Irrigation and Drainage最新文献

The Mekong Delta, South East Asia's ‘rice bowl’, sustains more than 18 million people through its agricultural output. This yield is secured by efficient water management systems but is susceptible to climatic changes. As Vietnam's policies aim to optimize the delta's semi-mountainous regions reliant on rain-fed agriculture, this study investigates drought risks and climate change impacts on runoff in the O Ta Soc and O Tuk Sa reservoirs, An Giang Province, Vietnam. Using simulation models, we determined runoff volumes for specific rainfall return periods and climate scenarios for the 2030s and 2050s. Using the storm water management model (SWMM), we simulated the reservoir water balance considering rainfall, evaporation and infiltration. Our findings suggest potentially increased runoff and reservoir storage due to intensified monsoons and reduced off-season rainfall. The 4.77 km² drainage of the O Ta Soc reservoir could benefit from this, while the 2.55 km² drainage of the O Tuk Sa watershed may require alternative water-sourcing strategies. This research offers insights for drought predictions, flood management and water strategies in An Giang. To refine these predictions, future research should consider upcoming rainfall patterns.

The aim of this study was to compare the performance of water user organizations (WUOs) in the agricultural sector in terms of their managerial efficiency. A survey was carried out across the study area to evaluate 67 WUOs, including irrigation cooperatives, municipalities, village legal entities (VLEs) and water user associations (WUAs). The findings were then used to create a management performance index. It has been determined that municipalities excel in terms of physical performance, irrigation cooperatives in enterprise and social performance and WUAs in institutional and investment performance. The general management performance index revealed that the most successful WUOs in the Konya closed basin were WUAs. Therefore, proposals have been put forward to begin institutionalization processes in other institutions to attain the successful institutionalization in WUAs. Additionally, the shift towards prepaid systems is recommended to mitigate collection problems, while water should be priced according to the full cost method. Finally, supporting the use of alternative energy sources for irrigation is crucial.

Climate change (CC) could lead to many crises. Therefore, increasing the number of cultivated varieties represents a low-cost factor in confronting this problem. The effect of the genotype × environment (G × E) interaction on yield stability was estimated for 28 new sesame lines in the Beni Suwef, El-Beheira and El-Menoufia governorates in Egypt across 15 environments from 2019 to 2022 using AMMI analysis. The SALTMED model was used to predict the yield of sesame plants under five increasing air temperature scenarios (CC factor) to obtain future projections of sesame yield to determine the lines that are most genetically stable and facing CC. Variance analysis revealed significant differences in yield between the G and E groups and between the G × E interaction group. Fifteen genotypes yielded better control, and C6.4, C5.8 and C9.6 were selected as genetically stable according to AMMI analysis. The SALTMED model predicted that the yields of lines C3.8 and C6.2 were not affected under the high-temperature scenarios across the three governorates, moreover lines C1.8, C2.3, and, C6.12 productions were not affected under Beni Suwef and El-Beheira governorates. of lines C1.8, C2.3 and C6.12 were also not affected by the Beni Suwef or El-Beheira governorates. It is now possible to establish a hybridization programme in sesame that combines parents with high productivity and high resilience to CC.

The main goal in water efficiency in agriculture is to obtain more products with the same amount of water. In this respect, the use of irrigation performance indicators is important for increasing agricultural water efficiency. This study was conducted to evaluate agricultural water efficiency in the Konya closed basin, which is the region most affected by drought in Turkey. For this purpose, performance indicators selected for evaluating agricultural water efficiency were determined in irrigation associations taken as material for the years 2016–2020.

In the research area, the following water use efficiency indicators were determined: annual amount of irrigation water distributed 1.750–517.462 million m³ yr⁻¹ (MCM yr⁻¹), annual amount of irrigation water distributed per unit area 0.529–8.688 MCM ha⁻¹, annual amount of irrigation water distributed per unit irrigated area 0.787–33.909 MCM ha⁻¹ and annual water supply ratio ranging between 0.220 and 52.600. The following agricultural water efficiency performance indicators were determined: income obtained for unit irrigation area, 127–5075 US$ ha⁻¹; income obtained per unit irrigated area, 656–12353 US$ ha⁻¹; income obtained per unit irrigation water taken into the network, 0.104–6.771 US$ m⁻³; and income obtained per unit irrigation water consumed, 0.236–37.358 US$ m⁻³. Correlation analysis was carried out to identify the significance of the relationships between the performance indicators, and the results were discussed.

This paper proposes a simple method for determining drip lateral length in relatively flat fields in which minor losses are not considered and a uniform emitter flow rate is assumed. This makes it possible to derive a useful relationship in a closed form to determine drip lateral length according to the Hazen–Williams and Blasius resistance equations. An important advantage of the proposed procedure for determining drip lateral length is that it helps users establish the characteristics of the commercial emitters that they should select, an issue that has been poorly addressed in the past. Finally, after deriving this new solution, the same relationship is extended to a case in which minor losses are considered, and the uniform emitters' flow rate assumption is relaxed. The results of all input data sets show that when neglecting minor losses, the relative error between the inlet pressure head estimated with the suggested procedure and that calculated with the exact numerical method is less than 2.5%. However, when minor losses are considered, the number of emitters must not exceed 300 to obtain this threshold error. Several applications are performed, showing the reliability of this new design procedure.

Effective drainage is a crucial factor in paddy fields, especially in regions with waterlogging or heavy clay soils. Identifying an effective drainage system is essential for the successful removal of excess soil water from paddy fields to prepare them for subsequent crops. This study aimed to evaluate three different drainage systems, shallow surface drainage (shallow ditch), conventional subsurface pipe drainage and trench-type subsurface drainage (French drain), in paddy fields in terms of drainage water volume, water table depth, drainage intensity, soil moisture and cracks. Experiments were carried out in a physical model capable of simulation with a 7.5 m drain spacing. The findings indicated that trench-type drainage was more effective in reducing soil moisture due to its higher drainage water volume compared to other systems. The time required for the topsoil to reach its lower plastic limit in the subsurface, trench-type and shallow surface drainage systems was 14, 11 and 15 h after the depletion of excess water over the soil surface, respectively. Although shallow surface drainage represented faster depletion of excess water, trench-type drainage eventually proved to be the most effective alternative for providing appropriate qualifications for secondary cultivation. Crack areas on the soil surface were twice as extensive in trench-type and subsurface drainage systems as in shallow surface drainage systems, indicating their superior performance.

In arid regions, harvesting floodwater can mitigate irrigation-induced groundwater depletion by providing additional surface water and recharging aquifers. We designed an experimental protocol to quantify these fluxes on a date farm located along the Wadi Satt, whose flow originates from the Anti-Atlas Mountains in south-eastern Morocco. Automatic barometric sensors were used to monitor the water level in a 6500 m³ floodwater harvesting pond and in surrounding boreholes. Six flood events occurred from 2021 to 2023. The pond water balance indicated that most stored water is pumped for irrigation (56% of harvested floodwater). More than 40% infiltrates at a rate of approximately 90 mm day⁻¹, and the remainder evaporated. Analytical modelling of the pond water table system showed that the radius of the piezometric mound resulting from pond infiltration is less than 360 m. Groundwater recharge from the irrigated plot could be observed after two close floods that enabled continuous pumping for several weeks, suggesting that in this specific context, over-irrigation using surface water allows the aquifer to be recharged. The hydrological effects of possible future expansion of these ponds at the watershed scale should be analysed to assess possible negative impacts on downstream water resources.