Determining water flow efficiencies at Kah Pulo Geto primary irrigation channels, Bengkulu, Indonesia

The primary problem in a region with limited water resources is the use of irrigation water and this limited water resource is associated with water volume losses in the irrigation channel, particularly in the primary, secondary, and tertiary channels through evapotranspiration, infiltration, and seepage. Therefore, the irrigation channel reguires effective and efficient management. The objective of this study is to evaluate the efficiency of Lomaya Irrigation Area to denote water use and to maximize the water use for agriculture. This study is conducted by applying field data in the primary channel of Lomaya Irrigation Area and data from the climatology of Bolango Bone Tumbihe Watershed. The data collected are a wet cross-sectional area of channel and flow speed in several vertical points. The average daily evaporation rate and water losses in the primary channel of Lomaya Irrigation Area are determined by employing Penman evaporation method. In addition, the efficiency value is obtained by comparing inflow and outflow debit in the irrigation channel. The result of water losses value analysis in the Lodelombongo irrigation channel due to evaporation is 5,14 m³/sec, and the value is not too influential for the water losses in the channel compared to the water losses due to leakage in the channel. In the meantime, the average efficiency value in the Lodelombongo irrigation channel is 61%, where it is no longer in compliance with the predetermined provision in the irrigation planning criteria. The greatest efficiency value in primary channel BLI-BL2 is 92,42%, whereas the smallest value in the primary channel BL3-BL.BI is 49,35Y%, the greatest efficiency value in secondary channel BL.B3-BL.B4 is 72,64%, whereas the smallest value in the secondary channel BL.BS-BL.B6 is 43,89%. The efficiency value is affected by water volume, which losses on its way where the water losses in the irrigation channel encompass water losses components through evapotranspiration, percolation, seepage, and leakage.

Research conducted in the primary canal of D.I Cipicung, Subang Regency, experienced damage to the irrigation network. Damage to the D.I Cipicung irrigation canal network in the primary canal, so that research is needed to find out how much silting volume is caused by sediment deposition in the irrigation canal. The method in this study uses a mathematical method to determine the volume of sediment deposition in the channel. The results show that the volume of sediment in the primary canal in the Cipicung D.I irrigation network is Vq Primary = 16.24 m3 (difference in depth 0.64 m) or 0.16% of the length per section 50.5 m of the total length of the primary canal 300 m and the change in the cross section of the primary channel is A = 1.25 m2 or 27.11%. So that the results of these calculations, it is necessary to resolve by repairing the right side of the canal lining with construction, the entrance channel from the river to the primary canal needs to be built a gate, dredging of sediment is required in the primary canal, and maintenance is required so that the canal is routinely once a week or once a month so that the strong channel is not quickly damaged.
 Keywords: Sediment Siltation, Primary Canal, Irrigation Network Damage.

Considering the bad impact of water loss which has an impact on its efficiency, the authors are interested in analyzing the efficiency and water loss in irrigation networks in the Sekampung Bunut Irrigation Area (DI). Efficiency and water losses were analyzed using the in-discharge discharge method. The data used in this analysis consist of primary data in the form of flow velocity data with current meters, irrigation channel cross-sections, temperature data, humidity data, then secondary data, namely data on the length of solar radiation and wind speed data. Loss of water in the secondary irrigation channel KR Irrigation Area (DI) of Sekampung Bunut lost an average of 17.15%. Meanwhile, the efficiency of the secondary channel in the Irrigation Area (DI) of Sekampung Bunut was 82.85%. The theoretical value of the average efficiency in the secondary channel KR is 90%. This shows that the amount of efficiency is still below the requirements of theoretical efficiency. One of the factors that cause water loss in the secondary channel in the Sekampung Bunut Irrigation Area is the evaporation factor that occurs along the irrigation channel. Keywords: Channel efficiency, water loss, water discharge.

