排序方式： 共有47条查询结果，搜索用时 884 毫秒
21.
Farooq Ahmad Dar Jerome Perrin Shakeel Ahmed Allu China Narayana 《Hydrogeology Journal》2014,22(7):1493-1506
About 3 % of India’s total land surface is occupied by carbonate rocks which are mostly karstified and constitute a significant source of groundwater. The groundwater drawn from these aquifers matches the water demand of ~35 million people living in 106 districts of the country and also the water needs of livestock, irrigation and industry. The studies on karst in India carried out so far have mostly addressed geology, hydrology and groundwater contamination. A literature survey suggests that there is a need for detailed research, applying new approaches and techniques for proper carbonate aquifer identification, characterization and management. Such specific approaches will improve modeling, exploitation and protection of karst groundwater. An overview of the research carried out on groundwater resources of karst formations in India is presented, which also throws light on the protection of karst aquifers from existing anthropogenic activities such as mining and groundwater over-exploitation. 相似文献
22.
Temporal variations in arsenic concentration in the groundwater of Murshidabad District,West Bengal,India 总被引：1，自引：0，他引：1
S. H. Farooq D. Chandrasekharam S. Norra Z. Berner E. Eiche P. Thambidurai D. Stüben 《Environmental Earth Sciences》2011,62(2):223-232
Systematic investigations on seasonal variations in arsenic (As) concentrations in groundwater in both space and time are
scarce for most parts of West Bengal (India). Hence, this study has been undertaken to investigate the extent of As pollution
and its temporal variability in parts of Murshidabad district (West Bengal, India). Water samples from 35 wells were collected
during pre-monsoon, monsoon and post-monsoon seasons and analyzed for various elements. Based on the Indian permissible limit
for As (50 μg/L) in the drinking water, water samples were classified into contaminated and uncontaminated category. 18 wells
were reported as uncontaminated (on average 12 μg/L As) and 12 wells were found contaminated (129 μg/L As) throughout the
year, while 5 wells could be classified as either contaminated or uncontaminated depending on when they were sampled. Although
the number of wells that alternate between the contaminated and uncontaminated classification is relatively small (14%), distinct
seasonal variation in As concentrations occur in all wells. This suggests that investigations conducted within the study area
for the purpose of assessing the health risk posed by As in groundwater should not rely on a single round of water samples.
In comparison to other areas, As is mainly released to the groundwater due to reductive dissolution of Fe-oxyhydroxides, a
process, which is probably enhanced by anthropogenic input of organic carbon. The seasonal variation in As concentrations
appear to be caused mainly by dilution effects during monsoon and post-monsoon. The relatively high concentrations of Mn (mean
0.9 mg/L), well above the WHO limit (0.4 mg/L), also cause great concern and necessitate further investigations. 相似文献
23.
D. Purushotham Mehnaz Rashid Mahjoor Ahmad Lone A. Narsing Rao Shakeel Ahmed E. Nagaiah Farooq A. Dar 《Journal of the Geological Society of India》2013,81(3):385-396
Anthropogenic activities in Maheshwaram watershed have deteriorated water, air and soil quality during the last ten years due to rapid urbanisation and industrial development. Maheshwaram watershed experienced drastic changes in land use pattern, being very close to the Hyderabad city. Base-line data was collected during post monsoon season (October-November) of 2010 in Maheshwaram watershed to assess the impacts of change in land use, urbanisation and industrialisation on air, water and soil quality for Environmental Impact Assessment (EIA). Air samples were analysed for Suspended Particulate Matter (SPM) and Respirable Suspended Particulate Matter (RSPM). Groundwater samples were analysed for pH; EC; TDS; TH; cations, anions and heavy metals viz., Fe, Mn, Al, Si, V, Cr, As, Sr, Rb, Se, Ba, Li, B, Be, Co, Ni, Zn, Cd, and Pb using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Analysed data were compared with the National and International Standards and subjected to Factor Analysis (FA) for six chemical variables to assess and characterise hydro-chemical processes. A comparison of the results of groundwater samples with WHO and BIS guidelines show that most of the groundwater samples are heavily contaminated with heavy metals like lead, chromium, nickel, barium, aluminium, boron and selenium, which was quantified and presented in the form of spatial variation diagrams prepared using ArcGIS. 9.3.1. Similarly the results of air samples compared with the Central Pollution Control Board, Ministry of Environment and Forests, Government of India guidelines show that most of the air samples for residential, rural and industrial areas are contaminated by SPM and RSPM. 相似文献
24.
