Journal of Geology and Geosciences最新文献

{"title":"Potential Impacts of Climate Change on the Hydrology and Water resources Availability of Didessa Catchment, Blue Nile River Basin, Ethiopia","authors":"Sintayehu Legesse Gebre, K. Tadele, B. G. Mariam","doi":"10.4172/2329-6755.1000193","DOIUrl":"https://doi.org/10.4172/2329-6755.1000193","url":null,"abstract":"This study was carried out in Didessa catchment, which is situated in the south-west part of Blue Nile River Basin. This part of the basin is very important due to the location of the place where different water resources development are undertaking, like the Grand Renaissance dam and other development projects, So it was crucial to study and evaluate the potential impacts of climate change on the hydrology and water resources availability. Future Climate change scenarios of precipitation, temperature and potential evaporation were developed using output of dynamically downscaled data of ECHAM5 (GCM) 50 Kms resolution under A1B emission scenario for 2030’s (2031-2040) and 2090’s (2091-2100). The future projection of the GCM model of climate variables showed an increasing trend as compared to the base line period (1991-2000). At 2030`s and 2090`s average annual precipitation may increases by +33.22% and+8.40% respectively over the Didessa catchment. The climate changes variables used as input in to HBV hydrological model to simulate the future runoff at the out let of gauging station of Near Arjo town. The impact of climate change on future runoff resulted a positive magnitude change in average runoff flow at the outlet of the catchment. The increase in average runoff is associated with the increase in precipitation projection over the catchment. During the main rainy season of summer, at 2030`s and 2090`s average seasonal runoff percentage change may increase up to+157% and+136% respectively as compared to the base line period. Hence, more likely in the future the water resources availability may increases in the catchment. This may create an opportunity for small scale farmers to harness enough amount of water during rainy season for later use.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"164 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124600651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Application of Vertical Electrical Sounding (VES) for Groundwater Exploration in Tudun Wada Kano State, Nigeria","authors":"Musa Garba Abdullahi, M. Toriman, M. B. Gasim","doi":"10.4172/2329-6755.1000186","DOIUrl":"https://doi.org/10.4172/2329-6755.1000186","url":null,"abstract":"A new simple and quick geophysical method for groundwater exploration in the crystalline rocks of Tudun Wada Kano State, Nigeria has been developed. A geophysical evaluation using Electrical Resistivity method for groundwater exploration at the study area was carried out which involved the utilization of Vertical Electrical Sounding (VES) technique with schlumberger array system. The study area is located within the sedimentary rocks, igneous, and metamorphic with alluvial as common types of rocks. The data acquired from six (6) VES stations using ABEM terrameter (SAS 300) was tabulated in a table which shows the resistivity, the thicknesses and the number of layers for each VES station. The data was analyzed using computer software called IPI2win, which yield an automatic interpretation of the apparent resistivity. The VES results revealed heterogeneous nature of the subsurface geological sequence. The geological profile sequence in the study area include the topsoil, weathered layer, fractured basement and fresh basement. The value for topsoil ranges from 16 Ωm to 550 Ωm with thickness varies from 1.45 m to 6.05 m. The weathered layer resistivity ranges from 14 Ωm to 541 Ωm and thickness of 5.70 m to 33.00 m. The fractured basement ranges in value from 189 Ωm to 785 Ωm with thickness ranges from 11 m to 20 m. The fresh or bedrock basement has a resistivity of 1011 Ωm to 3006 Ωm which move down infinitely. Therefore the depth of the bedrock from the topsoil or earth’s surface ranges from 2 m to 45 m.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122424766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of Nearly Perfectly Matched Layer with Second-order Acoustic Equations in Seismic Numerical Modeling","authors":"Gulsah Metin, Jingyi Chen, Can Ozsoy","doi":"10.4172/2329-6755.1000120","DOIUrl":"https://doi.org/10.4172/2329-6755.1000120","url":null,"abstract":"A crucial part of pre-stack reverse time migration is forward numerical computation of seismic wave propagation. However, there exist serious spurious reflections from truncated model edges during the simulation of wave propagation. In this work, we present a novel absorbing boundary layer named nearly perfectly matched layer (NPML) to suppress artificial reflections from model boundaries. Different from seismic numerical study on first-order partial differential equations, NPML with second-order acoustic equations is implemented here. Through checking snapshots of seismic wave propagation and seismograms, the numerical modeling results illustrate that the NPML is able to effectively absorb the outgoing waves at the truncated domain. Finally, our NPML algorithms are combined with the implementation of pre-stack reverse time migration to achieve accurate depth image of subsurface.