The effectiveness of canal blocking for hydrological restoration in tropical peatland

Sigit Sutikno,Koichi Yamamoto,Rinaldi Rinaldi,Eka Saputra,Rachmad Jayadi,Besri Nasrul,Haris Gunawan,M Olivia,D Andrio,G Wibisono,M Infantri Yekti,K Yamamoto,E Saputra,D Wishart,I.D Ketut Sudarsana,I.M Agus Ariawan,R Ridwan,G Pringgana,A Marto

doi:10.1051/matecconf/201927606003

Abstract

The Peatland Restoration Agency of the Republic of Indonesia (BRG-RI), an agency that is mandated to restore 2 million hectares of degraded peatland by 2020, has developed a 3-R approach towards tackling the problem based on the program of rewetting, revegetation, and revitalization of livelihood for the peatlands restoration in Indonesia. The Rewetting program that aims to rehabilitate hydrologically a peatland to a near natural state is carried out by canal blocking, canal backfilling, and construction of deep wells. To know the progress of the restoration activities by BRG, it is very important to understand the effectiveness of canal blocking on rewetting of the tropical peatland. The effectiveness of canal blocking was investigated through the monitoring of groundwater level (GWL) fluctuation around the canal block. This study was carried out at a canal block that is located at the peatland of Sungai Tohor Village, Kepulauan Meranti Regency, Riau Province. For monitoring of GWL fluctuation as the impact of canal blocking, five dipwells were set at the peatland that are perpendicular to the canal with the distance of 20 m, 70 m, 120 m, 170 m, and 220 m respectively. The results of this study show that the impact of canal blocking could raise the water table in the peatland at the radius of about 170 m from the canal. The radius impact of the re-wetting might be bigger or smaller, that strongly depends on the hydrotopography situation of the area.

Highlights

Peatlands are the most efficient terrestrial ecosystems in storing carbon in the world
The peatland degradation in Sumatera and Kalimantan shows that only about less than 4% of the peatland areas remain covered by pristine peat swamp forests (PSFs), while PSFs cover 37% with varying degree of degradation
The village is included in the Pulau Tebing Tinggi Peatland Hydrological Unit (PHU) that is one of the most priority areas for peat restoration program by Indonesian government due to the previous peatland degradation [9, 10] Historically, the village experienced severe peat fires in the last few years

Summary

Introduction

Peatlands are the most efficient terrestrial ecosystems in storing carbon in the world. While covering only 3% of the land area, they contain nearly 30% of all carbon on the land [1]. They are of crucial value for biodiversity conservation and climate regulation and provide https://doi.org/10.10 51/matecconf /201927606003 important support for human welfare [2, 3]. Inappropriate management of peatlands is leading to large-scale degradation with significant environmental and social impacts [4]. Over 20% is considered to be unmanaged degraded landscape, occupied by ferns, shrubs and secondary growth [5]. In order to restore their function, those peatlands need to be restored to their natural conditions [6]

Methods

Results

Conclusion