Analisis Tektonik Relatif Menggunakan Metode Morfotektonik Daerah Lintau Buo dan Sekitarnya, Tanah Datar, Sumatera Barat

The area of this research is in the Lintau Buo Region, Tanah Datar District, West Sumatra. Based on the regional geology, the location is on the boundary of the Ombilin Basin which has active tectonic conditions. This research is to get data of tectonic levels using a quantitative geomorphological approach carried out in the Batang Sinamar sub-watershed and the Batang Tampo sub-watershed. Some of the parameters used for this study include Drainage Density (Dd), Bifurcation Ratio (Rb), Hypsometric Integral (HI), Valley Floor Width and Height Ratio (Vf), Mountain Front Sinousity (Smf), and Asymmetry Factor (AF). And then the outcome of the parameters compared using IAT (Index of Active Tectonic) analysis. The results of the calculation are obtained with segment 1 entering class 3, namely moderate tectonics, and segments 2 and 3 entering class 2, namely high tectonics. The drainage pattern of the river at this research location is a pararellel drainage pattern which is controlled by geological structures such as folds. The results calculation of the IAT analysis is the landform of the morphology research location is controlled by moderate to high levels of tectonic activity and produces various denudational and erosional processes that cause soil movement and landslides

Evaluation of groundwater potential based on hybrid approach of geology, geophysics, and geoinformatics: Case study of Buffalo Catchment area, Eastern Cape, South Africa

This study focuses on the feasibility of exploring potential groundwater zones through assessment of catchment geo-hydrodynamic processes, using hydro-statistic principles and geographic information system-based approaches. The research work integrated analysis of hydrologic variables, geologic structures, and geomorpho-tectonic processes that provide information on spatial variability of hydrologic units in a watershed. The study is aimed at improving conceptual knowledge and presenting the technical feasibility of exploring potential groundwater zones through geo-hydrodynamic perspectives in hydrogeologically challenged environments. The study adopted a case design approach at the Buffalo hydrologic basin headwater in Eastern Cape, South Africa. The methods used in this study include: field mapping of geologic units and structures, digital processing of aeromagnetic map, cross-section profiling of borehole logs, auto-extraction of lineament, streamflow variability and recession assessment, geomorpho-tectonic analysis of surficial drainage pattern, vertical electrical sounding for imaging shallow subsurface layers, and geospatial integration of thematic maps of groundwater multi-influencing factors. The results indicate that the hydrogeological settings of Buffalo watershed comprised of good, moderate, fair, poor and very poor groundwater potential zones which cover 187 km2 , 338 km2 , 406 km2 , 185 km2 , and 121 km2 respectively. The results report that the groundwater system of Buffalo watershed is mainly hosted by the well-drained fractured dolerite and the shallow unconfined sandstone aquifer. The aquifer is bounded by two parallel impermeable valley walls in the north and south. Also, the Buffalo drainage system constitutes a variable head boundary as a groundwater discharge zone. The groundwater discharge which mostly occurs at the Tshoxa upper course, Mgqakwebe, Quencwe, Yellowwoods upper course and the Buffalo River center influence the status of the Buffalo River as a perennial river system. vi The groundwater recharge occurs through the networks of surficial lineaments and fractures concentrated on the sandstone lithosome, mostly in the northern half of the watershed. The surficial tectonic features trend in a WNW-ESE and E-W direction. The groundwater flow system is controlled by the subsurface lineaments which are oriented in west-northwest – eastsoutheast direction. Most of the groundwater recharge is driven by rain which is extreme at the north. The hydro-climatic pattern of the region influences the dendritic drainage system of Buffalo watershed. The geologic characterization and geomorpho-tectonic analysis indicate that the geologic settings are made up of upward-fining lithologic material and siliciclastic materials that were deposited as fill in paleochannels by braided and meandering fluvial systems. The variability in dissection property and the fluvial system indicates that Buffalo hydrologic and geomorphic systems are heterogeneous and complex. The possible impact of these variabilities aligns with the report of geoelectric sections which revealed the heterogeneity of the aquifer intrinsic properties and variability in groundwater yield. The electric resistivity tomography revealed the existence of a fault system and variation in the thickness of the aquifer. Hydrologic characterization indicates the vulnerability status of the rivers within the watershed. In particular, the Ngqokweni River is vulnerable to diminution while Quencwe River has the potential for a flash flood. Buffalo station is an important surface water capture zone. Delineation of groundwater potential zone should incorporate geologic, hydrologic, geophysical, geomorphotectonic, and environmental perspectives due to the inherent relationship among influencing factors. The study therefore identifies groundwater capture zones which can be further explored for groundwater development and to mitigate the stake of water shortage. The study therefore recommends the approach here to the department of water affairs for adoption to map the zones of groundwater potential at a regional scale. The study also provides resourceful information on vii groundwater recharge zones and therefore recommends that the environment and water stakeholders work together to protect the recharge zones from groundwater contamination due to land us

