scholarly journals Woody Plant Encroachment Impacts on Groundwater Recharge: A Review

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1466 ◽  
Author(s):  
Bharat Acharya ◽  
Gehendra Kharel ◽  
Chris Zou ◽  
Bradford Wilcox ◽  
Todd Halihan
Keyword(s):  
Water Resources ◽  
Groundwater Recharge ◽  
Woody Plant ◽  
Groundwater Resources ◽  
Plant Cover ◽  
Experimental Studies ◽  
Estimation Methods ◽  
Woody Plant Encroachment ◽  
Plant Removal ◽  
The Impact

Woody plant encroachment has profound impacts on the sustainable management of water resources in water-limited ecosystems. However, our understanding of the effects of this global phenomenon on groundwater recharge at local and regional scales is limited. Here, we reviewed studies related to (i) recharge estimation methods; (ii) mechanisms by which woody plants impact groundwater recharge; (iii) impacts of woody plant on recharge across different soil and geology; (iv) hydrological repercussions of woody plant removal; and (v) research gaps and needs for groundwater studies. We identified six different methods: water balance, water table, isotopes, chloride mass balance, electrical geophysical imaging, and modeling were used to study the impact of woody encroachment on groundwater. Woody plant encroachment could alter soil infiltration rates, soil water storage, transpiration, interception, and subsurface pathways to affect groundwater recharge. The impact is highly variable, with the extent and the magnitude varying across the soil, substrate, plant cover, and topographic locations. Our review revealed mixed effects of woody plant removal on groundwater recharge. Studies of litter interception, root water uptake, soil moisture dynamics, and deep percolation along with the progression of woody plant encroachment are still limited, warranting further experimental studies focusing on groundwater recharge. Overall, information about woody plant encroachment impacts on groundwater resources across a range of scales is essential for long-range planning of water resources.

scholarly journals Where to locate a tree plantation within a low rainfall catchment to minimise impacts on groundwater resources

2014 ◽  
Vol 11 (8) ◽  
pp. 10001-10041 ◽  
Author(s):  
J. F. Dean ◽  
J. A. Webb ◽  
G. E. Jacobsen ◽  
R. Chisari ◽  
P. E. Dresel
Keyword(s):  
Water Resources ◽  
Mass Balance ◽  
Groundwater Recharge ◽  
Water Table ◽  
Groundwater Resources ◽  
Chloride Mass Balance ◽  
Tree Plantation ◽  
Depth Analysis ◽  
Paired Catchment ◽  
The Impact

Abstract. Despite the fact that there are many studies that consider the impacts of plantation forestry on water resources, and others that explore the spatial heterogeneity of groundwater recharge in dry regions, there is little marriage of the two subjects in forestry management guidelines and legislation. Here we carry out an in-depth analysis of the groundwater and surface water regime in a low rainfall, high evapotranspiration paired catchment study to examine the impact of reforestation, using water table fluctuations and chloride mass balance methods to estimate groundwater recharge. Recharge estimations using the chloride mass balance method were shown to be more likely representative of groundwater recharge regimes prior to the planting of the trees, and most likely prior to widespread land clearance by European settlers. These estimations were complicated by large amounts of recharge occurring as a result of runoff and streamflow in the lower parts of the catchment. Water table fluctuation method estimations of recharge verified that groundwater recharge occurs predominantly in the lowland areas of the study catchment. This leads to the conclusion that spatial variations in recharge are important considerations for locating tree plantations with respect to conserving water resources for downstream users. For dry regions, this means planting trees in the upland parts of the catchments, as recharge is shown to occur predominantly in the lowland areas.

scholarly journals Evaluation of Climate Change Impact on Groundwater Recharge in Groundwater Regions in Taiwan

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1153
Author(s):  
Shih-Jung Wang ◽  
Cheng-Haw Lee ◽  
Chen-Feng Yeh ◽  
Yong Fern Choo ◽  
Hung-Wei Tseng
Keyword(s):  
Climate Change ◽  
Groundwater Recharge ◽  
Climate Change Impact ◽  
Groundwater Resources ◽  
Regression Equations ◽  
Impact Of Climate Change ◽  
Groundwater Systems ◽  
Change Impact ◽  
The Impact ◽  
Assessment Results

