Geostatistical approach for mapping the transmissivity of the Senegalese deep aquifer system

Mamadou Lamine L. O., El Hadji Bamba D. I. A. W., Mamadou Wade, Alassane B. A., Saidou N. D. A. O., Cheikh Tidiane Sall and Gregoire Sissoko

Accurate estimation of hydrodynamics parameters of aquifers is extremely important for the exploitation and the proper management of aquifers systems. Transmissivity is one of these parameters and the withdrawal into an aquifer depends highly on the transmissivity. So, by the methods of geostatistics, this paper studies the spatial pattern of transmissivity of the Senegalese deep aquifer system. The results showed that the semivariogram of the transmissivity coefficient could be described by spherical model. Based on the information obtained from the field of study, the isocline maps of the transmissivity coefficient were created by the geostatistical software Surfer with Kriging interpolation, and the resulting maps gave a clear indication about the spatial patterns of the transmissivity.

The characteristic of ground motion a cause the earthquake activity in north Sulawesi Indonesia

Lantu, M. Altin Massinai and R. A. Kiki

Has done research on the study of relationship between the peaks ground acceleration (PGA) and peak ground velocity (PGV). In this study we generated the shake map that indicate the earthquake occurrence, identify the area affect and estimate the severity of ground shaking, providing information rapidly asses and mitigate damage. The relation between peak ground acceleration (PGA) and peak ground velocity (PGV) with intensity is required to estimate the risk of the earthquake in north Sulawesi. In this research, we developed empirical relationship between peak ground velocity, peak ground acceleration and observed Modified Mercalli Intensity (MMI) by using earthquake data in north Sulawesi in period 2003 to 2014. In this study we used the intensity earthquake = 4.5 SR. the empirical relationship between PGV and PGA with the intensity MMI determined in this study can be expressed as: MMI=4.3log??PGV+2.2 forV<MMI<IX MMI= 4.81log?PGA-1.5 forV<MMI<IX .The PGV and PGA based intensity are important in real-time application for damage prediction and assessment is much important for infra structure building in modern society. The analysis shows that the value pga largest to sulawesi north is 46, 33 gal and value pgv the largest 20.67 cm / s. The areas have value of the greatest intensity is kabupaten bolaang mongondow north with MMI intensity VII.

X ray and inductively coupled plasma atomic emission spectroscopy analysis of cristallographic structure and composition of pavement based clay materials

Hilaire Elenga, Timothee Nsongo, Bernard Mabiala, David Bilembi and Ferland Ngoro Elenga

In order to predict technological properties of local clay based materials mixed to wood waste and to prevent human health and environment, experimental mineral structure and composition study were conducted. The influence of wood waste on the structural properties of clay samples were also investigated. Non and stabilized clay sample at 4% of cement were made at different conditions and waste wood at different content have been incorporated. Mineralogical X-ray analysis was carried out using X- ray diffract meter with Geiger counter using cobalt a radiation with wavelength inductively coupled plasma atomic emission spectroscopy (ICP/AES) and inductively coupled plasma optical emission spectroscopy (ICP/OES) were used respectively to determine major, Minor and trace elements. The results showed that incorporation of wood waste has a strong effect on the crystallographic structure, making partially amorphous clay structure. It is found that the waste wood content doesn’t influence the lattice constants of the components of the clay. Chemical analysis of clay sample indicates kaolinite and SiO2 as a dominant clay minerals. The results has shown some trace and heavy metal contamination.

Earthquake risks in Bangladesh: Causes, vulnerability, preparedness and strategies for mitigation

Raihanul Islam

Bangladesh is facing a high risk of moderate to strong earthquakes that may result in widespread damage and loss of thousands of lives also the risk of tsunami as four active sources of earthquake in the Bay of Bengal can generate tremors with a magnitude of over 7 on the Richter scale in the Bay affecting the country seriously. Bangladesh is ill prepared to tackle the aftermath of any strong earthquake. Five geological fault lines run through the country, exposing it to highly vulnerable of a major quake by the experts. If a massive earthquake with 7 or greater magnitude occurred in this country will led a major human tragedy due to the faulty structures of many buildings and proper awareness. Thus, the study has been taken to promote efficient knowledge of the major causes, emerging risks, vulnerable zones, proper preparedness, impacts and approaches of mitigate impacts of earthquake in Bangladesh perspective.

