Changes in groundwater regime during vegetation period in Groundwater Dependent Ecosystems

2016 ◽  
Vol 66 (3) ◽  
pp. 527-542 ◽  
Author(s):  
Ewa Krogulec ◽  
Sebastian Zabłocki ◽  
Katarzyna Sawicka
Keyword(s):  
Plant Communities ◽  
Vegetation Period ◽  
Large River ◽  
Entire Interval ◽  
Protection Measures ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Vistula River ◽  
Groundwater Dependent Ecosystems ◽  
Management Plans

Abstract An analysis of the dynamics of groundwater levels in the Groundwater Dependent Ecosystems (GDEs), which cover a vast part of the middle Vistula River valley in central Poland was carried out. The study area, typical of large river valleys, was investigated by detailed monitoring of groundwater levels. Based on statistical analysis and the geo-statistical modeling of monitoring data for 1999-2013, the range and dynamics of groundwater level fluctuations were determined for the entire interval and for the vegetation periods. The values of retention and infiltration recharge in various periods were compared with average values, indicating intervals of potential groundwater deficiency in GDEs. The amplitude of groundwater fluctuations, retention and infiltration were determined for vegetation periods characterized by the highest water intake by plants and the highest evapotranspiration. Particular attention has been drawn to the analysis of low groundwater levels in the vegetation periods, with water deficiencies potentially threatening the correct functioning of plant communities in GDEs. Moreover, the study has allowed us to indicate areas with insufficient groundwater levels during vegetation periods that may be hazardous to plant communities. The results may be a basis for the elaboration of correct management plans, protection measures and projects, or GDE renaturalization.

scholarly journals A floristic description of the Afromontane fynbos communities on Platberg, Eastern Free State, South Africa

Koedoe ◽  
2008 ◽  
Vol 50 (1) ◽  
Author(s):  
Robert F. Brand ◽  
Pieter J. Du Preez ◽  
Leslie R. Brown
Keyword(s):  
Natural Resources ◽  
Plant Communities ◽  
Conservation Management ◽  
Alien Invasive Species ◽  
Ecological Processes ◽  
The North ◽  
Shrub Community ◽  
Management Plans ◽  
Twinspan Classification

Within the Platberg area and the wider Drakensberg region, the shrinking natural resources and the threat posed to biodiversity are of concern to conservation management and require an understanding of long-term ecological processes. The vegetation of Platberg was investigated as part of an ecological survey to establish Afromontane floristic links to the Drakensberg as well as for the management of natural resources. From a TWINSPAN classification, refined by the Braun-Blanquet method, four main plant communities were identified, which were subdivided into fynbos, wetland, a woody/shrub community and grassland. A classification and description of the fynbos are presented in this article.The analysis showed the fynbos divided into two communities comprising four sub-communities and seven variants. The fynbos community had an average of 28.34 species per relevé, ranging from 14 to 54 species per sample plot. Twenty-four endemic or near-endemic Drakensberg Alpine Centre (DAC) species and 22 exotic (alien-invasive) species were recorded. Numerous floristic links with the DAC, Cape flora fynbos and grassland bioregions to the north and west were also found. The description of the fynbos plant communities can serve as a basis for the formulation of management plans for the area.

scholarly journals A vegetation description and floristic analyses of the springs on the Kammanassie Mountain, Western Cape

Koedoe ◽  
2004 ◽  
Vol 47 (2) ◽  
Author(s):  
G. Cleaver ◽  
L.R. Brown ◽  
G.J. Bredenkamp
Keyword(s):  
Plant Communities ◽  
Western Cape ◽  
Ecological Processes ◽  
Mountain Catchment ◽  
Habitat Factors ◽  
Management Plans ◽  
Twinspan Classification ◽  
Geological Origin ◽  
The Difference

The Kammanassie Mountain is a declared mountain catchment area and a Cape mountain zebra Equus zebra zebra population is preserved on the mountain. The high number of springs on the mountain not only provides water for the animal species but also contributes to overall ecosystem functioning. Long-term conservation of viable ecosystems requires a broader understanding of the ecological processes involved. It was therefore decided that a classification, description and mapping of the spring vegetation of the Kammanassie Mountain be undertaken. A TWINSPAN classification, refined by Braun-Blanquet procedures, revealed 11 major plant communities that could be related to geological origin. Habitat factors associated with differences in vegetation include topography, soil type and grazing. Descriptions of the plant communities include diagnostic species as well as prominent and less conspicuous species of the tree, shrub and herbaceous layers. The results also indicate a high species richness compared to similar regions and the difference between plant communities of wet and dry springs. This data is important for long-term monitoring of the spring ecosystems as well as for the compilation of management plans.

