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The wave of modernization and globalization in the last century has rapidly involved a technological paradigm shift from indigenous irrigation water systems to modern systems in arid regions. Despite interest in the drought resilience of indigenous water systems, the impact of this paradigm shift on drought resilience remains poorly understood because previous studies have focused on fixed irrigation water systems. To fill this gap, we investigated the drought resilience of an indigenous and modern irrigation water system that coexists in the drought-prone Mahaweli H region of the Sri Lankan dry zone. To explain drought resilience, we quantified the historical irrigation system performance (1985–2021) of both water systems using the water duty indicator (i.e., the volume of water required to cultivate a unit land area). The statistical Pettitt test was used to detect significant change points in the time series of water duty, and we divided the time line into few periods based on the change points. Furthermore, a quantitative trend analysis of several socio-hydrological variables and a qualitative analysis of their socio-hydrological backgrounds with triggers of water duty were conducted to explain drought resilience path dependency in modern and indigenous water systems. The results indicated a higher drought resilience is embedded in the indigenous system as the mean water duty increment in drought years compared to non-drought years is 16.4% for the indigenous system and 58.3% for the modern system. In addition, drought resilience pathways that elucidated by water duty change points also demonstrated that indigenous water system features a higher drought resilience compared to the modern water system. The findings of this comparative study can contribute to the design of drought resilience improvement strategies in arid region irrigation water systems in a more comprehensive manner.

This study was carried out to evaluate the system performances of Karataş and Karaçal irrigation associations located in Burdur province. Karataş irrigation association was put into operation in 1982 and Karaçal irrigation association in 2015 with irrigation areas are 5476 and 4975 ha, respectively. The same public personnel were appointed to both irrigation associations as the Head of the Association in 2018, and as of 2019, both irrigation Associations were gathered under the management of Karataş irrigation association. In this study, the performances of Karataş irrigation, which has an old and predominantly open canal system, and Karaçal irrigation systems, which are relatively new and have a pressurized irrigation system, between the years 2015-2019 have been evaluated. In the performance evaluation, a set of indicators under two main headings as water use efficiency, and financial efficiency recommended by the International Technology and Research Program in Irrigation and Drainage (IPTRID) was used. According to the results of the research, when the water use efficiency is examined, especially Annual relative irrigation supply (0.53-0.73 for Karataş; 0.47-0.96 for Karaçal) and irrigation ratio (20-72% for Karataş; 36% for Karaçal) 55) values were not at the desired levels. In terms of Financial Efficiency, cost recovery ratio (119-401% for Karataş; 144-311 for Karaçal) and revenue collection performance (78-442% for Karataş; 10-130 for Karaçal) were found to be high. Although this is a new irrigation, Karaçal irrigation shows that relatively high maintenance costs are incurred. Total operating maintenance and management (MOM) cost per unit area is US $ 9.60-14.98/ha for Karataş and as 1.32-22.92 US$ /ha for Karaçal. These values showed that, in general, both irrigations have sufficient financial strength. Bu çalışma, Burdur ilinde yer alan, Karataş ve Karaçal Sulama Birliklerinin sistem performanslarını değerlendirmek amacıyla yapılmıştır. Araştırma alanlarından, Karataş Sulama birliği 1982 yılında, Karaçal sulama birliği ise 2015 yılında işletmeye açılmış ve sırasıyla sulama hizmet alanları 5476 ve 4975 ha’dır. Her iki sulama birliğine 2018 yılında DSI tarafından alınan karara istinaden aynı kamu personeli birlik başkanı olarak atanmıştır. Ayrıca, 2019 yılı itibariyle de her iki sulama, Karataş sulama birliği çatısı altında toplanmışlardır. Bu çalışma ile eski ve ağırlıklı olarak açık kanal sisteme sahip Karataş sulaması ile nispeten yeni ve kapalı sisteme sahip Karaçal sulama sistemlerinin karşılaştırmalı olarak 2015-2019 yılları arası performansları değerlendirilmeye çalışılmıştır. Performans değerlendirmesinde Sulama ve Drenajda Uluslararası Teknoloji ve Araştırma Programı (IPTRID) tarafından tavsiye edilen gösterge setleri kullanılmıştır. Bu amaçla, su kullanım etkinliği ve finansal etkinlik olmak üzere iki ana başlık halinde hazırlanan bir gösterge seti kullanılmıştır. Araştırma sonuçlarına göre, su kullanım etkinliği incelendiğinde özellikle sulama suyu temin oranı (Karataş için 0,53-0,73; Karaçal için 0,47-0,96) ve sulama oranı (Karataş için %20-72; Karaçal için %36-55) değerleri istenen seviyelerde olmadığı görülmüştür. Finansal Etkinlik açısından, masrafların karşılanma oranı (Karataş için %119-401; Karaçal için %144-311) ve Tahsilat oranları (Karataş için %78-442; Karaçal için 10-130) yüksek bulunmuştur. Bakım masrafların gelire oranı Karataş için %7-43; Karaçal için %17-48 bulunmuştur. Bu durum yeni bir sulama olmasına rağmen Karaçal sulamasında nispeten yüksek miktarda bakım masrafı yapıldığını göstermektedir. Birim alana düşen toplam işletme bakım yönetim masrafı Karataş için 9,60-14,98 US $/ha; Karaçal için 1,32-22,92 US$ /ha olarak belirlenmiştir. Bu değerler, genel olarak her iki sulamanın finansal açıdan yeterli güce sahip olduklarını göstermiştir.

