Groundwater Basin Research Articles

Dam Environmental Impact Assessment in Java Island, Indonesia

Increasing demand for water requires the improvement of water infrastructure. Dams are one of the most prominent infrastructures for water supply, especially as water demand increases. Due to its size, the dam is bound to affect the local environment, including the hydrometeorological and hydro/geological condition. The impact of dam on the local scale is supposedly dependent on several variables, namely, the height of the dam, its age, and the area of the river basin. This study studies the impact of dams on the surrounding environment by investigating 12 dams located in Java and are spread all throughout Java in particularly West Java, East Java, Central Java and lastly Jogjakarta. The dam environmental impact will be analyzed using: firstly, linear regression to determine the relationship between dams and environmental impact and secondly cluster analysis to divide the researched dams into categories. Dams in the study area could be divided into three clusters based on the similarity in height, age and river basin area. Additionally, this study finds that there is no correlation between the river basin area and both (ground) water quality and local climate. However, there was a correlation between the dam height with temperature and precipitation, as well as the dam age with Dissolved Oxygen (DO), Total Dissolved Solid (TDS) and pH. Regarding groundwater, the values of DO, TDS and pH are higher in dams located inside of groundwater basins compared to the opposite.

Calibrated geochemical ages of the Baltic Artesian Basin groundwater

For the present study, geochemical ages were derived from radiocarbon and radiokrypton age calibration with groundwater chemical contents (Na+, K+, Mg2+, Ca2+, Cl−, SO42−, HCO3−). Geochemical ages may fill the dating gap (40–150 ka) between the isotope techniques mentioned. A case study of groundwater in the Baltic Artesian Basin has involved geochemical age calibration, data filtering (such as regional subdivision of the basin for more accurate results) and geochemical dating of groundwater of unknown age. Various approaches to interpretations of geochemical age results could be used. Bicarbonate and sulphate are sensitive to the hydrochemical environment and should be omitted from geochemical age calculations. Modern fresh groundwater samples should also be excluded from calibration in order to obtain more reliable trend lines. Calcium-sodium cation exchange occurs in deep aquifers and may be used for geochemical age determination of fossil groundwater.

Using COP Model to Map the Vulnerability of Groundwater Wells Adjacent to Landfills

Protecting the quality of the groundwater is of the utmost importance, particularly in countries such as Jordan, where the groundwater comprises a significant portion of the total water resources. A groundwater vulnerability assessment is one of the viable preventive measures that is normally used to preserve this strategic water resource. Groundwater vulnerability maps provide information on the groundwater basins that are vulnerable to contamination, particularly those coming from the landfills, and thus, they can be used for sustainable land use planning. The general goal of this study was to map the groundwater vulnerability to contamination and evaluate the impact of landfills on the groundwater quality at five landfill sites in Jordan, i.e., Akaider, Al-Husaineyat, Madaba, Dair Alla, and Azraq by using a COP hydrogeological model. The COP method is an European approach for aquifer vulnerability in the karst regions. This method uses the parameters: C—Concentration of flow; O—Overlying layers; P—Precipitation. Unlike the other methods, the COP model allows for us to assess the impact of the karst systems if they exist. For the study area, daily rain records from three weather stations surrounding each landfill were used. Along with the vulnerability maps, Peizometric maps for Akaider, Azraq, Dair Alla, Madaba and Al-Husaineyat were produced that assisted in our efforts to determine the wells located in the upstream and downstream of each targeted landfill. The water quality was tested two times in the upstream and downstream wells of each targeted landfill to explore the potential impacts of the landfills on the groundwater wells. The developed vulnerability maps show that most of the lands surrounding the landfills’ areas, within a diameter of 15 km, are located in low to very low vulnerability areas, except for the Al-Husaineyat landfill in Mafraq where a significant part of it lies in a moderate vulnerability area across a fault section. Additionally, the results of the water analysis from the surrounding wells indicated that there was no clear evidence of the contamination of the groundwater resulting from surrounding landfills, which was in agreement with the produced vulnerability maps.

