Geostatistical analysis of spatiotemporal variability of groundwater level fluctuations in Amman–Zarqa basin,Jordan: a case study

The main objective of this study was to assess the spatial and temporal variability of groundwater level fluctuations in the Amman–Zarqa basin, during the period 2001–2005. In the year 2003, as a consequence of war, there was a sudden increase in the population in this basin. Knowing that the basin is already heavily populated and witnesses most of the human and industrial activities in Jordan, this study was prompted to help make wise water resources management decisions to cope with the new situation. Data from 31 fairly distributed wells in the upper aquifer of the basin were subjected to geostatistical treatment. Kriging interpolation techniques have indicated that the groundwater flow directions remained almost constant over the years. The two main directions are SW–NE and E–W. Kriging mapped fluctuations have also showed that drop and rise events are localized in the basin. Forecasting possibilities for management purposes were tackled using autocorrelation analysis. The constructed autocorrelograms indicated, in general, the temporal dependence of seasonal water level fluctuations, and that forecasting can be carried out within a period of 3–21 months. Several suggestions were made to mitigate the drop and rise hazards in the detected sites.     

Imaging of sand lens at a barrage site in the Indian Himalaya — a case study using cross-hole seismic tomography

Drilling at the barrage site of a hydropower project usually gives a reasonable picture of the sub-surface rock mass condition. However, when the overburden (OB) comprising river borne materials is very thick and the basement rock is deep, the drilling results become unreliable. In the present case, the depth to the granitic gneiss basement is 45m from the river level and the height of the proposed diversion barrage is only 24.5 m. For this reason, stripping of the overburden up to the basement is not considered feasible. Cross-borehole seismic tomography (CST) was carried out at the barrage site to investigate the inclusions and structure of the OB material in order to facilitate a foundation design suitable for permeable formation. Three sets of CST surveys were carried out up to a depth of 30 m between the three vertical boreholes that were prepared at the vertices of an equilateral triangle with a separation of 17.8 m. The tomograms precisely imaged the nature and disposition of the different constituents of the overburden material. A lens shaped low velocity layer (LVL) with seismic velocity V_p=2000–2500 ms^?1 was mapped at a depth of 14.5m from the surface. Hence, it was recommended to shift the barrage axis by 50 m towards the downstream side of the proposed axis. The outcome of this study proved valuable for the designer who finalised the foundation design. Successful application of CST in OB characterisation has reiterated the need of such studies for barrage site investigations particularly in the Himalayan terrain.     

Geochemistry of gas emanations: A case study of the Réunion Hot Spot,Indian Ocean

The results of analysis of natural emanations in Réunion Island show a clear magmatic origin for CO₂ and He, while N₂ and Ar are predominantly derived from the atmosphere. The distribution of magmatic gases in the Piton des Neiges massif fits the local volcanotectonic context well and suggests that the areas concerned are still subject to volcanic activity at depth. A simple method is proposed for correcting gas concentration and isotope composition for water degassing. In doing so, the isotope and elemental (C, He) composition of gases is homogeneous for the two volcanoes. The isotope ratio of He (12.5 ± 0.5R/Ra) in the present discharges is in agreement with the results of previous studies on rocks of various ages from the two volcanoes. The isotope ratio of C(δ¹³C= −5 ‰ to −4 ‰ vs PDB) and the C/³ He ratio (∼4 × 10⁹) are similar to those found in other Hot Spot volcanic systems such as Kilauea (Hawaii) and Hengill (Iceland). These similarities suggest comparable volatile history for the respective mantle sources, the main differences being in the relative proportions of radiogenic ⁴He. In detail, Hot Spots appear enriched in C having a light composition with respect to MORB, possibly due to the addition of a C-rich (e.g. subducted) component, in addition to a relatively undegassed, ³He-rich, component.     

Assessing macroeconomic recovery after a natural hazard based on ARIMA—a case study of the 2008 Wenchuan earthquake in China

In this research the autoregressive integrated moving average model (ARIMA) was adopted to estimate GDP growth for assessing macroeconomic recovery from a natural hazard. ARIMA is a powerful tool for predicting future macroeconomic situations based on macroeconomic data and trends before a disaster. This research examined the economic recovery of severely affected counties 6 years after the Wenchuan Earthquake by comparing the simulated regional GDP values from 2008 to 2014 with actual regional GDP data following the disaster. A macroeconomic recovery ratio model was built to assess economic resilience of the affected counties. Although the GDP of the 10 most severely affected counties grew rapidly after the earthquake, in only one county—Pengzhou City—it recovered to the pre-disaster level under a no hazard scenario. The gaps in economic recovery between the severely affected counties were significant. Areas with competitive industries and locational advantage exhibited the highest rates of recovery. Therefore, industrial structure and relative location of the affected areas to traffic nodes and economic centers should be considered in pre-disaster assistance decisions and development plans in the future.     