Potential of natural groundwater recharge in the Chennai Basin with a special emphasis on the urban area

Groundwater is the primary source of drinking water in India, and the Chennai River Basin (CRB) is no exception. However, available resources of both groundwater and surface water, are constantly decreasing because of overexploitation and contamination. Well fields in the northern part of the CRB control the water supply for the region, including the Chennai Metropolitan Area (CMA), the capital of the state of Tamil Nadu. Thus, any changes in groundwater storage and availability in the basin directly affect the 11-million people who live in the CMA. So, even though the focus of this study is on the CMA, the entire basin must be considered in order to understand the hydrogeological condition and groundwater situation. This research aims to provide a holistic study of the topographic condition of the basin, the amount of water stress, the identification and mapping of the groundwater potential zones, a review of the groundwater recharge estimation techniques on national scale, and most importantly, the creation of an estimate of the natural groundwater recharge in the CRB and how climate and landuse patterns affect the recharge process. A critical review has been made of popular groundwater recharge estimation practices. The suitability of each method is found to be dependent on time-space, hydrogeological condition, and data availability. Considering the hydrogeological and climatic conditions, the Water Table Fluctuation (WTF) method is the most appropriate method of recharge estimation. Groundwater recharge is largely controlled by topographical factors such as morphometric and hypsometric analysis and understanding these factors is necessary in water resource development planning. Shuttle Radar Topographic Mission (SRTM) and Digital Elevation Model (DEM) data were used in the Geographical Information System (GIS) platform to derive the morphometry and hypsometry. The CRB is an elongated basin of the 7th order and has been classified into 11 sub-basins. Major linear, areal and relief aspects were calculated and discussed based on their hydrologic significance. Steep slopes in the basin may affect the infiltration rate and, subsequently, recharge. Hypsometric curves show the concave type for most of the sub-basins, indicating an old stage. These results provide vital information about the hydrological conditions of the basin. Protecting the resource from depletion and identifying potential zones is essential for sustainable development. Remote Sensing (RS) and GIS technologies with field data were used to map groundwater potential zones in the CRB. For the most accurate results, a total of 11 controlling factors were brought into the GIS platform and a multi-criteria decision making (MCDM) tool, Analytical Hierarchal Process (AHP), was also used. Based on this analysis, groundwater potential zones were classified into five categories- very poor, poor, moderate, good, and very good. The final groundwater potential map showed that 35% of the total area has good to very good groundwater potential, 27% has moderate potential, and 38% has poor to very poor potential. Comparison of the specific capacity obtained from borehole data with these results showed that the predicted groundwater potential identified in this study matches 80% of the area. Groundwater potential depends on climatic conditions such as droughts, atmospheric temperatures, and monsoonal patterns. Using long-term temperature and rainfall data, meteorological drought has been calculated and agricultural drought has been determined using NDVI, NDWI and VCI indices. Agricultural drought indices showed that the vegetation is healthy in the northern and southern regions. However, more than 40% of the area was found to be water stressed. The calculation was made on a decadal scale and the highest water stress was observed in the year 2010. Agricultural drought is more prominent than meteorological drought in the CRB. Chennai faces a severe water shortage in the summer season and flooding in the rainy seasons. The groundwater recharge rate for the Chennai River Basin has been estimated using the empirical method, the rainfall infiltration (RIF) technique, a