Long-term seasonal rainfall forecasting: efficiency of linear modelling technique     

Iqbal Hossain  H. M. Rasel  Monzur Alam Imteaz  Fatemeh Mekanik 《Environmental Earth Sciences》2018,77(7):280

Using the lagged (past) climate indices, including El Nino–Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) as input parameters and long-term spring rainfall as outputs, calibration and validation of the linear multiple regression (MR) models have been performed. Since Australian rainfall varies both temporally and spatially, the analysis on the linear MR models was performed on regional scale. These models show the capability of linear MR technique for long-term predictions of Western Australian spring rainfall. The emphasis was given to assess the statistical correlations between Western Australian spring rainfall and dominating large-scale climate modes. The efficiency of linear modelling technique was evaluated to predict seasonal rainfall forecasting. At the same time, the Pearson correlation (R), mean absolute error, root-mean-square error and Willmott index agreement (d) were used to assess the capability of MR models. The models which fulfilled the limits of statistical significances were used for the prediction of future spring rainfall using independent data set. The results indicate that during calibration periods maximum achievable correlations varied from 0.47 to 0.53 for the selected stations. In regard to predict peaks and troughs of rainfall time series, it was found that correlations between predicted and actual peaks varied from 0.82 to 0.94 and between predicted and actual troughs varied from 0.53 to 0.91.  相似文献   

Ghaleh-khargushi rhyodacite and Gorid andesite from Iran: characterization,uses, and durability     

Ahmad Zalooli  David Martín Freire-Lista  Mashalah Khamehchiyan  Mohammad Reza Nikudel  Rafael Fort  Shahram Ghasemi 《Environmental Earth Sciences》2018,77(8):315

Durability of building stones is an important issue in sustainable development. Crystallization of soluble salts is recognized as one of the most destructive weathering agents of building stones. For this reason, durability of Ghaleh-khargushi rhyodacite and Gorid andesite from Iran was investigated against sodium sulfate crystallization aging test. Petrographic and physico-mechanical properties and pore size distribution of these stones were examined before and after the aging test. The characteristics of the microcracks were quantified with fluorescence-impregnated thin sections. Durability and physico-mechanical characteristics of Ghaleh-khargushi rhyodacite are mainly influenced by preferentially oriented preexisting microcracks. Stress induced by salt crystallization led to the widening of preexisting microcracks in Ghaleh-khargushi rhyodacite, as confirmed by the pore size distributions before and after the aging test. The preexisting microcracks of Gorid andesite were attributed to the mechanical stress induced by contraction of lava during cooling. The number of transcrystalline microcracks was significantly increased after the aging test. The degree of plagioclase microcracking was proportional to its size. Durability of the studied stones depends on initial physico-mechanical properties, pore size distribution, and orientation of microcracks. Initial effective porosity is found to be a good indicator of the stones’ durability. Salt crystallization resulted in an increase in the effective porosity with a parallel decrease in the wave velocities. Surface microroughness parameters increased with the development of salt crystallization-induced microcracking. Gorid andesite showed higher quality and durability than Ghaleh-khargushi rhyodacite.  相似文献   

Biostratigraphy and paleogeography of the southeast desert phosphorites of Jordan     

Belal S. Amireh  Joerg Mutterlose  Mazen N. Amaireh  Tobias Puettmann  Abdulkader M. Abed 《Arabian Journal of Geosciences》2018,11(15):425

Three sections from the Al-Hisa Phosphorite Formation (AHP) were measured in the southeastern desert of Jordan: Batn El-Ghoul, Nagb Etayyeg, and Zgaimat Al-Hasah. A fourth section, Wadi Arfa, is added from a previous work. The three sections differ from the typical AHP Formation in central Jordan by having highly reduced thicknesses, omission/non-deposition of the underlying formations, rarity of fossils, abundant sand, and their stratigraphic ages. A Paleocene-Early Eocene age, based on calcareous nannofossils, has been assigned to the AHP Formation of the sections studied in the southeast desert. This Paleocene-Early Eocene age is younger than the Early Maastrichtian age of the AHP deposits in central Jordan. The published ages of the phosphorite deposits in the eastern Mediterranean countries suggest a younging to the east due to an interplay between paleodepositional environments and plate tectonics (paleohigh formation). The minor phosphorite deposits of Turkey and Iran are not involved in the discussion because they were not part of the Afro-Arabian Plate or the later Arabian Plate. The abovementioned differences between the southeastern desert phosphorites and the central Jordan deposits are here explained by the formation of paleohighs on the Neo-Tethys seafloor during the Late Cretaceous-Eocene. These include the Sirhan Paleohigh where the southeast desert phosphorites were deposited. The formation of the highs was due to the compression associated first, with the subduction of the Afro-Arabian Plate, below the Eurasian Plate and later with their collision.  相似文献   

Diagenetic evolution vis-a-vis reservoir characteristics of Dhosa sandstones,Ler dome,Kachchh, western India     

Asma A. Ghaznavi  Mohammad Masroor Alam  Zuhi Khan  A. H. M. Ahmad 《Arabian Journal of Geosciences》2018,11(14):387

