scholarly journals Modeling impacts of climate change and human activities on groundwater resources using MODFLOW

2017 ◽  
Vol 9 (1) ◽  
pp. 156-177 ◽  
Author(s):  
Hossein Malekinezhad ◽  
Fatemeh Barzegai Banadkooki

Abstract This paper analyzes the impacts of climate change and human pressures on Yazd-Ardakan aquifer using the Hadley Centre Coupled Model, version 3 (HADCM3) circulation Model and A2 emission scenario. Water levels in the study aquifer were simulated using three-dimensional finite-difference groundwater model (MODFLOW 2000) with GMS 8.3 as pre- and postprocessing software. Input for groundwater recharge time series under the climate change scenarios were derived using a regression equation based on the cumulative deviation from mean rainfall using MATLAB. Human pressures on the aquifer were modeled through climate change impacts on water requirements of cultivated areas. Three scenarios were simulated to represent the effects of climate change and human pressures on aquifer storage and hydraulic head. Climate change and human pressures (scenario 1) will reduce aquifer storage and result in decreasing hydraulic head by −0.56 m year−1. Reduction in pumping water under scenario 2 (irrigation system modification) and scenario 3 (irrigation system modification and cropping patterns) will result in groundwater level fluctuation of about −0.32 and 0.08 m year−1, respectively. Scenario 3 is capable of restoring and protecting the groundwater resources in Yazd-Ardakan aquifer. The results of this study are useful to obtain sustainable groundwater management in Yazd-Ardakan aquifer.

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2193
Author(s):  
Jayandra P. Shrestha ◽  
Markus Pahlow ◽  
Thomas A. Cochrane

Reservoir operations and climate change can alter natural river flow regimes. To assess impacts of climate and hydropower operations on downstream flows and energy generation, an integrated hydropower operations and catchment hydrological model is needed. The widely used hydrological model Soil and Water Assessment Tool (SWAT) is ideal for catchment hydrology, but provides only limited reservoir operation functions. A hydropower reservoir operation routine (HydROR) was thus developed for SWAT to analyze complex reservoir systems under different policies. The Hydrologic Engineering Center’s Reservoir System Simulation (HEC-ResSim) model, a well-established reservoir simulation model, was used to indirectly evaluate functionality of the HydROR. A comparison between HydROR and HEC-ResSim under a range of operation rule curves resulted in R2 values exceeding 0.99. The HydROR was then applied to assess hydrological alterations due to combined impacts of climate change and reservoir operations of 38 hydropower dams in the 3S basin of the Mekong River. Hydropower production under climate change varied from −1.6% to 2.3%, depending on the general circulation model chosen. Changing the hydropower operation policy from maximizing energy production to maintaining ecological flows resulted in a production change of 13%. The calculation of hydrological alteration indices at the outlet of the 3S basin revealed that over 113% alteration in the natural river outflow regime occurred from the combined impacts of climate change and reservoir operations. Furthermore, seasonal flows and extreme water conditions changed by 154% and 104%, respectively. Alterations were also significant within the basin, and, as expected, were larger for high-head and small-river reservoirs. These alterations will adversely affect ecological dynamics, in particular, habitat availability. HydROR proved to be a valuable addition to SWAT for the analyses of complex reservoir systems under different policies and climate change scenarios.


2021 ◽  

Abstract This book is a collection of 77 expert opinions arranged in three sections. Section 1 on "Climate" sets the scene, including predictions of future climate change, how climate change affects ecosystems, and how to model projections of the spatial distribution of ticks and tick-borne infections under different climate change scenarios. Section 2 on "Ticks" focuses on ticks (although tick-borne pathogens creep in) and whether or not changes in climate affect the tick biosphere, from physiology to ecology. Section 3 on "Disease" focuses on the tick-host-pathogen biosphere, ranging from the triangle of tick-host-pathogen molecular interactions to disease ecology in various regions and ecosystems of the world. Each of these three sections ends with a synopsis that aims to give a brief overview of all the expert opinions within the section. The book concludes with Section 4 (Final Synopsis and Future Predictions). This synopsis attempts to summarize evidence provided by the experts of tangible impacts of climate change on ticks and tick-borne infections. In constructing their expert opinions, contributors give their views on what the future might hold. The final synopsis provides a snapshot of their expert thoughts on the future.


