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Sushma Walia Sarbjit Singh Dikesh Chandra Loshali Richa Babbar 《Arabian Journal of Geosciences》2018,11(11):276
In this paper, the hypsometric curves and integrals of four neighboring micro-watersheds draining into Patiala-Ki-Rao stream which is situated in the Shivalik foothills of district SAS Nagar in the Punjab state (India) has been presented to access and compare the erosion regimes under different management practices. Area-elevation ratio method has been used to compute hypsometric curve and integral values for each micro-watershed through ArcGIS 10.3 and Microsoft Excel. The 9-year data of runoff and sediment yield for all these micro-watersheds under different management practices has been analyzed for their effect on land cover and soil quality. Thus, the results of present study are very useful for comparing, planning, implementing, and controlling soil erosion in similar watersheds. 相似文献
2.
V J Loveson A R Gujar R Barnwal Richa Khare G V Rajamanickam 《Journal of Earth System Science》2014,123(6):1375-1385
In this study, results of GPR profiling related to mapping of subsurface sedimentary layers at tsunami affected Karaikal beach are presented . A 400 MHz antenna was used for profiling along 262 m stretch of transect from beach to backshore areas with penetration of about 2.0 m depth (50 ns two-way travel time). The velocity analysis was carried out to estimate the depth information along the GPR profile. Based on the significant changes in the reflection amplitude, three different zones are marked and the upper zone is noticed with less moisture compared to other two (saturated) zones. The water table is noticed to vary from 0.5 to 0.75 m depth (12–15 ns) as moving away from the coastline. Buried erosional surface is observed at 1.5 m depth (40–42 ns), which represents the limit up to which the extreme event acted upon. In other words, it is the depth to which the tsunami sediments have been piled up to about 1.5 m thickness. Three field test pits were made along the transect and sedimentary sequences were recorded. The sand layers, especially, heavy mineral layers, recorded in the test pits indicate a positive correlation with the amplitude and velocity changes in the GPR profile. Such interpretation seems to be difficult in the middle zone due to its water saturation condition. But it is fairly clear in the lower zone located just below the erosional surface where the strata is comparatively more compact. The inferences from the GPR profile thus provide a lucid insight to the subsurface sediment sequences of the tsunami sediments in the Karaikal beach. 相似文献
3.
Power spectra of cosmic ray intensity variations at the ground and atmospheric pressure oscillations
M. S. Dhanju 《Planetary and Space Science》1970,18(12):1719-1728
Power spectrum estimates are computed for cosmic ray and pressure variations in the frequency range of 1.6 × 10−6 to 4.15 × 10−3 c/sec for three data sets each of 27 days length (2 min interval) recorded at Chacaltaya (Bolivia) during 1965–1966. The general trend of these spectra showy ƒ− fit having exponent values from −1.5 to −1.9 for L.F. side. From the semi-diurnal peaks both in cosmic rays and pressure, the average value of pressure coefficient is found to be 0.3 per cent/mm of Hg. For the same three sets of data, a detailed analysis of cross-spectrum, coherence and phase relationship between cosmic rays and pressure is carried out in the frequency range of 1–12 c/day. Besides semi-diurnal peak, variations of 3, 4, 7 and 8 c/day are found to be common both in cosmic rays and pressure. The value of pressure coefficient and residual amplitude of cosmic rays for these particular frequencies are calculated. 相似文献
4.
Urbanization is increasingly becoming a widespread phenomenon at all scales of development around the globe. Be it developing or developed nations, all are witnessing urbanization at very high pace. In order to study its impacts, various methodologies and techniques are being implemented to measure growth of urban extents over spatial and temporal domains. But urbanization being a very dynamic phenomenon has been facing ambiguities regarding methods to study its dynamism. This paper aims at quantifying urban expansion in Delhi, the capital city of India. The process has been studied using urban land cover pattern derived from Landsat TM/ETM satellite data for two decades (1998–2011). These maps show that built-up increased by 417 ha in first time period (1998–2003) and 6,633 ha during next period (2003–2011) of study. For quantification of metrics for urban expansion, the Urban Landscape Analysis Tool (ULAT) was employed. Land cover mapping was done with accuracy of 92.67 %, 93.3 % and 96 % respectively for years 1998, 2003 and 2011. Three major land covers classes mapped are; (i) built-up, (ii) water and (iii) other or non-built-up. The maps were then utilized to extract degree of urbanization based on spatial density of built-up area consisting of seven classes, (i) Urban built-up, (ii) Suburban built-up,(iii) Rural built-up, (iv) Urbanized open land, (v) Captured open land, (vi) Rural open land and (vii) Water. These classes were demarcated based on the urbanness of cells. Similarly urban footprint maps were generated. The two time maps were compared to qualitatively and quantitatively capture the dynamics of urban expansion in the city. Along with urbanized area and urban footprint maps, the new development areas during the study time periods were also identified. The new development areas consisted of three major categories of developments, (i) infill, (ii) extension and (iii) leapfrog. 相似文献
5.
