{"id":2757,"date":"2020-11-18T03:56:18","date_gmt":"2020-11-18T03:56:18","guid":{"rendered":"http:\/\/agri-research-journal.net\/SjarEn\/?p=2757"},"modified":"2020-11-18T03:56:20","modified_gmt":"2020-11-18T03:56:20","slug":"comparison-of-ordinary-kriging-and-inverse-weighting-%e2%80%8edistance-methods-in-estimating-shallow-groundwater-%e2%80%8econtamination-by-seawater-in-tripoli-libya","status":"publish","type":"post","link":"https:\/\/agri-research-journal.net\/SjarEn\/?p=2757","title":{"rendered":"Comparison of Ordinary Kriging and Inverse Weighting \u200eDistance Methods in Estimating Shallow Groundwater \u200eContamination by Seawater in Tripoli, Libya"},"content":{"rendered":"\n

Ahmed Ibrahim Khamaj(1)<\/sup> and Abdul Rahman Ahmed Alriyani*(2)<\/sup><\/strong><\/p>\n\n\n\n

(1). Soil and\nWater Department, University of Tripoli, Libya. <\/p>\n\n\n\n

(2). Advanced\nLaboratory of Chemical Analysis, Authority of Natural Science Research and\nTechnology, Tripoli, Libya.   <\/p>\n\n\n\n

(*Corresponding Author e-mail: abdllrahman817@gmail.com<\/a> ).<\/p>\n\n\n\n

Received: 01\/07\/2020                               Accepted: 14\/08\/2020<\/p>\n\n\n\n

Abstract<\/strong><\/p>\n\n\n\n

The Ordinary\nKriging (OK) and the weighted inverse distance (IDW) methods were used to\npredict the spatial distribution of seawater contamination extent the shallow\naquifer within Tripoli region, Libya. 42 water samples were analyzed to\ndetermine the Simpson ratio which was selected as an indicator of groundwater\ncontamination by seawater. Ordinary Kriging method was aimed to be applied on\nthe original and the logarithmic transformed data. The spatial structure was\nestimated using the spherical, exponential, and Gaussian models. The\ncross-validation technique was used to assess the interpolation process\nresulting from the use of the OK and IDW methods with an exponent value ranging\nfrom (1 to 5). The performance of the variogram models was evaluated using the\ndetermination coefficient (R2<\/sup>) and the sum squares of the residuals\n(RSS). The square root of mean square error (RMSE) and the relative mean error\n(MRE) were used to assess the accuracy of the results obtained from the\ncross-validation technique. The results showed that the performance of the\nvariogram models before the logarithmic transformation was more accurate, than\nthose obtained after the logarithmic transformation. The best performer is the\nGaussian model before the logarithmic transformation with 0.463 and 4.30, for\n(R2<\/sup>) and (RSS), respectively. The cross-validation technique also\nshowed that the method of (OK) by using the Gaussian model before the\nlogarithmic transformation and the method of IDW with exponent of 1 gave the\nmost accurate results, with the preference for the (OK) of calculating with\nvalues of 0.535, 0.246, 0.249 for RMSE, MRE, R2<\/sup>, respectively. The\nmap obtained from applying the (OK) method using the Gaussian model showed\nthat, although 76.55% of the area of the study area classified its groundwater\nas being slightly contaminated by seawater, there is an increase in the risk of\ngroundwater pollution in the southeastern and northwestern borders the region.<\/p>\n\n\n\n

Keywords: <\/strong>Groundwater, Seawater intrusion, Simpson ratio, Geostatistics, Cross validation.<\/p>\n\n\n\n

Full paper in Arabic: PDF<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"

Ahmed Ibrahim Khamaj(1) and Abdul Rahman Ahmed Alriyani*(2) (1). Soil and Water Department, University of Tripoli, Libya. (2). Advanced Laboratory of Chemical Analysis, Authority of Natural Science Research and Technology, Tripoli, Libya.   (*Corresponding Author e-mail: abdllrahman817@gmail.com ). Received: 01\/07\/2020                   … Continue reading →<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2757","post","type-post","status-publish","format-standard","hentry","category-sjar"],"_links":{"self":[{"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/posts\/2757","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2757"}],"version-history":[{"count":1,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/posts\/2757\/revisions"}],"predecessor-version":[{"id":2758,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=\/wp\/v2\/posts\/2757\/revisions\/2758"}],"wp:attachment":[{"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2757"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2757"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/agri-research-journal.net\/SjarEn\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2757"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}