GIS based distributed model, and the Water Table Fluctuation (WTF) method. The average groundwater recharge rates for different methods vary, with results of 196mm/ year (Empirical formula), 127mm/year (WTF method) and 122mm/year (RIF method). The ratio of effective recharge to rainfall is found as 10% for RIF and WTF methods and 16% using the empirical formula. Considering the conditions in India, as recommended by the Groundwater Estimation Committee (GEC), the WTF method was found to be the most reliable. Still, using multiple methods is suggested for a more fully accurate estimate. This is one of the first extensive studies that covers aspects such as terrain characteristics, proposing the most suitable groundwater recharge estimating methods, groundwater potential zone identification, water stress analysis and natural groundwater recharge estimations in the Chennai River Basin. During this study, large amount of field data on water level, atmospheric temperature, rainfall, and aquifer parameters was collected from different institutions and brought into a single scale. All this data has been brought into the GIS platform and created maps. Thus, a baseline has been created for future groundwater studies. After considering variable recharge estimates and the effective recharge ratio (approx. 10%), it is suggested that groundwater recharge be improved either by repairing existing structures or implementing artificial recharge structures based on the groundwater potential identified. This thesis contains both basic and advanced levels of scientific information, all that is necessary for policymakers to begin improvements, and even provides a number of recommendations for the most effective approach to groundwater management.Das Grundwasser stellt in Indien die wichtigste Quelle zur Gewinnung des Trinkwassers dar. Das Flusseinzugsgebiet Chennai (CRB) bildet dabei keine Ausnahme. Durch Übernutzung und Verunreinigung schwinden jedoch verfügbare Wasserressourcen, sowohl Grundwasser als auch Oberflächenwasser, stetig. Die sich im nördlichen Teil des Flussbeckens befindenden Brunnenfelder kontrollieren die Wasserversorgung der Region, einschließlich der Metropolregion Chennai (CMA) und somit der Hauptstadt des Bundesstaats Tamil Nadu. Aus diesem Grund haben jegliche Änderungen des Grundwasserspeichers und -verfügbarkeit im Flussbecken direkte Auswirkungen auf die 11 Millionen Einwohner der Metropolregion. Obwohl der Fokus dieser Arbeit auf der Metropolregion Chennai liegt, muss zum Verständnis der hydrogeologischen Verhältnisse und der Grundwassersituation das ganze Flussbeckens berücksichtigt werden. In dieser Arbeit wird eine ganzheitliche Betrachtung der topografischen Verhältnisse des Flussbeckens, der Stärke des Wasserstresses, der Bestimmung und Abbildung der möglichen Grundwasserzone, einer Überprüfung der Ermittlungsverfahren zur Grundwasserneubildung auf nationaler Ebene und, am wichtigsten, der Ermittlung der natürlichen Grundwassererneuerung im Flussbecken Chennai sowie der Weise, wie Klima- und Bodennutzungsmuster diesen Erneuerungsprozess beeinflussen, durchgeführt. Die gängigsten Praktiken zur Ermittlung der Grundwassererneuerung wurden kritisch untersucht. Es wurde festgestellt, dass die Eignung der einzelnen Methoden von den Raum- Zeit-Bedingungen, hydrogeologischen Umständen und der Datenverfügbarkeit abhängt. Bei Berücksichtigung der hydrogeologischen und klimatischen Bedingungen stellt die WTF-Methode (Water Table Fluctuation) die passendste Methode zur Ermittlung der Grundwassererneuerung dar. Die Grundwassererneuerung wird größtenteils von den topografischen Faktoren, wie der morphometrischen und hypsometrischen Analyse, bestimmt. Das Verstehen dieser Faktoren ist für die Planung der Wasserressourcenentwicklung unerlässlich. Für die Durchführung der Merphometrie und der Hypsometrie wurden SRTM- und DHM-Daten in geografische Informationssysteme (GIS) eingesetzt. Das Flusseinzugsgebiet Chennai ist ein längliches Becken der 7. Ordnung und wird in 11 Unterbecken unterteilt. Die wichtigsten Linear-, Areal- und Reliefaspekte wurden anhand ihrer hydrologischen Bedeutung berechnet und überprüft. Steilhänge in Becken können die Infiltrationsrate und somit die Grundwassererneuerung beeinflussen. Die