STUDI NERACA AIR DALAM MENENTUKAN DAERAH TANGKAPAN AIR (DTA) MATAAIR KARST (Studi Kasus Mataair Ngeleng, Giritirto, Purwosari, Gunungkidul)
| Main Authors: | , MUHAMMAD ABDUL AZIZ RAMDHANI, , Dr. Eko Haryono, M.Si. |
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| Format: | Thesis NonPeerReviewed |
| Terbitan: |
[Yogyakarta] : Universitas Gadjah Mada
, 2014
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| Subjects: | |
| Online Access: |
https://repository.ugm.ac.id/129022/ http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=69397 |
Daftar Isi:
- Karst is a landform known as hard water area, for it is very difficult to find the surface water storage there. This is because the rocks in the karst system have many cracks or fissures, so water is easier to be absorbed by the ground. In the karst area, the abundant water storage in good quality can be found in its groundwater that has outlet such as spring and underground river. Therefore, its existence is very significant to the people living around there. Ngeleng Spring in the Giritirto Village, Purwosari, Gunungkidul is a type of karst perennial spring that flow throughout the year. This fact attracts researcher to study these spring. This study specifically aims to (1) calculate the water balance as an approach to determine the boundary and size of Ngeleng Spring catchment area and (2) determine the boundary and size of Ngeleng Spring catchment area with topographic approach. Water balance approach and topographic approarch are applied to figure out the condition of Ngeleng Spring catchment area. Using water balance approach, rainfall is the main water input in the water balance, while the discharge spring are the main water output. Both data are obtained from direct measurements during 12 months, starting from October 2012 to September 2013. Moreover, evapotranspiration also influences the water balance calculation. The potential evapotranspiration is calculated using the Blaney-Criddle Method with parameter such as average air temperature, type of plant cover latitude location of the study sites. Topographic approach need the true condition of surface hydrology and geomorphology around the study sites from field observation. The size of catchment area, both calculation of water balance and field observation are validated by using Todd�s Nomogram (1980). The result of the water balance approach to determine the boundary of Ngeleng Spring catchment area shows that the width of the area is 29,77 Ha. Beside that, the boundary of Ngeleng Spring catchment area from field observation and then it is delineated by using ArcGIS 9.3 that the width of the area is 24,7 Ha. This catchment area includes some connecting hills along with the valley in the middle of the hill in the catchment area. The valley has a sinkhole that can recharge the spring through the conduit flows thst move fast. Meanwhile, the hills in the catchment area will recharge the spring through diffuse flows that move slowly, so they can recharge the spring in a long period of time.