Henrique Damásio

Ensuring the safe, efficient, and economically viable operation of irrigation and drainage infrastructures is essential for long-term system resilience. This field-based study presents a comparative evaluation of the semi-quantitative William T. Fine (WF) method and a simplified probability–consequence (SM) approach applied in the Lis Valley Irrigation and Drainage Association (Leiria, Portugal). Monthly on-site observations of routine maintenance and conservation activities were conducted between January 2023 and December 2024, covering eight main operation types and resulting in 87 distinct occupational risk scenarios (N = 87). The mean Hazard Risk Score (HRS) was 88.9 ± 51.1, corresponding predominantly to “Substantial” risk levels according to the William T. Fine classification (HRS = 70–200). Both methods consistently identified the highest-risk activities—tractor rollover, work at height, and boat-based removal of aquatic plants. Quantitative differences emerged for medium and chronic hazards; WF produced a wider dispersion of risk scores across tasks, while the SM aggregated most hazards into a limited number of intervention classes (74% classified as Intervention Level II and 26% as Level III). These differences reflect complementary methodological limitations; WF requires greater data input and expert judgment but offers finer prioritization, whereas SM enables rapid field application but tends to group ergonomic and low-intensity hazards when consequences are not immediately observable. Based on these findings, a combined assessment framework is proposed, integrating the discriminative capacity of WF with the operational simplicity of SM. Recommended mitigation measures include targeted personal protective equipment, task rotation, focused training, and technology-assisted monitoring to reduce worker exposure. The methodology is readily replicable for Water Users’ Associations with similar operational contexts and supports evidence-based decision-making for sustainable irrigation management. From a sustainability perspective, this integrated risk assessment framework supports safer working conditions, more efficient maintenance planning, and informed policy decisions for the long-term management of irrigation and drainage infrastructures.

Efficient water management is essential for optimizing agricultural productivity in water-scarce regions such as the Lis Valley, Portugal. In situ measurements of soil moisture content (SMC) and electrical conductivity (EC), together with Sentinel-2-derived vegetation indices, were used to assess the crop water status and evapotranspiration dynamics of pumpkin (Cucurbita moschata ‘Butternut’) during the 2020 growing season. SMC and EC were measured at depths of 10, 20, 30, 50, and 70 cm using a TDR sensor, with strong correlations observed in the upper layers, indicating that EC can complement direct SMC measurements in characterizing near-surface moisture conditions. Sentinel-2 imagery was acquired to compute NDVI, SAVI, EVI, and GCI. In addition, NDVI values obtained from both a GreenSeeker^® sensor and Sentinel-2 imagery were compared, showing a similar temporal pattern during the season. By replacing the standard FAO-56 K_c values with those derived from each vegetation index, ET_a was recalculated to incorporate actual crop condition variability detected via satellite. ET_a estimates from RS-assisted vegetation indices agreed with those obtained using the FAO-56 method; independent ET_a measurements were not available for validation. Although such agreement is partly expected due to calibration, its confirmation for Cucurbita moschata under Mediterranean conditions—where published references are scarce—reinforces the method’s practical applicability for water management in data-limited settings. Water Productivity (WP) was estimated as 8.32 kg m⁻³, and Water Use Efficiency (WUE FAO-56) was calculated as 0.64 kg m⁻³, indicating high water use efficiency under Mediterranean smallholder irrigation conditions. These findings demonstrate that integrating high-resolution RS with continuous soil moisture monitoring can enhance precision irrigation strategies, increase crop yields, and conserve water resources in the Lis Valley.

This study presents a remote sensing (RS) approach for monitoring invasive aquatic species and assessing their impact on water quality in the Lis Valley Irrigation District (LVID), Portugal. Using high-resolution PlanetScope imagery (3.7 m resolution), this method overcomes spatial limitations in narrow irrigation canals. Representative sub-zones were selected to analyze spatial and temporal trends, and vegetation indices (Normalized Difference Vegetation Index—NDVI, Enhanced Vegetation Index—EVI, Green Chlorophyll Index—GCI) were calculated to map the spread of Eichhornia crassipes (water hyacinth—WH) and Myriophyllum aquaticum (parrot’s feather—PF). All three vegetation indices exhibited significant linear regressions with pH, with the EVI showing the highest coefficient of determination (R² = 0.761), followed by the NDVI (R² = 0.726) and GCI (R² = 0.663), with p-values and ANOVA p-values below 0.05. Dissolved Oxygen (DO) also showed strong correlations, particularly with the GCI (R² = 0.886 for both DO concentration and saturation). The NDVI and EVI demonstrated significant regressions for these parameters, with R² values between 0.661 and 0.862. The results demonstrate the potential of RS to detect invasive species and assess their ecological impact, providing a cost-effective tool for management strategies in irrigation systems. Future research should integrate more field data and extend the study period to enhance classification accuracy.

