Irrigation Water Distribution Research Articles

Development of a coupled surface water–groundwater model for the spatiotemporal simulation of river–aquifer interactions

AbstractIntegrating surface and groundwater use is a crucial part of water management. When one type of water is depleted, the other follows suit because of the constant movement and interaction between them. Therefore, the primary objective of this research is to establish a method by which the water evaluation and planning system (WEAP) surface water model and the MODFLOW groundwater model can communicate with one another. This article aims to demonstrate the interdependence of groundwater and surface water. Here, we use MODFLOW to model the saturated soil region and the soil moisture method to model the unsaturated soil region. The interaction between surface water and groundwater will affect the region's water resources and how they will operate under the continuance of existing practices. The simulation of saturated and unsaturated soil zones using a connected model of surface and groundwater employing all the hydroclimatology balance components is one of the most significant accomplishments of this research. The findings show that the (Iran) Sonqor Plain's maximum aquifer recharge throughout the months of November to May during a period of 30 years (October 1991 to September 2020) ranges between 1.5 and 2.6 million m³. A lack of recharge from irrigation water infiltration occurs in some of these months in addition to rain. The highest rate of groundwater level increase in this area is 4.5 m yr⁻¹ as a result of the distribution of irrigation water provided from the dam in the north‐western region.

Pengaruh Variasi Diameter Pipa Primer Terhadap Pola Resapan Air Irigasi tetes Bertingkat Pada Media Tanam Polybag

Multilevel drip irrigation is an irrigation method that supports water-saving agricultural activities in limited areas by channeling water through perforated pipes from emitters. The ideal multistage drip irrigation system can provide the same drip volume to plants, so the distribution of irrigation water and its depth need to be important factors to pay attention to in order to provide optimal plant irrigation. This research aims to determine the effect of using variations in primary channel pipe diameter on the distribution of drip irrigation and the depth of infiltration of irrigation products in a 3 (three) tier drip irrigation network. Tests were carried out on primary pipes from floors 1 to 3 with a diameter of ½", ¾" and pipes 1", with lateral drip pipes with ½" PVC. The size of the test field is 4 m x 1 m x 1.8 m and the distance between levels is around 0.9 m and the irrigation water source from a 200 liter tank is 2.5 m high. The research results showed that irrigation distribution results were quite good at all levels of the irrigation network, namely 70 ml and 68 ml. Irrigation patterns do not have a significant effect on the results of irrigation distribution due to variations in primary pipe diameter. A soil composition of 30% compost has achieved irrigation infiltration with a depth of 21 cm, including the fastest, namely 25 minutes and for 70% soil, an irrigation infiltration time of 35 minutes is required.

Assessment of Agricultural Drought Using the Normalized Difference Drought Index (NDDI) to Prediction Drought at Corong River Basin

As a complex and widespread natural phenomenon, drought poses a significant threat to the agricultural sector, especially in developing countries, resulting in significant economic losses. Its close relationship with water resilience and crop production necessitates sophisticated monitoring approaches for agricultural drought. Leveraging satellite remote sensing technology and various data types such as multispectral, thermal infrared, and microwave, can monitors drought on a large scale. This technology provides a comprehensive perspective for timely and spatial data collection, facilitating monitoring vegetation in vast agricultural areas. The study focuses on developing an agricultural drought model from 2017 to 2021, using Landsat 8 imagery. The model integrates the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI), resulting in the establishment of the Normalized Difference Drought Index (NDDI) method. To predict agricultural drought in the Corong River Basin, the study employs the Seasonal Autoregressive Integrated Moving Average (SARIMA) model. Findings reveal varying degrees of dryness in the Corong River Basin, with 77% categorized as Strong dry conditions, 1% as Dry, 0.3% as Moderate wetness, and 21.6% as wetness. Drought predominantly occurs between July and October, impacting approximately 78% of the total dry area and extending across almost the entire region. The SARIMA (0,0,1)(3,0,0)12 model, with a MAPE value of 0.2399, emerges as the most effective for predicting agricultural drought. These forecasted results provide critical insights into the level of agricultural drought in the Corong River Basin and valuable information for drought mitigation strategies, especially in regulating the distribution of irrigation water.