QUANTITY AND QUALITY OF GROUNDWATER OF INTERMOUNTAIN BASIN OF KORÇA IN ALBANIA AND IMPLICATION FOR SUSTAINABLE MANAGEMENT

Korça intermountain basin is the largest of its kind in Albania and from the hydrogeological point of view represents a semiclosed intermountain basin developed in Pliocene-Holocene granular unconsolidated deposits, which maximal thickness is about 300 m. The aquifer consists of intergranular gravelly to sandy layers containing artesian groundwater and the drilling wells are free flowing on most of the basin surface. The main recharge of the intergranular aquifer comes mainly from the rivers and torrents flowing from mountain gorges around the Korça Plain. The natural groundwater drainage of Korça basin is realized through the vertical leakage in the area of the former Maliq marsh. Hydrochemistry of the aquifers show the presence of four main hydrochemical facies which are related mainly to the hydrochemistry of the recharge sources and to the solution processes and ion exchange. In the central part of the basin the water supply wells of the cities Korça and Maliq are located. The natural renewable groundwater resources of the basin are relatively restricted, but the volume resources (or static water resources) are abundant (about 1.1 × 10–9 m3). The perspective of their exploitation is very important, but respecting the “basin yield” concept that is defined as the maximum rate of withdrawal that can be sustained by the hydrogeological system of groundwater basin without causing unacceptable changes to any other environmental component of the basin. To face the problems related to the intensification of the groundwater pumping systematic observations of the hydraulic reaction of the basin and of the possible groundwater quality deterioration and other negative environmental impacts must be organized. The purpose of the present study is for the first time to analyze the abundant basin wide hydrogeological data and to evaluate: (1) geometry and hydraulic parameters of the aquifers: (2) groundwater hydrodynamic conditions; (3) their chemical composition and (4) the natural groundwater resources and the possibility to intensify the groundwater pumping in close relation to the environmental impact.

Utilization of Gravimetric Satellite Data for Delineating of Subsurface Model of The Purwokerto-Purbalingga Groundwater Basin

The utilization of gravimetric satellite data has been carried out to delineate the subsurface model of the Purwokerto-Purbalingga Groundwater Basin. Access and processing of satellite gravity anomalies data were carried out to obtain the residual gravity anomalies data. Modeling of the residual gravity anomalies data was conducted along the AA′, BB′, and CC′ trajectories. The modeling results show a basin model filled by alluvial deposits (1.75 g/cm3 and 2.28 g/cm3) with a maximum depth of about 402 m for the AA′ trajectory, 543 m for the BB′ trajectory, and 463 m for the CC′ trajectory. The modeling results show that this alluvial basin is delimited by impermeable and semi-impermeable layers, which include laharic deposits of Slamet Volcano (2.61 g/cm3), andesite lava deposits (2.90 g/cm3), Tapak formation rocks (2.50 g/cm3), breccia rocks of Tapak formation (2.70 g/cm3), and breccia rocks of Halang formation (2.80 g/cm3). The fairly large thickness of alluvial deposits supported by dug-well water tables data and resistivity data indicates that the potential of groundwater in the Purwokerto-Purbalingga Groundwater Basin area is very large. The results of the study are expected to be a solution to overcome droughts that often occur in the Banyumas and Purbalingga regencies, as well as for the development of groundwater-based irrigation.

