Satellite-based rainfall estimation and discharge measurement of Middle Indus River,Pakistan     

Syed Muhammad Zubair Younis  Muhammad Majid  Ahmad Ammar 《Arabian Journal of Geosciences》2017,10(18):404

The impacts of floods and droughts are intensified by climate change, lack of preparedness, and coordination. The average rainfall in study area is ranging from 200 to 400 mm per year. Rain gauge generally provides very accurate measurement of point rain rates and the amounts of rainfall but due to scarcity of the gauge locations provides very general information of the area on regional scale. Recognizing these practical limitations, it is essential to use remote sensing techniques for measuring the quantity of rainfall in the Middle Indus. In this research, Tropical Rainfall Measuring Mission (TRMM) estimation can be used as a proxy for the magnitude of rainfall estimates from classical methods (rain gauge), quantity, and its spatial distribution for Middle Indus river basin. In order to use TRMM satellite data for discharge measurement, its accuracy is determined by statistically comparing it with in situ gauged data on daily and monthly bases. The daily R ² value (0.42) is significantly lower than monthly R ² value (0.82), probably due to the time of summation of TRMM 3-hourly precipitation data into daily estimates. Daily TRMM data from 2003 to 2012 was used as input forcing in Soil and Water Assessment Tool (SWAT) hydrological model along with other input parameters. The calibration and validation results of SWAT model give R ² = 0.72 and 0.73 and Nash-Sutcliffe coefficient of efficiency = 0.69 and 0.65, respectively. Daily and monthly comparison graphs are generated on the basis of model discharge output and observed data.  相似文献   

Fishery stock assessment of Kiddi shrimp (Parapenaeopsis stylifera) in the Northern Arabian Sea Coast of Pakistan by using surplus production models     

Mohsin  Muhammad  Mu  Yongtong  Memon  Aamir Mahmood  Kalhoro  Muhammad Talib  Shah  Syed Baber Hussain 《中国海洋湖沼学报》2017,35(4):936-946

Pakistani marine waters are under an open access regime.Due to poor management and policy implications,blind fishing is continued which may result in ecological as well as economic losses.Thus,it is of utmost importance to estimate fishery resources before harvesting.In this study,catch and effort data,1996-2009,of Kiddi shrimp Parapenaeopsis stylifera fishery from Pakistani marine waters was analyzed by using specialized fishery software in order to know fishery stock status of this commercially important shrimp.Maximum,minimum and average capture production of P.stylifera was observed as 15 912 metric tons(mt)(1997),9 438 mt(2009) and 11 667 mt/a.Two stock assessment tools viz.CEDA(catch and effort data analysis) and ASPIC(a stock production model incorporating covariates) were used to compute MSY(maximum sustainable yield) of this organism.In CEDA,three surplus production models,Fox,Schaefer and Pella-Tomlinson,along with three error assumptions,log,log normal and gamma,were used.For initial proportion(IP) 0.8,the Fox model computed MSY as 6 858 mt(CV=0.204,R~2=0.709) and 7 384 mt(CV=0.149,R~2=0.72) for log and log normal error assumption respectively.Here,gamma error produced minimization failure.Estimated MSY by using Schaefer and Pella-Tomlinson models remained the same for log,log normal and gamma error assumptions i.e.7 083 mt,8 209 mt and 7 242 mt correspondingly.The Schafer results showed highest goodness of fit R~2(0.712) values.ASPIC computed MSY,CV,R~2,F_(MSY)and B_(MSY) parameters for the Fox model as 7 219 mt,0.142,0.872,0.111 and 65 280,while for the Logistic model the computed values remained 7 720 mt,0.148,0.868,0.107 and 72 110 correspondingly.Results obtained have shown that P.stylifera has been overexploited.Immediate steps are needed to conserve this fishery resource for the future and research on other species of commercial importance is urgently needed.  相似文献   

The electric potential gradient in mist,haze, and fog     

Syed Nizamuddin  R. Ramanadham 《Pure and Applied Geophysics》1983,121(2):353-359

The variation of potential gradient in mist, haze, and fog has been studied. During the formation of these hydrometers the potential gradients were found to increase. Large positive potential gradients were observed during dense fog conditions. Possible charge generation mechanisms responsible for these potential gradients during fog formation are discussed.  相似文献   

Petrography and mineral chemistry as indicators of variations of crystallization conditions in the Loch Lomond and Appin appinite suites, western Scotland   总被引：1，自引：0，他引：1  

Syed Hamidullah 《Proceedings of the Geologists' Association. Geologists' Association》2007,118(1):101-115

  相似文献   

Stable isotope systematics and geochemical signatures constraining groundwater hydraulics in the mining environment of the Korba Coalfield,Central India     

Rambabu Singh  A. S. Venkatesh  Tajdarul H. Syed  L. Surinaidu  Srinivas Pasupuleti  S. P. Rai  Manoj Kumar 《Environmental Earth Sciences》2018,77(15):548

