The Andean Glacier and Water Atlas

challenges, by improved water management infrastructure, and the strengthening of institutions and planning for integrated and participatory water resource management, is necessary. Reducing water loss from urban water and sanitation infrastructure will be key. For example, in Bolivia, the La Paz water utility installed equipment and implemented an efficiency programme, which worked to improve the effectiveness of water distribution. By doing so, it reduced water losses in the El Alto’s District 4 from 39.6 per cent, down to 26.5 per cent, which represents a water saving of approximately 619 m 3 /year (United Nations Population Division, 2018). Given the economic dependence on agriculture practices for the Andean countries and local communities, identifying agricultural practices that support water conservation, is an important adaptation measure. Much of the Andean agriculture and food production depends on rainfall, but irrigation has often been used to supplement this. The overall water efficiency of irrigation in most systems does not exceed 35–40 per cent, however improved irrigation technology can achieve average efficiencies in the order of 50–60 per cent or more, for example through the implementation of small sprinkler and drip irrigation systems (Hendriks, 2013). There are many public programmes aimed at promoting mechanized irrigation, but these programmes are usually oriented at the construction of medium and large systems. There is therefore an opportunity to promote the development of efficient small systems adapted to the situation of the most vulnerable. However, since even the introduction of efficient irrigation technologies can ultimately increase the total consumption of water, it is necessary to implement measures to simultaneously improve water conservation measures. Deficit irrigation is a technique in which the amount of water a plant receives through irrigation is restricted to certain critical periods. These are normally when a plant is undergoing vegetative stages and during the late ripening period. Outside of these periods, irrigation is restricted or even not applied if rainfall can provide the minimum requirements for the plant. The approach, while inducing some plant water stress, aims at providing stable crop yields rather than aiming for maximum yields. In areas where water may be a limiting factor – that is, in dry regions – deficit irrigation is widely seen as a sustainable production strategy, which can increase water productivity without causing severe yield reductions (Geerts & Raes, 2009). One study of deficit irrigation for quinoa in the Bolivian Altiplano found that only half of the typical irrigation water was needed to produce a sustainable yield (Geerts et al. 2008).i CASE STUDY Deficit irrigation as an adaptation tool to water stress

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