Novel insight into iodine enrichment in alluvial-lacustrine aquifers: Evidence from stable carbon and iron isotopes

Reductive dissolution of Fe (oxyhydr)oxides triggered by biodegradation of organic matter (OM) are considered to be key processes controlling iodine (I) release in groundwater systems. However, the precise mechanisms involved in release from organic matter degradation and from Fe (oxyhydr)oxides are unclear. In this study, dual stable isotope analysis (δ13C and δ56Fe) was combined with ultraviolet–visible spectral characterization of dissolved organic matter to elucidate the mechanisms of iodine enrichment in groundwater of the central Yangtze River basin, China, which represents Quaternary alluvial-lacustrine floodplains. High iodine groundwater mainly occurs along the Yangtze River (YR) and Han River (HR), with a maximum concentration of 1220 μg/L. The results suggest that methanogenesis driven by the biodegradation of high molecular weight organic compounds can promote the reductive dissolution of amorphous Fe (oxyhydr)oxides, which is the predominant process controlling iodine enrichment in the YR groundwater system. In addition, fermentation accompanied by sulfate reduction can also trigger the release of iodine into groundwater. The reductive dissolution of crystallized Fe (oxyhydr)oxides driven by the fermentation of small-molecule organic compounds is the dominant process responsible for iodine enrichment in the HR groundwater system. This study provides novel insight into the mechanisms of iodine enrichment in Quaternary alluvial-lacustrine aquifers.

Исследование многолетней динамики органолептических рисков здоровью населения волгоградского Заволжья, формируемых подземными водами, с использованием дистанционного зондирования

The paper considers the potential of using remote sensing methods in assessing the risks of olfactory effects in the population regularly drinking water from shallow underground sources vulnerable to climatic factors. The Volgograd Trans-Volga region, located on the territory of the Caspian lowland, is a typical representative of ardidized territories with highly mineralized groundwater. The xerophytic wormwood-fescue-feather-grass and solonetzic vegetation characteristic of the region determines the effectiveness of using the NDMI indicator to assess the degree of influence of soil aridity on the growth of hardness and total iron content in groundwater. A high degree of closeness of correlations between dependent indicators of the sanitary and hygienic quality of groundwater for drinking purposes and NDMI values in five-year dynamics for all groundwater basins (regions) of the North Caspian province was found. The data obtained can be useful in predicting and managing the risks of reflex-olfactory effects in consumers of water from underground sources in the organization of water supply and water treatment. Keywords: ORGANOLEPTIC RISK, NDMI, GROUNDWATER, HYDROGEOCHEMISTRY, ARIIDIZATION, HARDNESS, IRON

Mineral water as food for bone: an overview

Water is a primary asset and contributes significantly to human health. Although water requirements vary from person to person, an intake of 1.5-2 L per day is known to guarantee proper hydration, and is essential to maintaining the body’s water balance. Water for human use includes “water” (treated or not) intended to be drinkable, used for the preparation of food and drinks, and for other domestic uses, and “natural mineral water”, meaning waters that “originate from an aquifer or from a groundwater basin, which flow from one or more natural or reamed (perforated) springs and which have specific hygienic characteristics and, possibly, health properties”. According to European legislation (Directive 2009/54/EC), mineral waters can be classified on the basis of analysis of their main chemical-physical characteristics. Natural mineral waters can also be classified into many categories on the basis of their mineral composition and principal component. Natural mineral waters are known to have many beneficial (and non-beneficial) effects on human health and several studies have explored their properties and their role in different physiological and pathological conditions. Despite concerns about possible negative effects due to the plasticizers and/or endocrine disruptors that may be present in bottled mineral waters, their consumption is widespread. Calcium-rich mineral waters (calcium content >150 mg/L) supply excellent amounts of highly bioavailable calcium and are a very useful way of taking in calcium regularly and in a well distributed way throughout the day, without experiencing side effects; they therefore contribute to the achievement of the recommended intakes. Mineral waters can also be used as supplements to reduce the risk of deficiency of other micronutrients important for bone health such as boron, strontium and fluoride. Finally, gut microbiota is emerging as a key player in bone turnover regulation due to its ability to modulate the immune system, controlling inflammation and also influencing calcium absorption and vitamin D levels. Intestinal dysbiosis may promote bone mass loss in older people and after menopause. For this reason, the maintenance of a healthy and efficient intestinal microbiota is considered fundamental in the management of skeletal pathologies, both to prevent them and to support possible drug therapies.