2018 ◽  
Author(s):  
Nicholas D. Woodman ◽  
William G. Burgess ◽  
Kazi Matin Ahmed ◽  
Anwar Zahid

Abstract. The coupled poro-mechanical behaviour of geologic-fluid systems is fundamental to numerous processes in structural geology, seismology and geotechnics but is frequently overlooked in hydrogeology. Substantial poro-mechanical influences on groundwater head have recently been highlighted in the Bengal Aquifer System, however, driven by terrestrial water loading across the Ganges-Brahmaputra-Meghna floodplains. Groundwater management in this strategically important fluvio-deltaic aquifer, the largest in south Asia, requires a coupled hydro-mechanical approach which acknowledges poro-elasticity. We present a simple partially-coupled, one-dimensional poro-elastic model of the Bengal Aquifer System, and explore the poro-mechanical responses of the aquifer to surface boundary conditions representing hydraulic head and mechanical load under three modes of terrestrial water variation. The characteristic responses, shown as amplitude and phase of hydraulic head in depth profile and of ground surface deflection, demonstrate (i) the limits to using water levels in piezometers to indicate groundwater recharge, as conventionally applied in groundwater resources management; (ii) the conditions under which piezometer water levels respond primarily to changes in the mass of terrestrial water storage, as applied in geological weighing lysimetry; (iii) the relationship of ground surface vertical deflection to changes in groundwater storage; and (iv) errors of attribution that could result from ignoring the poroelastic behaviour of the aquifer. These concepts are illustrated through application of the partially-coupled model to interpret multi-level piezometer data at two sites in southern Bangladesh. There is a need for further research into the coupled responses of the aquifer due to more complex forms of surface loading, particularly from rivers.


2013 ◽  
Vol 10 (8) ◽  
pp. 10873-10911 ◽  
Author(s):  
M. B. Mabrouk ◽  
A. Jonoski ◽  
D. Solomatine ◽  
S. Uhlenbrook

Abstract. Serious environmental problems are emerging in the River Nile basin and its groundwater resources. Recent years have brought scientific evidence of climate change and development-induced environmental impacts globally as well as over Egypt. Some impacts are subtle, like decline of the Nile River water levels, others are dramatic like the salinization of all coastal land in the Nile Delta – the agricultural engine of Egypt. These consequences have become a striking reality causing a set of interconnected groundwater management problems. Massive population increase that overwhelmed the Nile Delta region has amplified the problem. Many researchers have studied these problems from different perspectives using different methodologies, following different objectives and, consequently, arrived at different findings. However, they all confirmed that significant groundwater salinization has affected the Nile Delta and this is likely to become worse rapidly in the future. This article presents, categorizes and critically analyses and synthesizes the most relevant research regarding climate change and development challenges in relation to groundwater resources in the Nile Delta. It is shown that there is a gap in studies that focus on sustainable groundwater resources development and environmentally sound protection as an integrated regional process in Nile Delta. Moreover, there is also a knowledge gap related to the deterioration of groundwater quality. The article recommends further research that covers the groundwater resources and salinization in the whole Nile Delta based on integrated three-dimensional groundwater modelling of the Nile delta aquifer.