hypsografischen Kurven der meisten Unterbecken weisen eine konkave Form vor und geben somit ihre Altersstufe an. Diese Ergebnisse bieten entscheidende Informationen über die hydrologischen Verhältnisse des Beckens. Der Schutz vor der Erschöpfung der Ressource und die Bestimmung der möglichen Zonen ist für eine nachhaltige Entwicklung unumgänglich. Die Felddaten der Fernerkundung und GIS-Technologien wurden zur Abbildung der möglichen Grundwasserzonen im FlusseinzugsgebietChennai eingesetzt. Um ein genaues Ergebnis erzielen zu können, wurden in die GIS-Plattform insgesamt 11 Kontrollfaktoren eingebracht und ein Hilfsmittel für mehrkriterielle Entscheidungen, ein analytischer Hierarchieprozess (AHP), genutzt. Aufgrund dieser Analyse wurden die möglichen Grundwasserzonen in fünf Kategorien eingeteilt: sehr schwach, schwach, mittel, gut und sehr gut. Die endgültige Karte der möglichen Grundwasserzonen zeigt, dass 35 % des Gesamtbereichs über ein gutes bis sehr gutes Grundwasserpotential, 27 % über ein mittleres Potential und 38 % über ein schwaches bis sehr schwaches Grundwasserpotential verfügen. Vergleiche der spezifischen Kapazität, die aus dem Bohrlochdaten gewonnen wurden, mit diesen Ergebnissen zeigen, dass das in dieser Arbeit vorhergesagte Grundwasserpotential zu 80% des Gebiets passt. Das Grundwasserpotential hängt von den Klimabedingungen wie Dürren, Atmosphärentemperaturen und Monsunmustern ab. Durch den Einsatz der Langzeitdaten über Temperatur und Regenfällen wurde die meteorologische Dürre berechnet, die landwirtschaftliche Dürre wurde mittels der Indexe NDVI, NDWI und VCI bestimmt. Die Indexe für die landwirtschaftliche Dürre zeigen, dass sich die Vegetation in den nördlichen und südlichen Gebieten im guten Zustand befindet. Eine Fläche von 40% des Gebiets erlebt jedoch Wasserstress. Die Berechnung erfolgte auf der dekadischen Skala, wobei der höchste Wasserstress im Jahr 2010 zu beobachten war. Im Flusseinzugsgebiet Chennai ist die landwirtschaftliche Dürre starker als die meteorologische Dürre zu spüren. In Chennai herrscht im Sommer gravierender Wassermangel, während der Regenzeit sind jedoch starke Überflutungen vorhanden. Die Grundwasserneubildungsrate für das Flussbecken Chennai wurde anhand der empirischen Methode, des Modells der Regeninfiltration (RIF), eines auf dem GIS-basierten verteilten Modells und der WTF-Methode ermittelt. Die durchschnittliche Grundwasserneubildungsrate variiert je nach Methode/Modell und zeigt die Ergebnisse von 196mm/Jahr (empirische Formel), 127mm/Jahr (WTF-Methode)und122mm/Jahr(RIF-Methode) vor. Der auf den Regen zurückgehender Anteil der effektiven Erneuerung liegt bei den Methoden RIF und WTF bei 10%, bei dem Einsatz der empirischen Formel erreicht dieser Anteil 16%. In Anbetracht der in Indien herrschenden Verhältnisse wurde die WTF-Methode, wie vom indischen Komitee für Grundwasserermittlung (GEC) empfohlen, als die zuverlässigste Methode bestimmt. Für eine möglichst genaue Ermittlung wird jedoch empfohlen, mehrere Methoden zu nutzen. Diese Arbeit gehört zu den ersten ausführlichen Studien, die sich mit Aspekten wie den Geländeeigenschaften, einer Empfehlung der geeignetsten Methoden zur Ermittlung der Grundwasserneubildung, der Bestimmung der möglichen Grundwasserzonen, der Wasserstressanalyse und der Ermittlung der natürlichen Grundwasserneubildung im Flussbecken Chennai beschäftigen. In dieser Arbeit wurde von diversen Einrichtungen eine hohe Zahl an Felddaten über den Wasserstand, Atmosphärentemperatur, Regenfälle und aquiferspezifische Parameter erworben und in einer Skala zusammengeführt. Alle diese gesammelten Daten wurden in die GIS-Plattform eingetragen und es wurden Karten erstellt. Somit wurde eine Ausgangsbasis für zukünftige Grundwasserstudien geschaffen. In Anbetracht der variablen Ermittlungswerte und des effektiven Erneuerungsanteils (etwa 10%) wird empfohlen, die Grundwasserneubildung entweder durch die Sanierung vorhandener Strukturen oder durch den Einsatz künstlicher Anreicherungsstrukturen auf der Grundlage des bestimmten Grundwasserpotentials zu verstärken. Es werden wissenschaftliche Basisinformationen vorgelegt, welche den Entscheidungsträgern zur Optimierung einer angepassten und nachhaltigen Wasserbewirtschaftung dienen können

