World Applied Sciences Journal 2 (3): 198-203, 2007 ISSN 1818-4952 © IDOSI Publications, 2007 Corresponding Author: Dr. Yetrie Ludang, Department of Forestry, Faculty of Agriculture, University of Palangka Raya, Jalan Yos Soedarso 11 Palangka Raya 73111, Central Kalimantan, Indonesia 198 Geohydrological Conditions of the Developed Peatland in Central Kalimantan 1 Yetrie Ludang, 2 Adi Jaya and 3 Takashi Inoue 1 Department of Forestry, Faculty of Agriculture, University of Palangka Raya, Jalan Yos Soedarso 11 Palangka Raya 73111, Central Kalimantan, Indonesia 2 Faculty of Agriculture and Centre for International Co-operation in Management of Tropical Peatland, University of Palangka Raya, Jalan Yos Soedarso 11 Palangka Raya 73111, Central Kalimantan, Indonesia 3 Faculty of Agriculture, University of Hokkaido, Kita 9 Nishi 9 Kita-ku, Sapporo-shi, Hokkaido 060-8589 Japan Abstract: Mega Rice Project in Central Kalimantan was launched in 1996, covering about 7% of total peatland area in Indonesia. After four years, the project was closed and the land use has changed for various purposes such as forestry, agriculture, energy and horticulture. A field study was carried out in the former project area of 1.5 Mha during March 2001-June 2002. Land use change has resulted in general change of geohydrological conditions in the peatland area. Although there was no significant difference on the quantity, intensity and duration of the rainfall, the peatland capacity to store water was decreasing. The rainfall and vegetation of peatland affect significantly surface temperature as well as ground water table. Key words: Peatland • rainfall • temperature • water table INTRODUCTION Peatland is wetland ecosystem characterised by accumulation of organic matter that is produced and deposited at a faster rate than it can be decomposed [1]. Peat formation in the tropics commences under conditions of constant waterlogging or in wet coastal areas where organic matter is produced in abundance by an adapted vegetation of mangroves, grasses or swamp forest trees [2, 3]. Approximately 12% of the global peatland area occurs in humid tropical zones, mainly in mainland East Asia, Southeast Asia, the Caribbean and Central America, South and southern Africa [4]. Peatland in Indonesia covers about 16 to 27 Mha [4, 5]. These ecosystems are vitally linked to conservation issues such as carbon sequestration affecting global climate change and provision of key habitat for a diverse range of the world's flora and fauna. They also are the source of a significant portion of the freshwater and many economic resources vital to human survival. In addition, peatland ecosystems are important for water resources conservation since their ability to store water is very high and can be up to 8 times of the peat volume [6]. Tropical peatlands, however, are also the subject to land use pressures including forestry development and agriculture on them as well as extraction for energy and horticulture [7]. In 1996, 1.5 Mha of Peatland in Central Kalimantan was developed for rice production. This project failed and was closed down in 1999 but left on legacy of habitat destruction and fire occurrence. The land use has changed to be developed forest, regrowing forest and agriculture. Therefore, the purpose of this study was to describe geohydrological conditions of the developed peatland, particularly ground water table in supporting water conservation in the area. MATERIALS AND METHODS Area descriptions: Research was carried out within the area of the former Mega Rice Project (MRP) in Central Kalimantan, Indonesia, that was launched through Presidential Decree No. 82/1995 on 26 th December 1995. The purpose of MRP was to develop wetland, mostly peatland, for rice crop production. The MRP covers an area of 1.5 Mha that is bounded by S. Sebangau in the west, Java Sea in the south, S. Barito in the east and the Main Parent Channel in the north (Fig. 1). Hydrometeorology: Information on fluctuations of the water table, incident rainfall and peat surface temperatures were obtained from monitoring instruments placed in the field. The location includes a forest area, regrowing forest as well as an agriculture area.