REKONFIGURASI 26 KANAL IRIGASI MENGGUNAKAN METODE BINARY FIREFLY ALGORITHMS (BFA)

Reconfiguration of irrigation water channels on agricultural land aims to meet the water needs of rice fields. In its use, irrigation water must be used optimally. An automatic irrigation system is needed to provide water to plants in the desired conditions. In the irrigation control system, a servo motor simulates the control system using the Matlab 2013b software programme. Control simulations applied to irrigation prototypes are used to increase efficiency and determine the amount of irrigation water needed to regulate irrigation water distribution according to needs. As a controller comparison, an artificial intelligence method is used for controller tuning based on Binary Firefly Algorithm (BFA). The farthest water discharge results can be reduced in the reconfiguration model using the BFA method. So reconfiguring the network with BFA can reduce water discharge losses by 43.4538% of the water discharge losses from before

Optimal Pumping Flow Algorithm to Improve Pumping Station Operations in Irrigation Systems

In Spain, irrigated agriculture is the most water-intensive sector, consuming around of 80% of water resources. Moreover, irrigation water distribution systems are the infrastructure by which one-third of water resource losses take place. Monitoring and controlling operations in irrigation canals are essential for mitigating leakages and water waste in operational actions. On the other hand, energy consumption by agriculture is around 5% of usage in developed countries and even higher in undeveloped countries. Although it is a small part of the total energy supply for a country, energy waste reduces the competitiveness of the agriculture sector, which continually reduces profit margins in an economic sector with very low profit margins already. The tool developed in this paper aims to increase the efficiency of water and energy management in the agricultural sector and is included in an overall control diagram for scheduled irrigation management. This tool, the optimal pumping flow (OPF algorithm), optimizes the pumping flow from the irrigation canal to the irrigation reservoir in terms of water level at the canal and reservoir, crop flow demand, system constraints, and energy prices. Regarding the results, the OPF algorithm can calculate the optimum pumping operations, being able to optimize water resource usage and energy expenses by ensuring that the water level at reservoirs remains within a specified range and that pump flow never exceeds a threshold. Further, it allows for the management of pump operations outside of peak hours. On the other hand, the OPF algorithm is also integrated into the overall control diagram in a second test. Here, the OPF algorithm collaborates with a control canal algorithm such as the GoRoSo algorithm to optimize canal gates and pump operations, respectively. In this scenario, OPF reduces cumulative energy expenses by 58% compared to the scenario where the pump station operates only when the reservoir water level is below a certain threshold.

Developing a Hybrid Irrigation System for Smart Agriculture Using IoT Sensors and Machine Learning in Sri Ganganagar, Rajasthan

The agriculture sector is one of the largest consumers of fresh water. Different types of irrigation systems are available, including center pivot, drip and sprinkler systems, and linear motion systems. However, the complex structure of existing irrigation systems and their high maintenance costs encourage Indian farmers to continue using these methods. Due to its ease of use and low energy consumption, surface irrigation is one of the most popular irrigation techniques. Although the main reasons for poor irrigation application efficiency are uneven irrigation water distribution and deep absorption, using a variety of technologies, countries are trying to increase the sustainability of agriculture. Automated irrigation systems contribute significantly to water conservation. The combination of automation and Internet of Things (IoT) improves agricultural practices. These technologies help farmers understand their crops, minimize their impact on the environment, and preserve resources. They also enable efficient monitoring of the weather, water resources, and soil. This research proposes an intelligent, low-cost field irrigation system. The proposed prototype can measure soil moisture, rain status, wind speed, water level, temperature, and humidity using a hardware sensor and unit. To decide whether to turn on or off the motor, a variety of sensors are used to get a range of readings and conclusions. They enable automatic watering when soil moisture levels are below a certain threshold, and if soil moisture is equal to the required moisture, then the irrigation process stops. Every few minutes, the sensors measure the environmental factors. Data are collected and stored on a ThingSpeak cloud server for analysis. To evaluate the data we collected, we used a variety of models, such as K-nearest neighbors (KNN), Naïve Bayes, random forest, and logistic regression. Compared to other Naïve Bayes and random forest models, the accuracy rate was 98.8%, the mean square error was 0.16, and the results of logistic regression, KNN, and SVM were in order: (98.3%/1.66), (99.3%/0.66), and (99.5%/0.5), respectively. In the end, an automated irrigation system run on IoT applications gives farmers access to remote monitoring and control, as well as information about the specifics of the irrigation field.