The detrital mineralogy as well as diagenetic characters of the Dhosa Sandstone Member of Chari Formation exposed at the Lerdome, south of Bhuj was studied. In order to assess the potential of the Dhosa Sandstone as a reservoir, it is substantial to understand the diagenetic processes that are controlled largely by post-depositional cementation and compaction in addition to framework composition and original depositional textures. The petrologic analysis of 33 thin sections was carried out to discern primary composition and diagenetic features including primary and secondary porosity patterns. Monocrystalline quartz dominates the detrital mineralogy followed by polycrystalline quartz. Among the polycrystalline variety recrystallized metamorphic quartz surpasses stretched metamorphic quartz in terms of abundance. Feldspars comprise microcline and plagioclase where the former is dominant over the latter. Orthoclase too comprises a very small percentage. Mica, chert, rock fragments, and heavies form the remaining detrital constituent in descending order of their constituent percentage. The diagenetic precipitates are mainly carbonate (8.30%) and iron (7.80%) followed by clay (0.66%) and silica (0.88%) that are minor constituent of the total cementing material. The main paragenetic events identified are early cementation, mechanical compaction, late cementation, dissolution, and authigenesis of clays. The overall reservoir quality seems to be controlled by compaction and authigenic carbonate cementation. The minus cement porosity average 29.4%. The porosity loss due to compaction is 21.92% and by cementation is 29.71%. The loss of original porosity was due to early cementation followed by moderate mechanical compaction during shallow burial. Preservation of available miniscule primary porosity was ascribed to dissolution of carbonates and quartz overgrowth which resisted chemical compaction during deep burial. The studied sandstones may have low reservoir quality owing to existing porosity of less than 9%. More carbonate dissolution and its transformation in dolomite in sub-surface condition and macro-fracture porosity may result in enhanced secondary porosity and good diagenetic traps.  相似文献   

Analysis of pervasive precipitation in similar gradient areas of Iran     

Hossein Asakereh  Mohammad Darand  Mehdi Doostkamian 《Arabian Journal of Geosciences》2018,11(17):511

Precipitation is a major climatic element with high spatial variations. Temporal and spatial variations may differ in large and small scales. It is, therefore, of utmost importance to study areas with similar gradients in terms of precipitation patterns in order to shed light on the complexities of precipitation variations. In the present study, attempts were made to identify areas with similar gradients experiencing the same precipitation pattern over a 50-year period (1964–2013). To this end, data were collected from synoptic stations in Iran in two phases (i.e., 1434 stations in the first phase and 673 stations in the second one). Alexanderson’s technique was adopted to examine sudden changes in precipitation patterns. The results showed that five regions with similar gradients could be identified in terms of precipitation patterns: negative and high variations, negative and moderate variations, positive and high variations, positive and moderate variations, and little or no variations. The distribution of such regions indicated that the regions with positive trends experienced more annual variations and had further spatial distribution. Furthermore, the findings revealed that the regions with negative precipitation patterns experienced more sudden changes in comparison with those with positive precipitation patterns. Additionally, more variations were observed in the precipitation patterns in recent years.  相似文献   

Synthesis of biochar from sugarcane filter-cake and its impacts on physiological performance of lettuce (<Emphasis Type="Italic">Lettuce sativa</Emphasis>) grown on cadmium contaminated soil     

Anum Sehar  Rukhsanda Aziz  Muhammad Tariq Rafiq  Muhammad Mazhar Hussain  Muhammad Rizwan  Adiba Khan Sehrish  Muhammad Khalid Rafiq  Jalal ud Din  Qaiser Hussain  Mohammad I. Al-Wabel  Shafaqat Ali 《Arabian Journal of Geosciences》2018,11(20):634

Soil contamination with cadmium has become major concern all over the world because of its adverse impacts on ecosystem health and agricultural land. Soil amendment with biochar may have varied effects on physical and chemical properties of soil. The objective of the study was to explore the impact of sugarcane filter-cake biochar on physiological performance and growth of lettuce in an aged soil. Four different doses (0, 1.5%, 3%, and 5%) of biochar were used in the soil and conditioned for 1 month. After this, lettuce seedlings were grown in the soil. The results showed that the biochar treatment improved the fresh and dry biomass of leaves and roots as well as plant height while diminished the bioavailability of cadmium from the soil. As compared to control, biochar significantly enhanced the chlorophyll content in lettuce leaves. Due to the biochar amendment, the oxidative stress decreased in lettuce shoots over the control. As compared to control, concentration of cadmium in lettuce significantly decreased after the application of biochar. It was concluded that biochar could mitigate the toxicity of cadmium in lettuce by altering the biochemical and physiological processes in cadmium contaminated soil.  相似文献   

Determining the hard rock groundwater pathway in Golgohar complex formation using hydrochemical data in AHP     

Saeid Maknouni  Mohammad Zare  Ezzatollah Raeisi 《Arabian Journal of Geosciences》2018,11(8):172