2021 ◽  
Author(s):  
Alaba Boluwade ◽  
Asma Al-Mamani ◽  
Amna Alruheili ◽  
Ali Al-Maktoumi

<p> </p><p>*Correspondence: [email protected]</p><p><strong>Abstract: </strong>The primary objective of this study was to quantify the impacts of climate change on groundwater recharge using the 3D numerical-based HydroGeoSphere (HGS) model in the Ubar/ Shisr Agricultural region in South of Oman. This region has multi-million US dollar irrigated agriculture project purposely developed for the food security of the country. Excessive abstraction of groundwater for irrigation use (using the center pivot irrigation system) has contributed to the “drying-up” of several groundwater wells located in this area. Therefore, there is an urgent need to characterize the long-term sustainability of this agricultural project under a changing climate. HGS model was calibrated on both steady and transient states using selected monitoring wells located within the study area (approximately 980-km<sup>2</sup>). The coefficient of determination (R<sup>2</sup>) for the steady-state performance was 0.93 while the transient state performances correctly reproduced the seasonality for each monitoring well. A transient-based calibrated version of the HGS model, using 30-year historical observations (1980-2018) was termed “Reference” while model configurations were developed for the immediate climatic projection (period: 2020 – 2039) based on two Representative Concentration Pathways (RCP): - RPC4.5 and RCP8.5 extracted from the World Bank Knowledge portal. These two configured models (scenarios) were evaluated for monthly transient simulations (2020-2039). From the total hydraulic head (THH) fluctuations standpoint, there were reductions when compared with “Reference” for all the scenarios with up to 20% THH reductions for groundwater well levels under persistent seasonal agricultural activities. This study is very important in quantifying the trade-offs and synergies involved between sustainable water management and food security initiatives, especially for an arid climate.</p><p>Keywords: groundwater recharge; climate change, hydrogeologic modeling; Sultanate of Oman</p>


2021 ◽  
Author(s):  
Ronan Abhervé ◽  
Clément Roques ◽  
Laurent Longuevergne ◽  
Stéphane Louaisil ◽  
Jean-Raynald de Dreuzy ◽  
...  

<p>While it is well understood and accepted that climate change and growing water needs affect the availability of water resources, the identification of the main physical processes involved remains challenging. It notably requires to filter interannual to interdecadal fluctuations and extreme events to isolate the underlying trends. Metropolitan areas are specifically subject to growing pressures because of the significant and increasing demand, combined with the strong anthropization of land uses.</p><p>The Meu-Chèze-Canut catchment supplies the city of Rennes with drinking water (680 km² - 500 000 users, Brittany, France). In this field laboratory, we explore the dynamics of the water cycle and water resources availability. In this context, water supply is mostly coming from reservoir storage for which levels shows a medium-term vulnerability in response to frequent relatively dry years. Based on retrospective data analysis, we describe the relationship between climatic forcing (precipitation, temperature) and water availability (aquifer storage, river discharge and reservoir storage) in different parts of the catchment that are characterized by distinct lithological and topographical settings. We then evaluate the resilience of both surface and groundwater resources, their past evolution and their resilience to climate change and increasing societal needs.</p><p>Water resources availability in these catchments relies on two geological formations with distinct hydrodynamics properties: the Armorican sandstone and Brioverian schist. To assess the resilience of the system, we specifically analyzed the relationships between monthly effective precipitation and stream discharge within nine sub-catchments over the past 30 years. We observe annual hysteresis relationships - that is, a time lag between precipitation and discharge highlighting the capacity of the landscape to temporarily store water - with significant variability in shapes across the catchments. We argue that topographic and lithological factors play key roles in controlling this variability through their impacts on subsurface storage capacity and characteristic drainage timescales. We propose perspectives based on the complementary use of calibrated groundwater models to leverage these results and provide adaptive water management strategies.</p>


2019 ◽  
Vol 11 (8) ◽  
pp. 2450 ◽  
Author(s):  
Noora Veijalainen ◽  
Lauri Ahopelto ◽  
Mika Marttunen ◽  
Jaakko Jääskeläinen ◽  
Ritva Britschgi ◽  
...  

