The hydrological and water level data in Yom River basin of Thailand

Abstract

Yom River basin located in Northern Thailand, faces perennial droughts and floods with great impact on agriculture and the economy in the surrounding landscape. Therefore, the purpose of the present study is to study the hydrological nature of the Yom River basin, by descriptive statistics analysis using daily water level data from four water level measurement stations, from April 1, 2007, to March 31, 2020.

The lower part of Mae Nam Yom river is almost half of the Yom River basin area. The water allocation plan in 2019-2020 for six reservoirs suggests usable water of 116.5 million m³, with the water allocated at the beginning of the rainy season more than during the dry season. During the dry season most of the water was allocated for agriculture. In most areas of Yom River basin, there are droughts and floods happened not more than 3 times in the last 10 year. The daily water level data of all four water level measurement stations showed relatively clear seasonal variations. The daily water level peaked every hydrological year during the rainy season. The average annual water level was the highest in 2011 (258.92 ± 1.09, 183.26 ± 1.64, 145.56 ± 1.89, and 96.20 ± 2.17 m(MSL)), and the lowest in 2015, except at the Y.1C station in 2019 (258.01 ± 0.49, 182.10 ± 0.61, 144.01 ± 1.24, and 94.50 ± 0.56, m(MSL)). The average monthly water level started to rise since May, with its highest peak value is in September (259.67 ± 0.86, 184.27 ± 1.14, 146.21 ± 1.39, and 97.09 ± 1.57 m(MSL)). The average monthly water level is low from December to April (dry season), the lowest values are from February to March (257.82 ± 0.19, 181.65 ± 0.12, 143.91 ± 0.32, and 94.31 ± 0.20, m(MSL)).