The escalating demand for water and the impact of climate change are posing significant challenges to global water scarcity and agricultural policies. The aim of this research is to investigate the factors influencing water losses in irrigation systems and provide recommendations to minimize such losses. The research methodology includes conducting studies to identify the factors causing water losses through evaporation and seepage from irrigation canals in the Kazakh part of the Ile River basin. The research results are theoretically substantiated, and a series of field studies are carried out at the inter-farm canal experimental site in Almaty province. Based on the factors affecting evaporation and seepage losses in irrigation canals, a new design of irrigation canal made from geocomposite material has been developed and introduced. This design helps to prevent water losses in inter-farm and on-farm canals of reclamation systems. The geocomposite polymer troughs have improved the technical level of irrigation systems and have enabled additional irrigation areas by increasing the efficiency of irrigation water use in land reclamation systems of Kazakhstan, thereby enhancing the efficiency factor of the irrigation network. Water seepage losses are influenced by several factors, including soil type, canal length, working flow, canal operation mode, canal condition, operation season, and wind impact. Under uniform canal operation mode, water losses are relatively small. However, intermittent modes and incomplete filling of the canal result in increased costs. The research findings indicate that for soils with a flow velocity between 0.10 and 0.30 M/s, water losses due to leakage and evaporation in constant-impact and intermittent-impact channels increase linearly. In intermittent-impact channels, irrigation water losses range from 33.7 to 40.1%. The introduction of geocomposite polymer troughs has the potential to enhance the technical level of irrigation systems by improving the efficiency of the irrigation network and enabling the addition of more irrigation plots. This research aims to reduce water losses in the irrigation canals of reclamation systems, optimize the management of water distribution in irrigation systems, enhance equipment measures, and introduce digital irrigation water metering technologies. Future studies propose the application of digital technologies to enhance irrigation water design and accounting as part of measures to minimize water losses in irrigation canals.

The Katingan I tidal lowland irrigation area (DIR Katingan I) is a sensitive area to salinity changes. This study aims to identify and estimate the spatial distribution of salinity in DIR Katingan I. The method used in this study is field measurement for collecting tidal and salinity data in the Katingan River as well as in several locations of primary and secondary canals. The measured data at the upstream canal, Katingan River, and primary canal as boundary conditions and calibration for hydraulic and water quality simulations. The simulations used HEC-RAS software to estimate salinity spatial distribution under tidal conditions at primary and secondary canals. The results showed that the distribution of water salinity can reach lower primary canals. It is necessary to take anticipatory actions to reduce the salinity intrusion. To overcome the problem, alternative recommended solutions that can be done are sluice gates installation on the lower primary canal, right primary canal, and left primary canal about 1 to 3 km from the mouth of the primary canal. The prediction of salinity spatial distribution is expected to be a useful recommendation for water management in DIR Katingan I, and it is expected to increase agricultural productivity.

The Vega Baja region lays on the lower course of the Segura River (southeastern Spain). It is one of the six traditional “huerta” European landscapes and has an ancient, extensive, and complex network of irrigation and drainage channels. The accumulation of floating waste causes numerous economic, environmental, and landscape problems in its irrigation infrastructures, hindering farmers’ water management practices. This work classifies and estimates the total volume of floating waste at various points along the Segura River and its irrigation channels as a first systematic approach to define and quantify the problem of floating waste accumulation. Aerial images taken by a drone were analyzed over time and a manual count of residues was performed on selected points. The results obtained show that reeds and residues of riparian vegetation represent more than 95% of the floating debris volume measured on the riverbed. Anthropogenic waste, which represents less than 5% of debris volume, was characterized, finding that plastics of domestic sources are the most abundant by count (14.9%) and only a reduced part of the floating waste can be attributed to agricultural activities (3.8%). Assessing the type and origin of the floating waste is essential to inform the actions required in order to avoid the floating waste reaching the Mediterranean Sea.

