified approach as compare to other physically based models, was evaluated for water balance studies in southern Ontario. The model was applied to the Upper Canagagigue Creek watershed of the Grand River basin. The model was run for a ten-year period (April 1990 - March 2000) and outputs from the hydrologic simulations were used to analyze streamflow hydrographs and water budget components on annual, seasonal, monthly, and daily time frames. The model partitioned the annual water budget into 60% evapotranspiration, 12% surface runoff, and 28% sub-surface flow. These values are supported by the long-term annual observed data and by literature. The analysis of water balances on seasonal and monthly basis revealed that the snowmelt component of the model, which is critical for winter and spring hydrology, requires improvement. The snowmelt equation used in the model is simplified degree-day equation. This study shows that in the Canagagigue Creek watershed, more than 90% of precipitation in summer months is lost to evapotranspiration and more than half of precipitations in the winter/spring months recharge groundwater. The CANWET model was found to be a useful tool in calculation of watershed-scale water budget components reasonably well on annual (R2 = 0.89), seasonal (R2 = 0.68), and monthly (R2 = 0.68) time frames.

Book review: Groundwater Hydrology of Springs: Engineering, Theory, Management, and Sustainability, edited by Neven Kresic and Zoran Stevanovic (Elsevier, 2010)

Book review: Groundwater Hydrology of Springs: Engineering, Theory, Management, and Sustainability, edited by Neven Kresic and Zoran Stevanovic (Elsevier, 2010)

Book Review: Groundwater Hydrology of Springs: Theory, Management, and Sustainability

Book Review: Groundwater Hydrology of Springs: Theory, Management, and Sustainability

Review of Krešić, N. and Stevanović, Z. (Editors) 2010.Groundwater Hydrology of Springs: Engineering, Theory, Management and Sustainability

Review of Krešić, N. and Stevanović, Z. (Editors) 2010.Groundwater Hydrology of Springs: Engineering, Theory, Management and Sustainability

Inference of the structure of karst conduits using quantitative tracer tests and geological information: example of the Swiss Jura

Karst aquifers are known for being particularly heterogeneous with highly transmissive conduits embedded in low permeability volumes of rock matrix. Artificial tracer experiments have been carried out in a complex karst aquifer of the folded Jura Mountains in Switzerland with the aim of deciphering the conduit organisation. It is shown that tracer experiments with multiple injection points under different flow conditions can lead to useful information on the conduits’ structure. This information has been combined with data from structural geology, spring hydrology, and speleological observations. A conceptual model of the conduit network shows that a detailed inference of the conduit organisation can be reached: geology controls conduit location and orientation; spring hydrology, including temporary springs, constrains conduit elevations and relative hydraulic heads in the aquifer subsystems; and tracer tests identify major flow paths and outlets of the system and dilution caused by non-traced tributaries, as well as the presence of secondary flow routes. This understanding of the Aubonne aquifer structure has important implications for the future management of the groundwater resource. Similar approaches coupling geological information, spring hydrology, and multi-tracer tests under various flow conditions may help to characterise the structure of the conduit network in karst aquifers.

The chemistry and hydrology of thermal springs on efate, vanuatu, sw pacific

Two zones of geothermal spring activity on the island of Efate are described. The hydrothermal systems are associated with a deep-seated graben through Pleistocene volcanics and fringing reef limestones. The Teuma group of springs have temperatures up to 59°C and discharge around 1 MW of heat, although total discharge into rivers is estimated from conductivity changes to be 10 MW. The hydrochemistry and stable isotope hydrology of these springs indicate that there are two thermal components: residual sea-water with estimated base temperature no more than 114°C and a less saline thermal water which has a much smaller surface discharge but is indicated by cation and SiO 2, geothermometry to have a base temperature up to 218°C. The Takara group of springs discharge in the coastal reef limestone where the meteoric water table intersects the ground surface; the proximity of this thermal water table also gives rise to an expanse of “hot ground” inland of the spring line. The excess heat flow from this system is around 20 MW, and varies according to the seasonality of fresh-water recharge and flux. A heat source at depth to the landward side of the thermal area is indicated. The hydrochemistry of the Takara system shows that it comprises sea-water, possibly mixed with meteoric water prior to circulation in the thermal reservoir. Mg 2+ and SO 2− 4 are strongly depleted in the thermal water relative to unreacted sea-water; however there is no detectable δ 18O shift which suggests a high water:rock ratio in the thermal reservoir. Quartz geothermometry indicates a base temperature up to 174°C which is similar to that indicated by cation geothermometry although the unusual absence of K + enrichment casts some doubt on use of the Na—K—Ca method. The interpretation emphasizes the need to examine and understand alteration mineralogy in order to place more confidence in geothermometry and to obtain more information on evolution of the geothermal systems. No drilling has yet taken place and much of the reservoir geology and description is speculation. The Teuma system probably comprises circulation in fractured basalt dykes associated with graben activity, and flow may therefore be very limited at depth. The Takara system has some similarities with other marine systems, mostly at oceanridge locations, where sea-water circulates convectively in basalts with a regionally-high geothermal gradient.