Гидравлические исследования поливного модуля системы комбинированного орошения

Purpose: to state hydraulic characteristics and determine priority directions for improving the irrigation module design for combined drip and micro-sprinkler irrigation. Materials and methods. The study is based on the joint use of theoretical methods – a well-known mathematical model for calculating the hydraulic characteristics of the irrigation module and experiment, which allows assessing the problem state and scale solutions in any necessary proportions. Results. According to calculations, the uniformity of watering is maintained at an acceptable level at a lower head level in the range of 1.56–1.68 atm when installing six microsprinklers on a drip line. When installing eight sprinklers, the water head along the length of the drip pipeline decreased to an unacceptable 1.39–1.40 atm. Experimental studies have shown that there is only an option with two sprinklers installed on the pipeline above the level of 1.5 atm. Already with the installation of four sprinklers, the water head along the length of the pipeline decreased to 1.45–1.47 atm. At the same time, the variation in the actual microsprinkler performance reached 16 % or more. The discrepancy between experimental and model data is explained by the fact that the calculation model does not fully take into account local resistances that arise when connecting sprinklers. Conclusions. Two main reasons of the increased uneven distribution of irrigation water over the irrigated area have been identified. The first reason is a significant increase in water flow in the irrigation pipeline when emitters and sprinklers work together. The solution to this problem is to develop structures that make it possible to separate the water flow through emitters and through sprinklers in time. The second reason is an increase in local resistance in the water diversion units to the sprinklers. The solution to this problem is to develop special water diversion structures that would be characterized by minimal local resistance.

Water productivity of barley crop under laser land leveling technique and minimum tillage

ABSTRACTLaser land leveling is an important method that helps to improve the spatial distribution of irrigation water and fertilizers applications, subsequently reduce water, nutrient, and energy inputs to agriculture and contributes to increasing productivity. Thus, the aim of the study was to improve the productivity of the barley crop grown in sandy lands under conditions of water scarcity and the negative impact of climate change in Egypt by using laser leveling and the minimum tillage method. Two experiments were conducted during the 2020/2021 and 2021/2022 seasons at the Nubariya farm, Buhaira Governorate, Egypt to study the effects of laser leveling and minimum tillage (zero – tillage, 10 cm, 20 cm, and 30 cm) affecting the distribution of soil moisture, water stress, effectiveness of water application, yield characteristics, water productivity, and some quality parameters of the barley crop. The statistical analysis’ findings revealed a considerable influence of both laser soil leveling and minimum depth of plowing on productivity, water productivity and quality properties of barley crop. Laser leveling with a plowing depth of 10 cm gave the most favorable values of the soil moisture content at the root-zone as well as better grain yield and water productivity in addition to improve the quality properties of barley. The grain yield has improved by 12.65% and 10.41%, while water productivity has increased by 12.75% and 10.06% during the seasons 2020/2021 and 2021/2022, respectively. This increase is likely the result of improving soil moisture distribution and increasing irrigation application efficiency, which resulted in less water stress in the root zone and subsequently increased yield, water productivity and quality properties of barley during the two growing seasons. Generally, the application of laser land leveling as eco-friendly practice will help in sustaining barley productivity in Egypt particularly in the sandy soil regions. According to this study, laser-assisted precision field leveling has the potential to improve grain yield and crop establishment, water productivity and barley quality properties in addition to achievement of the highest net income for farmers.

A Review of Optimal Design for Large-Scale Micro-Irrigation Pipe Network Systems

Micro-irrigation pipe network systems are commonly utilized for water transmission and distribution in agricultural irrigation. They effectively transport and distribute water to crops, aiming to achieve water and energy conservation, increased yield, and improved quality. This paper presents a model for the scaled micro-irrigation pipeline network system and provides a comprehensive review of the fundamental concepts and practical applications of optimization techniques in the field of pipeline network design. This paper is divided into four main sections: Firstly, it covers the background and theoretical foundations of optimal design for scaled micro-irrigation pipeline network systems. Secondly, the paper presents an optimal design model specifically tailored for scaled micro-irrigation pipeline networks. And then, it discusses various optimization solution techniques employed for addressing the design challenges of scaled micro-irrigation pipeline networks, along with real-world case studies. Finally, this paper concludes with an outlook on the ongoing research and development efforts in the field of scaled micro-irrigation pipeline network systems. In addition, this paper establishes a fundamental model for optimizing pipeline networks, to achieve minimum safe operation and total cost reduction. It considers constraints such as pipeline pressure-bearing capacity, maximum flow rate, and diameter. The decision-making variables include pipeline diameter, length, internal roughness, node pressure, future demand, and valve placement. Additionally, this paper provides an extensive overview of deterministic methods and heuristic algorithms utilized in the optimal design of micro-irrigation pipeline networks. Finally, this paper presents future research directions for pipeline network optimization and explores the potential for algorithmic improvements, integration of machine learning techniques, and wider adoption of EPANET 2.0 software. These endeavors aim to lay a strong foundation for effectively solving complex and challenging optimization problems in micro-irrigation pipeline network systems in the future.

