Hypoxia in the northern Gulf of Mexico: Does the science support the Plan to Reduce,Mitigate, and Control Hypoxia?     

N. N. Rabalais  R. E. Turner  B. K Sen Gupta  D. F. Boesch  P. Chapman  M. C. Murrell 《Estuaries and Coasts》2007,30(5):753-772

We update and reevaluate the scientific information on the distribution, history, and causes of continental shelf hypoxia that supports the 2001 Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force 2001), incorporating data, publications, and research results produced since the 1999 integrated assessment. The metric of mid-summer hypoxic area on the LouisianaTexas shelf is an adequate and suitable measure for continued efforts to reduce nutrients loads from the Mississippi River and hypoxia in the northern Gulf of Mexico as outlined in the Action Plan. More frequent measurements of simple metrics (e.g., area and volume) from late spring through late summer would ensure that the metric is representative of the system in any given year and useful in a public discourse of conditions and causes. The long-term data on hypoxia, sources of nutrients, associated biological parameters, and paleoindicators continue to verify and strengthen the relationship between the nitratenitrogen load of the Mississippi River, the extent of hypoxia, and changes in the coastal ecosystem (eutrophication and worsening hypoxia). Multiple lines of evidence, some of them representing independent data sources, are consistent with the big picture pattern of increased eutrophication as a result of long-term nutrient increases that result in excess carbon production and accumulation and, ultimately, bottom water hypoxia. The additional findings arising since 1999 strengthen the science supporting the Action Plan that focuses on reducing nutrient loads, primarily nitrogen, through multiple actions to reduce the size of the hypoxic zone in the northern Gulf of Mexico.  相似文献   

A simple approach for the determination of bulk modulus and equation of state under the effect of high temperature for minerals     

Vandana Pal  Munish Kumar  B. R. K. Gupta 《Physics and Chemistry of Minerals》1998,25(3):227-228

A simple theoretical method for the determination of bulk modulus and equation of state is investigated and applied for six minerals of geophysical importance. The results obtained at different temperatures are found to present a good agreement with the experimental data. The simplicity of the method is discussed in the light of other methods in high temperature research on minerals. Received: 7 January 1996 / Revised, accepted: 11 June 1997  相似文献   

DISCUSSION OF "Use of Laboratory Data to Predict Sulfate Sorption During Artificial Ground-Water Recharge," by Warren W. Wood, January-February 1978 issue, v. 16, no. 1, pp. 22–31; and A NOTE on "Determining Dispersion and Adsorption Coefficients"     

Suresh K. Gupta  R. N. Pandey 《Ground water》1978,16(6):453-454

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Total mercury content in some marine fish from the Indian Ocean     

Tariq W. Kureishy  M. D. George  R. Sen Gupta 《Marine pollution bulletin》1979,10(12):357-360

Total mercury was estimated in liver, gonads and muscle of some of the marine fishes from the Indian Ocean. The highest mercury concentration was observed in the muscle of sharks while the total mercury concentration was practically non-detectable in the liver and gonads. The range of all the values was 0.09–0.21 ppm (wet weight basis) and is quite low to reflect any possible mercury contamination.  相似文献   

Bridge dynamic loading due to road surface irregularities and braking of vehicle     

R. K. Gupta  R. W. Traill-Nash 《地震工程与结构动力学》1980,8(2):83-96

Single span highway bridges of composite construction are idealized as beams as well as orthotropic plates. A standard HS–20–44 highway vehicle is represented by a planar, two-axle, sprung mass system with frictional device. The response equations are derived in terms of the natural modal co-ordinates of the bridge and of displacement co-ordinates of the vehicle. The road surface irregularities, generally found at the junctions of the approach road and bridge ends, are idealized as a 45° ramp. The maximum impact factors for bending moment and deflection are obtained due to the ramp and in combination with the braking of vehicle for symmetric as well as essentric loading of the vehicle.  相似文献   

