Modification of the Horton model in tropical peatland

Abstract

This research aims to develop Horton infiltration for tropical peatland using an injection-well approach that relates soil moisture to the infiltration rate. The research was conducted in the peatland of Palangka Raya City – Sebangau District, Indonesia. Soil sampling was carried out to determine the depth of shallow peatland (50–100 cm) and medium peatland (100–200 cm) using an auger and ring samples. The methodology consisted of investigating a simple laboratory-scale injection-simulator model covering dimension, depth, number, and flow velocity, and then developing a Horton infiltration model for tropical peatland using an injection-well approach that relates soil moisture to the infiltration rate. The results show that the modified Horton infiltration analysis, with the addition of moisture in the simple injection-simulator tool, produces a very strong relationship between discharge and modified Horton infiltration, a very strong relationship between discharge and groundwater level, and a very strong relationship between modified Horton infiltration and groundwater level in medium-depth peatland deeper than one metre (>1 m). The modified Horton infiltration development model for tropical peatland is better than the original Horton infiltration model because peatland is porous and infiltration increases with increasing water volume and soil moisture. In addition, the injection well increases the infiltration-capacity system, whereas the original Horton model analyses only natural infiltration.