Analysis of urban growth using Landsat TM/ETM data and GIS—a case study of Hyderabad, India

Hyderabad is one of the fastest growing mega cities in India and it is facing many economic, social and environmental problems due to rapid urban growth. For the better planning of resources and to provide basic amenities to its residents, it is necessary to have sufficient knowledge about its urban growth activities. Also, it is necessary to monitor the changes in land use over time and to detect growth activities in different parts of the city. To accomplish these tasks with greater accuracy and easiest way, remote sensing and geographic information system (GIS) tools proved to be very advantageous. This study makes an attempt towards the mapping of land use classes for different time periods and analysis of apparent changes in land use using the Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper (ETM) data for the urban agglomeration of Hyderabad, India. In this study, three different time periods viz. 1989–2000, 2000–2005 and 2005–2011 are chosen for the analysis. The results have shown that high-density urban area had grown during 1989–2011 by encroaching into other land use classes. The urban growth has also affected water resources both, qualitatively and quantitatively in the region. The transformation of other land use types into urban area dynamically continued in the North-East and Southern parts of the city. In the North-East direction, the urban growth was mostly due to growth in industrial and residential area and in Southern part, mostly due to residential growth.     

Spatial distribution of soil shear-wave velocity and the fundamental period of vibration – a case study of the Saguenay region,Canada

The spatial distribution of soil shear-wave velocity and the fundamental period of vibration were selected as input parameters for the determination of potential seismic site effects in the Saguenay region, Canada. The methodology used in this study involved three clear steps. First, a 3D geological model of the surficial deposits was built taking into consideration the type, spatial distribution and thickness of the deposits. Second, representative average V_s values were determined for each of the major soil units. Finally, the average shear-wave velocity from the ground surface to bedrock (V_sav), the shear-wave velocity of the upper 30 m (V_s30) and the fundamental site resonance period (T₀) were calculated over a regular grid for the study area. The results include the spatial distribution of the fundamental site resonance period, the average shear-wave velocity in the first 30 m of the ground and the spatial distribution of National Building Code of Canada seismic soil classes for the Saguenay region.     

Geobotany of red sanders (Pterocarpus santalinus) – a case study from the southeastern portion of Andhra Pradesh

 RedSanders in their natural distribution occur almost exclusively in quartzites and shales. This indicates the geobotanical response to these rock types in the semi-arid tract of the southeastern portion of Andhra Pradesh in the tropical dry deciduous forests of Chittoor, Cuddapah and Nellore districts. Thus Red Sanders are important from a commercial point of view and also a useful tool to demarcate stratigraphic formations. Received: 27 April 1998 · Accepted: 21 July 1998     

Mapping areas of potential slope failures in cohesive soils using a shadow-casting algorithm – A case study from SW Sweden

When performing landslide susceptibility mapping of rotational slides in fine grained soils, slope algorithms found in common GIS software have two major shortcomings. Firstly, these types of terrain algorithms only consider the slope angle at the surface. Secondly, the algorithm is local by its design i.e. it only considers neighbouring pixels. Due to the behaviour of a retrogressive rotational landslide, it would be more preferable to consider slope information as a predetermined cross-section angle from the base of the slope. This paper presents a new method using shadow casting algorithms for preliminary landslide susceptibility mapping in cohesive soils. A case study from western Sweden is also presented.     

Assessing the ‘wicked problems’ associated with the quality of groundwater used in irrigation: a case study from the North China Plain

Studies on the quality of groundwater have moved beyond the physical realm of contamination and purification, towards the economic concerns of choice and the management of the problem. With these approaches the complex biophysical processes are assessed from the users’ perspective and the policy outcomes that could be used to resolve the problems of groundwater contamination are evaluated. However, in a set of unrelated studies, it has been found that attempts by governments to resolve the problems of groundwater contamination in agriculture have a poor record of success. This could be because the problem is too extensive and diverse to handle or it could be a case of poor policy selection. Taking an example from the North China Plain to illustrate some of the major issues raised in this study, it is concluded that the problem itself is unresolvable on a large scale. In other words, groundwater contamination can be defined as a ‘wicked problem’, i.e. unresolvable by applying pure science, closely linked with social issues, and for which there are no optimal solutions. In this situation, the best solution is possibly to encourage farmers to live with and handle the problem as they best see fit.     