Orchards are complex agricultural systems with various characteristics that influence crop evapotranspiration (ET_c), such as variety, tree height, planting density, irrigation methods, and inter-row management. The preservation of biodiversity and improvement of soil fertility have become important goals in modern orchard management. Consequently, the traditional approach to weed control between rows, which relies on herbicides and soil mobilization, has gradually been replaced by the use of permanent living mulch (LM). This study explored the potential of a remote sensing (RS)-assisted method to monitor water use and water productivity in apple orchards with permanent mulch. The experimental data were obtained in the Lis Valley Irrigation District, on the Central Coast of Portugal, where the “Maçã de Alcobaça” (Alcobaça apple) is produced. The methodology was applied over three growing seasons (2019–2021), combining ground observations with RS tools, including drone flights and satellite images. The estimation of ET_a followed a modified version of the Food and Agriculture Organization of the United Nations (FAO) single crop coefficient approach, in which the crop coefficient (K_c) was derived from the normalized difference vegetation index (NDVI) calculated from satellite images and incorporated into a daily soil water balance. The average seasonal ET_a (FAO-56) was 824 ± 14 mm, and the water productivity (WP) was 3.99 ± 0.7 kg m⁻³. Good correlations were found between the K_c’s proposed by FAO and the NDVI evolution in the experimental plot, with an R² of 0.75 for the entire growing season. The results from the derived RS-assisted method were compared to the ET_a values obtained from the Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) surface energy balance model, showing a root mean square (RMSE) of ±0.3 mm day⁻¹ and a low bias of 0.6 mm day⁻¹. This study provided insights into mulch management, including cutting intensity, and its role in maintaining the health of the main crop. RS data can be used in this management to adjust cutting schedules, determine K_c, and monitor canopy management practices such as pruning, health monitoring, and irrigation warnings.

Rice irrigation by continuous flooding is highly water demanding in comparison with most methods applied in the irrigation of other crops, due to a significant deep percolation and surface drainage of paddies. The pollution of water resources and methane emissions are other environmental problems of rice agroecosystems, which require effective agronomic changes to safeguard its sustainable production. To contribute to this solution, an experimental study of alternate wetting and drying flooding (AWD) was carried out in the Center of Portugal in farmer’s paddies, using the methodology of field irrigation evaluation. The AWD results showed that there is a relevant potential to save about 10% of irrigation water with a reduced yield impact, allowing an additional period of about 10 to 29 days of dry soil. The guidelines to promote the on-farm scale AWD automation were outlined, integrating multiple data sources, to get a safe control of soil water and crop productivity. The conclusions point out the advantages of a significant change in the irrigation procedures, the use of water level sensors to assess the right irrigation scheduling to manage the soil deficit and the mild crop stress during the dry periods, and the development of paddy irrigation supplies, to allow a safe and smart AWD.

Organic farming can play an important role in rural development and food production, by reinforcing the trend toward sustainable agriculture and its purpose of ecosystem conservation. The agribusiness of organic farming is particularly relevant in family farming, given the labor availability and the short marketing circuits. The innovative techniques of organic farming, namely with soil fertility, weed and pest control, opens a wide range of possibilities in its development and extension. The expectation of organic farming profitability in small-scale family farming, supported by known successful examples, were the theme of a field study on Lis Valley Irrigation District to assess the constraints to its expansion in order to outline the procedures for the acquisition of technical knowledge, the adaptation of technologies, the support for the conversion of production models, and the specialized training of farmers for action. Results revealed that the: (i) farmer’s land structure, (ii) their mature age, (iii) low education level, and (iv) markets, are the main constrains for organic farming development. Furthermore, other uncertainties were identified, namely: (i) the certification process, (ii) the knowledge of new technologies, especially of crop protection, and (iii) the marketing problems to guaranteeing profitability. This study concludes that organic farming has significant potential for development in the Lis Valley and that the efforts and resources of the various stakeholders, namely the state, need to be harmonized to deliver effective support to farmers to promote organic farming that prioritizes: (i) rural development policies, (ii) supporting land restructuring, (iii) modernization of irrigation, (iv) stimulation of young farmers, (v) conversion and implementation of innovative technologies, (vi) the organization of farmers for better productive efficiency, and (vii) to facilitate market access.

