Urban Hydrogeology Research Articles

Groundwater Rise and Associated Flooding in Coastal Settlements Due To Sea‐Level Rise: A Review of Processes and Methods

AbstractCoastal settlements are experiencing the effects of climate change‐induced sea‐level rise, including a significant but often poorly‐characterized impact on groundwater. The shallow water tables present in the built coastal environment contribute to an increased risk from natural hazards such as groundwater flooding and saltwater intrusion. Historical urban development was accompanied by impacts on shallow groundwater, and in the future subsurface environments, including underground infrastructure, will face additional pressure. This article reviews processes of the coastal groundwater zone and simulation tools used to evaluate possible impacts of sea‐level rise. The benefits and limitations of the two main methods to assess coastal groundwater rise and contribution to flooding are discussed using studies and investigations up to 2021. The review addresses challenges associated with the simulation tools to evaluate changes in urban hydrogeology due to sea‐level rise. The models reviewed do not specifically estimate groundwater contribution to land‐surface flooding. We highlight a critical need for methodology comparisons between spatial interpolation and numerical tools that will guide future work. An adequate validation of assessment methods is required and will be supported by improved coastal groundwater monitoring networks focused on water quality, saltwater intrusion, and continuous groundwater levels records. From current monitoring practices, evidence for groundwater rise with rising sea level is not widely observed at present. New monitoring sites are recommended near the coastline and tidally influenced surface water bodies, to better evaluate the rise of the water table and impacts on infrastructure.

Using GIS-Based Modified DRASTIC Modelling of the Cape Flats Aquifer to Assess Coastal Aquifer Vulnerability in Urban Hydrogeology, South Africa

Using GIS-Based Modified DRASTIC Modelling of the Cape Flats Aquifer to Assess Coastal Aquifer Vulnerability in Urban Hydrogeology, South Africa

Status of urban hydrogeology research with emphasis on India

Urban areas have witnessed an inexorable expansion in population density, urban sprawl, industrialization and agricultural activities in the past few decades. Withdrawal of groundwater to meet water demand has resulted in over-drafting of aquifers and, commonly, lowered water tables in many urban centres of India, like Delhi, Lucknow, Patna, Kolkata and others. Overdraft has also deteriorated the chemical and biogeochemical quality of surface water and groundwater. This paper highlights some of the research approaches, namely hydrogeochemical investigation, groundwater modeling, and use of geographic information systems and remote sensing, used worldwide to resolve issues specific to urban groundwater. The paper also highlights approaches that are practiced internationally (combined hydrogeologic and multi-isotopic studies, integrated modeling techniques, etc.) but still need to be developed on a large scale in India. A detailed overview of the literature indicates the need for a more holistic approach incorporating various types of conceptual and management models to strengthen the research level in India and elsewhere. For instance, a computational tool that can incorporate different models, such as for urban water and contaminant balance and pipeline leakage, should be developed to generate predefined scenarios of potential groundwater contamination and help in the socio-economic analysis of different scenarios. In hydrogeochemical approaches, multi-isotope ratios should be coupled with hydrogeologic approaches for better understanding of water quality problems.

Urban hydrogeology: Transport routes and mixing of water and solutes in a groundwater influenced urban lowland catchment

Urban areas in coastal lowlands host a significant part of the world's population. In these areas, cities have often expanded to unfavorable locations that have to be drained or where excess rain water and groundwater need to be pumped away in order to maintain dry feet for its citizens. As a result, groundwater seepage influences surface water quality in many of such urban lowland catchments. This study aims at identifying the flow routes and mixing processes that control surface water quality in the groundwater-influenced urban catchment Polder Geuzenveld, which is part of the city of Amsterdam. Geuzenveld is a highly paved urban area with a subsurface rain water collection system, a groundwater drainage system, and a main surface water system that receive runoff from pavement and roofs, shallow groundwater and direct groundwater seepage, respectively. We conducted a field survey and systematic monitoring to identify the spatial and temporal variations in water quality in runoff, ditch water, drain water, and shallow and deep groundwater. We found that Geuzenveld receives a substantial inflow of deep, O2-depleted groundwater, which is enriched in ammonium and phosphorus due to the subsurface mineralization of organic matter under sulfate-reducing conditions. This groundwater is mixed in the ditches during wet periods with O2-rich runoff, and iron- and phosphate-rich drain water. Unlike natural catchments, the newly created, separated urban flow routes lead to mixing of water in the main surface water itself, shortcutting much of the soil and shallow subsurface. This leads to low O2 and high ammonia concentrations in dry periods, which might be mitigated by water level management or artificially increasing O2 levels by water inlet or artificially aeration of the main water canals. Further research is necessary how to optimize artificial urban systems to deliver a better ecological and chemical status of the surface water.

