Dynamic groundwater resources of National Capital Territory,Delhi: assessment,development and management options   总被引：4，自引：2，他引：2  

Rana Chatterjee  B. K. Gupta  S. K. Mohiddin  P. N. Singh  Shashank Shekhar  Rajaram Purohit 《Environmental Earth Sciences》2009,59(3):669-686

Groundwater is one of the important source of water supply to meet the requirements of National Capital Territory (NCT) of Delhi, India which is a fast developing urban conglomeration. An assessment of dynamic groundwater resources of NCT Delhi has been attempted based on the methodology known as Ground Water Resources Estimation Methodology—1997. The methodology includes assessment of annual replenishable groundwater resources using water level fluctuation approach and empirical norms, estimation of the annual quantity of groundwater withdrawal and categorization of the assessment units based on the status of groundwater utilization and water level trend. Annual replenishable groundwater resources of NCT Delhi is about 297 million cubic meter (mcm) while the annual groundwater draft is about 480 mcm. This is because of over-exploitation of replenishable resources in seven out of nine districts of the Capital Territory. Based on the assessment of dynamic groundwater resources, a broad groundwater management plan has been proposed in this paper. This include augmentation of groundwater resources through rain water harvesting schemes to be implemented on a large scale, regulation on groundwater withdrawal in vulnerable areas, development of Yamuna flood plain aquifer and declaration of Delhi ridge as groundwater sanctuary.  相似文献   

Flooding and its relationship with land cover change,population growth,and road density     

Mahfuzur Rahman  Chen Ningsheng  Golam Iftekhar Mahmud  Md Monirul Islam  Hamid Reza Pourghasemi  Hilal Ahmad  Jules Maurice Habumugisha  Rana Muhammad Ali Washakh  Mehtab Alam  Enlong Liu  Zheng Han  Huayong Ni  Tian Shufeng  Ashraf Dewan 《地学前缘(英文版)》2021,12(6):16-35

Bangladesh experiences frequent hydro-climatic disasters such as flooding.These disasters are believed to be associated with land use changes and climate variability.However,identifying the factors that lead to flooding is challenging.This study mapped flood susceptibility in the northeast region of Bangladesh using Bayesian regularization back propagation(BRBP)neural network,classification and regression trees(CART),a statistical model(STM)using the evidence belief function(EBF),and their ensemble models(EMs)for three time periods(2000,2014,and 2017).The accuracy of machine learning algorithms(MLAs),STM,and EMs were assessed by considering the area under the curve-receiver operating char-acteristic(AUC-ROC).Evaluation of the accuracy levels of the aforementioned algorithms revealed that EM4(BRBP-CART-EBF)outperformed(AUC＞90％)standalone and other ensemble models for the three time periods analyzed.Furthermore,this study investigated the relationships among land cover change(LCC),population growth(PG),road density(RD),and relative change of flooding(RCF)areas for the per-iod between 2000 and 2017.The results showed that areas with very high susceptibility to flooding increased by 19.72％between 2000 and 2017,while the PG rate increased by 51.68％over the same period.The Pearson correlation coefficient for RCF and RD was calculated to be 0.496.These findings highlight the significant association between floods and causative factors.The study findings could be valuable to policymakers and resource managers as they can lead to improvements in flood management and reduction in flood damage and risks.  相似文献   

Predicting the impact of climate change on the distribution of two threatened Himalayan medicinal plants of Liliaceae in Nepal     

Santosh Kumar Rana  Hum Kala Rana  Suresh Kumar Ghimire  Krishna Kumar Shrestha  Sailesh Ranjitkar 《山地科学学报》2017,14(3):558-570

Predicting the potential distribution of medicinal plants in response to climate change is essential for their conservation and management. Contributing to the management program, this study aimed to predict the distribution of two threatened medicinal plants, Fritillaria cirrhosa and Lilium nepalense. The location of focal species gathered from herbarium specimen housed in different herbaria and online databases were geo-referenced and checked for spatial autocorrelation. The predictive environmental variables were selected, and MaxEnt software was used to model the current and future distributions of focal species. Four Representative Concentration Pathway (RCP) trajectories of the BCC-CSM1.1 model were used as the future (2050) projection layer. The MaxEnt modelling delineated the potential distribution of F. cirrhosa and L. nepalense. The current suitability is projected towards Central and Eastern Hilly/Mountainous regions. Both species gain maximum suitability in RCP 4.5 which decline towards other trajectories for L. nepalense. Overall, both the focal species shift towards the north-west, losing their potential habitat in hilly and lower mountainous regions by 2050 across all trajectories. Our results highlight the impact of future climate change on two threatened and valuable species. The results can be further useful to initiate farming of these medicinally and economically important species based on climatically suitable zone and for designing a germplasm conservation strategy.  相似文献   

The impacts on groundwater development on shallow aquifers in the lower Okavango Delta, northwestern Botswana   总被引：1，自引：0，他引：1  