Water resources can be utilized for various human needs including household needs, industrial needs, irrigation needs for agriculture as well as potential energy and kinetic energy for electricity generation. Sindupraja Primary / Primary Channels, which are the main canals serving irrigated areas covering 87,803 ha spread across Cirebon Regency and Indramayu Regency, with a water discharge of 10.3 m3 / sec and good discharge capacity and the large dimensions of the channel make it more optimal not to use only as a provider of irigas for agriculture but also as a potential and kinetic energy source for electricity generation. The purpose of this study was to determine the water resources in terms of hydraulics contained in irrigation channels, especially the Sindupraja Main Canal, which can be optimized as a source of kinetic energy. The purpose of irrigation is the use of water that is comprehensive and supports agricultural productivity in order to increase agricultural production, besides optimizing the management of irrigation water resources because there is stored energy namely potential energy (in falling water) and kinetic energy (in running water), where This energy can be used as the main medium to drive turbines and generators as a source of electrical energy. The amount of potential and kinetic energy produced from these water resources depends on the amount of water debit available, the speed of flowing water flow, and the consistency of water discharge in a certain size. Utilizing the potential of water resources contained in irrigation canals, water energy can be used as a source of MHP where kinetic energy contained in the flow of water in irrigation canals is used as a driver of waterwheels, where the waterwheel is used as a medium or means to convert water energy into energy mechanical form of torque on the wheel shaft to produce electrical energy. the amount of power produced depends on the water flow and speed of the water flow.

The Western North Tarum Irrigation channel plays a crucial role in supplying water to irrigated agricultural areas. However, it encounters challenges in ensuring adequate water delivery to all channel segments. This research assesses water loss during the distribution process in the Western North Tarum Irrigation channel, focusing on the evaluation of channel capacity and the impact of suboptimal water management on water loss. The study employs the HEC-RAS model, a hydraulic system analysis tool, to evaluate the channel’s capacity and simulates its behavior under various discharge conditions. The evaluation reveals that two channel segments, B.TUB 13 and B.TUB 25, have exceeded their capacity limits, resulting in overflow. Sedimentation downstream, particularly in these segments, exacerbates the issue by altering the channel slope and impeding water flow. This research identifies poor water distribution management as a significant factor contributing to water loss in the irrigation channel. Inadequate scheduling and the absence of proper water measurement tools result in instances of overwatering or underwatering in some areas. The lack of monitoring and control in the irrigation system hampers the detection of uncontrolled flow in the channels, leading to substantial water loss and inefficient water use. This research underscores the importance of evaluating and maintaining irrigation channel capacity to prevent overflow and water loss. Furthermore, it emphasizes the significance of effective water management to achieve more efficient water distribution and irrigation. Addressing these challenges is crucial for ensuring the long-term sustainability of irrigated agriculture in the Western North Tarum Irrigation area.Keywords: HEC-RAS, Irrigation Channel, Water Distribution, Water Loss, Western North Tarum

Irrigation Network Krueng Tuan North Aceh Regency was built in 1994 with 11,150-meter primary channel that is planned can irrigate paddy fields potential 2,226 ha. The Krueng Tuan irrigation area has enormous potential as a food granary, but the irrigation discharge to irrigate rice fields was reduced due to a decline in the functioning of facilities in the Krueng Tuan irrigation network considering the age of buildings that were already age-consuming. This condition can result in an increase in water losses that affect the efficiency of irrigation in the channel. The method used to analyze the efficiency of irrigation channels using the inflow-outflow method. The data were recorded about cross-section dimensions of the channel and measuring flow velocity using the current meter. The results of the efficiency analysis show that there are four primary channel sections was under the theoretical efficiency values, namely the measurement section BT-02 - BT-03 at 88.729%, where water losses are caused by the influence of the physical conditions of the channel on the wall and the bottom and wild leads from the channel using the pump house. Other sections are BT-06 - BT-07 at 80.378%, BT-07 - BT-08 at 73.975%, and BT-08 - BT-09 at 67.094%. Water losses on all channels are caused by the physical condition of the channel that has been damaged in the channel wall and leakage due to the rat hole so that water seeped out of the channels.