Sami Ullah Muhammad Shafique Muhammad Farooq Muhammad Zeeshan Matthias Dees 《Arabian Journal of Geosciences》2017,10(3):67
Satellite images of various spatial resolutions and different image classification techniques have been utilized for land cover (LC) mapping at local and regional scale studies. Mapping capabilities and achievable accuracies of LC classification in a mountain environment are, however, influenced by the spatial resolution of the utilized images and applied classification techniques. Hence, developing and characterizing regionally optimized methods are essential for the planning and monitoring of natural resources. In this study, the potential of four non-parametric image classification techniques, i.e., k-nearest neighbor (k-NN), support vector machine (SVM), random forest (RF), and neural network (NN) on the accuracy of LC classification was evaluated in the Hindu Kush mountains ranges of northern Pakistan. Moreover, we have assessed the impact of the spatial resolution of the utilized satellite imagery, i.e., SPOT-5 with 2.5 m and Landsat-8 with 30 m on the accuracy of the derived LC classification. For the classification of LC based on SPOT-5, we have achieved the highest overall classification accuracy (OCA) = 89% with kappa coefficient (KC = 0.86) using SVM followed by k-NN, RF, and NN. However, for LC classification derived from Landsat-8 imagery, we achieved the highest OCA = 71% with KC = 0.59 using RF and SVM followed by k-NN and NN. The higher accuracy derived from SPOT-5 versus Landsat-8 indicated that the results of LC classification based on SPOT-5 are more accurate and reliable than Landsat-8. The findings of the present study will be useful for the classification and mapping task of LC in a mountain environment using SPOT-5 and Landsat-8 at local and regional scale studies. 相似文献
25.
A study has been conducted in the heavily populated coastal areas of the Puri district (Odisha, India) with the aim to: (1) identify the factors that influence the major ion composition and concentrations of trace elements in groundwater; (2) determine the spatial distribution of the water-quality parameters and how they vary on a seasonal basis. To do this, groundwater samples were collected from 60 shallow tube wells located along the Puri coast during the pre-monsoon and post-monsoon seasons. Based on their TDS content, 52% of the collected groundwater samples were identified as being brackish-to-saline and unsuitable for drinking purposes in both the pre- and post-monsoon seasons. Significant concentrations of trace elements including Ba, Br, F, Fe, Mn, and Sr were detected in most of the samples. Iron concentrations were found to be higher than the WHO drinking water guideline value (0.3 mg/l) in 92% of the samples irrespective of seasons. Elevated Mn concentrations were observed in 37% and 40% of samples during the pre-monsoon and post-monsoon seasons, respectively. In addition, fluoride concentrations in excess of the WHO limit (1.5 mg/l) were found in 15% of samples during the pre-monsoon and 23% of samples during the post-monsoon season. The concentrations of major and trace elements show wide spatial and minor temporal variations. Large spatial and limited temporal variations in Cl and Na concentrations along with considerable Br and Sr concentrations in groundwater suggest that saltwater intrusion is the dominant process controlling groundwater quality in the study area, although other processes including ion exchange, the precipitation and dissolution of minerals, microbial activity, and the weathering of aquifer material also play roles to some extent in determining the spatial and seasonal distribution of the major and trace elements in coastal groundwater. Grouping of various water-quality parameters related to these processes by principal component analysis and their linking to one cluster in the hierarchical cluster analysis further supports the view that these processes control the groundwater chemistry in the coastal aquifer. 相似文献
26.
Aamir Shahzad Hamza Farooq Gabriel Sajjad Haider Ammara Mubeen Muhammad Junaid Siddiqui 《Arabian Journal of Geosciences》2018,11(14):383
Development of a well-calibrated, distributed hydrological model for flood forecasting based on rainfall and snowmelt is quite challenging, especially when in situ data is limited or unavailable. This paper presents the study carried out to parameterise the Integrated Flood Analysis System (IFAS) model for the trans-boundary, scarcely gauged catchments of Jhelum and Chenab rivers in Pakistan. Rainfall-runoff analysis was performed with a two-layered tank configuration, integrating snowmelt and dam and barrage operation from the very upstream in India to Trimmu Barrage in Pakistan. A grid size of 5?×?5 km was considered. Global map topography, land cover and soil data was utilised. The model was tested considering different magnitudes of floods of the years 2014, 2015 and 2017. The results showed that the satellite rainfall product, i.e. Global Satellite Mapping of Precipitation (GSMaP-NRT), underestimated the rainfall volume, compared to the ground-gauged rainfall. The GSMaP-IF correction method showed poor performance owing to the lack of ground observatory rainfall data for correcting the trans-boundary part of the basin. The GSMaP-Type1 correction method showed good results, except for the confluence point where complex flow conditions were not properly reproduced by the model. In addition, the incorporation of dam and barrages in the model improved the simulated flow results. It is concluded that the satellite rainfall estimates must be corrected to improve the results. Snowmelt module estimated the snowmelt contribution as 3 to 7% and 4 to 23% of the average daily discharge during the monsoon season at Mangla Dam and Marala Barrage, respectively, during 2014 and 2015. This study assessed various correction methods and concluded that the model and methodology used in the study functioned well with suitable precipitation. 相似文献
27.
