Evaluating Groundwater Management Sustainability under Limited Data Availability in Semiarid Zones

Combining monitoring and modelling tools as a basis for city-scale concepts for a sustainable thermal management of urban groundwater resources

Groundwater depletion and contamination: Spatial distribution of groundwater resources sustainability in China

Hydrogeochemical assessment of groundwater quality for drinking and irrigation applying groundwater quality index (GWQI) and irrigation water quality index (IWQI)

Hazards in Karst and Managing Water Resources Quality

Nigeria has greater challenges when it comes to groundwater development and management. The management of the resource is lagging behind the pace of development, and often, very little control is exercised in its exploitation. The current groundwater resources development and supply status is unacceptably low and needs a major transformation. With the rapid growth in population, urbanization, industrialization and competition for economic development, groundwater resource has become vulnerable to depletion and degradation. Management of this valuable resource is determined by its acceptability and utilizability in terms of quantity and quality. Due to imbalance between demand and availability, management approaches are facing various ethical dilemas. Against this context, relevant questions present themselves: What is the real extent of the problems? Why are the present efforts so limited? ; and what can be done to change the situation, to start on a path to more sustainable and equitable development and management of groundwater resources? To be able to adequately address the questions and devise intelligent answers, an analysis of the present impediments deserves attention. Only by clarifying the constraints and addressing them, will any significant changes be possible, let alone occur. This paper therefore emphasizes that the machinery of groundwater resources development and management needs an urgent overhauling with the aim of streamlining the overlapping functions of the various agencies that have operated the system up till now. More importantly, the paper suggested integrated approaches/strategies for sustainable management as well as offers some relevant policy recommendations for groundwater management in Nigeria. Key words: Groundwater resources, groundwater management, groundwater policy, sustainability, groundwater utilization, Nigeria.

شناسایی و تهیه نقشه پهنه‌بندی مناطق آسیب‌پذیر آبخوان، یعنی مناطقی که امکان نفوذ و پخش آلاینده‌ها از سطح زمین به سیستم آب زیرزمینی وجود دارد، یک ابزار مدیریتی مناسب برای جلوگیری از آلودگی منابع آب زیرزمینی می‌باشد. با توجه به اهمیت دشت نیشابور در تأمین آب کشاورزی، شرب و صنعت منطقه، از مدل دراستیک جهت ارزیابی آسیب‌پذیری آبخوان استفاده شده است. در مدل دراستیک از مشخصه‌های مؤثر در ارزیابی آسیب‌پذیری آبخوان آب زیرزمینی شامل عمق سطح ایستابی، شبکه تغذیه، جنس آبخوان، نوع خاک، شیب توپوگرافی، مواد تشکیل دهنده منطقه غیر اشباع و هدایت هیدرولیکی استفاده می‌شود که به صورت هفت لایه در نرم افزار ArcGis تهیه شدند و با وزن‌دهی و رتبه‌بندی و تلفیق هفت لایه فوق، نقشه نهایی آسیب‌پذیری آبخوان نسبت به آلودگی تهیه گردید. با انطباق یون نیترات بر روی نقشه نهایی دراستیک، مشخص شد کلیه نقاطی که دارای نیترات بالا هستند، در محدوده آلودگی زیاد قرار گرفته‌اند که دقت و صحت مدل را مورد تأیید قرار می‌دهد. با توجه به نقشه پهنه‌بندی به‌دست آمده حدود 55/23 درصد از منطقه مورد مطالعه در محدوده آسیب‌پذیری خیلی کم، 16/17 درصد آسیب‌پذیری کم، 21/19 درصد آسیب‌پذیری متوسط، 72/28 درصد آسیب‌پذیری زیاد و 36/11 درصد در محدوده آسیب‌پذیری خیلی زیاد قرار می‌گیرد. نتایج این تحقیق نشان می‌دهد بیشترین درصد پتانسیل آسیب‌پذیری مربوط به کلاس زیاد است و مناطق جنوبی و غربی دشت از پتانسیل آسیب‌پذیری زیادی برخوردار بوده و نواحی شمالی کمترین پتانسیل را دارند.

Performance of crop yield models is generally evaluated without testing their ability to capture yield spatial variability across a large area. Local soil and environmental conditions or management factors usually cause significant crop yield variability. In West Africa, landscape heterogeneity and data scarcity pose yet additional challenges to crop yield modeling. In this study, conditional autoregression (CAR) and geographical weighted regression (GWR) were used to better understand spatial patterns in sorghum [Sorghum bicolor (L.) Moench.], pearl millet [Pennisetum glaucum (L.) R. Br.], and cotton (Gossypium hirsutum L.) yields in Burkina Faso. A series of SPOT satellite normalized difference vegetation index (NDVI) 1‐km2 10‐d composite images spanning the crop growing season and observations of rainfall, topography, soil properties, and labor availability were used as explanatory variables in the CAR and GWR models. Regression analyses revealed that crop yield was significantly related to rainfall and topography in the semiarid and subhumid agroecological zones of Burkina Faso. Soil properties and labor availability mainly affected sorghum and millet yields in the semiarid zone. By addressing spatial dependency between crop yield observations in the two zones, GWR outperformed CAR models. For CAR models, adjusted R2 (Ra2) values for the sorghum, millet, and cotton yields were 0.76, 0.70, and 0.50, respectively, for the semiarid zone and 0.54, 0.32, and 0.30, respectively, for the subhumid zone. For GWR models, Ra2 values were 0.85, 0.70, 0.78, respectively, for the semiarid zone and 0.76, 0.67, 0.65, respectively, for the subhumid zone. Thus, despite limited data availability, GWR can be used to model the spatial variability of crop yields across large areas in West Africa.

