Flood frequency analysis of river swat using Log Pearson type 3, Generalized Extreme Value,Normal, and Gumbel Max distribution methods

In Pakistan, floods are among the most devastating and recurring natural hazards. Flood hazard assessment requires flood event magnitude and probability of occurrence. Flood frequency analysis is the most common technique used for the at-site estimation of flood recurrence magnitude. This paper evaluates four most commonly used distribution methods, i.e., Generalized Extreme Value (GEV), Log Pearson 3 (LP3), Gumbel Max, and Normal for the flood frequency and estimation of flood recurrence. Different hydrological stations data namely Khwazakhela, Chakdarra, Panjkora, and Munda Headwork located at Swat river was taken from Provincial Irrigation Department, Khyber Pakhtunkhwa. The analysis is done for 5-, 10-, 25-, 50-, and 100-year return periods by using annual maximum discharge data from 1980 to 2016 (37 yr). Three goodness-of-fit tests were applied to the fitted distributions, i.e., Kolmogorov–Smirnov, Anderson–Darling, and Chi-squared at 5% significance level. Results indicate that LP3 and GEV were ranked top two distributions at all locations while Gumbel Max and Normal were the least fitted having rank 3 and 4, respectively. Based on the goodness-of-fit ranking, LP3 was selected for the estimation of flood magnitude and return periods at Khwazakhela. Designed hydrographs based on probabilistic approach and flood 2010 hydrograph are presented for flood simulation.     

Large scale mass movements triggered by the Kashmir earthquake 2005, Pakistan

The SPOT image analysis in Muzaffarabad Azad Kashmir,northwest Himalayas,Pakistan reveals that the Kashmir earthquake 2005 triggered a number of coseismic mass movements along the hanging wall block of the Muzaffarabad Fault.The Neelidandi and Langarpura rock falls have been identified as two major reactivated mass movements with an estimated volume of 3.1 × 106m3and 5.76 × 106m3,respectively.The Neelidandi and Langarpura mass movements were initiated during earthquake in the direction of northwest-southeast extension and northeastsouthwest directed thrusting,respectively.The Neelidandi rock fall occurred in sheared cherty dolomites and limestones of the Cambrian Muzaffarabad Formation,whereas the Langarpura rock fall occurred in alternating clays,shales,claystones,siltstones and sandstones of the Miocene Murree Formation.These rock units along the fault are highly fractured and jointed.The geotechnical maps and geological longitudinal profiles show the relationship between the geometrical characteristics and mechanism of these mass movements.Their characteristics were analyzed according to the role of topographic,seismic,geological and tectonic factors.The steep topography,sheared rocks,lithology,coseismic uplift and strong ground shaking of the hanging wall block along Muzaffarabad Fault facilitated the gravity collapse of these mass movements.     

Optimization of chlorination boosters in drinking water distribution network for Al-Khobar City in Saudi Arabia

Water quality management in distribution networks is directly related to spatial distribution of chlorine boosters and its dosages. Water chlorination is essential to reduce the effects of bacterial and other microbiological contaminants. A higher dosage of chlorine generates harmful by-products in addition to changes in drinking water’s taste and odor. The optimization of chlorine dosage is necessary to decrease the microbial contaminants that affect water quality. Once the chlorine threshold is determined for microbial contaminant, it will help decision makers suggest optimal values. These decisions can rely on the estimated water quality index (WQI). WQI is an index to evaluate water quality and can be linked to adequate residual chlorine with optimal booster dosage, numbers, and locations in water distribution network (WDN). The city of Al-Khobar, Saudi Arabia’s WDN was selected to validate the application of this study. Based on geographic location, the city Al-Khobar water network was divided into five zones. The initial temporal and spatial analysis pointed out poor water quality zones. EPANET, a modeling and simulating software, was applied to evaluate the WQI. Those EPANET results were then integrated with an optimization model. The optimization model suggested new chlorine booster locations to improve water quality in the city of Al-Khobar water distribution network.     

