scholarly journals GIS-Based Sub-Basin Scale Identification of Dominant Runoff Processes for Soil and Water Management in Anambra Area of Nigeria

2017 ◽  
Vol 6 (2) ◽  
pp. 80-93 ◽  
Author(s):  
Babatunde Joseph Fagbohun ◽  
Oluwaseun Franklin Olabode ◽  
Abiodun Olufemi Adebola ◽  
Francis Omowonuola Akinluyi
Keyword(s):  
Overland Flow ◽  
Expert Knowledge ◽  
Regional Scale ◽  
Field Investigation ◽  
Deep Percolation ◽  
Percolation Process ◽  
Basin Scale ◽  
Least Area ◽  
Expected Increase

AbstractIdentifying landscapes having comparable hydrological characteristics is valuable for the determination of dominant runoff process (DRP) and prediction of flood. Several approaches used for DRP-mapping vary in relation to data and time requirement. Manual approaches which are based on field investigation and expert knowledge are time demanding and difficult to implement at regional scale. Automatic GIS-based approach on the other hand require simplification of data but is easier to implement and it is applicable on a regional scale.In this study, GIS-based automated approach was used to identify the DRPs in Anambra area. The result showed that Hortonian overland flow (HOF) has the highest coverage of 1508.3 km2(33.5%) followed by deep percolation (DP) with coverage of 1455.3 km2(32.3%). Subsurface flow (SSF) is the third dominant runoff process covering 920.6 km2(20.4%) while saturated overland flow (SOF) covers the least area of 618.4 km2(13.7%) of the study area. The result reveal that considerable amount of precipitated water would be infiltrated into the subsurface through deep percolation process contributing to groundwater recharge in the study area. However, it is envisaged that HOF and SOF will continue to increase due to the continuous expansion of built-up area. With the expected increase in HOF and SOF, and the change in rainfall pattern associated with perpetual problem of climate change, it is paramount that groundwater conservation practices should be considered to ensure continued sustainable utilization of groundwater in the study area.

scholarly journals Identifying Dominant Runoff Processes at a Regional Scale – A GIS - Based Approach

2017 ◽  
Vol 11 (2) ◽  
pp. 19-33
Author(s):  
Fagbohun Babatunde Joseph ◽  
Olabode Oluwaseun Franklin ◽  
Adebola Abiodun Olufemi
Keyword(s):  
Overland Flow ◽  
Expert Knowledge ◽  
Regional Scale ◽  
Field Investigation ◽  
Deep Percolation ◽  
Flood Prediction ◽  
Percolation Process ◽  
Least Area ◽  
Expected Increase

Abstract Identifying landscapes with similar hydrological characteristics is useful for the determination of dominant runoff process (DRP) and flood prediction. Several approaches used for DRP-mapping differ in respect to time and data requirement. Manual approaches based on field investigation and expert knowledge are time consuming and difficult to implement at regional scale. Automatic GIS-based approach on the other hand require simplification of data but are easier to implement and it is applicable on regional scale. In this study, GIS-based automated approach was used to identify the DRPs in Anambra area. The result showed that Hortonian Overland Flow (HOF) has the highest coverage of 1508.3 Km2 (33.5%) followed by Deep Percolation (DP) with coverage of 1455.3 Km2 (32.3%). Subsurface Flow (SSF) is the third dominant runoff process covering 920.6 Km2 (20.4%) while Saturated Overland Flow (SOF) covers the least area of 618.4 Km2 (13.7%) of the study area. The result reveal that considerable amount of precipitated water would be infiltrated into the subsurface through deep percolation process contributing to groundwater recharge in the study area. However, it is envisaged that HOF and SOF will continue to increase due to the continuous expansion of built-up area. With the expected increase in HOF and SOF and the change in rainfall pattern associated with perpetual problem of climate change, it is paramount that groundwater conservation practices be considered to ensure continued sustainable utilization of groundwater in the study area.

scholarly journals Identifying Dominant Runoff Processes at a Regional Scale – A GIS - Based Approach

2018 ◽  
Vol 12 (1) ◽  
pp. 19-33
Author(s):  
Babatunde Joseph Fagbohun ◽  
Oluwaseun Franklin Olabode ◽  
Abiodun Olufemi Adebola
Keyword(s):  
Overland Flow ◽  
Expert Knowledge ◽  
Regional Scale ◽  
Field Investigation ◽  
Deep Percolation ◽  
Flood Prediction ◽  
Percolation Process ◽  
Least Area ◽  
Expected Increase

