to Pontianak. Due to international opposition to Dutch attempts to reinstate control over Indonesia in the United Nations, the Dutch were forced to recognise Sukarno's Republic as the de facto government of Java and Sumatra and to grant independence to a Republic of the United States of Indonesia (RUSI) on 27 December 1949. Pontianak became the capital of the State of West Kalimantan, one of the federal states of the United States of Indonesia. It was led by Sultan Hamid II, the last sultan of the Pontianak Sultanate. However, Hamid II was accused of conspiring with the former KNIL Captain Raymond Westerling to organise an anti-Republican coup in Bandung and Jakarta. Hamid's role in the coup led to increased agitation in West Kalimantan for its integration into the Republic of Indonesia. Following a fact-finding mission by the Government Commission, the RUSI House of Representatives voted by 50 votes to one to merge West Kalimantan into the Republic of Indonesia. Following clashes with demobilised KNIL troops in Makassar and the attempted secession of an Ambonese Republic of South Moluccas, the federal United States of Indonesia was dissolved on 17 August 1950, turning Indonesia into a unitary state dominated by the central government in Jakarta. Pontianak then became the capital city of the new province of West Kalimantan. Geography Pontianak lies on the equator at a height ranging from 0.1 to 1.5 meters above sea level. It is divided into three parts by the Kapuas Besar and its major tributaries - the Kapuas Kecil and Landak rivers. The city lies on flat land in the delta of the Kapuas River with a ground level elevation ranging from 0.1 to 1.9 meters above sea level. The city is built on fall peneplain and alluvial sediments that are physically a clay type. This type of soil is in the form of peat and silt deposits of Kapuas river. Under these conditions, the soil is very unstable and has a very low carrying capacity. The soil composition along the river is formed from a precipitation process that produces a tropaquent area coupled with tropofluevent and under permanently saturated fluvawuent conditions. It is derived from the new sapphire sediment from various compositions and shapes, including organic matter. Pontianak consists of a kind of soil organosol, gray, humus, and alluvial with different characteristics. At some points, the thickness of the peat soils reaches up to 1–6 meters,