Developing Irrigation Management at District Scale Based on Water Monitoring: Study on Lis Valley, Portugal

Abstract

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.

Alternate Wetting and Drying in the Center of Portugal: Effects on Water and Rice Productivity and Contribution to Development

“…The experimental study was carried out in 2020 in the Lower-Mondego and Lis Valley Irrigation Districts, located in Coastal Center of Portugal, with a total irrigated area of about 14,000 ha, and a rice area of about 6000 ha [ 39 , 40 ] ( Figure 1 a). This region has a Mediterranean climate, Csb and Csa of Köppen classification, with an annual average precipitation of about 800 mm to 900 mm.…”

Virtual Tracers to Detect Sources of Water and Track Water Reuse across a River Basin

“…Subsequent conflicts over water resources have been described extensively for larger scales, such as river basins (e.g., in [48,49]). Additionally, on smaller scales, between irrigation systems or even within one canal system, those conflicts are often based on the uncertainty of source of water and reuse (e.g., in [50,51]).…”

Assessment of Precise Land Levelling on Surface Irrigation Development. Impacts on Maize Water Productivity and Economics

“…The PLL is particularly relevant on flat lands, on graded border or furrows with a mild slope and basin irrigation systems, and on rice paddies, to reach the high irrigation performance standards [17,18]. There are numerous studies reporting the relevance of PLL on surface irrigation development, namely in China [17,[19][20][21], Portugal [22,23], India [21,24], and USA [25].…”