Modeling Discharge of the Bangga Watershed under Climate Change

Abstract

The purpose of this research is to create a model of the discharge as the impact of climate change due to global warming. The study was conducted using data from the Bangga watershed. Monthly water balance model used is the development of a model FJ. Mock by entering the natural phenomena that occur at this time such as climate change, canopy interception, rainfall distribution based on land use, soil type and soil characteristics. Calibration of water balance is used to determine the performance of the models to variations in climate change. Then, analysis is conducted as the effect of rain and temperature on runoff at river Bangga. The conclusion of this research were: 1) Accuracy of discharge simulation models against observed discharge is quite good, which is characterized by the Nash coefficient (Ns) close to one except for a few periods and annual rainfall runoff ratio (RE) approaches one. 2) Changes in rainfall have a considerable influence on the runoff, while the effect of temperature on runoff is not too significant.

Effect of the climate change on groundwater recharging in Bangga watershed, Central Sulawesi, Indonesia

“…Thus, before using this model needs to be analyzed in advance whether there is a climate change study site by using Mann-Kendall models. Furthermore, the projected changes are analyzed by the method of non-parametric Sen's by Sutapa (2015) [9] there has been a climate change in Bangga watershed as mention in Table 2. Thus this model can be used SWB model calculation results are presented in Table 3.…”

“…Table Z Signs of significance in the calculation of the Mann-Kendall categorized into five categories, namely: three star (***), two (**), one (*), the (+) and empty (..) which indicates the level of confidence () = 0.001; 0.01; 0.05 and 0.1 respectively. If there is no sign (blank) means a significant level () of more than 0.1 or can be said to be insignificant [9]. Fig.…”

“…The median value is the estimated of "". [9]. rain is 120 mm/mon, the largest rainfall occurred in March 1996 of 160 mm/mon and the smallest occurred in February 2009 amounted to 92 mm/mon.…”

“…Potential evapotranspiration for each month is calculated from Penman Monteith method [9,11,12,14,15,17]:…”

“…For secondary data are required: 1) Data monthly rain of station Up Bangga and Down Bangga available from 1995 to 2011); 2) Data temperature of Bora station available from 1995 to 2011); 3) Data Potential Evapotranspiration available from 1995 to 2011; 4) Maps satellite imagery; 5) Maps the earth in such a scale of 1:50,000 and 6) Soil type maps, scale 1:50,000. 7) The primary data obtained by directly sampling the soil in the research site to obtain the percentage fraction of land, SM content, soil bulk density and soil type conducted in accordance vegetation land cover (mixed garden and forest) to make a hole in the soil profile depth of the surface soil, topsoil and subsoil below (SM storage) [9].…”