Concepts and Applications of AquaCrop: The FAO Crop Water Productivity Model

Predicting attainable yield under water-limiting conditions is an important goal in arid, semi-arid and drought-prone environments. To address this task, FAO has developed a model, AquaCrop, which simulates attainable yields of the major herbaceous crops in response to water. Compared to other models, AquaCrop has a significantly smaller number of parameters and attempts to strike a balance between simplicity, accuracy, and robustness. Root zone water content is simulated by keeping track of incoming and outgoing water fluxes. Instead of leaf area index, AquaCrop uses canopy ground cover. Canopy expansion, stomatal conductance, canopy senescence, and harvest index are the key physiological processes which respond to water stress. Low and high temperature stresses on pollination and harvestable yield are considered, as is cold temperature stress on biomass production. Evapotranspiration is simulated separately as crop transpiration and soil evaporation and the daily transpiration is used to calculate the biomass gain via the normalized biomass water productivity. The normalization is for atmospheric evaporative demand and carbon dioxide concentration, to make the model applicable to diverse locations and seasons, including future climate scenarios. AquaCrop accommodates fertility levels and water management systems, including rainfed, supplemental, deficit, and full irrigation. Simulations are routinely in thermal time, but can be carried out in calendar time. Future versions will incorporate salt balance and capillary raise. AquaCrop is aimed at users in extension services, consulting firms, governmental agencies, NGOs, farmers associations and irrigation districts, as well as economists and policy analysts in need of crop models for planning and assessing water needs and use of projects and regions

Indigenous Practices of Water Management for Sustainable Services

This article explores the possibility of incorporating traditional water management experiences into modern water management. After the literature review, two case studies are presented from Borana and Konso communities in southern Ethiopia. The study was conducted through interviews, discussions, and observations. The two cases were selected due to their long existence. Both communities have their own water source types, depending on local hydrogeological conditions. Borana is known for the so-called Ella (wells) and Konso for Harta (ponds), which have been managed for more than five centuries. All government and development partners strive to achieve sustainable services in water supply and sanitation. Therefore, they design various management packages to engage the communities and keep the systems sustainable. However, the management components are often designed with little attention to local customs and traditions. The cases in the two communities show that traditional knowledge is largely ignored when replaced by modern one. However, the concepts of cost recovery, ownership experience, equity, enforcement, integrity, and unity, which are highly pronounced in modern systems, can also be found in the traditional water managements of Borana and Konso. Naturally, one shoe never fits all. Borana and Konso experiences are working for their own community. This research implies that when we plan a project or a program for a particular community, the starting point should be the indigenous practices and thoughts on life