The detection of on-site farm reservoirs and ponds in large areas is a complex task that can be addressed through the combination of visual inspection of orthophotos and the application of automatic pixel classification algorithms.

This analysis applied a general workflow to detect and quantify the area and density of on-farm reservoirs and water bodies in three representative Mediterranean irrigated oases in Sicily-Italy, Northern of Morocco, and Israel. For each area of analysis, the most recent orthophotos available were collected from Google Earth, and the ilastik algorithms were implemented for the pixel classification (Random Forest -RF-) and semantic-segmentation. The RF classifier, which is previously applied to a set of filtered imagery and iteratively trained, provides probability maps of different classes that are finally used for quantitative analysis, or the retrieval of a segmentation-categorical (water vs non-water) maps.

The Middle East and North Africa (MENA) region is considered the most water-scarce region of the world. Disputes over water lead to tension within communities, and unreliable water services are prompting people to migrate in search of better opportunities. Water investments absorb large amounts of public funds, which could often be used more efficiently elsewhere. As the region’s population continues to grow, per capita water availability is set to fall by 50 percent by 2050, and, if climate change affects weather and precipitation patterns as predicted, the MENA region may see more frequent and severe droughts and floods

Map of yearly average precipitation in the MENA region (mm).

The need for alternative and improved water management options is therefore urgently needed, but a clear overview on what the main focus should be is lacking. A broad range of options exists which can be grouped by different approaches such as reducing the demand, increasing the supply, transfer between different sectors, transfer within different sectors, increase storage etc. An important aspect for the MENA region includes desalination.

Map of aridity in the MENA region.

To explore different options the World Bank initiated an initiative to generate an improved understanding of water issues in the region and overview of available options under different scenarios of water supply and demand management with special focus on desalination, taking into account the energy nexus and environmental concerns. As part of this initiative, FutureWater will carry out an assessment of water stress in the MENA region, including associated marginal cost of water supply to meet the water supply need. Conducting consultation workshops and meetings will be organized with relevant parties in the region (governmental, universities, civil society groups).

Appropriate planning in water resources, and more specifically in irrigation, is becoming increasingly important given the challenges of already-stressed water resources, climate change, growing population, increase in prosperity, potential food shortages, etc. However, policy makers and planners are often constrained, in this context of increasing complexity, by insufficient knowledge and tools to evaluate the consequences of alternative interventions and thus make the appropriate decisions. Furthermore, important misconceptions often underlie strategies proposed to address these problems.

To illuminate these issues, a scenario-based policy oriented demonstration model is presented here. The term model here refers more to a demonstration tool rather than a software package. The model as developed includes physical processes, but at a lumped and parametric level. Most importantly, the model will focus on scenario and intervention analysis, so that policy makers can better understand and evaluate the impact and interactions of a certain change or decision they plan to make, and the changing environment in which they are operating.

The model is developed in WEAP and is based on water scarce basin. A copy of the WEAP model can be obtained through SEI.

Green Water Credits can be seen as an investment mechanism for upstream farmers to practice soil and water management activities that generate benefits for downstream water users, which are currently unrecognized and unrewarded. This initiative is driven by economic, environmental and social benefits. The implementation of GWC has the potential of enhancing overall water management by reducing damaging runoff, increase groundwater recharge, simulate a more reliable flow regime, and reduce harmful sedimentation of reservoirs.

Green Water Credits: the concept.

The largest issues in the Sebou basin in Morocco are floods, droughts, erosion and the siltation of reservoirs, food and water security, and public health. These issues offer unique opportunities for the implementation of green water management measures. The implementation of these management options can enhance the water availability and reduce problems related to flooding and erosion. However, farmers need incentives to sustainably implement these measures. At the same time, downstream users may be unaware of the benefits they might gain through farmer implementation of these measures in upstream areas. This Proof-of-Concept phase is meant to demonstrate and quantify the potential benefits to all stakeholders in the basin.