There has been increasing pressure on water resources in cities due to the proliferation of urban green areas. In the Mediterranean climate, only a small part of the plants’ water needs is supplied by rainfall during the winter months. Thus, in Algarve (Portugal) irrigation of the urban landscapes is required almost all year round. The aims of this study were to evaluate the maintenance of the urban landscapes of São Brás de Alportel (Algarve) during a year, based on the characterization of the vegetation of the urban gardens, the climate data, the analysis of the irrigation systems, the calculation of the plants water requirements and the normalized difference vegetation index (NDVI). By crossing all this information, it was possible to understand if the current maintenance level is the most suitable for sustainable irrigated urban landscapes. In most of the gardens, it was possible to establish a relationship between the gross irrigation water requirements and NDVI. In general, the NDVI allowed us to study the urban landscape, through the monthly observation of the differences in the appearance and development of the vegetation.

The evaluation of irrigation uniformity can be affected by the sampling pattern in the field. Thus, this work aimed to compare the water application uniformities of a Center Pivot using three sampling patterns: along the equipment radius (radial), in the direction of movement of the pivot (circular) and in a two-dimensional way (meshed). For this, samplers were positioned under the spans of a Center Pivot system, being evaluated the effects of the sampling pattern and of the span, in a 3×3 statistical factorial design, with three replications. The results showed that circular and meshed arrangements were statistically equal and had higher values of Christiansen's and Distribution Uniformity Coefficients. The mesh type arrangement represented a more uniform distribution profile of irrigation depths on the surface. For areas of flat or slightly undulating topography and when using pressure regulating valves for the emitters, sampling in a radial pattern is sufficient, but for terrains with irregular topography or when pressure head variations along the lateral line are important for the operation of the emitters, the combination of the radial and circular pattern is interesting. The meshed sampling detects the stoppage effect of the towers and drift, however, in a reduced area.

Providing adequate pressure at the hydrant is an issue of great importance in the operation of pressurized irrigation distribution systems (PIDS). The hydraulic performance of these systems can be quantified by selected performance indicators to describe the performance of an irrigation system with regard to the objectives set for that system. Several indicators have been developed and used so far for the performance analysis of pressurized irrigation systems. However, none of them provides a comprehensive definition of the sensitivity of operating hydrants to the variation in the upstream discharge. The objective of this study is to develop an indicator that can quantify the sensitivity of a hydrant to the changes occurring upstream of an irrigation system. A new definition of the indicator is proposed, by considering the changes in the hydrant reliability to the changes in the upstream discharge. In other words, the sensitivity of a hydrant is simulated on the basis of the variation of its reliability to satisfy the required pressure for adequate on-farm service. This concept was applied to a case study in Italy and it showed the importance of the sensitivity indicator as defined herein in the decision-making process for proper operation of pressurized irrigation systems.

