Assessment of water resources for water irrigation purposes in Bintan island

Abstract

The raw water for irrigation must meet the minimum requirements of class IV water quality. This study aims at presenting a water quality assessment of several raw water sources in Bintan Island for irrigation purposes. The methods used are Standardized Precipitation Index, Pollution Index, and Sodium Adsorption Ratio. A climate analysis showed that the potential high risk of the flood was 16 events in 22 years, and severe-to-extreme dry soil moisture and streamflow were 8 to 10 events in 22 years, with durations of every event varying from 1 to 6 months. Severe-to-extreme reduction of reservoir level was five events in 22 years, with a duration of every event varying from 2 to 13 months. The water quality analysis showed that all water sources meet the quality standard to irrigation as a class IV water quality. While based on SAR values, all water sources have excellent categories and good categories, except Dompak pond and Kolong 6 reservoirs that are doubtful categories. The availability of raw water mainly causes the problem of water sources, so better surface water management is necessary for Bintan Island to support food resilience.