Geomorphometry 2020. Conference Proceedings

Geomorphometry is the science of quantitative land surface analysis. It gathers various mathematical, statistical and image processing techniques to quantify morphological, hydrological, ecological and other aspects of a land surface. Common synonyms for geomorphometry are geomorphological analysis, terrain morphometry or terrain analysis and land surface analysis. The typical input to geomorphometric analysis is a square-grid representation of the land surface: a digital elevation (or land surface) model. The first Geomorphometry conference dates back to 2009 and it took place in Zürich, Switzerland. Subsequent events were in Redlands (California), Nánjīng (China), Poznan (Poland) and Boulder (Colorado), at about two years intervals. The International Society for Geomorphometry (ISG) and the Organizing Committee scheduled the sixth Geomorphometry conference in Perugia, Italy, June 2020. Worldwide safety measures dictated the event could not be held in presence, and we excluded the possibility to hold the conference remotely. Thus, we postponed the event by one year - it will be organized in June 2021, in Perugia, hosted by the Research Institute for Geo-Hydrological Protection of the Italian National Research Council (CNR IRPI) and the Department of Physics and Geology of the University of Perugia. One of the reasons why we postponed the conference, instead of canceling, was the encouraging number of submitted abstracts. Abstracts are actually short papers consisting of four pages, including figures and references, and they were peer-reviewed by the Scientific Committee of the conference. This book is a collection of the contributions revised by the authors after peer review. We grouped them in seven classes, as follows: • Data and methods (13 abstracts) • Geoheritage (6 abstracts) • Glacial processes (4 abstracts) • LIDAR and high resolution data (8 abstracts) • Morphotectonics (8 abstracts) • Natural hazards (12 abstracts) • Soil erosion and fluvial processes (16 abstracts) The 67 abstracts represent 80% of the initial contributions. The remaining ones were either not accepted after peer review or withdrawn by their Authors. Most of the contributions contain original material, and an extended version of a subset of them will be included in a special issue of a regular journal publication

Assessment of groundwater resources in the north-central coast of Crete, Greece using geophysical and geochemical methods

