ISERME - 2019

Permanent URI for this collectionhttp://192.248.9.226/handle/123/14735

Browse

Browsing ISERME - 2019 by Author "Chaminda, SP"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    item: Conference-Full-text
    Analyzing the seasonal variation of groundwater characteristics in the Attanagalu Oya basin
    (Department of Earth Resources Engineering, 2019-08) Athukorala, DRM; Kohilan, C; Danushka, U; Jayarathna, WHDP; Chaminda, SP; Dassanayake, ABN; Hewavidana, SM; Dissanayake, DMDOK; Samaradivakara, GVI
    Gampaha district which has the second largest population in the country consists of many industrial establishments and residential areas. Attanagalu Oya Basin which almost entirely the Gampaha district is a major hydrologic feature in determining the seasonal variations of groundwater characteristics in the region. In this study, the groundwater characteristics in the Attanagalu Oya Basin analyzed both quantitatively and qualitatively to identify variations in the pre and post monsoon periods. The qualitative parameters such as pH, conductance, turbidity, calcium, magnesium, nitrate, phosphorous, ferrous, and heavy metal concentrations were analyzed for samples taken throughout the entire basin for the two time periods: pre and post monsoons. The groundwater quantity variations were observed through data loggers and field surveys of water wells. These recorded values were used to model the groundwater resources in the region using two numerical models, MODFLOW by USGS and a self-written Fortran code. The qualitative and quantitative variations were then analyzed spatially and temporally to correlate with the upstream to downstream flow and the monsoonal recharge. The possible reasons for the observed trends and variations were also studied to provide recommendations for the sustainable management of the groundwater resources in the Attanagalu Oya Basin.
  • Thumbnail Image
    item: Conference-Full-text
    Study on royalty for Sri Lankan quarry mining of industrial minerals using photogrammetric 3D modelling
    (Department of Earth Resources Engineering, 2019-08) Jayawardana, KPSR; Athukorala, DRM; Chathuranga, HMD; Chrishoban, M; Sampath, JAB; Hemalal, PVA; Dharmaratne, PGR; Premasiri, HMR; Chaminda, SP; Wickrama, MADMG; Dissanayake, DMDOK; Samaradivakara, GVI
    Royalty is a payment made to the owner of mineral rights for the privilege of extracting minerals from the ground on a lease agreement. Globally, there are three main methods used for the royalty calculation; namely unit based, value based and profit based methods. A combination of unit and value based systems is practised in Sri Lanka. However, an explosive based equation without any scientific base is adopted for the determination of excavated quantities of some minerals. The main objective of this study was to find an accurate method to calculate excavated quantity of a rock for calculation of royalty for industrial minerals in Sri Lanka. Initially, a multiple-borehole blast was carried out in a selected 'A Grade' quarry. A total station survey and an Unmanned Aerial Vehicle (UAV) survey were conducted to determine the excavated rock volume. The collected aerial photographs for photogrammetric 3D modelling were processed using Agisoft PhotoScan, Bentley ContextCapture and Drone Deploy softwares. The accuracy of each method was determined by comparing each estimated depleted volume with the value obtained from weighing the blasted tonnage. Photogrammetric 3D modelling gave the least deviation from the actual volume.