Muhammad Zia ur Rehman Muhammad Rizwan Shafaqat Ali Muhammad Irfan Sohail Amjad Hussain Muhammad Farooq Qayyum Hinnan Khalid Muhammad Zeeshan Naveeda Majid 《Arabian Journal of Geosciences》2018,11(21):685
Biochar is considered a promising amendment for the reduction of metal concentration in plants; however, the effects of biochar in terms of dose and feedstock on metal uptake by plants remain widely unclear. In the current study, three individual biochars were prepared at 450 °C from different feedstocks (wheat straw, sukh chain (Pongamia pinnata), and cotton sticks). The main aim was to evaluate their ability to remediate cadmium (Cd)-spiked soil in terms of growth response and Cd uptake by wheat (Triticum aestivum) tissues. Biochars were separately applied at 0, 1, and 2% (w/w) in Cd-spiked soil and wheat was grown until maturity in pots and then morphological and physiological parameters and Cd concentrations in grains, roots, and shoots were determined. The post-harvest soil was analyzed for extractable Cd concentrations. Plants grown in Cd-spiked soil treated with biochars had higher seed germination, lengths of roots, shoots, and spikes, grains per spike and leaf relative water contents, chlorophyll contents, and dry weight of roots, shoots, and grains as compared to the untreated control. Biochar treatments significantly decreased the Cd concentrations in shoots, roots, and grains as well as total Cd uptake by grains. Soil extractable Cd concentrations were significantly decreased with biochar treatments. The application of 2.0% wheat straw biochar was the most efficient treatment in increasing grain yield and decreasing Cd in grains as well as soil extractable Cd than the other two biochars and doses applied. 相似文献
28.
Urban sprawl development around Aligarh city: A study aided by satellite remote sensing and GIS 总被引：2，自引：0，他引：2
Rapid urbanization causes disorganized and unplanned growth of towns and cities. The pressure of an ever growing population
becomes a burden on the limited civic amenities which are virtually collapsing. Asymmetrical growth of urban centres consumes
agricultural land adjacent to these, resulting in lower agricultural productivity. Besides taxing the groundwater resources
available for an urban centre, an increase in the paved area severely reduces the groundwater recharge potential, leading
to situations which may truly be potential catastrophes. An understanding of the growth dynamics of urban agglomerations is
essential for ecologically feasible developmental planning. With almost a third of India’s population already having become
urban, it is necessary to acquire information on growth patterns of cities and how they impact the living environment. The
current trend of spatial urban growth in almost all Indian cities has a haphazard pattern, particularly along the urban-rural
fringe. There is an obvious need for continuously monitoring the phenomena of growth, and mapping and analyzing its patterns,
since this is of great concern to urban administrators and planners whose concern it is to provide basic amenities and infrastructure
for the complex urban environment.
Mapping urban growth by conventional methods is too tedious and a slow process, and by the time information becomes available
to planners, it is already outdated and redundant since the damage has already been done. Satellite remote sensing data and
application of GIS technologies provide an alter-native means of rapidly assessing the dynamics and development of sprawl
so that timely action may be taken. Besides being flexible and extensible, the datasets are easily rectified, updated and
may be used for other applications. 相似文献
29.
Farhan Ali Khalid Farooq Hasan Mujtaba Ahmad Riaz Ehsan Ulhaq 《Journal of the Geological Society of India》2016,88(6):718-724
On August 10, 2010 a series of landslides of more than 90,000 m3 occurred along the Muree-Kohala road in the northern area of Pakistan. A study was undertaken to evaluate the likely impacts of percent saturation and bulk density on mobilized shear strength along the basal rupture surface of the landslide. A series of unconfined compression test and unconsolidated undrained triaxial tests were performed on remolded samples of different densities with varied percentages of saturation. The results of these tests suggest that soil cohesion and friction decreases with increasing saturation. The tests also showed that the shear strength parameters tend to increase with increasing dry density; however, all the samples exhibited a noticeable loss of shear strength with increasing degree of saturation, independent of soil density.Limit equilibrium slope stability analyses were performed along the most probable failure planes, based on shear strength parameters corresponding to degrees of saturation, which varied between 30% to about 100%. This resulted in drop of factor of safety from FS = 1.64 down to 0.51 as the degree of saturation approaches unity.These results suggest that the causative factor in triggering the landslide along Murree-Kohala was the partial saturation of the zone that developed the basal rupture plane. As rain infiltrated the slope, the bulk unit weight of the soil increased, while the shear strength along the developing plane of rupture decreased sufficiently to concentrate shear strain when the material became more than 60% saturation (FS < 1.0). 相似文献
30.