Variably saturated dual-permeability flow modeling to assess distributed infiltration and vadose storage dynamics of a karst aquifer – The Western Mountain Aquifer in Israel and the West Bank

Available methods to quantify the recharge of karst aquifers usually rely on spatially and temporally aggregated precipitation measurements and simplified recharge models, employing transfer functions to account for the delay in infiltration and the distribution in time and space. They generally neglect the non-linear nature of infiltration dynamics through the vadose zone, characterized by dual flow behavior with slow diffuse and rapid focused recharge components. Here, we present a methodology that accounts for the physics of flow by employing a variably saturated dual-permeability flow model to simulate diffuse and preferential infiltration in a large-scale carbonate aquifer. The Western Mountain Aquifer (WMA) in Israel and the West Bank was selected as a suitable groundwater basin because of the large thickness of the vadose zone, extending over several hundred-meters, the availability of long-term data as well as the catchment size, stretching across a catchment area of circa 9000km2. Together, these characteristics allow the identification and quantification of the spatio-temporal distribution of the infiltration/recharge component, assessed at the level of the groundwater table. The presented methodology allows for improved water resources planning and generalization of the results, i.e., the robustness of large-scale model results with respect to local hydraulic parameter variations and data uncertainty. Semi-arid climate regions with a highly pronounced seasonality of precipitation and intense short-duration rainfalls, such as the Mediterranean region, represent a prime study location because of the clear and pronounced recharge input signals that are not superimposed by summer rainstorms. We simulate the complex dynamics of the dual-domain infiltration and partitioning of the precipitation input signal by employing HydroGeoSphere (HGS) for transient variably saturated water flow. Flow in the limestone rock matrix and high porosity system (i.e., conduits and fractures) is modeled by overlapping individual continua based on the bulk-effective Richards’ equation with van Genuchten (VG) parameters.

The hydrogeological karstic chalk system of the Yport springs (Seine-Maritime, France): investigations and resource exploitation

Abstract The small town of Yport in the northern part of the Pays de Caux, Normandy, is located on the shore of the English Channel between Étretat and Fécamp, at the outlet of a long dry valley that incises the chalk plateau. Eight hundred metres to the east, at the base of a cliff, is a cluster of springs, the ‘Fontaines d'Yport’, that emerge on the foreshore. Given their high discharge, measured at between 1 and 2.5 m 3 s −1 , the Le Havre authorities have been interested in these springs since the 1960s, in determining their origin, locating the karst conduit, developing them, and investigating the boundaries and vulnerability of the groundwater basin. Today, one third of the drinking water that supplies the Le Havre conurbation comes from the Yport wells, and investigations into their vulnerability and protection of their resource continues.

Groundwater Level Forecasting in the Jakarta Groundwater Basin

Groundwater is an important source of fresh water worldwide. Jakarta, the capital city of the Republic of Indonesia, is a large city with a population of more than 10 million and the center of the country’s economy and urban development. However, Jakarta has many challenges related to groundwater management. Changes in well GWL serve as a direct indicator of the effects of groundwater evolution, and GWL time series usually contain important information about aquifer dynamics. Therefore, water managers and engineers must model and predict GWL, identify and measure groundwater resources, and maintain a balance between supply and demand. Measuring and analyzing the groundwater table (GWL) of an aquifer are an important and valuable activity in the management of groundwater resources, and information on GWL variability can be used to determine groundwater availability. Accurate and reliable groundwater level estimation is very important because it provides important information about the quantitative groundwater status of an aquifer. The main advantage of AI models is their ability to reproduce nonlinear and complex processes without a full understanding of the underlying physics. As a result, the use of AI techniques in GWL modeling continues to grow, attracting the attention of scientists around the world. Using a nonlinear autoregressive network with extrinsic input (NARX) with a timestep of 14 days, this study is aimed at predicting the volatility of Jakarta’s GWL. Based on the research results, both JKT-01 and JKT-03 show a linear downward trend. On the other hand, JKT-02 and JKT-04 show a stable linear trend. GWL increases the linear trend of JKT-05. Variable results are generated by model performance. Model performance ( R ) varied between 0.2 and 0.9 during the training phase and between 0.2 and 0.9 during the validation phase. The overall performance of the model varies from 0.3 to 0.9. The diverse lithology and high pumping capacity in Jakarta are the reasons for the different modeling results. Forecasts for 14 days (14 timesteps) show that GWL remains constant at certain well locations, while GWL decreases at other locations. This is a consideration that stakeholders can consider to reduce the small effect of the daily GWL pattern as a result of NARX modeling.