Irrigation districts play a decisive role in Portuguese agriculture and require the adaptation to the new water management paradigm through a change in technology and practices compatible with farmers’ technical know-how and economic sustainability. Therefore, improvement of water management, focusing on water savings and increasing farmers’ income, is a priority. In this perspective, an applied research study is being carried out on the gravity-fed Lis Valley Irrigation District to assess the performance of collective water supply, effectiveness of water pumping, and safety of crop production due to the practice of reuse of drainage water. The water balance method was applied at irrigation supply sectors, including gravity and Pumping Irrigation Allocation. The average 2018 irrigation water allocated was 7400 m³/ha, being 9.3% by pumping recharge, with a global efficiency of about 67%. The water quality analysis allowed identifying some risk situations regarding salinization and microbiological issues, justifying action to solve or mitigate the problems, especially at the level of the farmers’ fields, according to the crops and the irrigation systems. Results point to priority actions to consolidate improved water management: better maintenance and conservation of infrastructure of hydraulic infrastructures to reduce water losses and better flow control; implementation of optimal operational plans, to adjust the water demand with distribution; improvement of the on-farm systems with better water application control and maintenance procedures; and improvement of the control of water quality on the water reuse from drainage ditches. The technological innovation is an element of the modernization of irrigation districts that justifies the development of multiple efforts and synergies among stakeholders, namely farmers, water users association, and researchers.

The innovation of agricultural systems management is a determinant factor that guarantees adaptation to a new paradigm of global economy, environmental protection, and social requirements. The conventional concepts of innovation, applicable to new products and processes, do not consider many characteristics of the agricultural sector, such as social innovation and innovation resulting from new or renewed processes. Nevertheless, the overall impact of innovation on yields, competitiveness, and value can be hampered by the limited understanding or misinterpretation of Agriculture Innovation paradigms. For instance, the Rural Development Program (RDP) applies a restrict concept of innovation, being unable to embrace the full range of activities intended to implement new practices within the framework of the Agricultural Knowledge and Innovation System (AKIS). Stimulating innovation in agriculture demands a change in policy innovation of RDP in order to preserve natural resources and combine agricultural priorities and the rural environment with the concepts of innovation. This paper focuses on the different views of the concept of innovation within the Program of Operational Groups (OGs) of the European Innovation Partnership for Agricultural Productivity and Sustainability (EIP-AGRI), analyzing the Portuguese case study of the Lis Valley Irrigation District whose main innovation objective was to achieve and implement new processes of water management aiming at the conservation of natural resources as well as sustainable social and economic agricultural development. The Portuguese experience highlights why the application of innovation in agriculture may not reach the desirable outcomes.

O desenvolvimento sustentável do território rural está relacionado com as condições socioeconómicas da agricultura e da preservação do ambiente e em estreita ligação com as tecnologias aplicadas. Os sistemas de produção agrícola convencionais podem revelar insuficiente competitividade devido à escala produtiva, o que resulta da menor dimensão das explorações ou da redução do preço dos produtos por constrangimentos na comercialização.Uma forma de resolver este problema é a adoção em modo de Produção Integrada ou Produção Biológica de produtos mais valorizados no mercado através da utilização de tecnologias de maior intensificação da mão-de-obra, melhor adaptabilidade a estruturas microfundiárias e com acrescido potencial de conservação dos recursos naturais e biodiversidade. Estas soluções vão ao encontro da Estratégia Nacional para a Agricultura Biológica e do Plano de Ação para a Produção e Promoção de Produtos Biológicos, bem como da Estratégia Nacional para as Compras Públicas Ecológicas 2020. A mudança de modo produtivo assume-se como um grande desafio, pois exige inovação tecnológica, novos conhecimentos na gestão agrícola e exigências especiais na relação com o mercado.Esta comunicação avalia a dimensão deste desafio em termos da motivação dos agricultores, das condições tecnológicas e gestão das empresas e da perceção de risco económico, num estudo aplicado ao Aproveitamento Hidroagrícola do Vale do Lis (AHVL), localizado no Centro Litoral de Portugal, com cerca de 2000 ha.Os objetivos específicos deste estudo compreendem: i) caracterização da agricultura do AHVL nas dimensões demográfica, social e económica; ii) identificação das tecnologias de inovação agrícola de produção integrada e agricultura biológica, incluindo os tipos de cultura; iii) avaliação da propensão dos agricultores para a mudança do modo produtivo; iv) identificação das principais dificuldades para efetivação da mudança e v) estabelecimento de um plano de ação para apoio aos agricultores, incluindo divulgação, formação, certificação e comercialização. A metodologia aplicada baseou-se num inquérito aos agricultores, através de amostragem representativa das várias classes de dimensão das explorações.Algumas das questões colocadas foram: i) modo de produção atual; ii) disponibilidade para adotar agricultura biológica e iii) principais medidas de apoio necessárias.Os resultados obtidos apontam para diversas dificuldades na reconversão dos modos produtivos, sendo de salientar a incerteza quanto ao acréscimo de custo dos fatores de produção sobre o rendimento económico, a insuficiência de conhecimento técnico sobre as novas tecnologias e a falta de garantias de escoamento dos produtos. Realça-se ainda a grande recetividade em aprofundar conhecimentos para fundamentar tomadas de decisão, através de ações de divulgação ou na participação em ações do tipo demonstrativo. Serão apresentadas as linhas gerais de um plano de ação para apoio aos agricultores, como corolário do estudo desenvolvido. FERREIRA, Susana; OLIVEIRA, Fátima; GOMES da SILVA, Francisco; TEIXEIRA, Margarida; EUGÉNIO, Rui; DAMÁSIO, Henrique; GONÇALVES, José Manuel