Teaching GIS in the Gulf Co-operation Council Universities – With a case study of the geography department, University of the United Arab Emirates

Within universities there has developed a clear theoretical convergence between Geographical Information Systems (GIS) and geography (Antenuccl, 1991). Studies have revealed that one of the qualified departments to teach GIS within universities is the geography department. This study focuses on: the importance of establishing GIS as a major curriculum element within universities. In geography departments, economic geography students require a strong statistical/mathematical background to allow them to work with major databases. They should know how to design a specific database for economic activities, such as agriculture and manufacturing, and tertiary industry and how to relate this database to a map, so that changes can be monitored more accurately. In any aspect of geography spatial location is a key factor and GIS allows spatial patterns to be interpreted with great facility. Therefore it is important that students have a good knowledge not only of computers and related software on economic geography, but also on GIS systems (Burrough, 1993). The work of geography students from the United Arab Emirates (UAE) and other Gulf Co-operation Council (GCC) geography departments is examined to evaluate the importance of training in GIS technology. This paper evaluates the effects of implementing GIS as a tool in teaching economic geography. At present there are 15 geography departments in the GCC which offer economic geography. Of those 15 departments, only 3 provide GIS courses within their curriculum, and 4 have basic equipment, although 6 additional departments are to introduce GIS in the near future. This revised version was published online in July 2006 with corrections to the Cover Date.     

The study of land desertification in transitional zones between the MU US Desert and the Loess Plateau using RS and GIS—a case study of the Yulin region

In this study, the land desertification of transitional zones of desert loess in the Yulin region (China) is studied from TM images in a geographical information system (GIS). It is found that the desertification in Yulin is still severe. The desertified land accounts for 67.7% of the total land areas. The distribution of desertified land shows obvious spatial imbalance, with severe desertification in northwestern regions and slight desertification in southeastern regions. This imbalance is related to the difference in physical factors and land-use pattern. The process of desertification in Yulin areas shows a steady and even reversed trend between 1987 and 1999, as a result of positive efforts. At the end of the paper the cause of desertification is discussed. It is believed that the interaction and confliction between the natural process and human activities may lead to the development of desertification.     

Landslide susceptibility using weights-of-evidence approach and multi-source data in Longzhong ecologically vulnerable area：a case study of Tianshui City北大核心CSCD

Analysis and assessment of landslide susceptibility using 3S technology and mathematical statistical model is still the current hot topics. It is very important for selection of unit and factor and model to the landslide susceptibility assessment reasonably. Tianshui City is selected as the study area which is in the typical regions of Longzhong ecologically vulnerable area. Based on the weights-of-evidence approach（WOE）and two kinds of assessment units（grid-unit,GU,slope-unit,SU）and also two resolutions（30 m,10 m）,a total of four differ⁃ ent data sets（GU30,SU30,GU10,SU10）is established. Then quantitative analysis and contrast assessment di⁃ vision of the loess landslide susceptibility in the study area though selected four kinds of thirteen factors. The re⁃ sults show that stratum lithology,altitude,relief amplitude,roughness and slope are the key control factors of landslide development in the area. The geological factors and topographic factors control and determine the for⁃ mation and development of the landslides in study area. The susceptibility value of stratum lithology is the high⁃ est value. Statistical analysis of susceptibility division is carried out according to the point and area of landslide respectively. The landslide ratio shows that the division based on the slope-unit is higher than that of the grid-unit. Landslide susceptibility area in highest division based on the slope-unit and 10m high resolution is account⁃ ed for the highest. Therefore,it has higher precision in landslide susceptibility analysis and assessment that us⁃ ing the slope-unit and high resolution data. The landslide susceptibility result is consistent with the actual land⁃ slide development in the study area. The division results can also be used for the landslide prevention and control and national spatial planning in the study area. © 2023 Chinese Journal of General Practitioners. All rights reserved.     