The aim of the article is to develop a method for calculating water losses from irrigation channels in determining the permeability of rock in the zone of filtration flow on the basis of the law of infiltration A.N. Kostyakov using the results of studies of free filtration from pits and foundation pits in loess loams.
 Pressure movement of water in irrigation canals is subject to the laws of two-phase flow, in which – in contrast to the Darcy law for the zone of saturation plays an important role, the volume and its change in time. The filtration rate (VF) increases with increasing rock moisture (θ) along the S-curve, while the pressure gradient (I = dh/dz) decreases.
 The dependences of these parameters on the pressure are represented by power functions, and their product CDP = VFI does not change in time and can serve as a characteristic of the filtration flow under the channel. When installing paired piezometers near the water chore line in the channel and determining the graph I(t) by the value of the twophase flow constant CDP, it is possible to calculate the filtration rate at a number of times and the water losses during unsteady filtration.
 Water losses from the channels at equilibrium humidity increases with increasing head according to the formula A.N. Kostyakova, in which the water permeability of rocks is characterized by a steady filtration rate at a head of 1.0 m, and the gradient is the function of pressure.
 The application of the proposed method of calculating losses in the design of irrigation systems will increase the reliability of the justification of the volume of anti-filtration measures and the forecast of the groundwater level.

Irrigation channels fulfill agricultural water needs by channeling water from various sources. Suradadi sub-district has great agricultural potential, but its productivity is constrained by a shortage of irrigation water and limited information on the condition of irrigation channels. The lack of complete data makes effective monitoring and policy making difficult. This research aims to identify irrigation channels using Landsat images, identify the level of damage to irrigation channels, and analyze the priority of follow-up repair of irrigation channels. The sampling method used was purposive sampling and the data analysis method used was spatial analysis. The results obtained primary irrigation channels have a total length of 5,344 meters in the southern part of Suradadi Sub-district and secondary irrigation channels have a total length of 18,388 meters scattered in Suradadi Sub-district. Most primary and secondary irrigation channels have mild to moderate damage, caused by soil expansion, erosion, root growth, water flow loads, road construction, and agricultural activities that damage the channel structure. There were 4 sites where damage to primary and secondary irrigation channels was prioritized for repair. The first site had significant damage, including collapsed walls and large cracks, which impeded water flow. The second site had moderate cracks and structural damage, while the third site required repairs to the lining. The fourth site had erosion in several sections, requiring intensive repairs including new walls and lining.

Water conservation is a special form of water management for water-short areas, where water must be used as efficiently as possible and water losses must be minimized. A water loss is defined as the transfer of water to a place or condition from which it cannot readily be recovered for further use. Such losses include evaporation and transpiration, discharge of fresh water into salt water (oceans, lakes, or aquifers), storage or transit in the vadose (unsaturated) zone, and serious pOllution by industrial, agricultural, or other chemicals. These are true losses of water. On the other hand, seepage of water from streams or irrigation canals to underlying aquifers is not always a realloss because the water can be recovered by pumping it from wells in the aquifers, or it may eventually drain into surface water. Yet, many irrigation canals are lined to “conserve” water. Thus, water conservation is best defined as water management to minimize transfer of water to a place or condition which diminishes its usefulness to the intended user. Water conservation can be achieved by reducing evaporation, transpiration, and quality degradation ; by cloud seeding ; increasing groundwater recharge or other storage ; seepage control ; and treating and reusing sewage or other contaminated water.