Abstract Identifying landscapes with similar hydrological characteristics is useful for the determination of dominant runoff process (DRP) and flood prediction. Several approaches used for DRP-mapping differ in respect to time and data requirement. Manual approaches based on field investigation and expert knowledge are time consuming and difficult to implement at regional scale. Automatic GIS-based approach on the other hand require simplification of data but are easier to implement and it is applicable on regional scale. In this study, GIS-based automated approach was used to identify the DRPs in Anambra area. The result showed that Hortonian Overland Flow (HOF) has the highest coverage of 1508.3 Km2 (33.5%) followed by Deep Percolation (DP) with coverage of 1455.3 Km2 (32.3%). Subsurface Flow (SSF) is the third dominant runoff process covering 920.6 Km2 (20.4%) while Saturated Overland Flow (SOF) covers the least area of 618.4 Km2 (13.7%) of the study area. The result reveal that considerable amount of precipitated water would be infiltrated into the subsurface through deep percolation process contributing to groundwater recharge in the study area. However, it is envisaged that HOF and SOF will continue to increase due to the continuous expansion of built-up area. With the expected increase in HOF and SOF and the change in rainfall pattern associated with perpetual problem of climate change, it is paramount that groundwater conservation practices be considered to ensure continued sustainable utilization of groundwater in the study area.

scholarly journals Determination in the District Area Galunggung Sukaratu as Strategic Areas Amusement

2016 ◽  
Vol 4 (1) ◽  
pp. 86
Author(s):  
Thomas Bustomi
Keyword(s):  
Action Research ◽  
Regional Scale ◽  
Evaluation Criteria ◽  
Policy Formulation ◽  
Regional Economic Growth ◽  
Business World ◽  
Tourism Sector ◽  
Research Action ◽  
Official Data

This study entitled “Determining Region Galunggung in District Sukaratu As Strategic Area Nature”. The purpose of this policy is to increase the activity of the business world in the tourism sector in KGG - KS so as to improve the regional economic growth both on a district or on a regional scale Tasikmalaya regency. The method used in this research is action research (action research) using a qualitative approach. Results of the study were divided into four categories: problem identification, determination of the terms of problem solving, determination of alternative policy formulation and determination of the alternative selected as the end result of this policy formulation. Official data are not obtained, shall be carried out exploration data / information through other means in order to identify the problems become whole / full. In this research, a lack of data / information that is experienced by the researchers can be overcome because there is input from the community although its accuracy is lower. Meanwhile, the establishment of technical provisions troubleshooting is done based on a reference from the rules of the policy object. Each process / stages of policy formulation are not always able to generate a specific output. Determination of the technical provisions of Resolution “or the theory of public policy referred to as” the evaluation criteria Resolution “is one very important part in the process of policy formulation.

Direct Determination of the Velocity of Vortices in High-Tc Superconductors by a Non-Equilibrium Method

1998 ◽  
Vol 12 (29n31) ◽  
pp. 3288-3291
Author(s):  
I. Kirschner ◽  
R. Laiho ◽  
A. C. Bódi ◽  
E. Lähderanta ◽  
I. Vajda
Keyword(s):  
Magnetic Field ◽  
Temperature Gradient ◽  
Vortex Motion ◽  
Direct Determination ◽  
Field Investigation ◽  
High Tc Superconductors ◽  
High Tc ◽  
Pinning Centers ◽  
Non Equilibrium

As is shown, thermally assisted vortex motion can come into being in high-T c superconductors due to the applied temperature gradient. Its behavior strongly depends on the local and global microstructure of the samples, moreover on the temperature and magnetic field. Investigation of the density, size and intensity of the pinning centers of specimens leads to the conclusion that the higher homogeneity immediately weakens and the lower one strenghtens the pinning, thus the former promotes and the latter impedes the vortex motion. The non-equilibrium experimental technique together with a.c. susceptibility measurements render possible the direct determination of the velocity of vortices. Depending on the actual microstructural state of samples it has the values between 6 × 10-2 mm/s and 18 × 10-2 mm/s in the case of Y-Ba-Cu-O specimens investigated.

scholarly journals DETERMINATION OF COST OF PRODUCTION IN CONDITIONS OF UNCERTAINTY OF ORDERS