scholarly journals A Review of Case Studies on Climate Change Impact on Hydrologic Cycle: An Indian Perspective

2021 ◽  
pp. 249-266
Author(s):  
P K Bhunya ◽  
Sanjay Kumar ◽  
Sunil Gurrapu ◽  
M K Bhuyan
Keyword(s):  
Climate Change ◽  
Climate Models ◽  
Hydrological Cycle ◽  
Groundwater Resources ◽  
Rainfall Events ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Change Impact ◽  
Heavy Rainfall Events ◽  
Flood Characteristics

In recent times, several studies focused on the global warming that may affect the hydrological cycle due to intensification of temporal and spatial variations in precipitation. Such climatic change is likely to impact significantly upon freshwater resources availability. In India, demand for water has already increased manifold over the years due to urbanization, agriculture expansion, increasing population, rapid industrialization and economic development. Numerous scientific studies also report increases in the intensity, duration, and spatial extents of floods, higher atmospheric temperatures, warmer sea, changes in precipitation patterns, and changing groundwater levels. This work briefly discusses about the present scenario regarding impact of climate change on water resources in India. Due to the insufficient resolution of climate models and their generally crude representation of sub-grid scale and convective processes, little confidence can be placed in any definite predictions of such effects, although a tendency for more heavy rainfall events seems likely, and a modest increase in frequency in floods. Thus to analyses this effect, this work considers real problems about the changing flood characteristics pattern in two river regions, and the effect of spatial and temporal pattern in rainfall. In addition to these, the work also examines the trend of groundwater level fluctuations in few blocks of Ganga–Yamuna and Sutlej-Yamuna Link interfluves region. As a whole, it examines the potential for sustainable development of surface water and groundwater resources within the constraints imposed by climate change.

scholarly journals Hydrological processes and water resources management in a dryland environment IV: Long-term groundwater level fluctuations due to variation in rainfall

1999 ◽  
Vol 3 (3) ◽  
pp. 353-361 ◽  
Author(s):  
J. A. Butterworth ◽  
R. E. Schulze ◽  
L. P. Simmonds ◽  
P. Moriarty ◽  
F. Mugabe
Keyword(s):  
Groundwater Resources ◽  
Water Levels ◽  
Shallow Aquifer ◽  
Balance Model ◽  
Specific Yield ◽  
Evaporative Demand ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Modelling Methods

Abstract. To evaluate the effects of variations in rainfall on groundwater, long-term rainfall records were used to simulate groundwater levels over the period 1953-96 at an experimental catchment in south-east Zimbabwe. Two different modelling methods were adopted. Firstly, a soil water balance model (ACRU) simulated drainage from daily rainfall and evaporative demand; groundwater levels were predicted as a function of drainage, specific yield and water table height. Secondly, the cumulative rainfall departure method was used to model groundwater levels from monthly rainfall. Both methods simulated observed groundwater levels over the period 1992-96 successfully, and long-term simulated trends in historical levels were comparable. Results suggest that large perturbations in groundwater levels area a normal feature of the response of a shallow aquifer to variations in rainfall. Long-term trends in groundwater levels are apparent and reflect the effect of cycles in rainfall. Average end of dry season water levels were simulated to be almost 3 m higher in the late 1970s compared to those of the early 1990s. The simulated effect of prolonged low rainfall on groundwater levels was particularly severe during the period 1981-92 with a series of low recharge years unprecedented in the earlier record. More recently, above average rainfall has resulted in generally higher groundwater levels. The modelling methods described may be applied in the development of guidelines for groundwater schemes to help ensure safe long-term yields and to predict future stress on groundwater resources in low rainfall periods; they are being developed to evaluate the effects of land use and management change on groundwater resources.