The present study attempts to assess the nature of effluents generated from textile bleaching and dyeing units located at Kalikapur area under Maheshtala region, West Bengal, India and to provide a sustainable management of ground water resources through installing CETPs with zero liquid discharge system. Effluent from medium, small and tiny units of this region is estimated at 2000 MLD. Studies with 40 units for 4 years (2012—2016) located in this area exhibited following mean values of different physic-chemical variables: pH (9), Biological Oxygen Demand (610 Mg/L), Chemical Oxygen Demand (1827 Mg/L), Total Dissolved Solids (6411 Mg/L), Total Suspend Solids (927 Mg/L) and toxic metals such as lead Pb (0.43 Mg/L), Chromium (0.031 Mg/L), Zinc (0.74 Mg/L), Nickel (0.07 Mg/L) and Cadmium (0.03 Mg/L). These finding of results surpass the standard allowable limits qualify by FAO (1985) and World Health Organization (2003). The waste water loaded with toxic trace metals is adversely affecting the environmental pollution and anthropomorphic eudemonia and also pollute the quality of both surface and ground water and consequently degraded agricultural and plant yield, vegetable and fruits and causes impairment to aquatic lives. Four to five Common Effluent Treatment Plants are urgently required to install at different areas of the Maheshtala cluster with a capacity of 500 MLD each, so that one in Kalikapur area, to manage sizeable volume of waste water (2000 MLD) and sustainable management of ground water resources in a thickly populated urban area near Calcutta, a principal city of India.

Sustainable Development and Management of Groundwater Resources in Mining Affected Areas: A Review

Abstract. In groundwater resource management, the hydrogeological framework significantly influences groundwater flow and storage. The complexity of groundwater systems in orogenic regions necessitates comprehensive investigations. To ensure sustainable groundwater management and address global climate change impacts, hydrogeological surveys and long-term monitoring at the catchment scale are essential. However, regional surveys are often limited by budget constraints and field accessibility. Therefore, integrating remote sensing and GIS technology to analyze terrain features, combined with field test results, facilitates the establishment of comprehensive terrain classifications and groundwater potential maps, aiding subsequent groundwater resource investigations and management. This study collected data from 75 field investigation sites spanning the mountainous to plain regions of central Taiwan at the catchment scale. The data included regolith thickness, hydraulic parameters, and nearly ten years of groundwater level observations. Terrain classifications were based on indices such as the topographic wetness index, topographic position index, and slope degree, resulting in seven distinct terrain types. The results revealed that in main riverbed deposits and flat slopes, there were higher average well yields and groundwater-level fluctuations. Greater fluctuations were observed in areas characterized by ridges, colluvium, and low elevation in slope areas and valleys. The variability in shallow aquifers was particularly pronounced, with outliers reaching higher levels in slope and valley terrains. These findings underscore the complexity of groundwater dynamics in diverse terrain types, highlighting the need for tailored management strategies to ensure sustainable groundwater resources.

Arid and semiarid regions are geographic units that cover approximately 43% of the earth’s surface worldwide, and conditions of extreme drought and reduced vegetation cover predominate in these regions. In Mexico, arid and semiarid ecosystems cover more than half of the territory, with desertification, mainly caused by anthropogenic activities and climatic events, as the main problem in these regions. The present research aimed to assess, identify, and classify arid and semiarid zones by employing a methodology based on multicriteria evaluation analysis (MCA) using the weighted linear combination (WLC) technique and geographic information systems (GIS) in the hydrological administrative regions (HARs) of the North Pacific, Northwest, and Baja California Peninsula, located in Northwest Mexico. Data related to aridity, desertification, degradation, and drought were investigated, and the main factors involved in the aridity process, such as surface temperature, soil humidity, precipitation, slopes, orientations, the normalized difference vegetation index (NDVI), and evapotranspiration, were obtained. For the standardization of factors, a fuzzy inference system was used. The weight of each factor was then determined with the analytical hierarchy process (AHP). To delimit arid regions, the classification of arid zones proposed by the United Nations Environment Program (UNEP) was used, and the result was an aridity suitability map. To validate the results, the sensitivity analysis method was applied. Quantitative and geospatial aridity indicators were obtained at the administrative hydrological level and by state. The main results indicated that semiarid and dry subhumid zones predominated, representing 40% and 43% of the surface of the study area, respectively, while arid regions represented 17%, and humid regions represented less than 1%. In addition, of the states for which 100% of the surface lay in the study area, it was observed that Baja California and Baja California Sur had the largest arid and semiarid zones, while subhumid regions predominated in Sonora and Sinaloa.