2016 ◽  
Vol 4 (4) ◽  
pp. 499-504
Author(s):  
Ольга Глод ◽  
Olga Glod ◽  
Виктор Ланкин ◽  
Viktor Lankin
Keyword(s):  
Fuzzy Logic ◽  
Expert Knowledge ◽  
Small Enterprises ◽  
Methodological Basis ◽  
Cost Of Production ◽  
The Cost

The purpose of this paper is to examine the model to determine the cost of production of small enterprises. The methodological basis for the model is a fuzzy logic based on expert knowledge. As a result, in this paper we consider an example of the model, determined the cost of production of confectionery

scholarly journals TERENO: German network of terrestrial environmental observatories

2016 ◽  
Vol 2 ◽  
Author(s):  
Heye Reemt Bogena
Keyword(s):  
Regional Scale ◽  
Scale Up ◽  
Climate Change Impacts ◽  
Integrated Modelling ◽  
Small Scale ◽  
Catchment Scale ◽  
Terrestrial Environment ◽  
Regional Analyses ◽  
Research Facilities

Central elements of the TERENO network are “terrestrial observatories” at the catchment scale which were selected in climate sensitive regions of Germany for the regional analyses of climate change impacts. Within these observatories small scale research facilities and test areas are placed in order to accomplish energy, water, carbon and nutrient process studies across the different compartments of the terrestrial environment. Following a hierarchical scaling approach (point-plot-field) these detailed information and the gained knowledge will be transferred to the regional scale using integrated modelling approaches. Furthermore, existing research stations are enhanced and embedded within the observatories. In addition, mobile measurement platforms enable monitoring of dynamic processes at the local scale up to the determination of spatial pattern at the regional scale are applied within TERENO.

Epithermal Precious Metal Deposits in South Korea—History and Pursuit

SEG Discovery ◽  
2021 ◽  
pp. 19-26
Author(s):  
Paul D. Wittwer
Keyword(s):  
South Korea ◽  
Precious Metal ◽  
Tectonic Setting ◽  
Regional Scale ◽  
Mining Operation ◽  
Mining Operations ◽  
Historical Mining ◽  
Mining Areas ◽  
Basin Scale ◽  
Gold Silver

Abstract The gold and silver endowment of Korea has historically been well known, with records alluding to production as far back as 1122 BC. The main gold production period was from 1925 to 1943 during the Japanese occupation of Korea, with more than 1 Moz recorded in 1939. Muguk was the most productive gold mining operation, located within the central region of South Korea, with a recorded 590 koz of gold produced from 1934 to 1998 (first mined in AD 912). The majority of the historical mining operations were closed by government order in 1943 during the Second World War and never reopened. A number of small mines operated between 1971 and 1998, with limited production during a period of gold prices generally lower than at present (~25–50% of current inflation adjusted prices, apart from a four-year period 1979–83). It is likely that significant resources remain within these historical mining areas. Gold-silver deposit types historically recognized and exploited in Korea include placers and orogenic and intrusion-related vein systems. Only more recently have epithermal vein and breccia systems been recognized. This is not surprising, given that the geologic and tectonic setting of the Southern Korean peninsula is prospective for epithermal precious metal deposits, spatially associated with basin-scale brittle fault systems in Cretaceous volcanic terranes. South Korea is an underexplored jurisdiction, with limited modern exploration and drilling until the mid-1990s, when Ivanhoe Mines Ltd. discovered the Gasado, Eunsan, and Moisan epithermal gold-silver deposits, all of which became mines. Exploration was limited for another 20 years until Southern Gold Ltd., an Australian Securities Exchange (ASX)-listed company, commenced regional-scale exploration for epithermal deposits, using a strategy similar to that successfully employed by Ivanhoe.

scholarly journals Contributions to local and regional-scale formaldehyde concentrations

2018 ◽  
Author(s):  
Lucas Bastien ◽  
Nancy Brown ◽  
Robert Harley
Keyword(s):  
Organic Compounds ◽  
San Francisco ◽  
Transport Model ◽  
Regional Scale ◽  
Air Pollutant ◽  
Chemical Transport Model ◽  
Adjoint Sensitivity ◽  
Voc Emissions ◽  
Mixing Ratios ◽  
Basin Scale

