Study Morfolog Sungai Putih Pasca Erupsi Gunung Merapi Tahun 2010

Sungai Putih or often referred by the community as "Kali Putih" is located
in Salam District, Magelang Regency, Central Java. Berhulu on Mount Merapi
flows towards the southwest. It is a river that has an important role in draining or
carrying the eruption material of Mount Merapi in the form of rocks, gravel and
sand to the side of the river which then settles as the material of the White Kali
itself. The purpose of the study was to find out the morphological changes in the
Sungai Putih after the 2010 eruption and to analyze the size of the degradation or
agradation flows that occurred using google earth pro satellite capture.The
methods used are secondary methods in the form of DEM in 2008, Cross Section
on Sungai Putih in 2012 and 2015. Significant transverse and elongated crosssectional changes occurred at a point of 42 + 0 elevation at that point decreased
from 2008 to 2012.The change in the elevation of the left cliff point 42 + 0
amounted to 43,433 m, the elevation change on the riverbed by 31.930 m, and the
elevation change on the right cliff by 31.937 m.
Morphological changes to agradation or degradation can be seen using
satellite imagery. Morphological changes in the Sungai Putih are caused by two
factors: artificial and natural factors.Examples of natural factors that affect
morphological changes are the rapid flow of cold lava that originates from
upstream and causes agradation and degradation along the river. Artificial
factors that influence morphological changes due to the mining of sand in river
areas and the construction of sabo dams. Sediment volume at point 19 + 0 of
465859295 m3 having agradation, sediment volume at point 34 + 0 amounted to
1224465,548 m3 was having agradation and underwent a degradation change of
46440,498 m3, sediment volume at point 42 + 0 amounted to 2692712.868 m3
and underwent a degradation change of 128574,820 m3, sediment volume at point
45 + 0 of 3153776.479 m3 undergoes agradation change, sediment volume at
point 48 + 0 of 3153776.479 m3 undergoes agradation change.