Baseflow is essential for water resource management in the dry season at the watershed scale. Management strategy water resources play a crucial role, especially those related to estimation efforts water supply, water quality management, water balance calculation, and strategy development of other water resources. This study aims to determine the value of baseflow using the Fixed Interval Method. This study used Hydro Office software with input daily discharge data from 2004 to 2013. The average baseflow value obtained was 5.53 m3/s, the process of calibrating by taking discharge data in the dry season, with no rainfall input. The BFI value obtained an average of 0. 9. This value indicates that the Miu watershed has high storage permeability characteristics. It indicates that the Miu watershed has a relatively stable flow during dry periods. The greater the BFI value, the better the water supply in a watershed.

The high sediment contained in the canals causes changes in the dimensions of the canals. It can reduce the cross-sectional capacity of the canals. The Baluase Irrigation Area is located in Sigi Regency, Central Sulawesi Province, with a functional area of 94 Ha. This study aims to determine the rate of sedimentation in the Baluase Irrigation Secondary canals, which is expressed in the correlation coefficient (R), which is the relationship between Sediment Discharge (Qs) and Water Discharge (Qw). Primary data were collected by direct measurements at the location by measuring canals dimensions, water level, velocity and water samples to test sediment concentration. Sediment samples were taken at 2 distances of flow depth, namely 0.2 h and 0.8 h with 8 cross sections in the longitudinal direction of the canal. From the research results, the average sedimentation rate in the Ramba secondary canal is 3,574 kg/day, while the Baluase secondary canal is 5,675 kg/day. The correlation coefficient (R) value at 0.2 h was 0.6994 and 0.8229 for a depth of 0.8 h. This shows that the relationship between sediment discharge (Qs) and water discharge (Qw) has a positive relationship between 0.6 < R < 1.0

Global Climate change has been discussed in the High-Level Conference in Rio de Janeiro, Brazil in 1992 and has given more impacts in the world. One of the global climate exchanges is the rising of intensity and frequency of climate extreme which included drought, flood, and hurricane. The objective of this study was to investigate the effects of climate change on evapotranspiration and rainfall for river water discharge of Rawa. The investigation has been carried out using daily data and analyzed on a daily, monthly and yearly. The rain stations that represent the location of this research are Palolo, Kulawi, and Wuasa. Climatological station nearest to the research station used Bora. Climate trends and projected changes in the method of Makesens analysis (Mann-Kendall, Sens) and the correlation of rainfall and evapotranspiration discharge used linear regression equation. Similarly, the correlation between changes in soil water storage with rainfall, evapotranspiration, and discharge was analyzed in a linear manner. The conclusion of this study is the climate changes in the River of Rawa watershed was characterized by slowly increasing temperature, increasing rainfall, and decreasing discharge.