Heavy metal accumulation and tolerance in plants from mine tailings of the semiarid Cartagena–La Unión mining district (SE Spain)

Predictive modeling of hydrological time series is essential for groundwater resource development and management. Here, we examined the comparative merits and demerits of three modern soft computing techniques, namely, artificial neural networks (ANN) optimized by scaled conjugate gradient (SCG) (ANN.SCG), Bayesian neural networks (BNN) optimized by SCG (BNN.SCG) with evidence approximation and adaptive neuro-fuzzy inference system (ANFIS) in the predictive modeling of groundwater level fluctuations. As a first step of our analysis, a sensitivity analysis was carried out using automatic relevance determination scheme to examine the relative influence of each of the hydro-meteorological attributes on groundwater level fluctuations. Secondly, the result of stability analysis was studied by perturbing the underlying data sets with different levels of correlated red noise. Finally, guided by the ensuing theoretical experiments, the above techniques were applied to model the groundwater level fluctuation time series of six wells from a hard rock area of Dindigul in Southern India. We used four standard quantitative statistical measures to compare the robustness of the different models. These measures are (1) root mean square error, (2) reduction of error, (3) index of agreement (IA), and (4) Pearson’s correlation coefficient (R). Based on the above analyses, it is found that the ANFIS model performed better in modeling noise-free data than the BNN.SCG and ANN.SCG models. However, modeling of hydrological time series correlated with significant amount of red noise, the BNN.SCG models performed better than both the ANFIS and ANN.SCG models. Hence, appropriate care should be taken for selecting suitable methodology for modeling the complex and noisy hydrological time series. These results may be used to constrain the model of groundwater level fluctuations, which would in turn, facilitate the development and implementation of more effective sustainable groundwater management and planning strategies in semi-arid hard rock area of Dindigul, Southern India and alike.

Fluoride contamination in groundwaters of a rural region in semi-arid Western India has been studied using combination of geochemical-and-isotopic techniques, in conjunction with Health Quotient assessment approach. The objective of this study is to determine the sources and controls on fluoride content and to evaluate probabilistic non-carcinogenic risk associated with its long-term consumption. F- ranges from 0.3 to 12mg L-1, shows high spatial variability, and ~ 35% of the samples have F- > 1.5mg L-1 (WHO maximum limit for drinking). Two sources are identified: high F- results from water-rock interaction of F-bearing minerals in granites and gneisses, while phosphate fertilizers can contribute up to ~ 0.46mg L-1 of groundwater F- that can be significant for low F- samples. High F- samples are characterized by high pH, Na and alkalinity, and low Ca. Calcite precipitation drives the solubility of F-bearing minerals. Kinetic fractionation of water isotopes (18O and 2H) demonstrates that evaporation plays role in enriching groundwater F-. Non-carcinogenic risk, estimated by Hazard Quotient ([Formula: see text]), ranges from 0.13-5.72 to 0.26-11.86 for adult and children, respectively. Conservative estimate shows that ~ 0.467 million of adults and~0.073 million of children in four sub-districts are under the risk of fluorosis-while the residents of other five sub-districts remain safe from it. Finally, we suggest stakeholders to install F- treatment plants to ensure the health safety of local residents in the high-risk zones, create awareness in farmers for optimum use of fertilizers, and promote rainwater harvesting, for better management of groundwater resources and quality in the region.

Groundwater plays a fundamental yet often little appreciated role in supporting economic development and human well-being in both urban and rural environments, as well as supporting many aquatic ecosystems in Africa. Thus, groundwater has high relevance to the development and well-being of Africa, if adequately assessed and sustainably exploited. Whilst the potential for groundwater-resources development continues to be reported in the literature, a quantitative understanding of these issues remains poor. The objective of this paper is to highlight the main groundwater issues and problems in Africa and the current and expected opportunities for sustainable groundwater management. This will be done through the review of existing knowledge of groundwater resources and of ongoing and planned groundwater management programs and initiatives. Groundwater resources in Africa face increasing threat of pollution from urbanisation, industrial development, agricultural and mining activities, and from poor sanitation practices and over-exploitation due to increasing demand to meet human and agricultural needs. However, despite the existence of a number of groundwater management challenges, groundwater resources in Africa are still generally under-developed and can meet the various needs in a sustainable manner if better managed. Thus, strategies to ensure sustainable development and management of groundwater resources need to be put in place. These include establishment of groundwater monitoring systems, understanding of the groundwater–aquatic ecosystem relationships, management of transboundary aquifers, addressing climate-change impacts on groundwater, assessing the impact of increased pumping from various types of aquifers on sustainability of groundwater abstraction, and capacity building in groundwater management.