Surface heat flow and igneous intrusion in the Cambay Basin, India     

Mohan L. Gupta 《Journal of Volcanology and Geothermal Research》1981,10(4):279-292

Heat flow values from some additional locations in the Cenozoic Cambay Basin have been determined. Together with the previously published data, they show that the heat flow is moderate (55–67 mW/m′) in the southern part of the basin towards Broach and Ankleswar, and that there is a clear trend of high heat flow (75–93 mW/m²; range of average values for six different, widely separated, locations) in a part of the basin located north of the Mahisagan river between Cambay and Mehsana along a stretch of about 140 km. Conductive steady state geotherms, calculated using observed high surface heat flow values and appropriate models show, beneath the Cambay-Mehsana area, a large degree of melting in the lower crust and upper mantle, which is not suggested by the existing geodata. Considering this aspect and taking into account the existence of a normal crust about 37 km thick below the Cambay-Tarapur and Ahmedabad-Mehsana blocks (as obtained from deep seismic soundings), it has been inferred that the heat flow anomaly is due to transient thermal perturbations introduced from tectonic activity in the form of magmatic intrusions. A careful analysis of heat flow, gravity and other related geodata point out and support the possibility of a Miocene/Pliocene basic intrusive body at a depth of around 10 km under the Cambay-Mehsana area. Further, the consistent trend of the thermal and gravity fields indicates thinning of the postulated intrusive body from Cambay towards Mehsana.  相似文献   

Solar x-ray control of the ionospheric absorption measured by the sweep frequency method     

G P Gupta 《Journal of Earth System Science》1978,87(11):231-234

The ionospheric absorption data measured by the sweep frequency method have been compared with the solar x-ray data in the band of 1–8 Å during quiet- and disturbed-sun conditions. The degree of solar x-ray control of the ionospheric absorption and the corresponding limit of solar x-ray flux have been discussed.  相似文献   

Hydrogeology of limited aquifer in a granitic terrain     

V. S. Singh  V. Krishnan  M. R. K. Sarma  C. P. Gupta  R. L. Dhar 《Environmental Geology》1999,37(1-2):90-95

 Detailed hydrogeological studies in a granitic micro-watershed have been carried out to determine the extent, behavior, and characteristics of the aquifer. The study includes analysis of lithologs, drill time log, pumping tests, and slug tests. Realistic field conditions have been taken into account for characterizing the aquifer system. Slug tests were carried out to estimate aquifer parameters at the wells which could not sustain pumping. Received: 20 November 1997 · Accepted: 23 February 1998  相似文献   

Use of SARAL/AltiKa Observations for Modeling River Flow     

Praveen Gupta  Amit Kumar Dubey  Nandita Goswami  Raghvendra Pratap Singh  Prakash Chauhan 《Marine Geodesy》2015,38(3):614-625

In the absence of many gauging stations in the major and mighty river systems, there is a need for satellite-based observations to estimate temporal variations in the river water storage and associated water management. In this study, SARAL/AltiKa application for setting up hydraulic model (HEC-RAS) and river flow simulations over Tapi River India has been discussed. Waveform data of 40 Hz from Ka band altimeter has been used for water levels retrieval in the Tapi river. SARAL/AltiKa retrieved water levels were converted to discharge in the upstream location (track-926) using the rating curve available for the nearby gauging site and using linear spatial interpolation technique. Steady state simulations were done for various flow conditions in the upstream. Validation of river flow model was done in the downstream location (track-367) by comparing simulated and altimeter retrieved water levels (RMSE 0.67 m). Validated model was used to develop rating curve between water levels and simulated discharge for the downstream location which enables to monitor discharge variations from satellite platform in the absence of in situ observations. It has been demonstrated that SARAL/AltiKa data has potential for river flow monitoring and modeling which will feed for flood disaster forecasting, management and planning.  相似文献   

A new model for charged anisotropic compact star     

S. K. Maurya  M. K. Jasim  Y. K. Gupta  T. T. Smitha 《Astrophysics and Space Science》2016,361(5):163

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