A multi-technique approach to aquifer characterization of Basement Complex terrain: A case study of the Polytechnic, Ibadan, South-Western Nigeria

Akanmu T. O. and A. dewumi A. J.

A multi-technique was used to characterize aquifer within the Polytechnic Ibadan, part of the South-Western Nigeria Basement Complex. Electricity resistivity method was employed using the vertical electrical sounding techniques (VES). Nine types of curves were observed in the area and the A-type is most dominant. The resistivity of top soil varies from 40 to 1000 ?/m with a mean of 294.33 ?/m. geoelectric section show that a maximum of five units are below the subsurface section which include the top soil, lateritic layer, clay or weathered rock and the fractured/fresh bedrock. The reflection coefficient of the VES points shows that VES 1 and 3-15 are fractured. Five parameters: aquifer thickness, depth to aquifer, hydraulic conductivity, apparent resistivity and transmissivity were used to infer aquifer characteristics in the area. Spatial analyses reveal that aquifer thickness is highest at VES point 15 and lowest at VES point 6. Depth to aquifer is highest at VES point 15 and lowest at VES point 1. Statistical analyses were carried out using factor, hierarchical cluster and bivariate analyses. Factor analysis revealed that all the parameters studied have influence of aquifer in the study area. Cluster analysis grouped the points into five groups of similar properties between the studied aquifer.

Influence of change in climate and urban characteristics on hydraulic designs and drainage system in Mampong-Ashanti, Ghana

Kotei R., Kyei-Baffour N., Atakora E. T. and Monney I.

The objective of the study was to explore the challenges imposed by changing climate, rapidly expanding and modifying urban landscape on the hydraulic design of drainage infrastructure in Mampong-Ashanti, in Ghana. Basic approach to designing of urban drainage infrastructure was established through empirical peak runoff method, considering hydrologic input and appropriate design parameters. The Arc view GIS was used to delineate and determine the catchments characteristics and the state of the urban drains was established through observation. The urban sub-catchments has a mean convex slope of 5.65o, a mean slope length of 1.3 km, a relief of 137 m, a mean soil depth of 0.7 m, 48.09 % of impermeable surface, 69.8 % of area located on 7-10o slope class, a 110.46 % increase in urban area and a population growth of 3.3% per annum. Drainage facilities have not been holistically designed and are poorly maintained. The highest rainfall intensity of 60 minutes has increased by 21.0 % with a 1.17 % increase in mean monthly temperature. The city’s development does not strictly follow its Master Plan and needs to be reviewed. Drainage designs were based on basic hydraulic formulae without critically taking into consideration variance in runoff control variables in a warming environment with rapidly increasing runoff coefficient.

Analysis of rain fall onset and recession for decision making in rainfall water management in the west Hararegae Zone, Ethiopia

Konjit Sifer, Fitsume Yemenu, Asfaw Kebede and Shoeb Quarshi

This study was undertaken to assess and characterize the onset and recession of rainy season for supporting crop production in the study area for selected station of west Hararghe Zone of Oromiya, Ethiopia, based on simple water balance model. The mean onset of the main growing season was found to occur during the first meteorological dekade of July at Hirna, Second meteorological dekade of July at Asebe Tefer and last meteorological dekade of July at Meiso While ended during the end of September at Hirna, first meteorological dekade of October at Asebe Teferi and second meteorological dekade of September at Meiso. Similarly, though unreliable and only few occurred during the entire study period, the mean onset of Belg season was found to occur during the beginning of the last dekade of March for all study area. The length of the growing season during the main rainy season were 116days,102days and 85days at Hirna, Asebe Teferi and Meiso, with coefficient of variation and standard deviation of 9.42% 27%, 39%,and 18, 19, and 17days, with their respective orders. Similarly, the mean growing length during the Belg season was found to be 39days with a standard deviation of 32 days and coefficient of variation of 78.25% at Hirna, with mean LGP of 47 days, standard deviation of 18 days and coefficient of variation of 37% at Asebe Teferi and found to be 32days with a standard deviation of 23 days and coefficient of variation of 72.34% at Meiso.