Modifying physical supply and use tables (PSUTs) in the system of environmental-economic accounting (SEEA) for off-farm irrigation water management

A reliable water accounting framework is crucial for understanding the contribution of water resources in meeting agricultural demands and selecting appropriate operating systems for off-farm water systems, including hydraulic conveyance and distribution structures. This ensures fair, adequate, and dependable irrigation water distribution, especially under water scarcity operational scenarios. This study presents a novel and effective method for modifying PSU tables in the SEEA water accounting framework that is specifically designed for small-scale agricultural water management study areas. The proposed approach entails a comprehensive analysis of the surface water distribution within the water holders using a hydraulic simulation model and a spatial analysis of the groundwater extraction for meeting on-farm water demands. This approach was implemented on Iran's Central Plateau and revealed notable variations in water rights and distribution effectiveness among stakeholders so that, surface water contributed 27–40% less than the legal water rights, leading to aquifer overexploitation. The evaluation indicated that changing crop patterns and upgrading to pressurized irrigation systems led to 4–7.5% overexploitation of groundwater and 3.5–6% water conservation on farm scales. Besides, the spatial assessment verified a considerable overlap of 59% between the farms with modern irrigation systems and those with cultivated area expansion, resulting in sustained overexploitation pressure on the aquifer. The present study has two significant practical implications. Firstly, it specifies the contribution of surface- and groundwater resources in fulfilling the water demands of individual water-holders. Secondly, it provides reliable information to decision-makers about the incentives for modernization, rehabilitation, and renovation projects in an irrigation district.

Penilaian Indeks Kinerja Sistem Irigasi (Studi Kasus Daerah Irigasi Cirompang Kabupaten Garut Jawa Barat)

Irrigation is an effort to provide, regulate and distribute irrigation water. The Cirompang Irrigation Area is located in Bungbulang District, Garut Regency, West Java Province, with a functional area of 847 Ha, covering the service area of 4 (four) villages, namely Cihikeu Village, Bungbulang Village, Margalaksana Village and Hanjuang Village, Bungbulang District. The location of the Cirompang Irrigation Area Weir is in the village of Cintarasa, Samarang sub-district. The availability of water in the upstream, downstream and main network areas during the planting season I to planting season III is felt to be sufficient but in the middle areas the availability of water is reduced or it can be said to be non-existent due to reduced water potential and there are damaged irrigation networks and accumulation of sedimentation which results in obstruction of water flow. The Cirompang secondary canal experienced moderate to moderate damage, there was accumulation of mud or sedimentation which affected the flow of water and besides that there was also a lack of personal O&M officers in the field such as irrigation officers, weir operation officers, water gate officers and workers who have so far relied on participation. water user farmers (P3A/GP3A). The research method was carried out by direct observation in the field, interviews and secondary data analysis. Calculation of the real need for operation and maintenance is needed to determine the O&M funding and priority recommendations proposed to increase the value of irrigation system performance appraisal (IKSI). The results of the IKSI assessment for the Cirompang irrigation area, the combined index value is in the bad criteria, namely with a weight value of 48.14%, meaning that the irrigation network requires rehabilitation of the irrigation system and needs immediate treatment. 117,626,150.00 In addition, O&M financing in Cirompang for the last 3 years is still far from ideal conditions, namely an average of only 10% of AKNOP. Efforts to increase the water discharge, it is suggested for the Public Works and Spatial Planning Office of Garut Regency is to increase the budget allocation, empower the participation of water-using farmers and rehabilitate irrigation networks.

