As a type of gate that is used to control the water level upstream, sluice gate is the gate with simple shape and outstanding ability to flush the sediment. The operation of the gate is considered an important process. The up and down movement of the gate would affect the velocity and cause local scour as the result of fluctuating rate. This research aims to assess the effects of discharge and gate-opening height variations, as well as the type of bedchannel material, on the change of depth of scour (d s ). The research was conducted of open channel flow model with a sluice gate able to up and down movement. The discharges used in the research were 9 types ranging from 1.0 to 5.0 dm . Calculated coefficient of determination of the relationship between two types of channel-bed material and the depth of scour was R 2 = 0.946. Consequently, it can be concluded that the equation can be applied on both types of bed-channel material.

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 operation of a damaged (jammed) sluice result unsuitable velocity distribution with the design. This causes turbulence of the flow which results the hydraulic jump. The hydraulic jumps as a function of energy absorbers. The large energy will cause damage to the water structure. Therefore, there is a need for research to obtain flow profiles. The aims of the research is to investigate the flow characteristic and hydraulics jump that occurred at downstream of manually moving of sluice gate. The height of opening gate set up variated at 0.4 cm to 1.4 cm. The range of using variated discharge from 0.108 lt/s to 0.524 lt/s. The result of investigation showed that the higher of opening gate at the same discharge value the hydraulics characteristic at the downstream of sluice gate decreasing. The hydraulics characteristic are the water depth, hydraulics jump and the flow characteristic. As a results variation discharge and opening gate are subcritical flow.

The aim is to know the effect of bedload sediment to river hydraulics parameters. The research was conducted by taking samples in three-part of the river. Each location is taken ten cross-sections with left, middle, and right parts of the river. Bedload sediment is calculated by the grain analysis method. There are several approaches in determining the roughness: Manning, Raudkivi, Subramanya, Meyer, and Muller roughness. From the analysis results, sediment in the form of fine sediment (d ≤ 0.15 mm) located in the middle of the cross-section does not settle due to high velocity. In contrast, in the wet area, the velocity is smaller so that grain material is deposited. The relationship of bedload sediment to the morphological form of the river shows that the middle part has the most material content in grain sediment (d ≤ 0.15 mm). The wet edge has the most content in gravel and sand (d < 6 mm). The Manning equation obtained a minimum roughness of 0.0257 and a maximum coefficient of 0.0365 with an average value of 0.0311. This value is matched with the coefficient of roughness on the Manning table does not differ much, i.e., natural, straight, and meandering channels.

Climate change in Indonesia is marked by changes in temperature, rainfall patterns, sea level and climate variability. The climate condition of the Sausu watershed is a natural process that occurs in a rainfall patterns, magnitude and changes in air temperature. This study was conducted to identify the dangers of climate change to the water sector in the Sausu watershed. The analytical method used is Modified Penman evapotranspiration, water balance analysis model F.J. Mock, Makesens, Cumulative Distribution Frequency (CDF) statistical analysis and hazard weighting. This study uses secondary data, namely rainfall sourced from the Sausu rain station in 2002-2021 and climate data (climatology) sourced from BMKG in 2002-2021. Results from this study is that climate change occurs in the Sausu watershed which is characterized by a positive Z value (an increasing trend) and negative (a decreasing trend). A positive Z value (increasing trend) occurs in June, and a negative Z value (declining trend) occurs in December. The danger of decreasing water availability (PKA) occurs in the period 2052-2061 with a low level of danger. Flood hazard occurs in the period 2052-2061 with a high level of danger. Drought hazards occur in the period 2042-2051 and the period 2052-2061 with a low level of danger.

The safe and clean water is necessary to the most of rural community. Slow sand system was proven to be sustainable and reliable drinking water treatment The majority of Sambo community using river as a source their daily activity. The water of the river containing a very high degree of contamination. The purpose of this study is to determine the model of Wisolo River Water treatment in order to obtain Clean Water in Sambo Village and then checked whether the physical content of the river water meets the water quality standard. From the results of the study using 3 (three) models of Wisolo River water filter processing layer variations, which are most ideal to use and meet the physical quality standards of clean water based on the Regulation of the Minister of Health of the Republic of Indonesia, the layer variations in model I, namely with successive material composition from bottom to top: gravel = 20 cm, palm fiber = 20 cm, and sand = 50 cm.

Evapotranspiration is an important parameter to know in the management of agricultural water resources. There are several methods for estimating evapotranspiration (ETo). The FAO Penman-Monteith method is considered the universal standard for estimating ETo, however, the climate parameter data needed to calculate the ETo of the FAO Penman-Monteith method are not always available, so it is necessary to evaluate performance using several ETo equations as a comparison in estimating evapotranspiration. This study aims to find the performance of the ETo 38 empirical method against the FAO Penman Monteith method and the climatological data parameters that most influence the accuracy of the calculations. The data used is in the form of climatological data for Bora Station which represents land and settlement areas, Boladangko Station representing mountainous areas and Singkoyo Station representing coastal areas with an observation period of 32 years (1986-2017). The performance of the 38 empirical methods was evaluated using the PE, RMSE, MAE, MR and slope methods. The results of this study indicate that: the Makkink method, Abtew1, Irmak et al., Tabari & Talaee1, Valiantzas1 and Abtew3 showed excellent performance, while the WMO and Mahringer methods performed poorly in the three research locations; the number of climatological parameters used had no significant effect on the ETo results obtained. The use of climatological parameters in the form of temperature and solar radiation in the ETo calculation has the greatest effect on the accuracy of the ETo value.

Sluice gate operation is necessary to keep the continuity the design discharge. The mis-operation of sluice gate occurs endanger stucture and destruct the bed irrigation channel. Investigation about sluice gate operation and bed configuration are needed to avoid the destruction of the structure bed irrigation channel. The changes in bed form result from interaction of the flow, fluid and bed material. The aim of this paper is to investigate the influence of different flow parameter, height of opening gate and types of bed material. Fourty five runs were executed at different discharge started from 1.0 l/s to 5.0 l/s with an increment of 0.5 where each discharge has five different opening gate to get all characteristics of bed configuration. The material used in the experiments were sandy loam. The experimental were conducted in an acrylic side flume with recirculating water at Applied Hydraulics Laboratory in Water Resources Engineering Faculty, Brawijaya University, Malang, Indonesia. The result of investigation showed that the bed configuration of sandy loam is ripple for most of the condition. At the same opening gate and various discharge the configuration is start by plane bed (no motion) and ripplee. Meanwhile, for the same discharge at the various opening gate occurs the ripple bed configuration. The various velocity that occur during the runing process cause the changing of bed configuration. For the greater discharge at the same opening gate occur the highest velocity. This condition cause the grain sediment material of the bed channel lift up and start to moving. This result is suitable with equation approaches from the van Rijn, Simon Richardson and Garde Albertson.