Urban hydrogeology in Indonesia: A highlight from Jakarta

In many cities in the developing countries, groundwater is an important source of public water supply. The interaction between groundwater systems and urban environments has become an urgent challenge for many developing cities in the world, Indonesia included. Contributing factors are, but not limited to, the continuous horizontal and vertical expansion of cities, population growth, climate change, water scarcity and groundwater quality degradation. Jakarta as the capital city of Indonesia becomes a good example to study and implement urban hydrogeology. Urban hydrogeology is a science for investigating groundwater at the hydrological cycle and its change, water regime and quality within the urbanized landscape and zones of its impact. The present paper provides a review of urban groundwater studies in Jakarta in the context of urban water management, advances in hydrogeological investigation, monitoring and modelling since the city was established. The whole study emphasizes the necessity of an integrated urban groundwater management and development supporting hydrogeological techniques for urban areas.

Urban hydrogeology studies in Bucharest City, Romania

Abstract Bucharest, a city of about 1.9 million inhabitants and covering a surface of about 228 km2, faces two main hydrogeological problems. Both are results of the interaction between the aquifer system and the underground infrastructure. The first problem consists in the barrier effect produced by the extensively channelized Dambovita River that cuts Bucharest city in two parts, increasing consequently the groundwater hydraulic heads. The second problem is actually a twofold concern and it is due to the strong hydraulic interaction between the sewer system and the groundwater. As consequence, the seepage into the sewer network increases the wastewater flow rates. Restoration of its conduits triggers consequently the hydraulic heads increase in several residential areas of the city. A Bucharest city urban hydrogeology project has been built, it’s primary milestone being the urban groundwater numerical flow model. This focuses on the interaction between the urban infrastructure and the groundwater system. The resulted hydrological water balance outlined that, for the entire Bucharest sewer network, about 0.92 m3/s wastewater surplus originates from the groundwater seepage. It has been also determined that about 16.9km (3.5%) of the sewer network is completely immersed into the groundwater and about 79.8km (16.5%) is partially immersed. The urban hydrogeological model framework is currently used to carry out distinct hydrogeological studies related to the city sewer system rehabilitation, infrastructure developments, groundwater protection, and environmental impact. The feedback from these studies increase further the city scale model knowledge and accuracy. A direct hydraulic connection between the surface water and the groundwater has been systematically confirmed.

Recent Hydrogeological Research in India

The hydrogeological setup of India represents a wide variation, from rugged Himalayan mountainous region in the north, extensive Indo-Ganga-Brahmaputra floodplain and deltaic region in the central and eastern part, aeolian- alluvial deposits in the west, vast basalt flows in the west central part, gently undulating central and southern region underlain by Precambrian crystalline, sedimentary and metamorphic, coastal deposits along the east coast etc. The research on hydrogeology has got special socioeconomic significance because India is now the largest extractor of groundwater in the world. The impact of overexploitation of the resource is surfacing in large parts of the country, in the form of lowering of water level, dwindling yield of well and deterioration in water quality. In recent years, extensive studies have been carried out in this field of geoscience. We have discussed these in different segments, after enumerating the broad hydrological framework of India. The segments are 1. Hydrogeological investigations in Indo-Ganga-Brahmaputra Plains holding one of the potential aquifer systems 2. Groundwater chemistry and contamination issues in Peninsular India 3. Urban hydrogeology 4. Groundwater modeling 5. Ground water exploration 6. Groundwater recharge and associated quality issues 7. Remote sensing and GIS applications 8. Coastal aquifers and 9. Groundwater management. It is observed that the potential groundwater reserve in the Indo-Gangetic basin and the Peninsular part of India has two serious issues: 1. Overexploitation of groundwater mainly in the western and north western parts and also in southern peninsular India in pockets and 2. Groundwater quality deterioration by anomalous concentration of arsenic, fluoride and salinity. The findings of the research will help in understanding the hydrogeological complexities in its entire gamut and also offers insight into the ways for sustainable management of groundwater resource of the country.

Hydrogeological Characterization in the Development of Underground Structures, Los Angeles Basin, California

Underground construction offers economic benefit to urban developments where land values demand maximizing the potential of available resources, and the vertical nature of urban development requires thorough characterization of the hydrogeological as well as the geotechnical properties of sites. This unique set of challenges, if ignored, can result in engineering complications and economic disadvantages for urban development projects. Urban hydrogeology has often been studied in its relationship to water-resources management and large-scale trends, rather than the site-specific testing and analysis required for dewatering during building construction. Aquifer pumping tests were performed at two sites in the Hollywood Basin in Los Angeles, California, where there are ongoing subsurface construction and dewatering operations. Step drawdown and constant-rate pumping tests were performed at each site, and data were collected from both pumping and observation wells screened in sand and gravel aquifer units. Time-drawdown curves were analyzed via well-known analytical solutions for drawdown in confined and leaky aquifers. While one site responded to pumping in accordance to traditional analytical models, the other exhibited evidence of secondary recharge to the aquifer from local underground construction features. As a result of these findings, construction and dewatering plans at each site were altered in ways that deviated significantly from preconceived estimates. These case studies demonstrate the need for rigorous aquifer testing and analysis at urban construction sites undergoing dewatering, and they show the pitfalls that can be avoided through the application of such methods.

