Irrigation and Drainage最新文献

A major challenge for agricultural water management (AWM) in the 21st century is to feed a growing population in the face of increasing intersectoral resource competition, evolving diets, degradation, pandemics, geopolitical conflicts and climate change. This has to be achieved within the planetary boundaries and without compromising the livelihood and environmental (ecosystem) objectives linked to water, including provisioning, supporting and regulating services. This paper uses a systems and nexus lens to unravel the centrality and complexities in AWM, with particular emphasis on the interconnected dimensions and objectives of AWM, as well as its practices and technologies. AWM exists beyond water and food with linkages to human and environmental well-being. AWM needs to catalyse transformation and integrate approaches across systems, users and scales to meet its objectives in a changing climate. It must provide perspectives beyond productivity, managing water risks and safeguarding food security – as important as these are – and integrate our understanding of the interconnected climate, land, water, food and ecosystems to address planetary health outcomes. By doing so, AWM could catalyse contextualised, equitable, innovative solutions that acknowledge local socio-economic and institutional structures and limitations while catalysing sustainable development and climate resilience.

Climate-resilient irrigation is a necessity for sustainable development, aligning with broader goals of poverty alleviation, food security and environmental stewardship. By embracing adaptive strategies and fostering collaborative efforts, communities can navigate the challenges posed by a changing climate, safeguarding livelihoods and ecosystems. Climate-resilient irrigation can improve coping measures and build resilience for communities through pathways which help improve agriculture. The relationship between agriculture, irrigation, water resources and climate change calls for an evolution of traditional irrigation practices towards climate-resilient irrigation approaches, such as farmer-led irrigation development; innovation and modernization to ensure the long-term viability and functionality of irrigation systems and infrastructure; financing mechanisms to support the transition towards climate resilience; partnerships between governments, international organizations and the private sector to mobilize resources effectively; and efficient service delivery mechanisms, promoting equitable access and effective management of water resources. Emphasizing the need climate-resilient irrigation to balance food production and water security, this essay advocates a paradigm shift towards sustainable water management, ensuring resilience in the face of climate uncertainties while safeguarding agricultural productivity and environmental integrity for a livable planet.

This study addresses the critical challenge of optimizing borehole drilling techniques and predictive models to improve groundwater utilization for irrigation in Burkina Faso. Initially, the analysis involved drilling 22 boreholes as part of a photovoltaic micro-sprinkler irrigation project (PRECIS), with only 11 deemed suitable for irrigation, highlighting the difficulty in achieving the required flow rate of 5 m³/h. To enhance the robustness of the study, additional data from 205 high-yield boreholes provided by the Office National de l'Eau et de l'Assainissement (ONEA) were incorporated. These boreholes, primarily intended for potable water supply, had flow rates often exceeding 5 m³/h. This extensive dataset was crucial in identifying significant predictors of the project flow rate (Qproj), including the flow rate at the end of drilling (QEndBorh) and lithological factors. The predictive model combining QEndBorh and lithological data explained 73.7% of the variance in Qproj, with an adjusted coefficient of determination (R²_adj) of 72.4%. The CART (classification and regression tree) regression model effectively identified branches with flow rates suitable for irrigation, such as Terminal Node 3 with a predicted Qproj of 6.67 m³/h and Terminal Node 4 with a predicted Qproj of 10.5 m³/h, demonstrating the model's robustness. These findings underscore the necessity of detailed lithological assessments and advanced predictive modelling to ensure efficient and reliable borehole drilling for irrigation purposes in regions with complex geological conditions.

This meta-analysis evaluated the impact of agro-ecological practices and water management techniques on lowland rice yield and water productivity (WP). A total of 573 observations were collected from 56 articles that met specific criteria from 445 publications. Five water management practices were assessed: continuous flooding (CF), soil saturation (SS), moderate (AWDm) and severe (AWDs) alternate wetting and drying, and the aerobic rice system (ARS). The response ratios (RRs) of yield and WP were compared for crop management, soil fertility, weed control and evaporation. The integration of agro-ecological practices such as short-cycle rice varieties, crop rotation, organic nutrient application and mechanical weeding with water management led to similar yields across CF, SS, AWDm and AWDs, with ARS consistently yielding the lowest yields. However, medium- and long-cycle varieties under AWDs experienced yield losses of 11 and 13%, respectively. Mineral fertilizer combined with AWDs resulted in a 14% lower yield than did CF. Mechanical weeding increased the rice yield and WP by 10 and 10% in SS, and only WP by 35% in AWDs, whereas chemical weeding decreased the yield by 13% in AWDs. Crop rotation enhanced yield and WP by 13 and 12%, respectively, under AWDm compared to that under CF. WP was greater under AWDs (36%) and AWDm (12%) than under CF.