Residence times of groundwater along a flow path in the Great Artesian Basin determined by 81Kr, 36Cl and 4He: Implications for palaeo hydrogeology

Understanding the age distribution of groundwater can provide information on both the recharge history as well as the geochemical evolution of groundwater flow systems. Of the few candidates available that can be used to date old groundwater, 81Kr shows the most promise because its input function is constant through time and there are less sources and sinks to complicate the dating procedure in comparison to traditional tracers such as 36Cl and 4He. In this paper we use 81Kr in a large groundwater basin to obtain a better understanding of the residence time distribution of an unconfined-confined aquifer system. A suite of environmental tracers along a groundwater flow path in the south–west Great Artesian Basin of Australia have been sampled. All age tracers (85Kr, 39Ar 14C, 81Kr, 36Cl and 4He) display a consistent increase in groundwater age with distance from the recharge area indicating the presence of a connected flow path. Assuming that 81Kr is the most accurate dating technique the 36Cl/Cl systematics was unravelled to reveal information on recharge mechanism and chloride concentration at the time of recharge. Current-day recharge occurs via ephemeral river recharge beneath the Finke River, while diffuse recharge is minor in the young groundwaters. Towards the end of the transect the influence of ephemeral recharge is less while diffuse recharge and the initial chloride concentration at recharge were higher.

Seasonal and geological controls of radon (222Rn) in groundwater of Vamanapuram river basin, SW India

The study investigates the spatio-temporal variability of radon (222Rn) with respect to the geology and hydrogeology of the Vamanapuram River Basin (VRB), SW India. A total of 40 groundwater samples were collected during three seasons of 2019. RAD7, RAD-H2O accessory (Durridge Co. USA) was used to analyse 222Rn, and physico-chemical parameters were measured in situ by Horiba Laqua water quality analyser. The results show that the 222Rn activity was in the range of 640–79,940 Bq/m3 in pre-monsoon, 250–36,950 Bq/m3 in monsoon and 420–59,790 Bq/m3 in post-monsoon season and 18% of samples exceeded the permissible limit of USEPA (11,000 Bq/m3) during all seasons. Remarkably, the samples exceeding the permissible limit of 222Rn were associated with khondalitic rocks with notable amount of uranium-bearing minerals and NW-SE trending lineaments, the most active type of lineament in the study area. The study shows the considerable influence of seasons and the highest activities were found during pre-monsoon compared to the other two seasons.

Health risks of shallow groundwater in the five basins of Shanxi, China: Geographical, geological and human activity roles