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.The Geropotamos aquifer on the north‐central coast of Crete, Greece, is invaded in some places by salt water from the Aegean Sea, with impact on freshwater supplies for domestic and business uses, including agriculture. The geological setting of the study area is considered complex, as Miocene biogenic limestones, marls, clays and conglomerates crop out in the central and the western part and clastic limestones and dolomites of the Tripolis and Plattenkalk nappe (the bedrock) in the eastern part of the study area. The phyllitequartzite nappe (which forms the oldest rock of the study area) lays on the northern part of Geropotamos basin. The local tectonic regime of the study area is characterized by faults of NW‐SE and NE‐SW directions. Investigation of the aquifer using Transient ElectroMagnetic method (TEM) and Vertical Electrical Resistivity (VES) measurement technique has resulted in 1D models and 2D/3D imaging of geoelectric structures, depicting the zones of salination of groundwater in the aquifer. 1179 TEM soundings in 372 sites have been carried out in a detailed survey grid (about 200m in X and Y dimension) and 3 VES soundings were acquired in three different sites (different geological conditions). For the 2 of them, multidirectional measurements were also acquired since the structure is more complex than a 1D model that VES technique is able to model. Moreover, 3 water samplings carried out. At each sampling, samples from 22 boreholes and 2 springs were analysed and 16 chemical parameters were determined. Detailed geochemical analysis, including Piper, Durov, Ternary, Stiff, Wilcox, Dispersion diagrams and Factors controlling the groundwater quality, was accomplished showing very good results and the relationship with the geophysical methods. All data were inserted in GIS environment and Groundwater Quality Maps were produced. Furthermore, Remote Sensing application, geological mapping and hydro‐lithological data showed that the physical characteristics of geomorphology and geology are in great relationship with the chemical and geophysical properties as well. Suggestions that Miocene evaporites led to groundwater salination are unconfirmed, and seawater intrusion is the most probable cause, supported by the results of this research. It is indicated that saline intrusion is likely to occur along fractures in a fault zone through otherwise low‐permeability phyllite‐quartzite bedrock, and it is emphasized the critical role of fracture pathways in salination problems of coastal aquifers

XXXV Congress of the International Association of Hydrogeologists, Groundwater and Ecosystems – Abstract Book

Resumos das comunicações do XXXV Congresso da Associação Internacional de Hidrogeólogos (IAH

Risk-Informed Sustainable Development in the Rural Tropics

Many people live in rural areas in tropical regions. Rural development is not merely a contribution to the growth of individual countries. It can be a way to reduce poverty and to increase access to water, health care, and education. Sustainable rural development can also help stop deforestation and reduce live-stock, which generate most of the greenhouse gas emissions. However, eorts to achieve a sustainable rural development are often thwarted by oods, drought, heat waves, and hurricanes, which local communities are not very prepared to tackle. Agricultural practices and local planning are still not very risk-informed. These deciencies are particularly acute in tropical regions, where many Least Developed Countries are located and where there is, however, great potential for rural development. This Special Issue contains 22 studies on best practices for risk awareness; on local risk reduction; on several cases of soil depletion, water pollution, and sustainable access to safe water; and on agronomy, earth sciences, ecology, economy, environmental engineering, geomatics, materials science, and spatial and regional planning in 12 tropical countries

Novel and Emerging Strategies for Sustainable Mine Tailings and Acid Mine Drainage Management

Renewable energy and clean storage technologies are at the forefront of the world’s fight against climate change, including the UN-led move towards a carbon-neutral society. Because these complex technologies require more ‘critical’ metals and elements than fossil fuel-based technologies, the demands for raw materials in their manufacturing are skyrocketing and are projected to continue to increase into the foreseeable future.With ore grades on a steep decline, huge amounts of low-grade ores will have to be mined and processed to satisfy the world’s current and future demands for ‘critical’ metals and elements. Expansion of mining and mineral processing operations would mean more mining-related wastes—tailings, waste rocks and acid mine drainage (AMD)—notorious for their devastating and long-term destructive impacts on the environment. This Special Issue explored repurposing/reprocessing of tailings and AMD treatment cost reduction as promising alternatives to manage mine wastes more sustainably. It also includes articles on the critical roles of redox conditions and galvanic interactions on mine waste stability, hydrogeochemical controls on waste rock weathering, and climate change impacts on AMD formation in closed mines