Characteristics,modification and environmental application of Yemen’s natural bentonite

The bentonite deposit of Lahij Province, Yemen, has very promising commercial applications due to its mineralogy and physical and chemical properties. It was examined to determine its mineralogical composition, chemical and physical properties of the bentonite deposit, purity and sodium-exchanged bentonite. Modified bentonite was synthesized by exchanging cetyltrimethylammonium cations for inorganic ions on the bentonite and its adsorption properties for ammonium were characterized in batch experiments. Analytical methods were carried out to study the bentonite comprising X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy, chemical analysis and kinetic and isotherm models were also tested. The results have shown that the purification of bentonite resulted in a bentonite fractions of the total sample composed of montmorillonite and <5 % quartz. The XRD data showed that the interlayer spacing (d ₀₀₁) of bentonite decreased from 15.3 to 12.5 Å and then increased to 19.7 Å. Moreover, high cation exchange capacity, good water absorption and high swelling capacity were also obtained. The results have shown that the modified bentonite was more effective than the natural bentonite for ammonium removal. In addition to that, pseudo-second-order kinetic model, Freundlich and the Langmuir models described the adsorption kinetics and isotherm well. It was concluded that Yemen (Alaslef) bentonite can be potential adsorbents for ammonium removal.     

The use of vertical electrical sounding resistivity method for the location of low salinity groundwater for irrigation in Chaj and Rachna Doabs

A geoelectrical resistivity survey using vertical electrical sounding (VES) was conducted at Chaj Doab (land between rivers Jhelum and Chenab, Pakistan) and Rachna Doab (land between rivers Chenab and Ravi, Pakistan), with the objective of investigating groundwater conditions. A total of 90 sites were selected with 43 sites in Chaj and 47 sites in Rachna Doabs. The resistivity meter (ABEM Terrameter SAS 4000, Sweden) was used to collect the VES data by employing a Schlumberger electrode configuration, with half current electrode spacings (AB/2) ranging from 2 to 180 m and the potential electrode (MN) from 1 to 40 m. The field data were interpreted using the Interpex IX1D computer software and the resistivity versus depth models for each location was estimated. The outputs of subsurface layers with resistivities and thickness presented in contour maps and 3-D views by using SURFER software were created. A total of 102 groundwater samples from nearby hydrowells at different depths were collected to develop a correlation between the aquifer resistivity of VES and the electrical conductivity (EC) of the groundwater and to confirm the resulted geophysical resistivity models. From the correlation developed, it was observed that the groundwater salinity in the aquifer may be considered low and so safe for irrigation if resistivity >45 Ω m, and marginally fit for irrigation having resistivity between 25 and 45 Ω m. The study area has resistivities from 3.9 to 2,222 Ω m at the top of the unsaturated layer, between 1.21 and 171 Ω m, in the shallow aquifers, and 0.14–152 Ω m in the deep aquifers of the study area. The results indicate that the quality of groundwater is better near the rivers and in the shallow layers compared to the deep layers.     

A Paleogeographic and Depositional Model for the Neogene Fluvial Succession,Pishin Belt,Northwest Pakistan: Effect of Post Collisional Tectonics on Sedimentation in a Peripheral Foreland Setting

Detailed facies analysis of the Neogene successions of the Pishin Belt (Katawaz Basin) has enabled documentation of successive depositional systems and paleogeographic settings of the basin formed by the collision of the northwestern continental margin of the Indian Plate and the Afghan Block. During the Early Miocene, subaerial sedimentation started after the final closure of the Katawaz Remnant Ocean. Based on detailed field data, twelve facies were recognized in Neogene successions exposed in the Pishin Belt. These facies were further organized into four facies associations i.e. channels, crevasse splay, natural levee and floodplain facies associations. Facies associations and variations provided ample evidence to recognize a number of fluvial architectural components in the succession e.g., low‐sinuosity sandy braided river, mixed‐load meandering, high‐sinuosity meandering channels, single‐story sandstone and/or conglomerate channels, lateral accretion surfaces (point bars) and alluvial fans. Neogene sedimentation in the Pishin Belt was mainly controlled by active tectonism and thrusting in response to the oblique collision of the Indian Plate with the Afghan Block of the Eurasian Plate along the Chaman‐Nushki Fault. Post Miocene deformation of these formations successively caused them to contribute as an additional source terrain for the younger formations.     