Current research in urban hydrogeology – A review

Urban groundwater is a heritage at risk because urban land use practises puts enormous and highly complex pressure on this resource. In this article, we review urban groundwater studies in the context of urban water management, discuss advances in hydrogeological investigation, monitoring and modelling techniques for urban areas and highlight the challenges. We present how techniques on contaminant concentration measurements, water balancing and contaminant load estimation were applied and further developed for the special requirements in urban settings. To fully understand and quantify the complex urban water systems, we need to refine these methods and combine them with sophisticated modelling approaches. Only then we will be able to sustainably manage our water resources in and around our urban areas especially in light of growing cities and global climatic change. We believe that over the next few years much more effort will be devoted to research in urban hydrogeology.

Importancia de la hidrogeología urbana; ciencia clave para el desarrollo urbano sostenible

Urban expansion as a result of continuous population growth as well as the creation of a large variety of industries and the parallel high human population density require a sufficient supply of clean water. In many cities around the world groundwater is the main source of potable water. In turn, anthropogenic activities discharge large volumes of waste water and industrial effluents. The use of a variety of chemicals and hydrocarbons causes pollution of groundwater supplies and soils. The complex interaction between groundwater flow systems and cities (infrastructure, city process, activities and discharge) requires increasingly complex studies, which is why a new branch of science has emerged under the name of “urban hydrogeology”, considered to be a specialization within the hydrogeological sciences. This paper provides a general vision of urban hydrogeology that allows understanding its conceptual aspects, its scope of application and management. The information presented refers to the interdependence of cities and groundwater use. The paper details the processes and mechanisms studied through this new branch of knowledge as well as their effects in relation to the physical and chemical properties of water quality (pollution processes). Case studies are discussed in order to have a variety of viewpoints on environmental impacts, theoretical development and technological advances developed in order to seek efficient solutions. We highlight guidelines and models for sustainable groundwater management in urban settings that have been developed with the aim

Mass fluxes of xenobiotics below cities: challenges in urban hydrogeology

Urban areas are the focus of major ecological, social and economical activity. They are thus also prime locations of increasing conflict with regard to water use and water protection. As a direct and/or indirect consequence of urban land use and human activity, urban water systems are frequently polluted with organic contaminants including waste water-born xenobiotics such as pharmaceuticals, personal care products (collectively known as PPCPs) and endocrine-active substances. This study reviews new integrated methodologies including flux calculations as well as chemical investigations for determining the impact of human activities on urban water systems and on processes within the urban watershed. The use of indicator substances, representing different contaminant sources and pathways, integral pumping tests and mass balance approaches are suitable alternatives within these environments. The issues are explored using contaminant mass balance examples from Halle/Saale and Leipzig, Germany.

Managed aquifer recharge: rediscovering nature as a leading edge technology

Use of Managed Aquifer Recharge (MAR) has rapidly increased in Australia, USA, and Europe in recent years as an efficient means of recycling stormwater or treated sewage effluent for non-potable and indirect potable reuse in urban and rural areas. Yet aquifers have been relied on knowingly for water storage and unwittingly for water treatment for millennia. Hence if 'leading edge' is defined as 'the foremost part of a trend; a vanguard', it would be misleading to claim managed aquifer recharge as a leading edge technology. However it has taken a significant investment in scientific research in recent years to demonstrate the effectiveness of aquifers as sustainable treatment systems to enable managed aquifer recharge to be recognised along side engineered treatment systems in water recycling. It is a 'cross-over' technology that is applicable to water and wastewater treatment and makes use of passive low energy processes to spectacularly reduce the energy requirements for water supply. It is robust within limits, has low cost, is suitable from village to city scale supplies, and offers as yet almost untapped opportunities for producing safe drinking water supplies where they do not yet exist. It will have an increasingly valued role in securing water supplies to sustain cities affected by climate change and population growth. However it is not a universal panacea and relies on the presence of suitable aquifers and sources of water together with effective governance to ensure human health and environment protection and water resources planning and management. This paper describes managed aquifer recharge, illustrates its use in Australia, outlining economics, guidelines and policies, and presents some of the knowledge about aquifer treatment processes that are revealing the latent value of aquifers as urban water infrastructure and provide a driver to improving our understanding of urban hydrogeology.