Abstract. Reducing ambient formaldehyde concentrations is a complex task because formaldehyde is both a primary and a secondary air pollutant, with significant anthropogenic and biogenic sources of volatile organic compounds (VOC) precursor emissions. This work uses adjoint sensitivity analysis in a chemical transport model to identify emission sources and chemical reactions that influence formaldehyde mixing ratios in the San Francisco Bay Area, and within three urbanized sub-areas. For each of these receptors, the use of the adjoint technique allows for efficient calculation of the sensitivity of formaldehyde to emissions of NOx, formaldehyde, and VOC precursors occurring at any location and time. Formaldehyde mixing ratios are found to be generally higher in summer than in winter. The opposite seasonal trend is observed for the sensitivities of these mixing ratios to formaldehyde emissions. In other words, even though formaldehyde is higher in summer, reducing formaldehyde emissions has a greater impact in winter. In winter, 85–90 % of the sensitivity to emissions is attributed to direct formaldehyde emissions. In summer, this contribution is smaller and more variable, ranging from 26 to 72 % among the receptor areas investigated in this study. Higher relative contributions of secondary formation versus direct emissions are associated with receptors located farther away from heavily urbanized and emission-rich areas. In particular, the relative contribution of biogenic VOC emissions (15–41 % in summer) is largest for these receptors. Ethene and other alkenes are the most influential anthropogenic precursors to secondary formaldehyde. Isoprene is the most influential biogenic precursor. Sensitivities of formaldehyde to NOx emissions are generally negative, but small in magnitude compared to sensitivities to VOC emissions. The magnitude of anthropogenic emissions of organic compounds other than formaldehyde is found to correlate reasonably well with their influence on population-weighted formaldehyde mixing ratios at the air basin scale. This correlation does not hold for ambient formaldehyde in smaller urbanized sub-areas. The magnitude of biogenic emissions does not correlate with their influence in either case.

Evaluation of aquifer parameters at regional scale by spectral analysis of discharge time series

2020 ◽  
Author(s):  
Mariaines Di Dato ◽  
Rohini Kumar ◽  
Estanislao Pujades ◽  
Timo Houben ◽  
Sabine Attinger
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Characteristic Time ◽  
Large Scale ◽  
Multiple Scales ◽  
Regional Scale ◽  
Hydrologic Model ◽  
Aquifer Parameters ◽  
Basin Scale ◽  
Linear Reservoir

<p>River stream is the result of several complex processes operating at basin scale. Therefore, the river catchment can be conceptualized as a series of interlinked compartments, which are characterized by their own response time to a rainfall event. Each compartment generates a flow component, such as the direct runoff, the interflow and the baseflow. The latter, typically generating from groundwater, is the slower portion of stream flow and plays a key role in studying the hydrological droughts.</p><p>In many catchment or large-scale hydrologic models, the groundwater dynamics are typically described by a linear reservoir model, which depends on the state of the reservoir and the parameter, known as recession coefficient or characteristic time. The characteristic time can be considered as the time needed until an aquifer reacts to a certain perturbation. So far, the characteristic time has been estimated by analyzing the slope of the recession (discharge) curve. However, as this method assumes that the recharge is zero within the basin, it may lead to inaccurate estimate when such a hypothesis is not fulfilled in reality.</p><p>The present work proposes to infer the characteristic time by using a stochastic approach based on spectral analysis. The catchment aquifer can be viewed as a filter, which modifies an input signal (e.g., rainfall or recharge) into an output signal (e.g., the baseflow or the hydraulic head). Since the transfer function, namely the ratio between the spectrum of baseflow and the spectrum of recharge, is dependent on the aquifer characteristics, it can be used to infer the aquifer parameters. In particular, the characteristic time is evaluated by fitting the spectrum and the variance of the measured baseflow with the analytical stochastic solutions for the linear reservoir. We compare six different methods for hydrograph separation, thereby highlighting a systematic uncertainty in determining the characteristic time due to the choice of filter used. To reduce the uncertainty in fitting, we will use the mesoscale Hydrological Model (mHM) (Samaniego et al., 2010; Kumar et al., 2013) to generate realistic time series for recharge. We apply the spectral analysis method to several river basins in Germany, with the goal to define a regionalization rule for characteristic time.</p><p> </p><p>References:</p><ul><li>Samaniego L., R. Kumar, S. Attinger (2010): Multiscale parameter regionalization of a grid-based hydrologic model at the mesoscale. Water Resour. Res., 46, W05523, doi:10.1029/2008WR007327.</li> <li>Kumar, R., L. Samaniego, and S. Attinger (2013): Implications of distributed hydrologic model parameterization on water fluxes at multiple scales and locations, Water Resour. Res., 49, doi:10.1029/2012WR012195</li> </ul>

Sign in / Sign up

Export Citation Format

Share Document