Operating inlet pressure head assessment for multi-outlet submain manifolds in a low-pressurized water distribution network system

Abstract Multi-outlet pipes can be used to distribute and collect fluids and have applications in various engineering fields, especially in the water supply system. The hydraulic design of a submain unit pipeline with multiple outlets is a very important concern for the proper hydraulic performance of irrigation water distribution systems. The operating inlet pressure head, H0I, is a main hydraulic component for the proper hydraulically efficient design and evaluation of pressure head distribution along the line. The energy-gradient ratio (EGR) approach is a useful tool to identify first which type of pressure profile occurs for a given uniform design slope with other hydraulic variables initially known and then, comprehensively evaluate its definite hydraulic characteristics along the line. Knowing the hydraulic properties of any type of pressure profile regarded enables the design engineer to evaluate pressure parameters through the line sections in a simple way. The procedure is simplified by regarding the localized head loss along the pipe but neglecting the change in kinetic head. The present analytical technique performs sufficiently accurately in comparison with the computer-aided software design technique, for all performed simulations.

Modelling farmland dynamics in response to farmer decisions using an advanced irrigation-related agent-based model

Often, individual, communal, regional, or even national conflicts arise when water resources are shared and used. For equitable water-sharing strategies to be implemented, adequate collective action is required to allocate water – not limited to, but specifically in irrigation systems. In this research, we develop an Advanced Irrigation-Related Agent-Based Model (AIRABM) to explore issues of unequal access to water in relation to water use on farm and system levels. By simulating farmer activities and system management decisions within an irrigation system, our research aims to explore farmland dynamics in response to different levels of decision-making according to water availability. We incorporate both individual and collective decision-making processes to explore patterns in farmers’ yields and the dynamics of farmlands. Our results show that (1) within a prevailing trend of increasing yields for higher river discharge and gate capacity, (2) the influence of water availability is characterized by nonlinear changes in yields in response to variations in river discharge and gate capacity, revealing thresholds and tipping points, with (3) strategies for water redistribution partially alleviate inequitable water allocation between upstream and downstream farmers, although considerable variation persists in individual farmers’ and system-wide harvest outcomes. The AIRABM emphasizes individual and collective decision-making processes, encapsulating the uncertainty stemming from water availability and harvests of individual farmers. The modeling framework serves as a valuable tool to explore cooperative approaches in shared (water) resource management. Our findings provide meaningful suggestions to study and promote communication and (conditional) cooperation measures between farmers and management, thereby enhancing the effectiveness of irrigation water distribution.

Developing a tactical irrigation and nitrogen fertilizer management strategy for winter wheat through drip irrigation.

Agricultural activities in the North China Plain are often challenged by inadequate irrigation and nutrient supply. Inadequate and improper resource utilization may impose negative impacts on agricultural sustainability. To counteract the negative impacts, a deeper understanding of the different resource management strategies is an essential prerequisite to assess the resource saving potential of crops. We explored plausible adaptation strategies including drip irrigation lateral spacings of 40 and 80 cm (hereafter referred to as LS40 and LS80, respectively), irrigating winter wheat after soil water consumption of 20 and 35 mm (hereafter represented as IS20 and IS35, respectively), and nitrogen fertilization scheme of a) applying 50% nitrogen as a basal dose and 50% as a top-dressing dose (NS50:50), b) 25% nitrogen as a basal dose and 75% as a topdressing dose (NS25:75), and c) no nitrogen application as a basal dose and 100% application as a top-dressing dose (NS0:100). The consecutive 2 years (2017-2018 and 2018-2019) of field study results show that growing winter wheat under LS40 enhanced the water use efficiency (WUE), grain yield, 1,000-grain weight, and number of grains per spike by 15.04%, 6.95%, 5.67%, and 21.59% during the 2017-2018 season, respectively. Additionally, the corresponding values during the 2018-2019 season were 12.70%, 7.17%, 2.66%, and 19.25%, respectively. Irrigation scheduling of IS35 treatment improved all the growth-related and yield parameters of winter wheat. Further, treating 25% nitrogen as a basal dose and application of 75% as a top-dressing dose positively influenced the winter wheat yield. While NS0:100 increased the plant height, leaf area index (LAI), and aboveground biomass as compared to the other application strategies, but high nitrogen was observed in deeper soil layers. Regarding soil environment, the lowest soil moisture and nitrate nitrogen contents were observed in LS80 during both growing seasons. Overall, coupling the IS35 with NS25:75 under 40-cm lateral spacing is a suitable choice for sustainable winter wheat production in theNorth China Plain. The results of our study may be helpful in advancing the knowledge of the farmer community for winter wheat production. The findings can also aid in advancing new insights among scientists working on soil water and nitrogen distribution in drip irrigation for better productivity.