Rapid economic development often leads to groundwater degradation, posing health risks to those who rely on it. The groundwater discharge conditions in basins are poor. The health risk of shallow groundwater in basins needs more attentions. The health risk of shallow groundwater in the five basins of Shanxi Province, China was discussed based on the hydrochemical evolution of shallow groundwater and the water quality assessment. The results showed that arsenic (As) and chromium (Cr) in the shallow groundwater of the basins caused prominent health risks followed by fluoride (F) and nitrate (NO3−). The non-carcinogenic risks of As, F and NO3- to children were higher than that to adults, and the carcinogenic risks of As and Cr were higher for adults than children. Various hydrogeochemical reactions, geological conditions, climatic factors, and human activities are closely related to groundwater health risks, and basin topography is considered as one of key factors. Water-rock interaction, dedolomitization and cation exchange are the natural processes in the evolution of groundwater hydrochemistry, while agricultural and mining activities are the anthropogenic factors causing groundwater degradation. The leaching/dilution effects of infiltration precipitation in the basin-mountain systems cause distinct temporal changes in the chemical composition and health risks of the groundwater in the basins. Differences in climate and farming practices among the basins further complicate the spatio-temporal changes. The basin-mountain system is conducive to the convergence and enrichment of water flow and solutes in the basins, which aggravates the degradation of groundwater quality. This study highlights that the combined influences of geographical and geological factors and anthropogenic activities amplify the human health risks of groundwater in the basins.

Combining the Morris method and multiple error metrics to assess aquifer characteristics and recharge in the lower Ticino Basin, in Italy

Groundwater flow model accuracy is often limited by the uncertainty in model parameters that characterize aquifer properties and aquifer recharge. Aquifer properties such as hydraulic conductivity can have an uncertainty spanning orders of magnitude. Meanwhile, parameters used to configure model boundary conditions can introduce additional uncertainty. In this study, the Morris method of sensitivity analysis is performed on multiple quantities of interest to assess the sensitivity of a steady-state groundwater flow model to uncertain input parameters. The Morris method determines which of these parameters are less influential on model outputs. Uninfluential parameters can be set constant during subsequent parameter optimization to reduce computational expense. Combining multiple quantities of interest (e.g., RMSE, groundwater fluxes) when performing both the Morris method and parameter optimization offers a more complete assessment of groundwater models, providing a more reliable and physically consistent estimate of uncertain parameters. The parameter optimization procedure also provides an estimate of the residual uncertainty in the parameter values, resulting in a more complete estimate of the remaining uncertainty. By employing such techniques, the current study was able to estimate the aquifer hydraulic conductivity and recharge rate due to rice field irrigation in a groundwater basin in Northern Italy, revealing that a significant proportion of surficial aquifer recharge (approximately 81–94%) during late summer is due to the flood irrigation practices applied to these fields.

Individual to collective adaptation through incremental change in Colorado groundwater governance

Designing adaptive institutions for achieving sustainable groundwater use is a central challenge to local and state governments. This challenge is exacerbated by the growing impacts and uncertainty of climate change on water resources. Calls to reform water governance systems are often made in the context of these challenges, and reform efforts increasingly emphasize the need for solutions that are locally designed and administered. Such reforms often require fundamental institutional change that is difficult to achieve amid the myriad forces that stabilize and reproduce existing institutional structures and functions. In practice, governance change is instead overwhelmingly incremental and tends to be punctuated by periods of adjustment in response to social or environmental shocks and disturbances. We present a comparative study of four major Colorado river basins and examine how each has evolved distinct arrangements of groundwater governance in response to regulatory and drought disturbances over the past century. We interrogate concepts of path-dependence and apply a historical lens to understand why locally designed institutions for self-regulation emerge in some Colorado groundwater basins but not in others. We uncover a pattern of collective action by groundwater users that first seeks to oppose state regulation, followed by acceptance and efforts to comply, and eventual attempts to get ahead of state regulation by enacting local institutions for self-regulation. We report these findings and discuss the insights they offer for understanding how adaptive natural resources institutions are shaped through time by the constraints and opportunities of path-dependence and local contexts.

Seawater intrusion mapping using hydrochemical ionic ratio data: an application in northern part of Jakarta groundwater basins, Indonesia

Seawater intrusion mapping using hydrochemical ionic ratio data: an application in northern part of Jakarta groundwater basins, Indonesia

Groundwater sustainability assessment based on socio-economic and environmental variables: a simple dynamic indicator-based approach.