A presente comunicação apresenta resultados da atividade do Grupo Operacional para a gestão da água no Vale do Lis, desenvolvida no Aproveitamento Hidroagrícola do Vale do Lis (AHVL), um regadio coletivo público localizado no Centro Litoral de Portugal, com cerca de 2000 ha. Compreende aluviossolos modernos, cultivando-se milho-grão, prados e forragens, arroz, pomares, viveiros e hortícolas. Este grupo operacional visa a melhoria da planificação, gestão e uso da água e a modernização sustentável do AHVL, em articulação com a Associação de Regantes e Beneficiários do Vale do Lis . O aproveitamento estrutura-se em nove blocos hidráulicos com funcionamento relativamente independente. A adução ao perímetro é a fio de água através de vários açudes e estações elevatórias (EE), captando-se água do rio Lis, afluentes e valas de drenagem. A rede de distribuição é gravítica em canal, regadeiras e tomadas de água.A monitorização da redes coletiva de abastecimento baseia-se na observação do modo operativo e dos hidrogramas de afluência. Foi efetuada a medição de caudais na entrada dos vários blocos, nas derivações na rede gravítica ou nas EE de reforço, recorrendo-se a molinete electromagnético e ao método secção-velocidade, com observações regulares durante a campanha de rega. As observações foram complementadas com os registos de operação e maneio da rede e os registos contínuos do nível de água nos açudes principais do rio Lis, de Arrabalde e Salgadas. As condições de drenagem e o potencial contributo hídrico para as culturas por ascensão capilar foram avaliadas por medição de nível freático em furos piezométricos com 3 m de profundidade. Foram igualmente registados os consumos de energia nas EE. A monitorização da qualidade físico-química e microbiológica da água de rega e drenagem foi efectuada em pontos de entrada e saída do aproveitamento. A análise físico-química foi efetuada com sonda multiparamétrica portátil e em laboratório. As observações microbiológicas foram efetuadas no período de ponta de estiagem com a colheita de amostras em condições de assépsia para análise em laboratório.Nesta comunicação serão apresentados os resultados da monitorização de 2018 e a sua aplicação no apoio à gestão do sistema. A análise dos resultados permitiu identificar alguns aspectos de constrangimento do sistema, dando informação sobre medidas a adoptar. São exemplo a manutenção e limpeza de canais, auditorias energéticas nas EE e avaliação das condições de fertilização orgânica. O balanço hídrico ao nível dos blocos hidráulicos, baseado em informação hidrométrica, meteorológica e cultural, permitirá aplicar um modelo de integração de informação visando o apoio à gestão da água no aproveitamento. Gonçalves, José Manuel; Nunes, Manuel; Amador, Paula; Filipe, Olga; Ferreira, Susana; Eugénio, Rui; Duarte, Isabel Maria; Teixeira; Marques; Oliveira, Fátima; Gonçalves, Madalena; Damásio, Henrique