The Unsteady Irrigation Water Distribution and Consumption (UIWDC) model is applied to analyze causes of uneven water distribution between the upstream and downstream beneficial areas of the Mae Lao Irrigation Scheme (MLIS). The uneven water distribution may be caused by inadequate water distribution facilities or improper operation rule; therefore, its causes are examined systematically and quantitatively from the aspects of “water allocation” and “operation rule”. The water allocation is considered focusing on the dry season irrigation, where equity and efficiency should be especially balanced because of the scare water resources. The “EQTY index” (the equity index) is defined to widen the range of consideration between the equity and the efficiency, instead of alternative judgment of which has a priority. The operation rule for facilities in the MLIS is assumed considering their capacities, and two coordinate values of “ineffective spillage” and “water deficit” in the scheduled areas are incorporated into operation rule to quantitatively diagnose the system performance. As a result, the original causes of uneven water distribution will presumably be identified. The informative and quantitative results are utilized to set a new benchmark performance of the MLIS for the water distribution. It can be described by the “Expected Ratio of Irrigable Area” (ERIA) and “Present Ratio of Irrigable Area” (PRIA). Based on this standard, the general recommendations can be more concretely proposed to raise the water distribution performance of the MLIS such as by improving distribution facilities and/or by installing vertical pumps.

Improving irrigation water management is a key concern for the agricultural sector, and it requires extensive and comprehensive tools that provide a complete knowledge of crop water use and requirements. This study presents a novel methodology to explicitly estimate daily gross and net crop water requirements, actual crop water use, and irrigation efficiency of center pivot irrigation systems, by mainly utilizing the Sentinel-2 MultiSpectral Instrument (MSI) imagery at the farm scale. ETMonitor model is adapted to estimate actual water use (as the sum of canopy transpiration and evaporation of water intercepted by canopy and evaporation from soil) at daily/10-m resolution, benefiting from the high-resolution Sentinel-2 data and thus to assess the irrigation efficiency at the farm scale. The gross irrigation water requirement is estimated from the net crop water requirement and the water loss, including the water droplet evaporation directly into the air during application before droplets fall on the canopy and canopy interception loss. The method was applied to a pilot farmland with two major crops (wheat and potato) in the Inner Mongolia Autonomous Region of China, where modern equipment and appropriate irrigation methods are deployed for efficient water use. The estimated actual crop water use showed good agreement with the ground observations, e.g. the determination coefficients range from 0.67 to 0.81 and root mean square errors range from 0.56 mm/day to 1.24 mm/day for wheat and potato when comparing the estimated evapotranspiration with the measurement by the eddy covariance system. It also showed that the losses of total irrigated volume were 25.4% for wheat and 23.7% for potato, respectively, and found that the water allocation was insufficient to meet the water requirement in this irrigated area. This suggests that the amount of water applied was insufficient to meet the crop water requirement and the inherent water losses in the center pivot irrigation system, which imply the necessity to improve the irrigation practice to use the water more efficiently.

Irrigation system performance regards as a function of climatic conditions. The present study was carried out to study this phenomenon. Sugar beet and sesame corps were cultivated during two agricultural seasons of 2017/2018 and 2018/2019 irrigated with drip and sprinkler systems. The drip and sprinkler systems performance was evaluated in terms of hydraulic characteristics added to irrigation water requirements. The recorded monthly values were compared to the traditional estimation method. The results revealed that irrigation system efficiency was increased by increasing ambient temperature for the drip irrigation system, and vice versa was noticed with the sprinkler irrigation system. Emission uniformity and application efficiency of emitters were increased by increasing ambient temperature. While the sprinkler flow rate and distribution uniformity were decreased by increasing ambient temperature. For drip irrigation system, the average total amount of irrigation water requirements using traditional estimation for sugar beet (2372 m 3 /fed) was less than the actual calculated (2439 m 3 /fed), while for sesame crop, the traditional estimation method (2556 m 3 /fed) was higher than actual calculated (2477 m 3 /fed). Using a sprinkler system, the average total amount of irrigation water requirements by the traditional estimation (2689 and 2897 m 3 /fed) was less than the actual calculated (2709 and 3044 m 3 /fed) for sugar beet and sesame crops, respectively. So, it is important to consider the effects of climatic conditions through the agricultural season.