The paper proposes a capacity-building programme (CBP) on water for food/agricultural water management in sub-Saharan Africa contained within an academy on the water–energy–food (WEF) nexus. The paper is informed by a study funded by the International Water Management Institute and supported by the Water Research Commission of South Africa. It also reports on a stakeholder consultation workshop on 26 April 2023 in Pretoria, South Africa. It identifies key components of capacity-building design and delivery, including six teaching and learning pathways. These are managed ad hoc self-directed learning; continuing professional development; short-course training; vocational college training; part-time online postgraduate training; and full-time in-person postgraduate training. The accompanying budget analysis is speculative based on the size of the student cohorts per year for each of the six CBP pathways. The total budget of the academy is estimated at approximately US$60 million for a 10-year programme training 2,800 individuals. This works out at an average per-student cost of US$21,600. One question, debated at the stakeholder workshop but unresolved, was the emphasis on irrigation versus the agricultural water management continuum including rainfed agriculture.

Drip irrigation using poor-quality water is effective for addressing agricultural water shortages, but it can lead to emitter clogging. However, little is known about the formation behaviour of clogging substances inside emitters when using reclaimed effluent. This study used industrial computed tomography (ICT) to determine the spatial distribution of clogging substances within emitter flow channels. The results showed that 21%–27% of the clogging substances were on the top face, and 20%–26% were on the substrate face, with less than 20% on the downstream and root faces. Clogging substances concentrated at the front of flow channels accounted for 38%–61% of the first structural unit. As the flow channel length increased, there was a significant fluctuation in the volume of clogging substances on the upstream and downstream faces, while changes on the upstream face, downstream face and root face exhibited relatively minor fluctuations. It is recommended to focus on controlling clogging substances on the top and substrate faces, as well as at the front of the emitter flow channel. These findings contribute to a better understanding of the spatial distribution of clogging substances in emitter flow channels, which is crucial for the development of anti-clogging emitters and the promotion of poor-quality water drip irrigation technology.

We developed a comprehensive set of tools to simplify the design and layout of subsurface drainage systems. These tools, which utilize publicly available LiDAR (light detection and ranging) datasets, may also be used for other applications. The tool streamline operations include harmonizing geographic information system (GIS) layers into a single State Plane or Universal Transverse Mercator Coordinate System, clipping and thinning LiDAR data within a defined boundary, generating drainage networks with contour lines and laylines for surface flow visualization, identifying depressions and creating gridlines with user-specified angles and spacings. To showcase their use, an illustrative example using a diverse dataset from the University of Illinois’ South Farm is provided. These user-friendly tools, optimized for compatibility with all versions of QGIS3 (quantum geographic information system 3), are freely accessible for download or installation from the official QGIS plugin repository. A user manual with step-by-step instructions is available online on the Illinois Drainage Guide website.

In Japan, agricultural drainage facilities such as pumping stations and drains are designed by calculating an approximately 10–30-year return period based on observed precipitation in the past. However, damage to farmlands and agricultural facilities caused by heavy rainfall has become more severe and frequent in Japan. The Ministry of Agriculture, Forestry and Fisheries of Japan (MAFF) is urged to develop new design standards in consideration of projected future precipitation, keeping in mind that MAFF needs to avoid building unnecessarily large-scale facilities. Therefore, more accurate and reasonable projection methods for precipitation are needed. Based on recent advancements and discussions of climate change projections through the Coupled Model Intercomparison Project Phase 5 (CMIP5) and the Intergovernmental Panel on Climate Change (IPCC), Japanese universities and research institutes are developing datasets for future precipitation projections, especially for assessing weather extremes in small areas. In light of the above, we conducted a case study in a model area to design drainage facilities using the latest climate change outlook. This study introduces how to apply climate change projection in drainage project planning for agricultural infrastructure in Japan and shows the result of future projections in the selected area.