The Dehgolan aquifer, which lies in semiarid western Iran, was evaluated using a multi-influencing factor (MIF) analysis to determine groundwater sustainability. Eight indicators, including climatic variability, groundwater exploitation (pumping), groundwater quality, groundwater vulnerability, public participation, legal framework, water productivity, and occupation related to groundwater, were quantified and placed into a series of thematic maps within a GIS framework. Each factor was weighted based on the analyses obtained from the MIF model and the stacked maps were summed to yield a final map showing the degree of sustainability within the groundwater basin. The final groundwater sustainability map showed that 4% of the basin was in a critically unsustainable zone, 30% in an unsustainable zone, 40% in a semisustainable zone, 25% in a sustainable zone, and 1% in an ideally sustainable zone. The final map was validated using a receiver operating characteristic (ROC) method, cross-tabulation, and chi-square tests using groundwater-level decline as a test proxy. The analysis assessed the correlation between water levels that exhibited declines versus the degree of unsustainability of water levels and sustainable water use. The area under the curve was calculated to be 88%, cross-tabulation 64.4%, and the chi-square value was 260.5 with 4 degrees of freedom and values <0.05 (3.627E−55), which suggest that the final map has statistical significance. The sustainability analysis developed is useful as a baseline for development of governance laws to implement management methods in groundwater basins and it can be applied to a wide range of aquifer types in variable climates worldwide.

Sustainable Management of a Renewable Fishery Resource with Depensation Dynamics from a Control Systems Perspective

Human societies are exploiting natural renewable sources such as fisheries, forests, groundwater basins, rivers, and soil at an increasing intensity. Around the world, these resources are being managed by various institutions or governments. One of the challenges faced by institutions is to develop strategies and policies to effectively manage these renewable resources under social and ecological uncertainties, disturbances, policy implementation difficulties, and measurement errors. In this paper, a fishery is considered as an example and the problem of managing a fishery is approached from a control systems perspective. The justification behind this approach is due to the observation that the problem of managing a renewable resource can be posed as a control systems problem and that the discipline of control systems possesses tools and methods to deal with model uncertainties, external disturbances, measurement errors and implementation issues. For the fishery, a depensation type population dynamics model is considered. Depensatory models are used in social/ecological systems in order to model dynamics of certain species of fish populations. An optimal control strategy based on Pontryagin’s Maximum Principle is derived and its sustainability and robustness properties with respect to parametric uncertainties, measurement errors and disturbances are examined. Finally, a sub-optimal but more robust control strategy is proposed and its robustness properties are provided. The main objective of the paper is to show that a control systems engineering approach can be applied to a social-ecological problem and it can provide easy to implement management strategies, insight, and guidance into the management of renewable resources.

Assessment of Aquifer Systems for The Sustainable Development of Groundwater Use in The Batutua Groundwater Basin

Groundwater exploration is an alternative to meet raw water needs because of the increasing water demand and the dwindling surface water availability. Water use continues to increase along with the rate of population growth in the Rote Ndao Regency. Therefore, an initial assessment of the presence of groundwater can be carried out by identifying the groundwater basin area. Batutua is one of the groundwater basin areas occupied by the most population because it is the capital of Rote Ndao Regency. This study aims to identify aquifer systems and flow patterns as the basis for groundwater exploration in the Batutua groundwater basin area. The method used in this groundwater aquifer system study is the Vertical Electrical Sounding (VES) method. The VES method is a geoelectrical method used to investigate the layers of an aquifer by interpreting the current that penetrates the soil using two electrodes and the potential response. Geoelectrical investigations were carried out at 8 points in the Batutua groundwater basin area. The aquifer is found in water-containing coral limestone areas where water flows through fractures as secondary permeability. The groundwater flow direction was obtained by measuring the groundwater levels in 14 dug wells and 24 springs. The research’s area aquifer system is formed by upper shallow aquifer as an unconfined aquifer with a thickness less than 20 m and lower shallow aquifer as a semi-confined aquifer that has clay or marls on upper layer and limestone in below with the flow direction from the East to the West and the North part of the study area.