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121791986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Water Resources of African Circum-Sahara Sub Region (Renewable and Non-renewable Approach)","authors":"Samir Anwar Al-Gamal, Y. Hamed","doi":"10.4172/2329-6755.1000181","DOIUrl":"https://doi.org/10.4172/2329-6755.1000181","url":null,"abstract":"Circum is a preposition in Latin meaning “around” and Sahara is a preposition in Arabic meaning “Desert” so it is the regions around African desert. Studies related to Circum-Sahara are too little in-depth knowledge and focus on certain basins but, are generally limited by national boundaries, and do not take account of the transboundary portions of the reservoirs. The resulting development plans for these limited resources, thus, are seriously impeded by ignorance of the mutual effects of intensive withdrawal. Circum –Sahara region has the least renewable water resources of all geopolitical regions of the world, after the Middle East where the renewable fresh natural water resources amounts to 520 km3/year compared to 42,600 km3/yr worldwide. Surface water resources: These are represented by nine border crossing river basins of 1. Nile, 2. Niger 3. Senegal, 4. Gambia, 5. Volta, 6. Chari, 7. Guir-Saoura; 8. Mejerdah; 9. Juba-Shebelle. However and as a result of the arid or semi-arid climatic conditions which prevail in most of the region, the renewable surface water resources are not only temporally irregular but also often difficult to store. Groundwater resources: These are represented by eight border crossing aquifers and can be classified as renewable and non-renewable groundwater resources, these are 1- Nubian Aquifer System (NSAS); 2- North-Western Sahara Aquifer System (NWAS); 3-Senegalo-Mauritanian Aquifer System (SMAS); 4-Taoudeni Aquifer System (TAS); 5-Mourzouk-Djado Aquifer System (MDAS); 6-Irhazer-Iullemeden Aquifer System (IMAS); 7-Chad Aquifer System (CAS); 8- Errachidia Aquifer System (EAS). The yield of natural resources per inhabitant amounts to 1,000 m3/yr per inhabitant (which corresponds to a population density of 1,000 inhabitants per million m3/yr of resource) .At the present time, six countries of the Circum-Sahara region have natural water resources below 1,000 m3/yr per inhabitant (essentially the Maghreb, in addition to Egypt and Kenya). One of these, Libya, has less than 500 m3/yr. In 2025, another four more countries (Burkina Faso, Ethiopia, Morocco and Somalia) will have resources below 1,000 m3/yr per inhabitant, making a total of ten countries and 405 million inhabitants (69% of the total of all the Circum-Sahara countries).The future hydrology of this region is not rosy and may lead to political disputes.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134146806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave Polarization and Gradient Ratio (MPGR) for Global Land Surface Phenology","authors":"M. Boori, R. Ferraro","doi":"10.4172/2329-6755.1000114","DOIUrl":"https://doi.org/10.4172/2329-6755.1000114","url":null,"abstract":"Satellite-generated brightness temperatures (BT) are largely influenced by soil moisture and vegetation cover. Microwave polarization and gradient ratio (MPGR) is an effective indicator for characterizing the land surface phenology from sensors like EOS Advanced Microwave Scanning Radiometer (AMSR-E).The MPGR combines the microwave gradient ratio with polarization ratio to determine surface characteristics (i.e., bare soil/developed, ice, and water) and under cloud covered conditions when this information cannot be obtained using optical remote sensing data. This investigation uses the HDF Explorer, Matlab, and ArcGIS software to process the pixel latitude, longitude, and BT information from the AMSR-E imagery. This paper uses the polarization and gradient ratio from AMSR-E BT for 6.9, 10.7, 18.7, 23.8, 36.5, and 89.0GHz to identify seventeen land cover types. A smaller MPGR indicates dense vegetation, with the MPGR increasing progressively for mixed vegetation, degraded vegetation, bare soil/developed, and ice and water. This information can help improve the characterization of land surface phenology for use in weather forecasting applications, even during cloudy and precipitation conditions which often interferes with other sensors.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114954545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Vegetation Discontinuities Related to the Yazoo City Tornado Scar and Enhanced Convection","authors":"Gutter Bf, Brown Me, C. Da","doi":"10.4172/2329-6755.1000185","DOIUrl":"https://doi.org/10.4172/2329-6755.1000185","url":null,"abstract":"The Yazoo City tornado occurred on April 24, 2010, traveling 240 km from Tallulah, Louisiana through Yazoo City, Mississippi and ending near Starkville, Mississippi. The tornado reached a maximum wind speed of 76 m s-1 and obtained a maximum width of 2.8 km. Landsat imagery showed a distinct vegetation scar along the majority of the path of the tornado. Abrupt changes in vegetation and the related sensible and latent heat fluxes have been shown to enhance convective activity along and near the resulting land surface discontinuities. The enhancement of convection is likely related to mesoscale circulations generated along thermal and moisture discontinuities and is best identified during synoptically benign periods. This study analyzed heightened convective activity (analyzed by looking at cloudto- ground lightning data) along the Yazoo City tornado track on days of weak synoptic forcing. 2010 had the greatest percentage of convectively active synoptically benign days with 66 percent. Years prior to the Yazoo City tornado had a lower percentage of convectively active synoptically benign days with 50 percent.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125386174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Some Aspects of Numerical Simulation of Seismic Wave Propagation","authors":"Jingyi Chen","doi":"10.4172/2329-6755.1000E109","DOIUrl":"https://doi.org/10.4172/2329-6755.1000E109","url":null,"abstract":"Copyright: © 2013 Chen J. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Over the last decades, numerical simulation of seismic wave propagation has become an important tool to better understand the characterization of wave propagation and rock properties. It also plays a significant role in seismic data processing and interpretation [1]. Here, several important aspects of seismic numerical modeling of wave propagation will be mentioned, such as numerical algorithms for solving partial differential wave equations, absorbing boundary condition and high performance computing techniques.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"290 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123108301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parallel Buffer Generation Algorithm for GIS","authors":"Xiaomeng Huang, Tian Pan, Huabin Ruan, H. Fu, Guangwen Yang","doi":"10.4172/2329-6755.1000115","DOIUrl":"https://doi.org/10.4172/2329-6755.1000115","url":null,"abstract":"A buffer generation algorithm that identifies areas of a given distance surrounding geographic features is one of the most frequently used functions in GIS. With the increase of scale and precision in geographic data, the efficiency of the buffer generation algorithm has been of great concern. This study presents a novel integrated solution consisting of a points-based, load-balanced method and a binary union tree method to accelerate the buffer generation. By comparing several parallel candidates, the experimental results show that our new parallel algorithm achieves greater performance and scalability, and its speed increases by 21 times with 32 processes.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129253042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Global Warming Gas Balance in Response to Increasing Concentrations: Perspectives from a Laser Induced Ablation and Gas Evaporation","authors":"Melissa B. Blau","doi":"10.4172/2329-6755.1000141","DOIUrl":"https://doi.org/10.4172/2329-6755.1000141","url":null,"abstract":"Tremendous work and results of prognostic models were yielded in the field of global warming in the past three decades. In a laser experiment we discovered an unusual relation between the expansion and collapse dynamics of the observed gas bubbles, whereas these two values were always related to each other, their sum being always equal to their product. Analyzing the results, we discovered an unknown intrinsic mechanism being the cause of global warming, which is associated with the increase in concentration of carbon-13, carbon-14, oxygen-17, nitrogen-14 and 15 and flour-19 of global warming gases in the atmosphere. While the saturation of these gases depends on the revealed special relation between emitted infra-red rays and the wavelength of absorbed rays, which is an important new finding, an increase in concentration of global warming gases can create an imbalance, leading to an increase in global temperature. The formula which was calculated is able to accurately predict atmospheric warming and global climate changes.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116173866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis and Geotectonic Settings of the Granitic Rocks of Idofin-osi-eruku Area, Southwestern Nigeria using Trace Element and Rare Earth Element Geochemistry","authors":"S. Odewumi, V. Olarewaju","doi":"10.4172/2329-6755.1000109","DOIUrl":"https://doi.org/10.4172/2329-6755.1000109","url":null,"abstract":"The Idofin-Osi-Eruku area occur in the south-eastern margin of the southwestern sector of the Nigerian Basement Complex. Granitic rocks and early gneiss samples were studied geologically and geochemically using ICP-MS. The study focuses on the trace elements and rare earth elements geochemistry in determining the geochemical characteristics and geotectonic processes of formation of the granitic rocks. Geologically, Idofin-Osi-Eruku area is underlain by early gneiss, quartzite and marble which have been intruded by granite gneiss, porphyritic granite and fine to medium-grained granite of probable Pan-African (ca. 600Ma) age. Geochemical data indicate that the granitic rocks are Fe-rich potassic granites. The varying ratios of the incompatible elements of Rb/Sr ratios (0.664-1.388) in porphyritic granite, (0.338-2.390) in the fine to medium-grained granite and (0.593-1.509) in granite gneiss are higher than Rb/Sr ratio (0.029) in the early gneiss. Also, Ba/Sr ratios (2.815-5.424) in porphyritic granite, (3.463-4.636) in fine to-medium grained granite and (2.132-4.734) in granite gneiss are higher than Ba/Sr ratio (0.912) in the early gneiss. And Ba/Rb ratios (2.486-6.192) in porphyritic granite, (1.473-1.520) in the fine to-medium grained granite and (3.183-3.595) in the granite gneiss are lower than Ba/Rb ratio (31.02) in the early gneiss. Higher ratios of Rb/Sr and Ba/Sr, and lower ratio of Ba/Rb in the granitic rocks than the early gneiss indicate high fractionation associated with magmatic differentiation. The granite rocks have fractionated REE patterns characterized by enrichment in the LREE which is confirmed by high values of the normalized ratios of La/Yb, Ce/Yb and La/Sm, with negative europium anomalies and varying degrees of HREE depletion which is typical of the crust and also of calc-alkaline rocks. Based on the overall abundances of REE, the similarities in the REE patterns of the granitic rocks suggest the same origin. Geotectonically, the granite gneiss, fine to medium-grained granite and porphyritic granite plot as syncollisional and volcanic arc granites. The granitic rocks are products of volcanic arc magmatism emplaced in the late phase of the Pan-African Orogeny.","PeriodicalId":344421,"journal":{"name":"Journal of Geology and Geosciences","volume":"2 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114036442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}