Builders in this irrigation area are a great opportunity to improve the economy of the community Lubuk Buntak. In order to improve and maintain agricultural production of food crops, the Pagar Alam City Government has until now built irrigation facilities and infrastructure both for the construction of new irrigation or rehabilitation in order to support the planned food security program. Irrigation channels located in the Lubuk Buntak irrigation area during the rainy season the water found on the irrigation canal has exceeded the capacity of the irrigation channel so that the irrigation can not work optimally, due to the high rainfall that occurs Thus the irrigation of Lubuk Buntak City Pagaralam irrigation area needs to be analyzed for the rainfall that occurs, in order to determine the ideal irrigation canal design and in accordance with the magnitude of the planned flood discharge, so that the planned irigassi channel works optimally. The purpose of this survey is about Rainfall Analysis, Calculation of planned flood discharge, Irrigation Channel Dimension, in this thesis using five Smirnov-Kolmogorov matching medotas from the calculation of the suitability of the method used is the gumbel method because the maximum difference (Dmax) -4, 70 <from Critical Value 41% (0.41), and analyze flowrate, so that the Irrigation Channel remains optimal for water resources can be utilized according to its designation, based on the parameters obtained. Next, identify the irrigation channel, calculate the intensity of rainfall, determine the flood discharge and the last design the channel dimensions for the area. The research carried out with a land area of ​​50 ha was obtained by the value of the intensity of the 50-year return rainfall of 530.76 m3 / sec, the planned flood return period of 50 years was 1.48 m3 / sec and the design of the channel dimension was (h) = 1, 42 m (B) = 1.40 m, (wf) = 0.29 m, and (TMA) = 1.17m

Unit Tamban is a fork system of lowland irrigation areas in Kapuas District. It has three primary canals, and each of them has a settling pond at the end. Most of the 3,506 ha planting area still apply once a year cropping patterns. A quick assessment based on field observations is carried out to determine the existing problems, including water management, water quality, and soil quality. The problem in the water management system is silting in the primary and secondary canals. The settling pond at the primary canal was no longer functioning, and it makes the silting worse because the water flow became uncontrolled. Water quality is measured with pH and TDS, the average pH at canal water was 4,22, and TDS was 71 mg/l. The soil type is mainly acid sulphate with pyritic materials, mostly 70 cm below the surface. Increasing cropping patterns twice a year requires improving the water circulations and increasing the soil pH higher than five. The problem in the secondary canal is expected to solve by changing the flow pattern from two way to 1-way flow is needed to avoid dead spots of water so that the leaching processes can work well.

The project Land and Water Management of Tidal Lowlands (LWMTL) was set forth in Indonesia to reclaim vast areas of waterlogged tidal land for agricultural exploitation. The objective of this study was to simulate water management systems near the farmers field by controlling flap gate culverts in secondary canals (SDU) and stop logs in tertiary canals under different scenarios of irrigation, drainage and flushing. Based on data (hydraulic and hydrometric) collected during a field survey in August 2005, a 1D mathematical model (DUFLOW) for the canal system was developed and calibrated. For boundary conditions of the model, tidal water level fluctuations in the primary canals were used. Different rainfall intensities (10 mm/day, 30 mm/day and 80 mm/day) and evaporation of 3 mm/day were modelled in order to evaluate the hydraulic response of the system. Water normally flows from the secondary canals to the tertiary canals. Water level is kept and maintained as high as possible. The model shows that water level in the tertiary canals increases in time; the level also depends on tidal water level outside and rainfall intensity. In the case of 80 mm/day rainfall, water level in tertiary canals will reach around 2.00 m above median sea level (+MSL, more or less the ground surface elevation) after one day. At this level, water can be utilized for agricultural production. Flushing can be done by operating the culverts and water can flow out from SDU to the primary canal. Water in the tertiary canal can be set at low elevation +1.30 m +MSL for flushing to the SDU and primary canal. Based on the hydraulic performance of the mathematical model, water level can be controlled to improve the hydro-topographical conditions of the area which can change from C/D to A/B category. A one way flow system can be realized where the flow will start from the SDU to tertiary canal and to the field. During low water, drainage can also be regulated from field to the tertiary canal and to the SDU. Finally, related to the water management system in this secondary block some suggestions can be presented. In the future this temporary dam in the SDU should be replaced by a permanent control structure and culverts should be completed with a flap gate. Based on the water level in the SDU (behind the dam), operational rules of the tertiary water control structures have to be derived and used by the farmers.