F. Linn  M. Masie  A. Rana 《Environmental Geology》2003,44(1):112-118

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Location-allocation modeling for emergency evacuation planning with GIS and remote sensing: A case study of Northeast Bangladesh     

Mahfuzur Rahman  Ningsheng Chen  Md Monirul Islam  Ashraf Dewan  Hamid Reza Pourghasemi  Rana Muhammad Ali Washakh  Nirdesh Nepal  Shufeng Tian  Hamid Faiz  Mehtab Alam  Naveed Ahmed 《地学前缘(英文版)》2021,12(3):101095

This work developed models to identify optimal spatial distribution of emergency evacuation centers(EECs) such as schools, colleges, hospitals, and fire stations to improve flood emergency planning in the Sylhet region of northeastern Bangladesh.The use of location-allocation models(LAMs) for evacuation in regard to flood victims is essential to minimize disaster risk.In the first step, flood susceptibility maps were developed using machine learning models(MLMs), including: Levenberg–Marquardt back propagation(LM-BP) neural network and decision trees(DT) and multi-criteria decision making(MCDM) method.Performance of the MLMs and MCDM techniques were assessed considering the area under the receiver operating characteristic(AUROC) curve.Mathematical approaches in a geographic information system(GIS) for four well-known LAM problems affecting emergency rescue time are proposed: maximal covering location problem(MCLP), the maximize attendance(MA), p-median problem(PMP), and the location set covering problem(LSCP).The results showed that existing EECs were not optimally distributed, and that some areas were not adequately served by EECs(i.e., not all demand points could be reached within a 60-min travel time).We concluded that the proposed models can be used to improve planning of the distribution of EECs, and that application of the models could contribute to reducing human casualties, property losses, and improve emergency operation.  相似文献   

Precision pulsar timing with the ORT and the GMRT and its applications in pulsar astrophysics     

Bhal Chandra Joshi  Prakash Arumugasamy  Manjari Bagchi  Debades Bandyopadhyay  Avishek Basu  Neelam Dhanda Batra  Suryarao Bethapudi  Arpita Choudhary  Kishalay De  L. Dey  A. Gopakumar  Y. Gupta  M. A. Krishnakumar  Yogesh Maan  P. K. Manoharan  Arun Naidu  Rana Nandi  Dhruv Pathak  Mayuresh Surnis  Abhimanyu Susobhanan 《Journal of Astrophysics and Astronomy》2018,39(4):51

Radio pulsars show remarkable clock-like stability, which make them useful astronomy tools in experiments to test equation of state of neutron stars and detecting gravitational waves using pulsar timing techniques. A brief review of relevant astrophysical experiments is provided in this paper highlighting the current state-of-the-art of these experiments. A program to monitor frequently glitching pulsars with Indian radio telescopes using high cadence observations is presented, with illustrations of glitches detected in this program, including the largest ever glitch in PSR B0531+21. An Indian initiative to discover sub-\(\mu \)Hz gravitational waves, called Indian Pulsar Timing Array (InPTA), is also described briefly, where time-of-arrival uncertainties and post-fit residuals of the order of \(\mu \)s are already achievable, comparable to other international pulsar timing array experiments. While timing the glitches and their recoveries are likely to provide constraints on the structure of neutron stars, InPTA will provide upper limits on sub-\(\mu \)Hz gravitational waves apart from auxiliary pulsar science. Future directions for these experiments are outlined.  相似文献   

Estimate of Ablation Rate of Glacier Ice under a Supraglacial Debris Layer     

Masayoshi Nakawo  & Birbal Rana 《Geografiska Annaler: Series A, Physical Geography》1999,81(4):695-701

The ablation rate under a debris layer is very difficult to measure directly at debris-covered glaciers, because the surface is highly heterogeneous, and the ablation rate varies tremendously from place to place. Heat budget considerations with a debris layer on top of glacier ice suggested that 'thermal resistance' of the debris layer could be estimated from surface temperature and the heat fluxes at the debris surface, and the ablation rate of the underlying glacier ice from the thermal resistance and meteorological data. The method was tested at the Lirung Glacier in Langtang Valley, Nepal Himalayas, using the thermal band of LANDSAT satellite for estimating surface temperature distribution of the debris top surface. The amount of melt water thus estimated was compatible with the observed discharge data from the glacier basin for periods of the monsoon season in 1985 and the pre-monsoon to the monsoon season in 1996. The investigation also revealed that the amount of discharge was much larger than the amount of precipitation over the basin, and it was suggested that the melt water from the debris-covered glacier contributes significantly to the river flow as a result of the shrinkage of the glacier.  相似文献   

Determination and validation of corn crop transpirationby sap flow measurement under field conditions     

