No abstract

The purpose of this study is to investigate the accuracy of the Inverse Distance Weighted (IDW) interpolation method to estimate and map the surface water salinity along the coastal waters of Pulau Tuba, Langkawi. Sea surface salinity was recorded using a refractometer during two sampling activities that were carried out in November 2018. The Global Positioning System (GPS) was used to record the geo-location of each sampling point. IDW method was applied in data collection using ArcGIS Software. Statistical analyses such as correlation analysis, regression analysis, and error analysis were employed to assess the prediction of salinity values. The transformation of the spatial model to map was carried out later to assess the accuracy of the map. The study found that there is a strong positive correlation, r= .753 (p< .05) with the coefficient of determination of 56.80% between observed and predicted salinity values. Mean Absolute Error (MAE) and Root Mean Square Error (RMSE) were calculated at 0.724466 and 0.921728, respectively. The accuracy of the map was found at 81.25%. The study also found that the salinity reading is polyhaline along the coastal water of Pulau Tuba. Overall, the study found that the IDW method has provided a tool to predict and map the surface salinity along the coastal waters of Pulau Tuba, Langkawi.

No abstract

This research aims to assess the spatial-temporal pH variations on the surface water of Kuala Perlis, Perlis. The sampling points were determined and recorded using the Global Positioning Systems (GPS) in December 2021. A total of five sampling points for each morning, afternoon, and evening period were established, and the pH meter readings were recorded. The analysis of variance (ANOVA) was set at 0.05 to determine the significant difference in the spatial-temporal mean pH readings using the Statistical Package for the Social Sciences (SPSS) version 26. The research found that the pH readings were 6.98 – 7.24, 6.76 -7.41, and 6.58 – 7.54 for the morning, afternoon, and evening periods. The research also found no significant difference in the mean pH readings with respect to temporal variations (> .05). However, the research found a significant difference in pH readings (p< .05) concerning spatial variations. The local government and non-government bodies can utilize the output of this research to monitor river acidification processes and the social-economic development of this area.