Rivers as groundwater-dependent ecosystems: a review of degrees of dependency, riverine processes and management implications

2006 ◽  
Vol 54 (2) ◽  
pp. 133 ◽  
Author(s):  
A. J. Boulton ◽  
P. J. Hancock
Keyword(s):  
Base Flow ◽  
Management Approach ◽  
River Channels ◽  
Management Implications ◽  
River Types ◽  
Groundwater Dependent Ecosystems ◽  
Management Plans ◽  
Explicit Recognition ◽  
Local Water ◽  
Chemical Conditions

Many rivers are classified as groundwater-dependent ecosystems (GDEs), owing to the contribution of groundwater to their base flow. However, there has been little explicit recognition of the way groundwater influences riverine biota or processes, how degrees of ecological dependency may vary, and the management implications of this dependency. The permeable beds and banks of these GDEs where surface water and groundwater exchange are termed ‘hyporheic zones’. They are often inhabited by invertebrates, with varying reliance on groundwater, although the ecological roles of these invertebrates are little known. Upwelling hyporheic water can promote surface primary productivity, influence sediment microbial activity, and affect organic matter decomposition. In many intermittent streams, variable groundwater inputs alter the duration of flow or water permanence, and the duration and timing of these largely govern the biota and rates of many ecosystem processes (e.g. leaf decomposition). Not only is the physical presence of water important, thermal and chemical conditions arising from groundwater inputs also have direct and indirect effects on riverine biota and rates or types of in-stream processes. Differing degrees of dependency of rivers on groundwater mediate all these influences, and may change over time and in response to human activities. Alteration of groundwater inputs through extraction from riparian wells or changes in local water table have an impact on these GDEs, and some current management plans aim to restrict groundwater extraction from near permeable river channels. However, these are often ‘blanket’ restrictions and the mechanisms of GDE dependency or timing of groundwater requirements are poorly understood, hampering refinement of this management approach. More effective management of these GDEs into the future can result only from a better understanding of the mechanisms of the dependency, how these vary among river types and what in-stream changes might be predicted from alteration of groundwater inputs.

scholarly journals Application of HEC-RAS model for estimating changes in watercourse geometry during floods

2012 ◽  
Vol 34 (2) ◽  
pp. 63-72 ◽  
Author(s):  
Joanna Markowska ◽  
Jacek Markowski ◽  
Andrzej Drabiński
Keyword(s):  
River Channel ◽  
Groundwater Table ◽  
Water Levels ◽  
Primary Role ◽  
Flood Wave ◽  
Initial State ◽  
Wave Impact ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Flood Waves

Abstract Groundwater table levels in a river valley depend, among other factors, on meteorological and hydrogeological conditions, land use and water levels in watercourses. The primary role of a watercourse is to collect surface and groundwater, and it becomes an infiltrating watercourse at high water levels. Changes in groundwater levels and the range of these changes depend chiefly on the shape, height and duration of the flood wave in the river channel. The assessment of flood wave impact on groundwater was based on long-term measurements of groundwater levels in the Odra valley and observations of water levels in the river channel. Simulations were performed with the use of in-house software FIZ (Filtracja i Zanieczyszczenia; Filtration and Contamination), designed for modelling unsteady water flows within a fully saturated zone. A two-dimensional model with two spatial variables was employed. The process of groundwater flow through a porous medium, non-homogeneous in terms of water permeability, was described with Boussinesq equation. The equation was solved with the use of finite element method. The model was applied to assess groundwater level fluctuations in the Odra valley in the context of actual flood waves on the river. Variations in groundwater table in the valley were analysed in relation to selected actual flood water levels in the Odra in 2001-2003 and 2010. The period from 2001 to 2003 was used to verify the model. A satisfactory agreement between the calculated and the measured values was obtained. Based on simulation calculations, it was proved that flood waves observed in 2010 caused a rise in groundwater table levels in a belt of approximately 1000 metres from the watercourses. It was calculated that at the end of hydrological year 2009/2010, the highest growths, of up to 0.80 m, were observed on piezometers located close to the Odra river channel. The passage of several flood waves on the Odra caused an increase of subsurface retention by 3.0% compared to the initial state.

scholarly journals The Role of Environmental Background Processes in Determining Groundwater Level Variability—An Investigation of a Record Flood Event Using Dynamic Factor Analysis

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2336
Author(s):  
Balázs Trásy ◽  
Norbert Magyar ◽  
Tímea Havril ◽  
József Kovács ◽  
Tamás Garamhegyi
Keyword(s):  
Factor Analysis ◽  
Groundwater Level ◽  
Coefficient Of Determination ◽  
Dynamic Factor Analysis ◽  
Dynamic Factor ◽  
Climate Change Scenarios ◽  
Background Factors ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Environmental Background