O. Bethenod  N. Katerji  R. Goujet  J. M. Bertolini  G. Rana 《Theoretical and Applied Climatology》2000,67(3-4):153-160

Summary  Transpiration of an adult corn crop was measured with the sap flow method using the stem heat balance technique. The 1 ha-field was located in the Parisian region and the measurements were taken over two consecutive years (1993 and 1994). The experiments were carried out during the active growing season, leaf area index being ≈4.0. In order to individuate the “mean plant” a preliminary analysis was carried out to determine the frequency distribution of plant stem diameters as measured on 34 randomly chosen samples. According to this analysis, the mean corn plant diameter was around 20 mm for both years. As a consequence, the sap flow gauges were installed on plants having this diameter. The sap flow transpiration data was compared with the actual evapotranspiration measured by the Bowen ratio method on the same experimental field at the hourly and daily scales. The comparison between sap flow transpiration and actual evapotranspiration showed that the values are more widely spread at the hourly scale than at the daily scale due to the kinetics of plant water content during the day. Sap flow transpiration was 88–90% of actual evapotranspiration: this lack of about 10–12% is of the same order as soil water evaporation. In conclusion, the sap flow transpiration method could be considered a valuable method to use for measuring transpiration of certain crop plants in the field, especially for small plots. This method is substantially improved if sap flow measurement is carried out on plants screened by the analysis of plant diameter distribution in the field. Received October 6, 1999 Revised June 21, 2000  相似文献   

Land suitability analysis for cereal production in Himachal Pradesh (India) using Geographical Information System     

R. M. Bhagat  Sharda Singh  C. Sood  R. S. Rana  V. Kalia  S. Pradhan  W. Immerzeel  B. Shrestha 《Journal of the Indian Society of Remote Sensing》2009,37(2):233-240

Land suitability analysis is prerequisite for sustainable agriculture and it plays a pivotal role in the niche based agricultural planning in mountain regions. In this paper different parameters viz. climatic (precipitation and temperature), topographic (elevation), soil type and land cover/land use have been used in order to perform land suitability evaluation for cereals food-grain crops in Himachal Pradesh using Geographic Information System (GIS). The suitability analysis was performed by digital processing of geo-referenced data (elevation, climate, soil and landcover) and calculating potential production areas by combining different types of geographical data through decision rules framed for each crop in ArcView spatial analyst. Suitable areas have been delineated for cereal crops in the form of land suitability maps. In comparison to the actual area under cereal crops, the possibility of further expansion under each cereal crop was determined. These discriminated areas appear suitable for growing these crops and can be harnessed efficiently for achieving long term sustainability and food security.  相似文献   

Parameterizing canopy resistance using mechanistic and semi‐empirical estimates of hourly evapotranspiration: critical evaluation for irrigated crops in the Mediterranean     

Nader Katerji  Gianfranco Rana  Salim Fahed 《水文研究》2011,25(1):117-129

In this paper two models are presented for calculating the hourly evapotranspiration λE (W m^?2) using the Penman–Monteith equation. These models were tested on four irrigated crops (grass, soya bean, sweet sorghum and vineyard), with heights between 0·1 and 2·2 m at the adult growth stage. In the first model (Katerji N, Perrier A. 1983. Modélisation de l'évapotranspiration réelle ETR d'une parcelle de luzerne : rôle d'un coefficient cultural. Agronomie 3(6): 513–521, KP model), the canopy resistance r_c is parameterized by a semi‐empirical approach. In the second model (Todorovic M. 1999. Single‐layer evapotranspiration model with variable canopy resistance. Journal of Irrigation and Drainage Engineering—ASCE 125: 235–245, TD model), the resistance r_c is parameterized by a mechanistic model. These two approaches are critically analysed with respect to the underlying hypotheses and the limitations of their practical application. In the case of the KP model, the mean slope between measured and calculated values of λE was 1·01 ± 0·6 and the relative correlation coefficients r² ranged between 0·8 and 0·93. The observed differences in slopes, between 0·96 and 1·07, were not associated with the crop height. This model seemed to be applicable to all the crops examined. In the case of the TD model, the observed slope between measured and calculated values of λE for the grass canopy was 0·79. For the other crops, it varied between 1·24 and 1·34. In all the situations examined, the values of r² ranged between 0·73 and 0·92. The TD model underestimated λE in the case of grass and overestimated it in the cases of the other three crops. The under‐ or overestimation of λE in the TD model were due: (i) to some inaccuracies in the theory of this model, (ii) to not taking into account the effect of aerodynamic resistance r_a in the canopy resistance modelling. Therefore, the values of r_c were under‐ or overestimated in consequence of mismatching the crop height. The high value of air vapour pressure deficit also contributed to the overestimation of λE, mainly for the tallest crop. The results clarify aspects of the scientific controversy in the literature about the mechanistic and semi‐empirical approaches for estimating λE. From the practical point of view the results also present ways for identifying the most appropriate approach for the experimental situations encountered. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献