Refined GIS Mapping to Reinvestigate Groundwater Mining Potential Surrounding the Manmade Reservoirs and Tributaries in the Deduru Oya Basin, Sri Lanka

International Journal of Economic and Environment Geology

C. Jayasuriya, H.A.H. Jayasena¹ 

[1] Geological Survey and Mines Bureau, 569, Epitamulla Road, Pitakotte, 10100, Sri Lanka, Department of Geology, University of Peradeniya, Peradeniya, 20400, Sri Lanka;

关键词: deduru oya;    fractures;    reservoirs;    recharge;    gis mapping;    groundwater mining;   

DOI  :  

来源: DOAJ

【 摘 要 】

Ahydrogeologicstudywascarriedout tounderstandtheinfluenceofMan-MadeReservoirs(MMR), tributariesand fractureintensity onwellyields within the Deduru Oya Basin(DOB),Sri Lanka. Anumber of cascadedMMRsinterconnectedby tributariesaredistributedthroughoutthebasin.Fracture traces,lineamentsandreservoir boundaries were initially demarcatedusing aerial photographs, however, subsequently re-plotted them on to a Google Earthmapwithcorrectionstorectifythedistortion. The GPSbasedwelllocationswereregeneratedandplottedto obtainaccuratedimensions.ArcGISwasusedtoredrawthebufferzones from0-200,200-400and400-600maway from the MMRsand tributaries. After eliminating dry wells, box plots were prepared where lower and upper quartiles indicateyieldvariationsfrom18-470;15.8-165and12.8–55liters/minuterespectively. It clearlyexhibitsdecreasing yieldswithrespecttodistanceawayfromtheMMR.However,wellsdrilled withinthealluvialplainsof tributariesafterfiltering those controlledby the MMRs andeliminating dry wells indicate differentyield variations,viz: 7-36.8; 12.8-67.5and6.5-142.5 liters/minute. The resultsassigned higheryieldsto the wells located away from the tributarieswith steep hydraulic gradientswhereas loweryields to the wells closerto the tributarieswith gentle hydraulic gradients. Moreover,wellsdrilledatfractureinterconnectionsindicateapotentialforhighyieldscomparedwiththosedrilled alongwithasinglefracture.Thestudy concludes thatthepotentialforgroundwaterminingcanbeenhancedby identifying high recharging areas such as MMRs,zones of steeper hydraulic gradients and high fracture interconnectivity

【 授权许可】

Unknown