The present study explores the use of stable isotopes and major ion chemistry of various water sources such as mine water, groundwater, river water, and rainwater to identify the dominant hydrogeochemical process that controls the water quality in the active opencast coal mining area of the Korba Coalfield, India. Different hydrochemical models have revealed that the study area is mostly characterized by two facies alongside a dominance by ion exchange: i.e., a slightly mineralized Ca²⁺–Mg²⁺–Cl^? and a meteorically derived Ca²⁺–HCO₃^? fresh water facies. In the isotope bivariate plot, the samples plot to the right of the LMWL and slopes observed in pre (4.94) and post-monsoon (5.85) seasons are not as steep as the LMWL (7.95) and this warrants the suggestion that meteoric water is the major source that replenishes the dynamic groundwater resource in the study area after being subjected to evaporation. The negative d-excess values (<?0) and enrichment of the δ¹⁸O ratio observed at some locations suggests a non-equilibrium process and a “mechanism of mixing”. A noteworthy fact is that isotopically river water is in tandem with the mine water samples for both seasons and testifies to a hydraulic connectivity between Hasdeo River water and mine water through a major fault. It is substantiated by mine inflows assessed by the sump test for Kusmunda and Gevra, which is two times higher than the predicted values by Darcy’s law. The wide variation in the isotopic composition is attributed to different vapor sources viz., southwest monsoon (SW) that originates in the Arabian Sea and locally driven air moisture from surface water bodies.  相似文献   

Identification of suitable sites for groundwater recharge in Awaspi watershed using GIS and remote sensing techniques     

Sarkawt Ghazi Salar  Arsalan A. Othman  Syed E. Hasan 《Environmental Earth Sciences》2018,77(19):701

Groundwater is a valuable natural resource for drinking, domestic, livestock use, and irrigation, especially in arid and semi-arid regions like the Garmiyan belt in Kurdistan region. The Awaspi watershed is located 50 km east of Kirkuk city, south Kurdistan, Iraq; and covers an area of 2146 km². The paper presents result of a study aimed at: (1) mapping and preparing thematic layers of factors that control groundwater recharge areas, and (2) determination of sites suitable for groundwater recharge. We used available data such as geological map, groundwater depth map, digital elevation model (DEM), Landsat 8 imagery, and tropical rainfall measuring mission (TRMM) data for this study. These data, supplemented by slope features, lithology, land use land cover, rainfall, groundwater depth, drainage density, landform, lineament density, elevation and topographic position index, were utilized to create thematic maps to identify suitable areas of groundwater recharge, using GIS and remote sensing techniques. Analytic hierarchy process (AHP) was applied to weight, rank, and reclassify these maps in the ArcGIS 10.3 environment, to determine the suitable sites for groundwater recharge within the Awaspi watershed. Fifty-five percent of the total area of the watershed was found to be suitable for groundwater recharge; whereas 45% of the area was determined to have poor suitability for groundwater recharge, but can be used for surface water harvesting.  相似文献   

Origin of Boron in the Gas Hure Salt Lake of NorthwesternQaidam Basin,China: Evidence from Hydrochemistry andBoron Isotopes     

HAN Jibin  XU Jianxin  Syed Asim HUSSAIN  JIANG Hongchen  MA Yunqi  XU Kai  MA Haizhou 《《地质学报》英文版》2021,95(2):531-540

The Gas Hure Salt Lake(GHSL) in the northwestern Qaidam Basin, western China, is rich in boron(B)resources, but its B-resource origin is hardly known. Hydrochemical compositions and B isotope characteristics of different waters were collected around the GHSL, including the river water, stream water, spring water, salt-lake brine,intercrystalline brine, well water, drilling brine, and solar pond brine. The hydrochemical signatures suggest that silicates,carbonates and evaporates are the main B-bearing rocks during the water dynamic. The reservoir estimation of B resources shows that the Kulamulekesay River(KLMR) and the Atekan River(ATKR) contribute annually 18.3 tons and 22.84 tons of B, respectively, with a total amount of 11.72 × 10~4 tons of B during the past 5.7 ka. In comparison with the known B reservoir(32.96 × 10~4 tons) in the GHSL, a significant amount of B in the GHSL was probably recharged from deep fluids and sediments around the GHSL. The B concentration and B-enrichment degree are shaped by the evaporation process,which are highly elevated at the carnallite and bischofite stages.  相似文献   

Tropical Atlantic influence on Pacific variability and mean state in the twentieth century in observations and CMIP5   总被引：1，自引：0，他引：1  

F. Kucharski  F. S. Syed  A. Burhan  I. Farah  A. Gohar 《Climate Dynamics》2015,44(3-4):881-896

  相似文献   

Evaluation of standoff distance method to determine the coronal magnetic field using CME-driven shocks     

K. Suresh  A. Shanmugaraju  M. Syed Ibrahim 《Astrophysics and Space Science》2016,361(11):360

  相似文献   

Dynamics of Bianchi type I,III and Kantowski-Sachs solutions in f(R,T) gravity     

M. Zubair  Syed M. Ali Hassan 《Astrophysics and Space Science》2016,361(4):149

  相似文献