Integrasi Metode Objective Tree Diagram dan Quality Function Deployment dalam Perancangan Hydraulic Ram Pump (Hydram Pump) untuk Sistem Distribusi Air Irigasi Ramah Lingkungan di Sumatera Barat

This study proposes an integration between the Objective Tree Diagram (OTD) and Quality Function Deployment (QFD) methods in the design of a Hydraulic Ram Pump (Hydram Pump) for an environmentally friendly irrigation water distribution system in West Sumatra. The hydram method uses the potential energy of river water to drive the pump without the need for electricity or fossil fuels, thereby reducing negative environmental impacts. This study involved a design phase of Identifying user requirements, Developing an Objective Tree Diagram to decompose the ultimate goals, and Integrating Quality Function Deployment to link user requirements with technical specifications. The design results indicate that the hydram pump can be designed to meet the needs of irrigation systems in West Sumatra. With a minimum waterfall height of 0.5 meters, the hydram pump can produce a head of 10 meters. The inlet flow rate is designed to be a maximum of 0.0354 m3/second, while the outlet flow rate is 0.028 m3/second or approximately 2448 liters daily. Integrating OTD and QFD methods allows designers to comprehensively understand user requirements, connect them with precise technical specifications, and reduce the gap between design and actual needs. This research is expected to contribute to developing an environmentally friendly irrigation water distribution system in West Sumatra. By using an integrative approach of the OTD and QFD methods, the design of the hydram pump can be more targeted and meet user needs. The implications of this research can be utilized as a guide in designing efficient and sustainable irrigation water distribution systems while reducing negative environmental impacts in the region.

LandInG 1.0: a toolbox to derive input datasets for terrestrial ecosystem modelling at variable resolutions from heterogeneous sources

Abstract. We present the Land Input Generator (LandInG) version 1.0, a new toolbox for generating input datasets for terrestrial ecosystem models (TEMs) from diverse and partially conflicting data sources. While LandInG 1.0 is applicable to process data for any TEM, it is developed specifically for the open-source dynamic global vegetation, hydrology, and crop growth model LPJmL (Lund–Potsdam–Jena with managed Land). The toolbox documents the sources and processing of data to model inputs and allows for easy changes to the spatial resolution. It is designed to make inconsistencies between different sources of data transparent so that users can make their own decisions on how to resolve these should they not be content with the default assumptions made here. As an example, we use the toolbox to create input datasets at 5 and 30 arcmin spatial resolution covering land, country, and region masks, soil, river networks, freshwater reservoirs, irrigation water distribution networks, crop-specific annual land use, fertilizer, and manure application. We focus on the toolbox describing the data processing rather than only publishing the datasets as users may want to make different choices for reconciling inconsistencies, aggregation, spatial extent, or similar. Also, new data sources or new versions of existing data become available continuously, and the toolbox approach allows for incorporating new data to stay up to date.

CROP WATER CONSUMPTION MODELLING AT OUTLET LEVEL BY USING REMOTE SENSING AND GIS

The enlarged demand of water due to agriculture expansion, increasing industrial and domestic needs, compounded with climate change is causing scarcity of water globally and Pakistan is also facing same conditions. Due to limited availability of water, it is necessary to adopt global best practices being employed for sustainable agricultural water management. Remote sensing techniques are being intensively used around the globe with confidence to monitor the crops growth and crop water use. The aim of the research is to develop crop water consumption monitoring system at the outlet level to regulate irrigation water distribution at farm level. Surface Energy Balance Algorithm for Land (SEBAL) is used to develop pilot case study for year 2017-18 at a distributary canal command level named 5R-Yousafwala located in Sahiwal District. Crop classification based on Landsat-8 imagery was provided by Punjab Irrigation Department. Landsat-8 and Sentinel-2 images were acquired for NDVI monitoring. Metrological data for Penman Monteith based evapotranspiration calculation was acquired from Global Land Data Assimilation System (GLDAS). Analogue cadastral maps of outlet command areas were converted to digital georeferenced format. The provided crop classification was verified after discussion with farmers during detailed field survey. In Rabi season of 2017-18, mean evapotranspiration (ET) actual was estimated about 352 mm, while in Kharif season of 2018, it was estimated as 425 mm. The crop water deficit was estimated as 36 % in rabi season and 30 % in kharif season. Irrigation share was only 37 % in Rabi season and 48% in Kharif season. Rainfall contributed 09 % in Rabi season and 30% in Kharif season. Groundwater was paramount contributor with 54 % share in rabi season while in Kharif season it contributed relatively minor share of 22%. The ET potential and ET actual fluctuate in all outlet commands due to the diverse crop cover and economic capacity to pump groundwater. The results could be proved very useful for irrigation department to monitor and reform the irrigation supplies at particular outlets by observing the crop demand, weather conditions and crop stage instead of monitoring outlet discharge only.

