Assessment of surface water management institutions: a case of public irrigation schemes in northern Algeria

The pressure on water resources that Algeria encounters is due to the scarcity and the water demand increase by different sectors of activity. This induces managers to reconsider the traditional supply management approach. The new water policies aim to adopt water demand management by improving the efficiency of its use in the agricultural sector, which consumes more than 59% of freshwater withdrawals. Economic, regulatory, and voluntary instruments have been adopted for better governance of water resources. This study aims to (i) define institutional arrangements on the exploitation of surface water in large irrigation schemes in Algeria and (ii) assess the effectiveness of the current water management instruments. Findings from farmers’ and water distribution agencies’ surveys suggest that objectives expected by the application of the different economic instruments are far from being achieved. Moreover, the absence of effective executive agencies for the implementation of regulations suggests that an improvement in the performance of public administration is necessary to achieve better governance of irrigation water in Algeria. At the local level, and despite a lack of farmers’ will to formally engage in a collective of farmers, they organize themselves around informal arrangements to overcome the challenges associated with water scarcity.

Smart Control and Energy Efficiency in Irrigation Systems Using LoRaWAN

Irrigation installations in cities or agricultural operations use large amounts of water and electrical energy in their activity. Therefore, optimising these resources is essential nowadays. Wireless networks offer ideal support for such applications. The long-range wide-area network (LoRaWAN) used in this research offers a large coverage of up to 5 km, has low power consumption and does not need additional hardware such as repeaters or signal amplifiers. This research develops a control and monitoring system for irrigation systems. For this purpose, an irrigation algorithm is designed that uses rainfall probability data to regulate the irrigation of the installation. The algorithm is complemented by checking the sending and receiving of information in the LoRa network to reduce the loss of information packets. In addition, two temperature and humidity measurement devices for LoRaWAN (THMDLs) and an electrovalve control device for LoRaWAN (ECDLs) were developed. The hardware and software were also designed, and prototypes were built with the development of the electronic board. The wide coverage of the LoRaWAN allows the covering of small to large irrigation areas.

Optimizing the Sowing Date to Improve Water Management and Wheat Yield in a Large Irrigation Scheme, through a Remote Sensing and an Evolution Strategy-Based Approach

This study aims to investigate the effects of an optimized sowing calendar for wheat over a surface irrigation scheme in the semi-arid region of Haouz (Morocco) on irrigation water requirements, crop growth and development and on yield. For that, a scenario-based simulation approach based on the covariance matrix adaptation–evolution strategy (CMA-ES) was proposed to optimize both the spatiotemporal distribution of sowing dates and the irrigation schedules, and then evaluate wheat crop using the 2011–2012 growing season dataset. Six sowing scenarios were simulated and compared to identify the most optimal spatiotemporal sowing calendar. The obtained results showed that with reference to the existing sowing patterns, early sowing of wheat leads to higher yields compared to late sowing (from 7.40 to 5.32 t/ha). Compared with actual conditions in the study area, the spatial heterogeneity is highly reduced, which increased equity between farmers. The results also showed that the proportion of plots irrigated in time can be increased (from 40% to 82%) compared to both the actual irrigation schedules and to previous results of irrigation optimization, which did not take into consideration sowing dates optimization. Furthermore, considerable reduction of more than 40% of applied irrigation water can be achieved by optimizing sowing dates. Thus, the proposed approach in this study is relevant for irrigation managers and farmers since it provides an insight on the consequences of their agricultural practices regarding the wheat sowing calendar and irrigation scheduling and can be implemented to recommend the best practices to adopt.

THE SOVIET AGRARIAN POLICY IN THE IRRIGATION FIELD IN UZBEKISTAN (1950-1990)

In the article it is analyzed the policy of the centre of the further strengthening mono cultural clap in Uzbekistan that in undertaken measures on building of large irrigation canals and pumping stations in republic on the bases of archival sources and a historical material in 50-80 XX century. Besides, research showed that Soviet government, having outlined the appropriate political and economic goals in Uzbekistan, began to introduce into practical life a policy related to the development of the irrigation system and the construction of reclamation facilities.

Carnivores cross irrigation canals more often through overpasses than through culverts

As rainfall becomes scarcer or more erratic, we rely more on irrigation systems for water provision. Impacts of irrigation canals such as the barrier effect on wildlife movements are poorly documented. Although canal culverts and overpasses can be used by wildlife, little is known about their crossing patterns to guide barrier effect mitigation efforts. Over 7 years, we recorded medium-sized carnivore crossings by video-surveillance through 30 culverts and 28 overpasses in a large irrigation project in south-central Portugal. We examined the influence of the structures' features and landscape context on the likelihood of canal crossing. Culvert crossings were positively influenced by the proportion of nearby montado, a high nature value farming system. Overpass crossings were more likely in areas away from paved roads and with more nearby wetlands. Overpasses increased the crossing rates by about 11 % relative to culverts and both were crossed more often in landscapes with evenly distributed land uses. In the project area, 20% of the montado has recently transitioned to irrigated agriculture, and wetlands have increased by 43%. It is therefore plausible that the increase in the crossing rate of overpasses relative to culverts will be accentuated. Our study produced the first evidence of a contrast in crossing rates among irrigation canal crossing structures. We have shown that the landscape can be a driver of animal crossings but irrigation projects can in turn be transformative of the landscape. Broadly, the fact that the deployment of irrigation canals may favor some land uses over others creates a conundrum that needs careful consideration when planning barrier effect mitigation interventions.

Optimization of Layout and Pipe Sizes for Irrigation Pipe Distribution Network Using Steiner Point Concept

In tropical countries like India, irrigation is necessary to grow crops in the nonmonsoon period. The conventional methodology for conveying irrigation water from the source to the field is through open canals. However, considering huge losses due to evaporation and percolation, a modern system of irrigation like pipe irrigation network (PIN) is desired. Advancement in technology has led to the progress in the PIN as they are compatible with modern irrigation facilities such as sprinkler and drip irrigation systems. In the present study, the layout of the PIN is designed and optimized in two phases. Initially, the looped network is traced out for the Bakhari distributary of the Kanhan Branch Canal, India. Minimum spanning tree (MST) network is obtained from the looped network using Prim's algorithm to calculate the nodal demands. The layout optimization of the MST is carried out using the Steiner concept to obtain the initial Steiner tree (IST). The steady-state hydraulic analysis and design are carried out for the looped and IST network. The results show that the percentage of length decreasing from the looped network to the MST network is 51.58%. The IST network is the optimized network having the minimum length showing a 12.21% length reduction compared to the MST network. The total reduction in the cost of the Steiner tree is found to be 4.25% compared to the looped network. Steiner concept application to large irrigation networks can reduce the length of the network thereby minimizing the total project cost.