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Assessing the physical impact of gravel and sand extraction in Krueng Aceh River Basin Area, Aceh Province, Indonesia

Mutia, Debi (2011) Assessing the physical impact of gravel and sand extraction in Krueng Aceh River Basin Area, Aceh Province, Indonesia.

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Abstract:and sand is one of the natural resources used as construction material. In the Aceh Besar Regency, Indonesia, it is mostly taken from the river bed and flood plain within Krueng Aceh river basin area. After the Tsunami of 2004, many houses, buildings and other infrastructures were damaged and needed to be reconstructed. Therefore, an increasing demand for gravel and sand occurred. The extensive exploitation of gravel and sand from the river may change or damage the physical environment. In 2006, GTZ carried out an intensive and costly survey to assess the damage of gravel and sand extraction for 32 extraction sites. In this research, the use of remote sensing and GIS is explored as a less expensive approach to assess the physical impact of gravel and sand extraction within the Krueng Aceh river basin area. The assessment was conducted for 14 extraction sites which operated from 2005 to 2009 and which were also assessed by GTZ. This research focuses on the physical impact of change in land cover, in river morphology and damage to bridges. Therefore, indicators like bare soil expansion, distance from extraction site to road, distance from extraction site to the river, average slope within extraction area, change in river shape and distance from extraction site to bridge were selected. The overall impact of the extraction sites was assessed using multi criteria evaluation. An effect table was created based on the six above mentioned criteria and scores are assigned for 14 extraction sites. Different stakeholders were asked to assign weights to the criteria. Besides an equal vision (all criteria get the same weight), four other visions were created: Mining and Energy Office vision, Environment Office vision, GTZ vision and researcher vision. After standardisation of all the scores and the assignment of weights, an appraisal score was calculated for each extraction site, resulting in a ranking of all the extraction sites, per vision. The Appraisal scores for the 14 extractions sites were classified into three impact classes: low, moderate and high. As result, two extraction sites (3 and 11) always showed a high physical impact for all visions and six extraction sites (2, 4, 7, 8, 10, and 14) always gave a moderate physical impact. The remaining extraction sites vary in impact for different visions. In terms of legal status, the eight illegal extraction sites never showed a high impact for all visions, but were categorized as having moderate to low physical impacts, while the six legal extraction sites are categorized as having moderate to high physical impact. Based on this result, the local government of Aceh Besar Regency needs to give more attention to monitoring and evaluating the legal extraction sites while enforcing the law at the illegal extraction sites. Keywords: physical impact assessment, gravel and sand extraction, remote sensing, GIS analysis, multi criteria evaluation
Item Type:Essay (Master)
Faculty:ITC: Faculty of Geo-information Science and Earth Observation
Programme:Geoinformation Science and Earth Observation MSc (75014)
Link to this item:https://purl.utwente.nl/essays/93191
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