Climate change can directly or indirectly influence groundwater resources. The mechanisms of this influence are complex and not easily quantified. Understanding the effect of climate change on groundwater systems can help governments adopt suitable strategies for water resources. The baseflow concept can be used to relate climate conditions to groundwater systems for assessing the climate change impact on groundwater resources. This study applies the stable baseflow concept to the estimation of the groundwater recharge in ten groundwater regions in Taiwan, under historical and climate scenario conditions. The recharge rates at the main river gauge stations in the groundwater regions were assessed using historical data. Regression equations between rainfall and groundwater recharge quantities were developed for the ten groundwater regions. The assessment results can be used for recharge evaluation in Taiwan. The climate change estimation results show that climate change would increase groundwater recharge by 32.6% or decrease it by 28.9% on average under the climate scenarios, with respect to the baseline quantity in Taiwan. The impact of climate change on groundwater systems may be positive. This study proposes a method for assessing the impact of climate change on groundwater systems. The assessment results provide important information for strategy development in groundwater resources management.

scholarly journals Drought Risk under Climate and Land Use Changes: Implication to Water Resource Availability at Catchment Scale

Water ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1790 ◽  
Author(s):  
Muhammad Afzal ◽  
Ragab Ragab
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Land Use Changes ◽  
Future Climate Change ◽  
Emission Scenarios ◽  
Catchment Scale ◽  
High Emission ◽  
The Impact

Although the climate change projections are produced by global models, studying the impact of climatic change on water resources is commonly investigated at catchment scale where the measurements are taken, and water management decisions are made. For this study, the Frome catchment in the UK was investigated as an example of midland England. The DiCaSM model was applied using the UKCP09 future climate change scenarios. The climate projections indicate that the greatest decrease in groundwater recharge and streamflow was projected under high emission scenarios in the 2080s. Under the medium and high emission scenarios, model results revealed that the frequency and severity of drought events would be the highest. The drought indices, the Reconnaissance Drought Index, RDI, Soil Moisture Deficit, SMD and Wetness Index, WI, predicted an increase in the severity of future drought events under the high emission scenarios. Increasing broadleaf forest area would decrease streamflow and groundwater recharge. Urban expansion could increase surface runoff. Decreasing winter barley and grass and increasing oil seed rape, would increase SMD and slightly decrease river flow. Findings of this study are helpful in the planning and management of the water resources considering the impact of climate and land use changes on variability in the availability of surface and groundwater resources.

Precipitation trends and ruptures effect on catchment hydrology and water resources availability for agricultural lands under climate change

2020 ◽  
Author(s):  
Youness Hrour ◽  
Zahra Thomas ◽  
Ophélie Fovet ◽  
Pauline Rousseau-Gueutin ◽  
Pascal Pichelin ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Agricultural Land ◽  
Catchment Hydrology ◽  
Agricultural Adaptation ◽  
Stream Discharge ◽  
Precipitation Indices ◽  
The Impact ◽  
Precipitation Trends

<p>Water resources depletion under climate change is a major concern over the world. Mediterranean countries are deeply affected by changes in precipitation intensity, duration and frequency. Such changes lead to decrease in the averaged stream discharge and groundwater recharge consequently decreasing water resources availability. Our research focused on a case study performed in the Loukkos catchment, draining an area of 3730 km², located in the north of Morocco. Trend analysis of 8 to 62 years of precipitations was conducted based on statistical tests at about ten stations over the catchment. 20 to 70 years of temperature and discharge data were also analyzed. The time series were investigated using several non-parametric tests in order to characterize trends, to track down changes and their effect on agricultural land changes at the catchment scale. The present study highlights the impact of climate and catchment hydrology on agricultural practices and water resources used for irrigation. Analysis of precipitation indices showed that the temporal distribution of precipitation in the study area has changed since the 1970s. This change results from a reduction in precipitation, a shift in the hydrological year and a reduction in the number of wet days per year. Severe drought periods appear after the climatic rupture, which occurred around 1971. An increase in the intensity and frequency of droughts, in addition to an increase in the annual and seasonal average temperature (more than 1°C) were observed. Such changes contributed to agricultural practice modifications, with development of irrigated agriculture and later sowing period to adapt to the delay in the onset of the rains. For the future, the use of IPCC/CMIP5 climate projections for the Mediterranean region will help to evaluate how the precipitation indices will evolve. The impact of irrigation on stream discharge and groundwater recharge needs to be considered through agro-hydrological modeling including agricultural trajectory. Such tools will help to strengthen agricultural adaptation strategies and promote resilient farming practices.</p><p>Keywords: Precipitation trends, agricultural land use, water use for irrigation, agricultural adaptation strategies.</p><p> </p>

scholarly journals Creation of an observation network for assessment of the impact of the pig complex on the groundwater aquifer

