Ugbor Charles Chibueze, Ikwuagwu Ifeanyi Emmanuel, Ogboke Osim Jethro
Department of Geology, University of Nigeria, Faculty of Physical Sciences, Nsukka, 410001, Enugu State, Nigeria.
Nigerian National Petroleum Corporation (NNPC-NAPIMS), 38 Gerard Road, Ikoyi, Lagos, Nigeria.
Sci Rep. 2021 Jun 4;11(1):11854. doi: 10.1038/s41598-021-91019-3.
The study tries to utilize vertical electrical sounding (VES) and 2D resistivity tomography to evaluate the region of influence of the leachate plume on the groundwater around a dumpsite at Onitsha expressway, southeastern Nigeria. The borehole log data were acquired and their respective geoposition logged with Garmin GPS device. In addition, four 1D (VES) soundings and 2D electrical profile data were acquired in the field utilizing the Schlumberger and Wenner profiles respectively. Petrozenith PZ-03 Resistivity meter was used to acquire the electrical data, while RES2DINV and WinResist software were used to interpret the 2D and 1D data respectively. The resulting geoelectic layers were correlated with the borehole logs and were interpreted according to their resistivity distribution. Results of the 2D inversion at profiles 1 and 3 showed low resistivity zones indicating influence from the leachate plume. Profiles 2 and 4 gave low resistivity zone within 14.6 and 44.3 Ωm from surface to between 0.375 and 3.60 m depths indicating influence from leachate plume. Likewise, profiles 1 and 3, which penetrated groundwater, also showed very low resistivity with resistivity ranging from 3.12 to 8.7 Ωm, from surface to few meters depths. This indicates that it has been polluted by the leachate. In contrast, Profiles 2 and 4, from the 2D inversion, has no leachate influence on the groundwater. The VES result showed that the depth to the water table at location 1, 2, 3 and 4 are 21.7 m, 17.9 m, 15.9 m and 12.2 m respectively, with the leachate plume flowing in the southeast direction in line with the groundwater flow direction.
该研究试图利用垂向电测深（VES）和二维电阻率层析成像技术，评估尼日利亚东南部奥尼沙高速公路一处垃圾场渗滤液羽状物对周边地下水的影响区域。获取了钻孔测井数据，并使用佳明GPS设备记录了它们各自的地理位置。此外，在野外分别利用施伦贝格剖面和温纳剖面获取了四个一维（VES）测深数据和二维电剖面数据。使用Petrozenith PZ - 03电阻率仪采集电数据，而RES2DINV和WinResist软件分别用于解释二维和一维数据。所得的地电层与钻孔测井数据进行了对比，并根据其电阻率分布进行了解释。剖面1和3的二维反演结果显示出低电阻率区，表明受到渗滤液羽状物的影响。剖面2和4在地表至0.375至3.60米深度范围内，电阻率在14.6至44.3Ωm之间出现低电阻率区，表明受到渗滤液羽状物的影响。同样，穿透地下水的剖面1和3，从地表至数米深度，也显示出极低的电阻率，电阻率范围为3.12至8.7Ωm。这表明它已被渗滤液污染。相比之下，二维反演得到的剖面2和4，其地下水未受渗滤液影响。VES结果表明，位置1、2、3和4处的地下水位深度分别为21.7米、17.9米、15.9米和12.2米，渗滤液羽状物沿东南方向流动，与地下水流向一致。