The efficiency of water distribution at primary, secondary, and tertiary levels in the Indus Basin Irrigation System (IBIS) has historically suffered due to poor design, suboptimal operation, and water scarcity. To address these issues, the system has been designed with ungated irrigation outlets to ensure equitable water allocation at secondary and tertiary levels. This research evaluates the hydraulic performance of three irrigation outlets: adjustable proportional module (APM), adjustable orifice semi-module (AOSM), and open flume (OF) using a physical model study. A distributary channel model with these outlets was constructed at the Centre of Excellence in Water Resources Engineering, where discharge coefficients (Cd) were calibrated and measured under various hydraulic and geometric conditions, including free and submerged flow conditions, and with adjustments to flow depths and outlet settings. The results showed variability in Cd values under free flow and submerged flow conditions with APM and AOSM ranging from 6.07 to 8.20 and 0.56 to 0.74, respectively, and OF between 2.46 and 4.31. Additionally, the behavior of outlet tampering on Cd values was also assessed under three scenarios: tampering with the half wing wall (1st), tampering with the full wing wall (2nd), and lowering the bed level downstream of the outlet (3rd). The increase in Cd values for APM and AOSM was + 10.84% and + 14.49% under 1st scenario, + 17.12% and + 22.36% under 2nd scenario, and + 24.25% and + 26.30% under 3rd scenario, respectively. The results reveal that even minor tampering with outlet structures can lead to significant deviations in performance, highlighting the importance of maintaining stringent control over outlet configurations to ensure equitable and efficient water distribution. There is a critical need for rigorous, site-specific calibration of irrigation outlets to optimize their performance under local conditions and redesigning outlet structures to minimize the impacts of tampering, thereby enhancing the overall sustainability of water use in large-scale irrigation systems. The findings from this study provide essential insights for irrigation engineers and policymakers tasked with upgrading and maintaining irrigation infrastructure. By adopting a more customized approach to outlet design and management, it is possible to significantly improve water use efficiency and achieve more sustainable irrigation practices.

The exogenous application of osmoprotectants [e.g., proline (Pro)] is an important approach for alleviating the adverse effects of abiotic stresses on plants. Field trials were conducted during the summers of 2017 and 2018 to determine the effects of deficit irrigation and exogenous application of Pro on the productivity, morph-physiological responses, and yield of maize grown under two irrigation systems [surface irrigation (SI) and drip irrigation (DI)]. Three deficit irrigation levels (I 100 , I 85 , and I 70 , representing 100, 85, and 70% of crop evapotranspiration, respectively) and two concentrations of Pro (Pro 1 = 2 mM and Pro 2 = 4 mM) were used in this study. The plants exposed to drought stress showed a significant reduction in plant height, dry matter, leaf area, chlorophyll content [soil plant analysis development (SPAD)], quantum efficiency of photosystem II [Fv/Fm, Fv/F0, and performance index (PI)], water status [membrane stability index (MSI) and relative water content (RWC)], and grain yield. The DI system increased crop growth and yield and reduced the irrigation water input by 30% compared with the SI system. The growth, water status, and yield of plants significantly decreased with an increase in the water stress levels under the SI system. Under the irrigation systems tested in this study, Pro 1 and Pro 2 increased plant height by 16 and 18%, RWC by 7 and 10%, MSI by 6 and 12%, PI by 6 and 19%, chlorophyll fluorescence by 7 and 11%, relative chlorophyll content by 9 and 14%, and grain yield by 10 and 14%, respectively, compared with Pro 0 control treatment (no Pro). The interaction of Pro 2 at I 100 irrigation level in DI resulted in the highest grain yield (8.42 t ha –1 ). However, under the DI or SI system, exogenously applied Pro 2 at I 85 irrigation level may be effective in achieving higher water productivity and yield without exerting any harmful effects on the growth or yield of maize under limited water conditions. Our results demonstrated the importance of the application of Pro as a tolerance inducer of drought stress in maize.