Severe droughts cause substantial damage to different socio-economic sectors, and even Finland, which has abundant water resources, is not immune to their impacts. To assess the implications of a severe drought in Finland, we carried out a national scale drought impact analysis. Firstly, we simulated water levels and discharges during the severe drought of 1939–1942 (the reference drought) in present-day Finland with a hydrological model. Secondly, we estimated how climate change would alter droughts. Thirdly, we assessed the impact of drought on key water use sectors, with a focus on hydropower and water supply. The results indicate that the long-lasting reference drought caused the discharges to decrease at most by 80% compared to the average annual minimum discharges. The water levels generally fell to the lowest levels in the largest lakes in Central and South-Eastern Finland. Climate change scenarios project on average a small decrease in the lowest water levels during droughts. Severe drought would have a significant impact on water-related sectors, reducing water supply and hydropower production. In this way drought is a risk multiplier for the water–energy–food security nexus. We suggest that the resilience to droughts could be improved with region-specific drought management plans and by including droughts in existing regional preparedness exercises.


Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1201 ◽  
Author(s):  
Pantelis Sidiropoulos ◽  
Georgios Tziatzios ◽  
Lampros Vasiliades ◽  
Nikitas Mylopoulos ◽  
Athanasios Loukas

Groundwater quantity and quality degradation by agricultural practices is recorded as one of the most critical issues worldwide. This is explained by the fact that groundwater is an important component of the hydrological cycle, since it is a source of natural enrichment for rivers, lakes, and wetlands and constitutes the main source of potable water. The need of aquifers simulation, taking into account water resources components at watershed level, is imperative for the choice of appropriate restoration management practices. An integrated water resources modeling approach, using hydrological modeling tools, is presented for assessing the nitrate fate and transport on an over-exploited aquifer with intensive and extensive agricultural activity under various operational strategies and future climate change scenarios. The results indicate that climate change affects nitrates concentration in groundwater, which is likely to be increased due to the depletion of the groundwater table and the decrease of groundwater enrichment in the future water balance. Application of operational agricultural management practices with the construction and use of water storage infrastructure tend to compensate the groundwater resources degradation due to climate change impacts.


2011 ◽  
Vol 59 (5) ◽  
pp. 440 ◽  
Author(s):  
M. J. Laidlaw ◽  
W. J. F. McDonald ◽  
R. John Hunter ◽  
D. A. Putland ◽  
R. L. Kitching

The potential for anthropogenic climate change to impact upon native vegetation has emphasised the need for monitoring and for dynamic management regimes. Potential impacts are numerous, but will likely include the upslope movement of species’ ranges and increasing in situ turnover (compositional change) within plant assemblages. By assessing the potential impacts of climate change on subtropical rainforest communities in south-east Queensland through the establishment of an altitudinal transect, we aimed to establish the baseline composition of the vegetation and to develop two hypotheses against which climate change scenarios can be tested. The study identified existing high levels of turnover across tree assemblages from low to mid elevations absent at higher elevations and we predict: (1) subtropical rainforest communities which currently sit at the level of the cloud base (800–900 m) will experience increasing floristic turnover, and (2) novel vegetation communities will emerge as species move upslope in response to a changing climate. Monitoring floristic turnover as a surrogate for shifting climatic habitats may be confounded both by a lack of knowledge regarding the underlying turnover rates of rainforest communities and by the disparity in temporal scales of tree community turnover and accelerating anthropogenic climate change. The identification of ‘break points’ in the relationship between current vegetation communities and gradients of precipitation and temperature will allow better direction of monitoring efforts.


2014 ◽  
Vol 955-959 ◽  
pp. 3777-3782 ◽  
Author(s):  
Xiao Feng Zhao ◽  
Bin Le Lin

We evaluated land suitability for Jatropha cultivation at a global scale under current and future climate scenarios. Areas that are suitable for Jatropha cultivation include southern South America, the west and southeast coasts of Africa, the north of South Asia, and the north and south coasts of Australia. In the predicted climate change scenarios, areas near the equator become less suitable for Jatropha cultivation, and areas further from the equator become more suitable. Our analyses suggest that the rank order of the six climate change scenarios, from the smallest to the largest effects on Jatropha cultivation, was as follows: B1, A1T/B2, A1B, A2, and A1FI.


Sign in / Sign up

Export Citation Format

Share Document