SURVEY IN A WATER RESOURCE MANAGEMENT PROJECT OF AN UNDERGROUND RIVER IN INDONESIA

Resumo

The district of Gunung Kidul in the Yogyakarta Special Province in middle Java is
known as one of the poorest regions in Indonesia. One of the essential reasons is the
acute water scarcity during the dry season. This karst area is composed of hundreds
of networked caves. Due to these cave structures there is a total exchange of the
surface run off and an infiltration through wide branched underground flow
systems. Since 2003 the Federal Ministry of Education and Research (BMBF),
Germany, is funding an interdisciplinary pilot project at the University of Karlsruhe
comprising a water resources management in one of the caves, Gua Bribin. The
basic idea is a partial damming up of the underground water flow by means of a
barrage with an integrated micro hydro power plant. The main objective of the
project is a strongly increased water supply of the population combined with a
general improvement of the living conditions especially in the dry season. The
paper describes, in addition to the interdisciplinary aspects of the project, the
geodetic contribution, the surveying work and the data processing. The single topics
are the basic survey for the installation of the drilling and the underground
construction site, the control measurements for the vertical drilling of the shaft of
100 m depth, the surveying of the cave geometry in detail (1,5 km length) and the
presentation of the cave within a three dimensional model as the basis for further
applications such as navigation through the cave, simulation of constructions,
special calculations (for example profiles and volumes) etc. The paper ends with an outlook to a new project under application concerning a comprehensive water
resources management in the whole region, in the frame of a new research funding
program of the BMBF.