Thirty percent of present industrial water consumption of the Golgohar Iron Ore Mine (GIOM) is supplied from a hard rock well (PW-A15) and the rest from 25 wells located in 4 disconnected alluvial aquifers. This well is drilled in the metamorphic complex of Golgohar formation. Attempts have been made to develop extraction of water from other hard rocks existing in the area with no success. Therefore, extensive researches have been carried out to find the pathway, or a provision pathway of water discharged from this well. To study the hydrochemical similarity of this water with other water resources, 122 water samples from an area of 7132 km² were collected from the existing pumping wells, piezometers, mine exploration bore holes, and three salt pans in the vicinity of the area for hydrochemical analysis. The analyses were performed for concentration of major ions and some minor elements. Furthermore, the spatial distribution of ion concentration was plotted in the GIS to delineate the similarity of the PW-A15 water with other water sources and their hydrochemical neighborhood by analytical hierarchy process (AHP). The AHP was performed in two steps: first, iso-concentration maps of seven major ions, eight minor elements, and TDS were used to produce an AHP map (Map1) using weights for different hydrochemical parameters; and second, a similarity index (SI) map was prepared by performing a suggested clustering approach in SPSS using K-means clustering, which was overlaid on Map1 producing Map2. The result of AHP Map2 was then overlaid on the iso-potential map of the sampled locations in GIS software using a mask operator. Therefore, the zones having the most similarity and higher hydraulic potential than PW-A15 were nominated as the zones which possibly could recharge this well, and the groundwater (GW) pathway was proposed. The result of the study method showed to be successful and will be used as a guide for future exploration drillings.  相似文献   

Retrieving of Land Surface Temperature Using Thermal Remote Sensing and GIS Techniques in Kandaihimmat Watershed,Hoshangabad, Madhya Pradesh     

Mohammad Subzar Malik  J. P. Shukla 《Journal of the Geological Society of India》2018,92(3):298-304

Remotely sensed thermal infrared (TIR) data have been widely used to retrieve land surface temperature (LST). LST is an important parameter in the studies of urban thermal environment and dynamics. In the study, an attempt has been made using LANDSAT 8 thermal imagery to compute LST and the associated land cover parameters viz; land surface emissivity (LSE), normalized difference vegetation index (NDVI), normalized difference built-up index (NDBI) and normalized difference water index (NDWI). Landsat 8 TIRS band 10 & 11 (thermal bands) during 21 Oct. 2016, 22 Nov.2016, 24 Dec. 2016 and 09 Jan. 2017 were processed for LST analysis. However, band 5 & band 4 of the imagery was processed for NDVI, band 6 & band 5 for NDBI and band 2 & band 5 for NDWI analysis. LST has been derived from both the bands 10 &11 and validated by in-situ observations on the date and time of satellite overpass from the study area. Band 10 derived LST have shown much temperature difference while comparing with the in-situ observations. However, LST derived from band 11 found similar & close to the in-situ measurements. Relationship between band 11 results and in-situ observed measurements were developed, which has showing a strong correlation with (r² = 0.991). Land surface emissivity were also evaluated which shows variation in different land cover surfaces like vegetation, settlement, forest cover and water body. The study has proven that land surface temperature derived from satellite band 11 is the actual surface temperature of the study area.  相似文献   

Geology and Active Tectonics of the Lalmai Hills,Bangladesh–An Overview from Chittagong Tripura Fold Belt Perspective     

Md. Sharif Hossain Khan  Md. Sakawat Hossain  Md. Azim Uddin 《Journal of the Geological Society of India》2018,92(6):713-720

The Lalmai Hills is a low amplitude anticline with significant variations in landforms, situated along the western fringe of the Chittagong-Tripura Fold Belt (CTFB) and immediate east of the Indo-Burmese deformation front. This fold belt of the Bengal Basin along with more easterly Indo-Burman Range (IBR) developed as a consequence of the oblique collision between Indian and Burmese plates. This neotectonic activity is still continuing and shaping the geomorphology of the area. This study is conducted based on the geomorphological observation of the topo maps and satellite images, and through reconnaissance field work. Stream length gradient index (SL Index) and Mountain front sinuosity (S_mf) reveals the relative status of tectonic activity. Anomalous SL index values confirm the position of the sympathetic minor faults and also relate to the local stratigraphy. A 2D structural model based on the seismic section reveals thrusts controlled wedge-shape upliftment of the central part as pop-up anticlinal structure. The western thrust is the direct result of the collision of the Indian and Burmese plates, and the eastern one is the back thrust of the western fault. Low S_mf value found in the western flank signifies recent tectonics and relatively high S_mf value in the eastern flank indicates that weathering intensity is relatively greater compared to western flank. Finally, the findings not only enhanced the understanding of geomorphic evolution and active tectonics of the Lalmai Hills area but also the overall tectonic and geomorphic evolution of the western most folded part of the CTFB.  相似文献   

Petrogenesis and tectonic association of rift-related basic Panjal dykes from the northern Indian plate,North-Western Pakistan: evidence of high-Ti basalts analogous to dykes from Tibet     

Sajid  Muhammad  Andersen  Jens  Arif  Mohammad 《Mineralogy and Petrology》2018,112(3):415-434

Mineralogy and Petrology - Rift related magmatism during Permian time in the northern margin of Indian plate is represented by basic dykes in several Himalayan terranes including north western...  相似文献