Changes in Drip Irrigation Water Distribution Patterns Improve Fruit Quality and Economic Water Productivity in Early-Season Lemon Trees

The physiological and agronomic responses of two irrigation systems were compared in ‘Fino 49′ lemon trees (Citrus limon [L.] Burm. fil.). The irrigation systems consisted of different designs of the irrigation installation (same amount of water and irrigation frequency): a conventional design (2L, two drip lines with six drippers per tree), and a design with a larger wetted surface (3L, implementing the conventional design with a third drip line with nine drippers per tree). Results indicated that the 3L design promoted a better distribution of water and fertilisers in the soil profile, improving some gas-exchange parameters in periods of low evaporative demand or after rain. The agronomic response showed two main effects on fruit quality: (1) the total numer of fruits affected by endoxerosis was reduced, and (2) the first harvest (the earliest fruits harvested) moved forward in time. From an economic point of view, economic water productivity was increased, mainly due to an increment in the proportion of first-harvested lemon, but also due to the decrease in lemon produced for the industry (affected by endoxerosis). The 3L irrigation system could be an interesting alternative to favour fruit precocity, improving the use of the available water resources for early lemon tree growers.

Assessment of irrigation water allocation, Koftu, Ethiopia

Abstract This research investigates the fair and efficient distribution of water among irrigators, focusing on the timely and uniform delivery of water. To achieve this, the study utilized various methods such as group discussions, critical informant and expert interviews, and field flow measurements. The degree of fairness in the distribution of irrigation water was determined by analyzing the shift in the relative water supply to end users. The effectiveness of irrigation is inversely proportional to the relative irrigation supply, which can be observed in the scheme's water delivery indicators. The study found that while the estimated delivered flow of water in the head, middle, and tail reaches of the canal was 1.21, 0.58, and 0.23 m3/s respectively, the required quantity of discharge was only 0.81, 0.31, and 0.15 m3/s. This discrepancy resulted in the inadequate, unreliable, and unequal water supply to irrigators. The research revealed that canal operation and maintenance were the main factors limiting the system's capacity. The findings showed that the adequacy, dependability, equality, and efficiency values were 0.8, 0.14, 0.40, and 0.71, respectively, suggesting that improvements are needed to ensure the timely and equitable distribution of water to irrigators.

Drainage and Irrigation Water System in Peripheral Urban Areas

Polluted water, floods, and inefficient irrigation water distribution system are the main issues of water system conditions of Indonesia especially in peripheral urban areas. In those areas, because of the rapid increased of land prices, the occurrences of small residential areas are massive replacing the existence of productive rice fields. Not only land conversion and mixed land use have been the results, the mix function is also experienced in water system between drainage system and irrigation water system in those areas. Taken Sukoharjo Regency in Central Java Indonesia as a case study, the study is aimed to investigate the integration between irrigation and drainage water system. To trace that, we undertook three analyses: 1) comparing the physical layout of both water system in practices; 2) collating and analysing Indonesia regulations on irrigation and drainage system; 3) analysing the association between 1) and 2). We identified why there is an overlap or intertwined function in the practices. This was done by elaborating the discrepancies and incompatibility through the content analysis of the regulations. The study reveals that the mix function between drainage system and irrigation water system happened because there is dualism in their regulations. This is crucial to coordinate between the provision of drainage system and irrigation water system in Indonesia regulations to prevent the occurrence of intertwined problems and steer water system management toward sustainable condition.