Baseflow index assessment and master recession curve analysis for karst water management in Kakap Spring, Gunung Sewu

International Conference on Environmental Resources Management in Global Region 2017

地球科学;生态环境科学

Fatchurohman, H.^1 ; Adji, T.N.^1 ; Haryono, E.^1 ; Wijayanti, P.^1

Karst Research Group, Faculty of Geography, Universitas Gadjah Mada, Indonesia^1

关键词: Aquifer characteristics;    Aquifer properties;    Discharge measurements;    Hydrological system;    Interior conditions;    Master recession curves;    Secondary porosity;    Waterresource management;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/148/1/012029/pdf
DOI  :  10.1088/1755-1315/148/1/012029

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Karst terrain occurs in combination of high solubility rock and well developed secondary porosity. Over the time, groundwater resources have not been well managed including karst aquifers. Karst aquifers formed in a very complex hydrological system. Developed in fracture media and soluble rocks have led karst aquifers into various porosity types and aquifer properties. Karst spring hydrograph is an essential element for water resource management. The form of karst spring hydrograph reflects the aquifer characteristics. The shapes of flood discharge hydrographs represent aquifer responses to recharge and contain information about the interior condition of karst drainage basin. Every year, Gunung Sewu karst area is suffering to severe water scarcity. The development of sub-terrain drainage networks lead into the minimum surface water resources. Kakap Spring is perennial gravity spring that located adjacently to the border of Gunung Sewu and the alluvial formation of Baturetno. Kakap spring play vital role regarding water supply in Giriwoyo sub-district as the spring fulfill most of the water needs in Giriwoyo sub-district. Kakap Spring utilized by the local authorities as the main source for pipeline water and distributed to the households. Water level data series obtained using automatic water level data logger and then correlated with manual discharge measurement to generate stage-discharge rating curve. The stage-discharge rating curve formula for Kakap Spring calculated as y = 14,504e8,9763x with r2 value = 0.8582. From the MRC result, flow regimes formula determined as + 400 (1-0,005t) + 700 (1-0,01t)., indicated that the aquifer dominated by turbulent flow regime. From the MRC formula, the degree of karstification in Kakap Spring classified at eighth scale. The average baseflow index in Kakap Spring calculated using recession curve analysis with the BFI index = 0,7485.