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Linking participatory approach and rapid appraisal methods to select potential innovations in collective irrigation systems

Publication . Cameira, Maria do Rosário; Rodrigo, Isabel; Garção, Andreia; Neves, Manuela; Ferreira, Antónia; Paredes, Paula

This paper presents a novel approach that integrates participatory methods and a rapid appraisal process to identify constraints and select potentially innovative solutions aimed at improving water and energy use effi- ciency at different levels in collective irrigation systems. First, a set of quantitative performance indicators is calculated, allowing the identification of the main problems. The study then adopts a bottom-up approach and emphasizes the need for active involvement of stakeholders from different backgrounds to identify potential opportunities to improve the sustainability of the collective irrigation system. From this collaborative and integrative approach, an innovation basket is developed, that includes a variety of techniques, technologies and management practices tailored to the specific challenges of the Lucefecit Collective Irrigation System. The results show that high-energy consumption is the main problem, with high values for energy consumption per hectare (2919.9 kWh) and per m3 of water delivered at the hydrants (0.43 kWh). Another problem is the lack of support for farmers in irrigation scheduling, which leads to large variations in irrigation water productivity across farms. The results of this study provide valuable insights into the effectiveness of the participatory approach and the feasibility of implementing innovative solutions in collective irrigation systems.

2024-06Journal article

Open access

Methodology for Obtaining ETo Data for Climate Change Studies: Quality Analysis and Calibration of the Hargreaves–Samani Equation

Publication . Ferreira, Antónia; Cameira, Maria do Rosário; Rolim, João

Reference evapotranspiration (ETo) is an important part of the water cycle, essential for cli- mate studies, water resource management, and agricultural planning. However, accurate estimation of ETo is challenging when meteorological data are insufficient or of low quality. Furthermore, in climate change studies where large amounts of data need to be managed, it is important to minimize the complexity of the ETo calculation. This study presents a comprehensive approach that integrates data quality analysis with two calibration methods—annual and cluster-based—to improve ETo estimates based solely on temperature data from a set of weather stations (WS). First, the quality and integrity of meteorological data from several WS were analyzed to reduce uncertainty. Second, the Hargreaves–Samani equation (HS) is site calibrated using two approaches: (a) annual calibration, where the radiation coefficient (kRs) is adjusted using a data set covering the entire year; (b) cluster- based calibration, where independent radiation coefficients are adjusted for clusters of years and months. The methodology was evaluated for the Alentejo region in Southern Portugal, using data from 1996 to 2023. When using the original HS equation with a kRs = 0.17 ◦C−0.5, ETo was estimated with errors from 14.9% to 22.9% with bias ranging from −9.0% to 8.8%. The annual calibration resulted in kRs values between 0.157 and 0.165 ◦C−0.5 with estimation errors between 13.3% and 20.6% and bias ranging from −1.5% to 1.0% across the different weather stations. Calibration based on clusters of months and years produced unclear results. Dry season months showed better results using cluster-based calibration, while wet season months performed poorly regardless of the calibra- tion approach. The results highlight the importance of meteorological data quality and site-specific calibration for refining temperature-based ETo estimation methods, and for the region studied, the gains do not justify the increased complexity of the cluster-based approach.

2024-12Journal article

Open access