2021 ◽  
pp. 35-45
Author(s):  
Viktoriia Serdiuk ◽  
Viktor Maksin
Keyword(s):  
Water Resources ◽  
Anthropogenic Impacts ◽  
Groundwater Resources ◽  
Monitoring Network ◽  
Geological Structure ◽  
Rural Settlements ◽  
Association Agreement ◽  
Groundwater Aquifer ◽  
Observation Network ◽  
The Impact

Ukraine, as a party to the Association Agreement, in accordance with Directive 2000/60/EC of the European Parliament and of the Council, recognizes water as the most expensive resource on our planet, which must be protected and saved. Every country and every inhabitant of the planet must do everything possible to reduce the thoughtless use of water and stop water pollution. The priority is the identification of water users and "polluters", as well as the detection and prevention of pollution of water resources, which includes the identification of water sampling points around potential sources of pollution. The aim of the research is to determine the impact of pig farms on the qualitative and quantitative characteristics of groundwater using existing water intakes to preserve natural water resources from pollution and depletion. An important point for monitoring in this situation is the use of existing water intakes (bores and wells) without additional construction of observation bores and interference in the environment. To complete the study, it is necessary to create an observation (monitoring) network of selected points and establish the frequency of their study. The observation network should determine the level (static and dynamic) as well as the quality of groundwater, which reflects background concentrations (natural or "conditionally natural"). "Conditionally natural" concentrations may indicate an excess of pollutants, associated with anthropogenic impacts that occurred prior to the activities of a particular entity, in respect of which the study is conducted. Given the changes in the quality characteristics of water, caused by external factors, "conditionally natural" concentrations can be taken as background. The obtained information will allow, depending on the quality and quantity of groundwater (their level) to make management decisions on the management of groundwater resources. Groundwater in rural settlements near enterprises is in most cases the only source of water supply. The laboratory analysis of water samples from selected points in 2020 showed an excess of color, odor at 60 °C, turbidity, total iron in bores and wells. The detected elevations are due to the peculiarity of the geological structure (aquifer of Eocene sediments). The excess in the hydrogen index is almost 10 times from the surface water body, which can be taken as "conditionally natural" (background) with further study of the specific impact of the complex on the environment. The main indicators that may indicate direct contamination of the pig complex, such as nitrates, nitrites, ammonium nitrogen and microbiological studies, do not exceed the normalized values, set for drinking water. In this case, the specific indicators are within normal limits. Petroleum products were not detected in the studied samples

scholarly journals Multi-Scale Hydrologic Sensitivity to Climatic and Anthropogenic Changes in Northern Morocco

Geosciences ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 13 ◽  
Author(s):  
Adam Milewski ◽  
Wondwosen M. Seyoum ◽  
Racha Elkadiri ◽  
Michael Durham
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Groundwater Resources ◽  
Water Storage ◽  
Scale Model ◽  
Climate Projections ◽  
Monitoring Networks ◽  
Total Water ◽  
Anthropogenic Changes ◽  
The Impact

Natural and human-induced impacts on water resources across the globe continue to negatively impact water resources. Characterizing the hydrologic sensitivity to climatic and anthropogenic changes is problematic given the lack of monitoring networks and global-scale model uncertainties. This study presents an integrated methodology combining satellite remote sensing (e.g., GRACE, TRMM), hydrologic modeling (e.g., SWAT), and climate projections (IPCC AR5), to evaluate the impact of climatic and man-made changes on groundwater and surface water resources. The approach was carried out on two scales: regional (Morocco) and watershed (Souss Basin, Morocco) to capture the recent climatic changes in precipitation and total water storage, examine current and projected impacts on total water resources (surface and groundwater), and investigate the link between climate change and groundwater resources. Simulated (1979–2014) potential renewable groundwater resources obtained from SWAT are ~4.3 × 108 m3/yr. GRACE data (2002–2016) indicates a decline in total water storage anomaly of ~0.019m/yr., while precipitation remains relatively constant through the same time period (2002–2016), suggesting human interactions as the major underlying cause of depleting groundwater reserves. Results highlight the need for further conservation of diminishing groundwater resources and a more complete understanding of the links and impacts of climate change on groundwater resources.

