Prediksi Curah Hujan Bulanan Di Wilayah Lombok Barat Menggunakan Principal Component Regression (PCR)

Rainfall is a significant climate parameter in various sectoral of human activities. Despite that, precise rainfall prediction is necessary. One factor which can affect the rainfall is Sea Surface Temperature. We used Sea Surface Temperature data in Indonesia limited by 14° LS - 10° LU and 90° BT - 142° BT to predict monthly rainfall in West Lombok. The method used in this study is Principal Component Regression. Regression is calculated using 1998-2013 data, with Principal Component Analysis result of Indonesian Sea Surface Temperature as the predictor. Validation using contingency table for 2014-2018 rainfall characteristic data in West Lombok showed that rainfall prediction is appropriate with the rainfall pattern observation data.

Assessment of the Water Quality of Boreholes in Selected Areas in Benin City, Edo State, Nigeria

The water quality of selected boreholes in Oredo, Egor and Ovia North-East Local Government Areas in Benin City metropolis was assessed in terms of their physical, microbial and chemical parameters. A total of nine water samples (three per local government) were collected from randomly selected public boreholes in the month of July, 2018. The physicochemical parameters determined and values obtained are as follows: Electrical conductivity ranged 12.85 to 101.94 µS/cm, Temperature 25.00 to 25.01, pH of 4.32 to 5.55, TDS 0.67 to 4.00 mg/l, COD 3.20 to 16.00 mg/l, Turbidity 1.14 to 5.38FTU, Cl- 106.50 to 426.00 mg/l, SO42- 0.41 to 2.87 mg/l, TSS 0.33 to 1.67 mg/l, TS 1.33 to 4.33 mg/l, NO3- 23.73 to 41.48 mg/l, Mg 0.03 to 0.61mg/l, Ca 0.10 to 0.41 mg/l, HCO3- 7.00 to 22.00 mg/l, Na 0.20 to 7.75 mg/l, K 0.41 to 1.20 mg/l, Mn 0.01 to 0.11 mg/l, Fe 0.01 to 0.02 mg/l, Zn 0.01 to 0.65 mg/l, PO4- 0.07 mg/l for all locations, while some metals like Cd, Pb were not detected. Microbial evaluation was done on the samples to assess the level of E. coli, coliforms and bacteria. The principal component analysis result extracted two components each from the three LGAs; In Oredo LGA, Factor 1 accounted for 84.9% while Factor 2 accounts for 15.1%. In Egor LGA, Factor 1 accounts for 51.1% while Factor 2 accounts for 48.9%. In Ovia North-East LGA, Factor 1 accounted for 59.0% while Factor 2 accounts for 49.0% contributions.