POTENSI KETERSEDIAAN AIR DAS LOGAWA DENGAN MEMPERHITUNGKAN PERUBAHAN IKLIM

Abstract

Water is one of the non-biological natural resources which can be renewed through the

hydrological cycle. As the human population increases and the phenomenon of climate change, the

availability of water tends to decrease both in terms of space, time, quality and quantity resulting

in an imbalance between demand and availability. In addition to the increase in human

population, climate change and the distribution of rain that is not always evenly distributed, the

availability of groundwater is always different at any given time and place. The Logawa sub-

watershed is one of the most influential watersheds in Banyumas Regency. Therefore, an analysis

is needed regarding the impact of changes in rainfall on the condition of water availability in this

watershed. One of the analyzes that can be done is to use the HEC-HMS software and a scenario

neutral approach. The aims of this study were (i) to know the parameters of the Logawa watershed

using the HEC-HMS model; (ii) Applying the HEC-HMS software to determine water availability

in the Logawa watershed; (iii) Knowing the HEC-HMS model calibration process); and (iv) know

how to calculate climate change using a scenario-neutral approach. The research method used is

quantitative using secondary data. The data used are watershed geospatial data and watershed

biogeophysical characteristics data. The HEC-HMS simulation method used is the User

Hyetograph Model, Soil Moisture Accounting, Clark's Unit Hydrograph, Recession Baseflow. The

results are (i) a hydrological model with a PBIAS value of -2.474% and an NSE of 0.153 is

obtained; (ii) results of 130 rainfall scenarios; and (iii) reliable debit from the GPCC satellite rain

data input and scenario-neutral approach rainfall data.