GIS技术在城市地下水重金属浓度识别与分级中的应用（英文）     

Sobia Ashraf  Farhat Abbas  Muhammad Ibrahim  Umer Rashid  Shoaib Khalid  Hammad Raza Ahmad  Khalid Rehman Hakeem  Tahir Majeed 《地理学报(英文版)》2015,(2):225-235

Groundwater is the most appropriate and widely used source of drinking water,which is increasingly threatened by pollution from industrial and agricultural activities.To check the severity of the problem,156 groundwater samples were collected from various depths(60-110 ft) of 52 different localities in Faisalabad city,the third largest metropolis in Pakistan,and analyzed for the metals(Zn,Cu,Cd,Ni,Pb,Mn and Fe) concentration in 2009.Quantification was done by using Flame Atomic Absorption Spectrophotometer technique and the results were compared with WHO standards for drinking water quality.Results showed that the levels of Cu,Mn and Fe were below the WHO standards while the concentrations of Zn,Cd,Ni and Pb were above the recommended levels of safe drinking water.Correlation analysis among the occurrence of these heavy metals revealed a highly significant and positive correlation of Mn with Zn and Fe.A significant and positive correlation of Cd was also found with Cu and groundwater depth showing that there is strong association between Cu-Cd pair and that the Cd concentration varies with depth of groundwater in the study area.Regional patterns of heavy metals occurrence were mapped using Geographical Information System(GIS) for the identification and demarcation of risk areas.The concentration maps may be used by policymakers of the city to mitigate groundwater pollution.  相似文献   

Observations of Antarctic precipitable water vapor and its response to the solar activity based on GPS sensing     

Wayan Suparta  Zainol Abidin Abdul Rashid  Mohd. Alauddin Mohd. Ali  Baharudin Yatim  Grahame J. Fraser 《Journal of Atmospheric and Solar》2008,70(11-12):1419-1447

Predicting global climate change is a great challenge and must be based on a thorough understanding of how the climate system components behave. Precipitable water vapor (PWV) is one of the key components in determining and predicting the global climate system. It is well known that the local surface temperature and pressure have a direct influence on the production of PWV. However, the influence of solar activity on atmospheric dynamics and their physical mechanisms is still an open debate, where past studies are focused at mid-latitude regions. A new method of determining and quantifying the solar influence on PWV based on GPS observations to correlate the GPS PWV and total electron content (TEC) variations is proposed. Observed data from Scott Base (SBA) and McMurdo (MCM) stations from 2003 to 2005 have been used to study the response of PWV to solar activity. In the analysis, the effects of local conditions (wind speed and relative humidity) on the distribution of PWV are investigated. Results show significant correlation between PWV and solar activity for four geomagnetic storms, with correlation coefficients of 0.74, 0.77, 0.64 and 0.69, which are all significant at the 95% confidence level. There was no significant correlation between TEC and PWV changes during the absence of storms. On a monthly analysis, a strong relationship exists between PWV and TEC during storm-affected days, with correlation coefficients of 0.83 and 0.89 (99% confidence level) for SBA and MCM respectively. These indicate a statistically significant seasonal signal in the Antarctic region, which is very active (higher) during the summer and inactive (lower) for the winter periods.  相似文献   

Stability of LRS Bianchi type-I cosmological models in f(R,T)-gravity     

Umesh Kumar Sharma  Rashid Zia  Anirudh Pradhan  Aroon Beesham 《天文和天体物理学研究(英文版)》2019,(4):63-76

This paper examines the stability of the transition from the early decelerating stage of the Universe to the recent accelerating stage for the perfect fluid cosmological locally rotationally symmetric(LRS) Bianchi-I model in f(R, T) theory. To determine the solution of field equations, the idea of a timevarying deceleration parameter(DP) which yields a scale factor, for which the Universe attains a phase transition scenario and is consistent with recent cosmological observations, is used. The time-dependent DP yields a scale factor a=exp■, where β and k are respectively arbitrary and integration constants. By using the recent cons_traints(H_0 _= 73.8, and q_0 =-0.54) from Type Ia Supernova(SN Ia) data in combination with Baryonic Acoustic Oscillations(BAO) and Cosmic Microwave Background(CMB) observations(Giostri et al.), we obtain the values of β = 0.0062 and k = 0.000016 for which we have derived a cosmological model from the early decelerated phase to the present accelerating phase. By applying_ other r_ecent constraints(H_0 = 73.8, q_0 =-0.73) from SNe Ia Union data(Cunha), we obtain the values of β = 0.0036 and k = 0.000084 for which we have derived a cosmological model in the accelerating phase only. We have compared both models with experimental data. The stability of the background solution has been examined also for the metric perturbations alongside the properties of future singularities in a Universe ruled by dark energy with phantom type fluid. We demonstrate the presence of a stable fixed point with a condition of state ω <-1 and numerically affirm this is really a late-time attractor in the ghost overwhelmed Universe. Some physical and geometric properties of the model are found and examined.  相似文献   

Sourcing seafood for the three major markets: The EU,Japan and the USA   总被引：1，自引：0，他引：1  

Wilf Swartz  U. Rashid Sumaila  Reg Watson  D. Pauly 《Marine Policy》2010

This paper describes the marine fish and invertebrate consumption in three of the world’s major seafood markets (the EU, Japan and the USA) using a series of global maps indicating the likely origin of the seafood consumed by each market. These maps display a high level of dependence by these markets on foreign sources as the serial depletion of local fisheries resources forced the fleets in search for new seafood supplies well beyond their domestic waters. The acquisition of foreign (and high seas) seafood by these markets is conducted through two channels: by dispatching distant water fishing fleets that directly exploit foreign stocks; and by importing catch landed elsewhere by local fleets. The results also demonstrate that each of the three major markets occupies a zone of influence within which it is dominant.  相似文献   