Geochemistry and mineralogical composition of the airborne particles of sand dunes and dust storms settled in Iraq and their environmental impacts

Five dust storms that occurred in 2008 (15 March, 11 April, 28 April, 25, May and 26 June) in addition to the many sand dunes disseminated in the Western Desert of Iraq are sampled. The worse dust storm that occurred in Iraq in 11 April, 2008 covered 75% of the Iraq area and deposited 6.9?million tons approximately as a total weight of fallout during just 8?h, declining temperature 6°C. During the episodes of dust storms, visibility decreased enormously, no more than 30?m. Many people were taken to hospitals after sustaining breathing problems. Some of them died. Clay fraction is the dominant part in the dust storms forming 70% besides a little silt (20.6%) and sand (9.4%), then classified as mature arkose of clay to sandy clay, whereas sand dunes are formed from 72.7% sand, 25.1% silt and 2.19% clay, then classified as mature arkose of silty sand. Sand dunes have much maturity. Mineralogical composition of dust storms and sand dunes are Quartz (49.2%, 67.1%), feldspar (4.9%, 20.9%), calcite (38%, 5%), gypsum (4.8%, 0.4%), dolomite (0.8%, 1%) and heavy minerals (3.2%, 6.6%), respectively. Heavy mineral suites in the dust storms are represented by zircon, pyroxene, hornblende, chlorite and magnetite; whereas the sand dunes are represented by zircon, tourmaline, garnet and pyroxene, concentrated within sand fraction. Heavy minerals according to satellite images revealed the dry land of Sahara Desert in North Africa and the Arabian Peninsula as well as Syria and Jordan were a major source of the dust storms that have occurred in Asia, including Iraq.     

Mineralogy, geochemistry, and reserve estimation of the Euphrates limestone for Portland cement industry at Al-Najaf area, South Iraq

This study deals with the mineralogical and geochemistry of the Euphrates Formation (Lower Miocene) in Bahr Al-Najaf area in order to assess the lithofacies of the Euphrates Formation for Portland cement manufacturing. Petrographic and mineralogical studies were carried out on 210 core samples, collected from 21 boreholes, and showed that calcite is the dominant mineral with few amounts of quartz, gypsum, feldspar, and a rare amount of dolomite. Clay mineral suites (palygorskite, kaolinite, montmorillonite, and illite) formed about 5% from the total mineral composition. Palygorskite precipitated directly in alkali shallow water rich with Si and Mg ions. Chemical weathering of feldspar under acidic conditions participated in formation of Kaolinite. Geochemistry showed that there is no high variation in chemical constituents with depth, and the average of CaO (51.5), MgO (0.83), SO₃ (0.54), SiO₂ (4.3), Fe₂O₃ (0.45), Al₂O₃ (0.93), L.O.I (40.7), Na₂O₃ (0.08), K₂O (0.14), and Cl^- (0.1) qualified the lithofacies of Euphrates Formation to be raw materials suitable for manufacturing the Portland cement. Triangle Block method is applied to estimate the reserve on square area (2?×?2 km²) which is computed to be 63 million tons of medium-tough limestone as potential probable reserve.     

Influence of rainfall infiltration on the stability of unsaturated coal gangue accumulated slope

The slope instability is associated with increasing rate of rainfall infiltration which cause shear strength reduction and suction loss and the slope tend to fa...     

Exploring Placer Gold Deposits through Integrated Geophysical and Geochemical Techniques at the Confluence of the Indus and Kabul Rivers, NW Pakistan

Analysis of the anomalous magnetic mineral intensities and geochemistry for placer gold deposits are presented for those of the Attock area at the confluence of the Indus and Kabul rivers in northwestern Pakistan. Two grids covering an area of 10 x18 m² and 8 x10 m² were analyzed using a G-858 Cesium Vapor Magnetometer. The anomalous zones obtained were plotted on contour maps, 2 D and 3 D magnetic intensity maps. Based on the magnetic anomalies, grid-1 of the study area wa...