Author
Jarkko Okkonen
Other affiliations: University of Oulu
Bio: Jarkko Okkonen is an academic researcher from Geological Survey of Finland. The author has contributed to research in topics: Groundwater & Groundwater recharge. The author has an hindex of 8, co-authored 19 publications receiving 327 citations. Previous affiliations of Jarkko Okkonen include University of Oulu.
Papers
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TL;DR: In this article, a robust conceptual and statistical approach is presented for the study of ground water table fluctuations with precipitation and temperature as input variables, where a conceptual hydrological model was developed to generate daily rainfall, snowmelt, evapotranspiration values and these values were cross-correlated with observed ground water levels to find representative time lags and significant correlations to describe the ground water system.
76 citations
TL;DR: In this article, a coupled heat and mass transfer model for soil-plant-atmosphere systems (CoupModel) was used to simulate recharge of an unconfined esker aquifer in northern Finland.
60 citations
TL;DR: In this paper, a shallow unconfined low-lying coastal aquifer in southern Finland surrounded by the Baltic Sea is vulnerable to changes in groundwater recharge, sea-level rise and human activities, and the intrinsic vulnerability of groundwater under climate scenarios was performed for the aquifer area by utilising the results of a published study on the impacts of climate change on groundwater recharge and sea level rise on groundwater interaction.
Abstract: A shallow unconfined low-lying coastal aquifer in southern Finland surrounded by the Baltic Sea is vulnerable to changes in groundwater recharge, sea-level rise and human activities Assessment of the intrinsic vulnerability of groundwater under climate scenarios was performed for the aquifer area by utilising the results of a published study on the impacts of climate change on groundwater recharge and sea-level rise on groundwater–seawater interaction Three intrinsic vulnerability mapping methods, the aquifer vulnerability index (AVI), a modified SINTACS and GALDIT, were applied and compared According to the results, the degree of groundwater vulnerability is greatly impacted by seasonal variations in groundwater recharge during the year, and also varies depending on the climate-change variability in the long term The groundwater is potentially highly vulnerable to contamination from sources on the ground surface during high groundwater recharge rates after snowmelt, while a high vulnerability to seawater intrusion could exist when there is a low groundwater recharge rate in dry season The AVI results suggest that a change in the sea level will have an insignificant impact on groundwater vulnerability compared with the results from the modified SINTACS and GALDIT The modified SINTACS method could be used as a guideline for the groundwater vulnerability assessment of glacial and deglacial deposits in inland aquifers, and in combination with GALDIT, it could provide a useful tool for assessing groundwater vulnerability to both contamination from sources on the ground surface and to seawater intrusion for shallow unconfined low-lying coastal aquifers under future climate-change conditions
57 citations
TL;DR: In this article, a literature review of the impacts of anticipated climate change on unconfined aquifers is presented, along with a conceptual framework for evaluating the complex responses of surface and subsurface hydrology to climate variables in cold regions.
Abstract: A literature review of the impacts of anticipated climate change on unconfined aquifers is presented, along with a conceptual framework for evaluating the complex responses of surface and subsurface hydrology to climate variables in cold regions. The framework offers a way to conceptualize how changes in one component of the system may impact another by delineating the relationships among climate drivers, hydrological responses, and groundwater responses in a straight-forward manner. The model is elaborated in the context of shallow unconfined aquifers in the boreal environment of Finland. In cold conditions, climate change is expected to reduce snow cover and soil frost and increase winter floods. The annual surface water level maximum will occur earlier in spring, and water levels will decrease in summer due to higher evapotranspiration rates. The maximum recharge and groundwater level are expected to occur earlier in the year. Lower groundwater levels are expected in summer due to higher evapotranspiration rates. The flow regimes between shallow unconfined aquifers and surface water may change, affecting water quantity and quality in the surface and groundwater systems.
54 citations
TL;DR: In this article, the impact of climate change and Baltic Sea level rise on groundwater resources in a shallow, unconfined, low-lying coastal aquifer in Hanko, southern Finland, was assessed using the UZF1 model package coupled with the three-dimensional groundwater flow model MODFLOW to simulate flow from the unsaturated zone through the aquifer.
Abstract: The impact of climate change and Baltic Sea level rise on groundwater resources in a shallow, unconfined, low-lying coastal aquifer in Hanko, southern Finland, was assessed using the UZF1 model package coupled with the three-dimensional groundwater flow model MODFLOW to simulate flow from the unsaturated zone through the aquifer. The snow and PET models were used to calculate the surface water availability for infiltration from the precipitation data used in UZF1. Infiltration rate, flow in the unsaturated zone and groundwater recharge were then simulated using UZF1. The simulation data from climate and sea level rise scenarios were compared with present data. The results indicated changes in recharge pattern during 2071–2100, with recharge occurring earlier in winter and early spring. The seasonal impacts of climate change on groundwater recharge were more significant, with surface overflow resulting in flooding during winter and early spring and drought during summer. Rising sea level would cause some parts of the aquifer to be under sea level, compromising groundwater quality due to intrusion of sea water. This, together with increased groundwater recharge, would raise groundwater levels and consequently contribute more surface leakage and potential flooding in the low-lying aquifer.
48 citations
Cited by
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University College London1, University of Texas at Austin2, Goethe University Frankfurt3, Goddard Space Flight Center4, Utrecht University5, University of Rennes6, James Cook University7, University of California, Irvine8, University of Oxford9, United States Geological Survey10, United States Department of Agriculture11, Sun Yat-sen University12, British Geological Survey13, Rutgers University14, Colorado School of Mines15, San Francisco State University16, Simon Fraser University17, University of East Anglia18, Cranfield University19
TL;DR: In this paper, the authors critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system, and highlight the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies.
Abstract: As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.
1,536 citations
TL;DR: In this article, the authors provide an overview and synthesis of the key aspects of subsurface hydrology, including water quantity and quality, related to global change and potential impacts of groundwater on the global climate system.
809 citations
01 Jan 2016
TL;DR: A statistical methods for environmental pollution monitoring always becomes the most wanted book and many people are absolutely searching for this book as mentioned in this paper, which means that many love to read this kind of book.
Abstract: If you really want to be smarter, reading can be one of the lots ways to evoke and realize. Many people who like reading will have more knowledge and experiences. Reading can be a way to gain information from economics, politics, science, fiction, literature, religion, and many others. As one of the part of book categories, statistical methods for environmental pollution monitoring always becomes the most wanted book. Many people are absolutely searching for this book. It means that many love to read this kind of book.
624 citations
TL;DR: In this paper, the authors present a biostatistical introduction of the Time Series, a time series for time series, and a Biostatistic Introduction of time series.
Abstract: (1992). Time Series—A Biostatistical Introduction. Technometrics: Vol. 34, No. 2, pp. 229-230.
551 citations
TL;DR: In this paper, a review examines climate change effects on groundwater and dependent ecosystems, focusing on the impacts of changes to groundwater on GDE biodiversity and future threats posed by climate change.
419 citations