Our study examines the relationships among various environmental variables in Surat city using remote sensing. Landsat Thematic Mapper satellite data were used in conjugation with geospatial techniques to study urbanization and correlation among satellite-derived biophysical parameters namely, normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI), normalized difference water index (NDWI), normalized difference bareness index (NDBaI) and land surface temperature (LST). A modified NDWI (MNDWI) was used for extracting areas under water. Land use/land cover classification was performed using hierarchical decision tree classification technique using ERDAS IMAGINE Expert classifier with an accuracy of 90.4% for 1990 and 85% for 2009. It was found that city has expanded over 42.75 sq.km within two decades. Built-up, fallow and sediment land use classes exhibited high dynamics with increase of nearly 200% and 50% and decrease of 55% respectively from 1990 to 2009. Vegetation and water classes were less dynamic with 20% decrease and 15% increase. The transformation of land parcels from vegetation to built-up, vegetation to fallow and fallow to built-up has resulted in increase of LST by 5.5 ± 2.6°C, 6.7 ± 3°C and 3.5 ± 2.9°C, respectively. 相似文献
6.
This paper examines a Rajasthan (India) drinking water supply project that relied on hybrid governance reforms in its original design. Decentralization and marketization, combined with a participatory approach, were intended to facilitate an empowering shift in state-citizen relationships. Paying citizens were expected to make quantity and quality demands of the state as consumers, not welfare beneficiaries. Research on the project 3 years after its completion revealed that although payment for water and community participation were intended to compel the state to provide clean water, they failed in this regard. The problem of an unreliable state supply was solved through small scale privatization, a decision ‘independently’ reached at the local scale, but one that served to further undermine the state’s ability to provide clean water.In this paper, we trace the shifts in regulation that evolved in the post-project phase at both the state and village scale that resulted in the delivery of contaminated water. Ethnographic research indicates that community participation was introduced as a set of institutions that would govern how villagers interacted with the state and its water supply, but villagers altered community participation by introducing reforms in water governance as a way of coping with an unresponsive state and increased work burden. Community participation evolved in contradictory ways as the impacts of neoliberal environmental governance were felt. The paper contributes to understandings of neoliberalization processes’ local impacts by analyzing their ongoing hybridization at multiple scales. It further calls into question foundational notions that community participation in resource governance is the appropriate solution to drinking water supply. 相似文献
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8.
B.K. Rastogi H.K. Gupta Prantik Mandal H.V.S. Satyanarayana M. Kousalya R. Raghavan Richa Jain A.N.S. Sarma N. Kumar C. Satyamurty 《Journal of Seismology》2001,5(4):609-615
A large destructive earthquake occurred on 26 January 2001 in the region of Kutch, Gujarat, in Western India, with magnitude Mw 7.7. The earthquake caused very heavy damage and a large number of casualties with more than 20,000 deaths. A preliminary study of ground deformation, damage pattern and aftershock distribution is presented. 相似文献
9.
Richa?JainEmail author B. K.?Rastogi V. P.?Dimri 《Pure and Applied Geophysics》2003,160(12):2329-2341
The Aftershock sequence of Chamoli earthquake (M
w 6.4) of 29 March 1999 is analyzed to study the fractal structure in space, time and magnitude distribution. The b value is found to be 0.63 less than which is usually observed worldwide and in the Himalayas. This indicates that the numbers of smaller earthquakes are relatively less than the larger ones. The spatial correlation is 1.64, indicating that events are approaching a two-dimensional region meaning that the aftershocks are uniformly distributed along the trend of the aftershock zone. Temporal correlation is 0.86 for aftershocks of M 1, indicating a nearly continuous aftershock activity. However, it is 0.5 for aftershocks of M 1.75, indicating a non continuous aftershock activity. From the assessment of slip on different faults it is inferred that 70% displacement is accommodated on the primary fault and the remainder on secondary faults. 相似文献
10.
This paper demonstrates the application of data mining techniques to predict river water quality index. The usefulness of these techniques lies in the automated extraction of novel knowledge from the data to improve decision-making. The popular classification techniques, namely k-nearest neighbor, decision trees, Naive Bayes, artificial neural networks, rule-based and support vector machines were used to develop the predictive environment to classify water quality into understandable terms based on the Overall Index of Pollution. Experimentation was conducted on two types of data sets: synthetic and real. A repeated k-fold cross-validation procedure was followed to design the learning and testing frameworks of the predictive environment. Based on the validation results, it was found that the error rate in defining the true water quality class was 20 and 28%, 11 and 24%, 1 and 38% and 10 and 20% for the k-nearest neighbor, Naive Bayes, artificial neural network and rule-based classifiers for synthetic and real data sets, respectively. The decision tree and support vector machines classifiers were found to be the best predictive models with 0% error rates during automated extraction of the water quality class. This study reveals that data mining techniques have the potential to quickly predict water quality class, provided data given are a true representation of the domain knowledge. 相似文献