Landfill site selection based on reliability concepts using the DRASTIC method and AHP integrated with GIS – a case study of Bengaluru city,India

The selection of landfill sites for municipal solid waste (MSW) disposal involves consideration of geological, hydrological and environmental parameters which exhibit large spatial variability. Therefore, it is necessary to define, to what extent the chosen sites are reliable such that the probability of environmental pollution and health risks to population is minimal. In the present study, groundwater vulnerability to contamination has been assessed using the standard DRASTIC method. The results showed that the study region has 9.45% of very less, 32.94% of less, 25.47% of moderate, 22.79% of high and 9.35% of very high vulnerable zones. The study also revealed that none of the landfills are located in safe zones. This suggests that it requires proper remedial measures to avoid environmental pollution. A landfill site selection process has been carried out using the Analytical Hierarchy Process integrated with Geographical Information System tools. The obtained results showed that only 3.59?km² (0.08%) of the total area is suitable for landfills. The reliability analysis of the site suitability revealed that landfills are located at unreliable locations where the probability of risk to environmental pollution is high. The presented approach assists decision-makers in selecting reliable locations for the safe disposal of MSW.     

Impact of agricultural activity and geologic controls on groundwater quality of the alluvial aquifer of the Guadalquivir River (province of Jaén,Spain): a case study

The alluvial aquifer of the Alto Guadalquivir River is one of the most important shallow aquifers in Jaén, Spain. It is located in the central-eastern part of the province, and its groundwater resources are used mainly for crop irrigation in an agriculture-dominated area. Hydrochemical and water-quality data obtained through a 2-year sampling (2004–2006) and analysis program indicate that nitrate pollution is a serious problem affecting groundwater due to the use of nitrogen (N)-fertilizers in agriculture. During the study, 231 water samples were collected from wells and springs to determine water chemistry and the extent of nitrate pollution. The concentration of nitrate in groundwater ranged from 1.25 to 320.88 mg/l. Considerable seasonal fluctuations in groundwater quality were observed as a consequence of agricultural practices and other factors such as annual rainfall distribution and the Guadalquivir River flow regime. The chemical composition of the water is not only influenced by agricultural practices, but also by interaction with the alluvial sediments. The dissolution of evaporites accounts for part of the Na⁺, K⁺, Cl⁻, SO₄ ²⁻, Mg²⁺, and Ca²⁺, but other processes, such as calcite precipitation and dedolomitization, also contribute to groundwater chemistry.     

Analysis of influence of natural disaster on the economy and prediction of recovery time based on grey forecasting–difference comparison model: a case study in the upper Min River

Natural Hazards - After the 2008 Wenchuan earthquake, secondary geological disasters occurred frequently and caused huge economic losses in the upper reaches of Min River. In this paper,...     

Numerical simulation of groundwater under complex karst conditions and the prediction of roadway gushing in a coal mine: a case study in the Guang’an Longtan Reservoir in Sichuan Province,China

Numerical simulation of groundwater in karst areas has long been restricted by the difficulty of generalizing the hydrogeological conditions of reservoirs and of determining the relevant parameters due to the anisotropy and discontinuity of the karst water-bearing media in these areas. In this study, we used the Guang’an Longtan Coal mine in Sichuan as an example, and generalized the complex hydrogeological conditions in the reservoir area. A finite element numerical flow model was used to simulate current and future scenarios of roadway gushing at the bottom of the coal mine at pile number 1 + 700 m. The results show that the roadway section corresponding to valleys has a gushing quantity of 4323.8–4551.25 m³/d before impoundment. Modeled water inflow after impoundment increased to 1.6 times the water inflow before impoundment, which threatens the impoundment as well as the roadway’s normal operation. Therefore, roadway processing measures are needed to guarantee the safety of the impoundment and of the mining operation.     

Application of cathodoluminescence to magmatic quartz in a tin granite – case study from the Schellerhau Granite Complex, Eastern Erzgebirge, Germany

A model of the cooling history of tin-bearing granitic magma forming the Schellerhau granites (Eastern Erzgebirge, Germany) is shown on the basis of quartz textures. Similar grain size, similar grain habit and correlatable growth textures of phenocrysts in different granite varieties give proof of a common crystallization history before the melts of the Schellerhau granite varieties were intruded. Four nucleation events occurred during crystallization in different crustal levels between about 20 and 1 km depth. The parental melt of the Schellerhau granites is interpreted to have contained<2.5 wt% H₂O originally. The water content of the melt during the subvolcanic intrusion stage amounted to more than 5 wt% and characterizes highly evolved residual melts that enable the formation of tin deposits. This study contributes to a better understanding of the development and behaviour of fractionated tin-bearing granitic melts, and links quartz cathodoluminescence (CL) with microanalytical studies. Received: 28 October 1998 / Accepted: 18 August 1999