Since groundwater is a major source of water for drinking and for industrial and irrigation uses, the identification of the environmental processes determining groundwater level fluctuation is potentially a matter of great consequence, especially in light of the fact that the frequency of extreme climate events may be expected to increase, causing changes in groundwater recharge systems. In the recent study, data measured at a frequency of one hour were collected from the Szigetköz, an inland delta of the Danube. These were then used to determine the presence, or not, and magnitude of any hidden environmental background factors that may be causing groundwater level fluctuations. Through the application of dynamic factor analysis, it was revealed that changes in groundwater level are mainly determined by (i) the water level of neighboring rivers and (ii) evapotranspiration. The intensity of these factors may also be estimated spatially. If the background factors determined by dynamic factor analysis do indeed figure in the linear model as variables, then the time series of groundwater levels can be said to have been accurately estimated with the use of linear regression. The accuracy of the estimate is indicated by the fact that adjusted coefficient of determination exceeds 0.9 in 80% of the wells. The results, via an enhanced understanding of the reasons for changes in the fluctuation of groundwater, could assist in the development of sustainable water management and irrigation strategies and the preparation for varying potential climate change scenarios.

scholarly journals Groundwater Modeling with Machine Learning Techniques: Ljubljana polje Aquifer

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 697 ◽  
Author(s):  
Klemen Kenda ◽  
Matej Čerin ◽  
Mark Bogataj ◽  
Matej Senožetnik ◽  
Kristina Klemen ◽  
...  
Keyword(s):  
Machine Learning ◽  
Groundwater Level ◽  
Groundwater Modeling ◽  
Machine Learning Techniques ◽  
Physical Parameters ◽  
Strongly Correlated ◽  
Groundwater Levels ◽  
Groundwater Level Fluctuations ◽  
Decision Making Processes ◽  
Input Variables

In this study a thorough analysis is conducted concerning the prediction of groundwater levels of Ljubljana polje aquifer. Machine learning methodologies are implemented using strongly correlated physical parameters as input variables. The results show that data-driven modelling approaches can perform sufficiently well in predicting groundwater level changes. Different evaluation metrics confirm and highlight the capability of these models to catch the trend of groundwater level fluctuations. Despite the overall adequate performance, further investigation is needed towards improving their accuracy in order to be comprised in decision making processes.

Integrated biostratigraphy of the Santonian through Maastrichtian (Upper Cretaceous) of extra-Carpathian Poland

2016 ◽  
Vol 66 (3) ◽  
pp. 321-358 ◽  
Author(s):  
Ireneusz Walaszczyk ◽  
Zofia Dubicka ◽  
Danuta Olszewska-Nejbert ◽  
Zbigniew Remin
Keyword(s):  
Upper Cretaceous ◽  
Entire Interval ◽  
Benthic Foraminifers ◽  
Southern Poland ◽  
South Eastern ◽  
Vistula River ◽  
Composite Section ◽  
First Occurrence ◽  
Western Ukraine ◽  
Stage Boundaries

AbstractThe biostratigraphic importance, current zonations, and potential for the recognition of the standard chronostratigraphic boundaries of five palaeontological groups (benthic foraminifers, ammonites, belemnites, inoceramid bivalves and echinoids), critical for the stratigraphy of the Santonian through Maastrichtian (Upper Cretaceous) of extra-Carpathian Poland, are presented and discussed. The summary is based on recent studies in selected sections of southern Poland (Nida Synclinorium; Puławy Trough including the Middle Vistula River composite section; and Mielnik and Kornica sections of south-eastern Mazury-Podlasie Homocline) and of western Ukraine (Dubivtsi). The new zonation based on benthic forams is presented for the entire interval studied. Zonations for ammonites, belemnites and inoceramid bivalves are compiled. All stage boundaries, as currently defined or understood, may easily be constrained or precisely located with the groups discussed: the base of the Santonian with the First Occurrence (FO) of the inoceramid Cladoceramus undulatoplicatus; the base of the Campanian with the Last Occurrence (LO) of the crinoid Marsupites testudinarius and approximated by the range of the foraminifer Stensioeina pommerana; and the base of the Maastrichtian approximated by the FO of the inoceramid bivalve Endocostea typica and the FO of the belemnite Belemnella vistulensis. The positions of substage boundaries, as currently understood, are constrained in terms of the groups discussed.

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