An approach to identify urban groundwater recharge

Abstract. Evaluating the proportion in which waters from different origins are mixed in a given water sample is relevant for many hydrogeological problems, such as quantifying total recharge, assessing groundwater pollution risks, or managing water resources. Our work is motivated by urban hydrogeology, where waters with different chemical signature can be identified (losses from water supply and sewage networks, infiltration from surface runoff and other water bodies, lateral aquifers inflows, ...). The relative contribution of different sources to total recharge can be quantified by means of solute mass balances, but application is hindered by the large number of potential origins. Hence, the need to incorporate data from a large number of conservative species, the uncertainty in sources concentrations and measurement errors. We present a methodology to compute mixing ratios and end-members composition, which consists of (i) Identification of potential recharge sources, (ii) Selection of tracers, (iii) Characterization of the hydrochemical composition of potential recharge sources and mixed water samples, and (iv) Computation of mixing ratios and reevaluation of end-members. The analysis performed in a data set from samples of the Barcelona city aquifers suggests that the main contributors to total recharge are the water supply network losses (22%), the sewage network losses (30%), rainfall, concentrated in the non-urbanized areas (17%), from runoff infiltration (20%), and the Besòs River (11%). Regarding species, halogens (chloride, fluoride and bromide), sulfate, total nitrogen, and stable isotopes (18O, 2H, and 34S) behaved quite conservatively. Boron, residual alkalinity, EDTA and Zn did not. Yet, including these species in the computations did not affect significantly the proportion estimations.

Geospatial mapping of potential recharge zones in parts of Pune city

Runoff has increased many fold in urban areas due to increase in paved areas, training of streams and construction of storm water drains. The recharge is therefore continuously decreasing; resulting in depleting groundwater reserves beneath large cities, especially those situated on water divides. In order to reduce surface runoff and replenish groundwater many advocate artificial recharge through rainwater harvesting. Conventionally, detailed hydrogeological survey is needed by expert hydrogeologists to suggest suitable sites for rooftop rainwater harvesting and storage in the subsurface aquifers. Pune, a rapidly growing city, is under severe stress due to shortage of water in some areas. An effort has been made in this study to identify areas suitable for rooftop rainwater harvesting by integrating traditional hydrogeological survey data with the help of Remote Sensing and Geographic Information System. This endeavour has led to develop a program called SLUGGER-DQL which helps to identify potential sites for rooftop rainwater harvesting and artificial recharge. The program is open ended and several other factors controlling potential recharge can be easily added on. Based on the results of the present study, potential sites for rainwater harvesting and artificial recharge have been identified in the Pune University-Shivajinagar-Kothrud area. The present paper demonstrates the utility of traditional hydrogeological surveys combined with modern techniques in solving problems related to urban hydrogeology and town planning.

Integrated methods and scenario development for urban groundwater management and protection during tunnel road construction: a case study of urban hydrogeology in the city of Basel, Switzerland

In the northwestern area of Basel, Switzerland, a tunnel highway connects the French highway A35 (Mulhouse–Basel) with the Swiss A2 (Basel–Gotthard–Milano). The subsurface highway construction was associated with significant impacts on the urban groundwater system. Parts of this area were formerly contaminated by industrial wastes, and groundwater resources are extensively used by industry. During some construction phases, considerable groundwater drawdown was necessary, leading to major changes in the groundwater flow regime. Sufficient groundwater supply for industrial users and possible groundwater pollution due to interactions with contaminated areas had to be taken into account. A groundwater management system is presented, comprising extensive groundwater monitoring, high-resolution numerical groundwater modeling, and the development and evaluation of different scenarios. This integrated approach facilitated the evaluation of the sum of impacts, and their interaction in time and space with changing hydrological boundary conditions. For all project phases, changes of the groundwater system had to be evaluated in terms of the various goals and requirements. Although the results of this study are case-specific, the overall conceptual approach and methodologies applied may be directly transferred to other urban areas.

Construction and interpretation of a hydrogeological data base for the Seoul groundwater system

This paper presents a GIS-based study of the urban hydrogeology of the Seoul area. The groundwater relationship between the Han River and adjacent aquifer has been analyzed. Line type fluctuations of groundwater level are decreased along the Han River from Inchun to Chamsil Low Dam. The pumping rate are difficult to extrapolate to the past, since seepage of groundwater into the subway system has increased in recent years, and the amount of increase is unknown. A groundwater flow model is developed to simulate the flow characteristics of ground-water in and around the subway lines. Water-level changes associated with the subway pumping station are estimated. The water budget of the groundwater system in the Seoul area and the movement of groundwater flow are estimated. The amount of ground-water available for use from an aquifer of Seoul area is not supplied from the natural recharge only. The additional sources are expected to be the increase in recharge or leakage from urban activity induced by well development and subway line, along with the reduction in discharge.