The GWC methodology was applied to the Sebou river basin. Data was gathered, prepared and verified to set up a bio-physical assessment tool (SWAT) to quantify the upstream-downstream interaction in the basin. Three green water management scenarios were analyzed, in order to evaluate the effect of these scenarios on soil evaporation, crop transpiration, surface runoff, sediment inflow into the reservoirs, and groundwater recharge. The GWC scenarios analysed were:

  • Stone lines (cordons de pierres)
  • Bench terraces (banquette)
  • Contour tillage
Green Water Credits measure: stone lines

For the scenarios analyzed, Contour tillage showed the largest decrease in sediment inflow into the reservoirs. The other two scenarios also showed decreases in sediment inflow. Another positive effect is the decrease in surface runoff, and increase in groundwater recharge. The increase in groundwater recharge is especially large for the areas where rainfed broad beans are grown. The increase in groundwater recharge leads to more water inflow into the reservoirs. This increases the water availability for farmers who use the water extensively for irrigation purposes.

By using the SWAT model in combination with WEAP the potential benefits can be assessed. The overall purpose of the WEAP model is to provide a first estimate of the potential impact of the green water management measures. The most effective measures, in terms of benefits only are implementation of bench terraces, followed by carrying out contour tillage, and then constructing stone lines. However, bench terraces are much more expensive than the other two measures, and contour tillage is the most preferable in terms of benefit-cost ratio.

Water shortage (unmet demand) for the future and the three green water management scenarios

El proyecto “Sustainable use of irrigation water in the Mediterranean Region” (SIRRIMED) es un proyecto europeo de cooperación del VII Programa Marco, enmarcado en la temática “Alimentación, Agricultura, Pesca y Biotecnologías”, que cuenta con un presupuesto superior a 4 millones de euros, y en el que participan quince socios de ocho países distintos: España, Italia, Francia, Inglaterra, Holanda, Marruecos, Líbano, Egipto. Se trata de un proyecto coordinado por el Centro de Edafología y Biología Aplicada del Segura (CEBAS-CSIC).

El proyecto SIRRIMED aborda cuestiones relacionadas con la optimización del uso del agua de riego en el Mediterráneo. La originalidad de Sirrimed reside en su carácter integrador, tanto a nivel espacial, los estudios van de la escala de la finca agrícola hasta la escala de la Cuenca Hidrográfica, como a nivel de los campos científicos agronomía, hidrología, climatología, y tecnológicos, sensores, algoritmos de programación, modelización biofísica, sistemas de información integrando la teledetección.

El consorcio lo forman empresas, centros de investigación, universidades y asociaciones, estrechamente relacionadas con la gestión del agua en la agricultura: La Agencia Estatal Consejo Superior de Investigaciones Científicas (CSIC), Universidad Politécnica de Cartagena (UPCT), Canale Emiliano-Romagnolo (CER), Institut National de la Recherche Agronomique (INRA), Lancaster Environment Centre (LEC), Center for Research and Technology – Thessaly (CERETETH), Universidad de Córdoba (UCO), Asociación Fabricantes de Riego Españoles (AFRE), Euromediterranean irrigators community (EIC), Institute for Environmental Studie.- Vrije Universiteit Amsterdam (IVM-VU), Litani River Authority (LRA), Debbane S.L. (DEB), Institut Agronomique et Véterinaire Hasssan II (IAV-CHA), Sapiama S.L (SAPIAMA), y National Research Center (NRC).

FutureWater participa dentro de los paquetes de trabajo que tienen como objetivo poner a la disposición de los usuarios finales, que pueden ser tanto agricultores como comunidades de regantes o confederaciones hidrográficas, indicadores de gestión, herramientas y modelos que permitan la optimización y la armonización de la gestión del agua de riego a diferentes niveles de toma de decisión. Debido al carácter multidisciplinario de los estudios, colabora con varios grupos de investigación de la UPCT y del CEBAS en diferentes áreas de conocimiento, entre las que destacan ingeniería agroforestal, producción vegetal y economía agraria.

Se han elegido varias cuencas piloto que son monitorizadas simultáneamente por equipos de medida de terreno y por datos de teledetección. De esta forma, se adquiere la información espaciotemporal necesaria para la evaluación de la evapotranspiración de los cultivos y de la productividad del agua en estas cuencas. A partir de modelos de cultivos asociados a modelos hidrológicos alimentados con datos agro-meteorológicos y de teledetección, se llevan a cabo simulaciones del funcionamiento de los regadíos, en función de diferentes escenarios de cultivos, de disponibilidad de agua, de sistema de riego y de modo de gestión del regadío.

Para más información visita la web del proyecto