Remote sensing for assessment of groundwater resources, A case study of Stampriet Transboundary Aquifer

2021 ◽  
Author(s):  
Irene Kinoti ◽  
Marc Leblanc ◽  
Albert Olioso ◽  
Maciek Lubczynski ◽  
Angelique Poulain
Keyword(s):  
Remote Sensing ◽  
Water Resources ◽  
Groundwater Recharge ◽  
Real Time ◽  
Unsaturated Zone ◽  
Driving Forces ◽  
Groundwater Resources ◽  
Time Step ◽  
Groundwater Storage ◽  
Spatio Temporal

<p>Distributed integrated hydrological models (IHMs) are the most effective tools for estimating groundwater recharge in arid and semi-arid areas characterized by thick unsaturated zone. It is also important to capture spatio-temporal aquifer dynamics by using real-time or near-real-time data, for sustainable water resources management. However, such data is often unavailable in developing countries where monitoring networks are scarce. In recent years, remote sensing has played an important role in providing spatio-temporal information for evaluation and management of water resources. Nevertheless, application of remote sensing in groundwater studies is still limited and has mainly focused on assessment of groundwater recharge and groundwater storage as well as to provide boundary conditions and driving forces for both standalone groundwater models and IHMs. This study entails application of remote sensing data in developing the distributed integrated hydrological model for Stampriet transboundary multi-layered aquifer system shared between Namibia, Botswana and South Africa. A numerical model has been set – up using MODFLOW 6 coupled with the Unsaturated Zone Flow (UZF) Package where Climate Hazards Infrared Precipitation with stations (CHIRPS) rainfall data and Global Land Evaporation Amsterdam Model (GLEAM) potential evapotranspiration data were implemented as the model driving forces. Other input data used include digital elevation model, and land-use/landcover and also soil datasets to define unsaturated zone parameters. The model has been calibrated with groundwater level measurements as the state variables in transient conditions at daily time step for a period of 16 years. The model-simulated unsaturated zone and groundwater storage was compared to GRACE-derived sub-surface storage anomaly, further also used to constrain the model. The calibrated model provides spatio-temporal water flux dynamics as well as water balances and hence an understanding of the groundwater-resource dynamics and replenishment. This information is shown useful for proper management of the transboundary water resource as well as for policy making.</p>

scholarly journals Comparing SWAT with SWAT-MODFLOW hydrological simulations when assessing the impacts of groundwater abstractions for irrigation and drinking water

2019 ◽  
Author(s):  
Wei Liu ◽  
Seonggyu Park ◽  
Ryan T. Bailey ◽  
Eugenio Molina-Navarro ◽  
Hans Estrup Andersen ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Groundwater Resources ◽  
Swat Model ◽  
Temporal Patterns ◽  
Simulation Performance ◽  
Model Complex ◽  
The Impact ◽  
Streamflow Depletion ◽  
Catchment Model

Abstract. Being able to account for temporal patterns of streamflow, the distribution of groundwater resources, as well as the interactions between surface water and groundwater is imperative for informed water resources management. We hypothesize that, when assessing the impacts of water abstractions on streamflow patterns, the benefits of applying a coupled catchment model relative to a lumped semi-distributed catchment model outweigh the costs of additional data requirement and computational resources. We applied the widely used semi-distributed SWAT model and the recently developed SWAT-MODFLOW model, which allows full distribution of the groundwater domain, to a Danish, lowland, groundwater-dominated catchment, the Uggerby River Catchment. We compared the performance of the two models based on the observed streamflow and assessed the simulated streamflow signals of each model when running four groundwater abstraction scenarios with real wells and abstraction rates. The SWAT-MODFLOW model complex was further developed to enable the application of the Drain Package of MODFLOW and to allow auto-irrigation on agricultural fields and pastures. Both models were calibrated and validated, and an approach based on PEST was developed and utilized to enable simultaneous calibration of SWAT and MODFLOW parameters. Both models demonstrated generally good performance for the temporal pattern of streamflow, albeit SWAT-MODFLOW performed somewhat better. In addition, SWAT-MODFLOW generates spatially explicit groundwater-related outputs, such as spatial-temporal patterns of water table elevation. In the abstraction scenarios analysis, both models indicated that abstraction for drinking water caused some degree of streamflow depletion, while abstraction for auto-irrigation led to a slight total flow increase (but a decrease of soil or aquifer water storages, which may influence the hydrology outside the catchment). In general, the simulated signals of SWAT-MODFLOW appeared more plausible than those of SWAT, and the SWAT-MODFLOW decrease in streamflow was much closer to the actual volume abstracted. The impact of drinking water abstraction on streamflow depletion simulated by SWAT was unrealistically low, and the streamflow increase caused by irrigation abstraction was exaggerated compared with SWAT-MODFLOW. We conclude that the further developed SWAT-MODFLOW model calibrated by PEST had a better hydrological simulation performance, wider possibilities for groundwater analysis, and much more realistic signals relative to the semi-distributed SWAT model when assessing the impacts of groundwater abstractions for either irrigation or drinking water on streamflow; hence, it has the potential to be a useful tool in the management of water resources in groundwater-affected catchments. However, this comes at the expense of higher computational demand and more time consumption.