Heinrich事件期间的混合层增深：多种浮游有孔虫的δ^18O研究     

Harunur Rashid  徐明芝 《海洋地质前沿》2009,25(3):22-24

北大西洋晚更新世Heinrich事件（HEs）以Laurentide冰盖的冰筏碎屑（IRD）层为标志。有8个这样的事件与约65000a以来格陵兰冰心记录的部分Dansgaard-Oeschger（D／O）事件的最冷亚冰期相对应。判断一个D／O事件的开始,根据这样一个典型特征：在仅仅几十年的时间内温度突然上升了9～15℃,其后便是数千年时间的气温逐渐变冷。  相似文献   

A Study of Largest Active Region AR12192 of 24th Solar Cycle Using Fractal Dimensions and Mathematical Morphology     

Asma Zaffar  Abbas  Shaheen  Ansari  Muhammad Rashid Kamal 《Solar System Research》2020,54(4):353-359

Solar System Research - An active region (AR) of the sun is an area of strong magnetic field. Sunspots are frequently formed in an AR. Solar activity exhibits in the form of solar flares and...  相似文献   

Municipal Solid Waste Management in Moradabad City,India     

Masood Ahsan Siddiqui  Syed Mohammad Rashid  Lubna Siddiqui  Shahzad Ali Ansari 《Journal of the Indian Society of Remote Sensing》2012,40(1):109-119

The paper tries to estimate the rate of waste generation per head/per day, to identify suitable sites for waste disposal, to find out optimal route for collection vehicles and to analyze the financial aspects of solid waste management in Moradabad City, India.The study is based on sample of 2,500 households and secondary data. The City generates about 318 tones of solid waste with an average per capita rate of 460 gram per day. Collection and disposal efficiency is nearly 64%. Sensitivity analysis of the present disposal site as per the norms of Central Pollution Control Board indicates that it is moderately suitable. Subsequently two new disposal sites were identified. Redefined routes and related issues were evaluated in financial terms. It is estimated that by adopting the proposed plan, the expenditure on waste management will increase by about 52%, but at the same time about 90% of city area and 95% of city population will be served.  相似文献   

Utilization of geoinformation tools for the development of forest fire hazard mapping system: example of Pekan fire, Malaysia     

Ahmad Rodzi Mahmud  Iwan Setiawan  Shattri Mansor  Abdul Rashid Mohamed Shariff  Biswajeet Pradhan  Ahmed Nuruddin 《Central European Journal of Geosciences》2009,1(4):456-462

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Long-term resilience, bush encroachment patterns and local knowledge in a Northeast African savanna     

Graciela Gil-Romera  Henry F. Lamb  David Turton  Miguel Sevilla-Callejo  Mohammed Umer 《Global Environmental Change》2010,20(4):612-626

Bush encroachment is a significant phenomenon in savanna environments as it affects wildlife and local livelihoods by preventing new pasture generation. In this article we present a 2000-year record of vegetation change in the Dara range of the Mago National Park, southwestern Ethiopia, an area inhabited by Mursi agro-pastoralists. We use an interdisciplinary approach to understand whether bush encroachment in this area is a recent event or a transitional state of the savanna and describe the local understanding of encroachment as a species-specific process. The vegetation record was obtained from a fossil hyrax midden, a type of sediment already used in Southern Africa but never before in East Africa. Six encroaching phases, led by Capparaceae and Grewia, were found over the last two millennia. The system proved to be resilient, with alternating open and encroached phases, and showed a non-linear response to environmental change, thereby fitting the control theory hypothesis for hysteresis loops. Determining the thresholds conditioning the system's resilience could help to improve savanna management for both local people and National Park authorities.  相似文献   

Toothfish crises, actor diversity and the emergence of compliance mechanisms in the Southern Ocean   总被引：1，自引：0，他引：1  

Henrik Österblom  Ussif Rashid Sumaila 《Global Environmental Change》2011,21(3):972-982

Illegal, unregulated and unreported (IUU) fishing is a challenging form of non-compliance in many marine ecosystems. IUU fishing has attracted substantial political attention in the Southern Ocean, where a series of crises created windows of opportunity for change. A crises-response framework was used for examining these dynamics between 1995 and 2009. Crises were defined in relation to their perceived threat, decision time and surprise. Published material was combined with the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLRs) expert interviews, to evaluate changing perceptions of IUU fishing and corresponding actions. A first crisis led to an increased use of informal shortcuts and a concentration of power. A second crisis created windows of opportunities for policy entrepreneurs and stimulated policy innovation. A third crisis led to the implementation of existing contingency plans. These responses were consistent with predictions from the crisis-response framework used. The series of crises threatened the credibility of CCAMLR and changed the incentives for engaging in coalitions, which led to the development of both management and enforcement approaches to compliance. State and non-state actors became increasingly involved in developing these diverse compliance mechanisms, thereby actively contributing to the adaptive capacity of CCAMLR. Synergies between fisheries industry, environmental conservation, and state sovereignty interests were effectively utilized. Individual actors, organizations and countries providing leadership had strong incentives for doing so. Trust and reputation was important for the compliance mechanisms leading to a substantial reduction of IUU fishing.  相似文献