scholarly journals Woody Encroachment Extent and Its Associated Impacts on Plant and Herbivore Species Occurrence in Maswa Game Reserve, Tanzania

2019 ◽  
Vol 9 (3) ◽  
pp. 63 ◽  
Author(s):  
Houssein Samwel Kimaro ◽  
Ayoub M. Asenga ◽  
Linus Munishi ◽  
Anna C. Treydte
Keyword(s):  
Structural Changes ◽  
Woody Plant ◽  
Plant Cover ◽  
Fire Regimes ◽  
Management Tool ◽  
Herbaceous Plant ◽  
Woody Plant Encroachment ◽  
Species Occurrence ◽  
Game Reserve ◽  
Herbivore Species

Habitat degradation caused by woody plant encroachment has been a common phenomenon in savanna ecosystems. An increasing woody plant cover in open grassland reduces grazing grounds and, consecutively, impacts mammalian herbivores, but structural changes and their associated impact have rarely been assessed and quantified. We analyzed the extent of woody plant encroachment via remote sensing and used transects and plots to assess encroaching woody plant species and their associated impacts on herbaceous plant and herbivore species in Maswa Game Reserve, Tanzania. We found that woody plant cover had increased by 0.5% to 2.6% per annum over the last thirty years, while in other parts of the park it has decreased by 0.5% to 1.5% per annum. Acacia drepanolobium was the dominant encroaching woody species, and the number of stems in heavily encroached sites was seven times and three times higher than in open grassland and at medium encroached sites, respectively. In encroached plots, grazer and mixed feeder species occurrence were reduced while the presence of browser species was slightly elevated. Furthermore, our finding shows that bare ground cover is positively correlated with an increase of woody plant cover. Additionally, the number of herbaceous species slightly increased with the increase of woody plant encroachment, while the herbaceous cover was negatively correlated with the increase of woody plant cover. We suggest that fire regimes should be taken up to suppress the ongoing encroachment processes while strongly encroached sites might need mechanical intervention to control dense vegetation. This emphasis is on fire, particularly prescribed fire as a management tool of vegetation in Savanna ecosystem. We conclude that, woody plant encroachment is driven by different factors such as fire, mega-herbivores and topology that may interactively trigger woody plant encroachment in Savanna ecosystem.

scholarly journals Impact of Climate Change on Groundwater Resources

2016 ◽  
pp. 196-221 ◽  
Author(s):  
C. P. Kumar
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Groundwater Resources ◽  
Climate Variables ◽  
Groundwater Levels ◽  
Impact Of Climate Change ◽  
Surface Water Resources ◽  
The Impact ◽  
The Relationship

Climate change poses uncertainties to the supply and management of water resources. While climate change affects surface water resources directly through changes in the major long-term climate variables such as air temperature, precipitation, and evapotranspiration, the relationship between the changing climate variables and groundwater is more complicated and poorly understood. The greater variability in rainfall could mean more frequent and prolonged periods of high or low groundwater levels, and saline intrusion in coastal aquifers due to sea level rise and resource reduction. This chapter presents the likely impact of climate change on groundwater resources and methodology to assess the impact of climate change on groundwater resources.

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