The changing water cycle: climatic and socioeconomic drivers of water‐related changes in the Andes of Peru

Abstract

Water resources in high mountains play a fundamental role for societies and ecosystems both locally and downstream. Impacts of global change, including climate change, glacier shrinkage, and socioeconomic forces related to demographics, agroindustrial development, and hydroelectricity generation; pose new hydrological risks for human livelihoods. However, these hydroclimatic and socioeconomic drivers of water resource change are often poorly quantified and interconnected, while data scarcity poses challenges in these regions. Here we review the state of knowledge for two major catchments in the Peruvian Andes, which hold the largest tropical glacier mass worldwide: the Santa River (Cordillera Blanca) and Vilcanota River (Cordillera Vilcanota). Our integrative review of water resource change and comparative discharge analysis of two gauging stations in the Santa and Vilcanota River catchments show that the future provision of water resources is a concern to regional societies and must be factored more carefully into water management policies. In this context, observed hydroclimatic and socioeconomic changes represent important drivers of water availability, allocation, and conflicts over water resources. The legal framework and decentralized institutional architecture in Peru could potentially provide a basis for participatory integrative water management; however, unequal power relations, institutional fragility and increasing competition over water resources hamper these efforts. We identify several research gaps, including the need for more in situ data, cultural analyses, and a risk‐based framework that combines climate‐related hazards with human and natural vulnerabilities. Finally, this review suggests that future adaptation plans for water management should better link science, society, and policy. WIREs Water 2015, 2:715–733. doi: 10.1002/wat2.1105 This article is categorized under: Science of Water > Water and Environmental Change

Rapid decline of snow and ice in the tropical Andes – Impacts, uncertainties and challenges ahead

“…glacier retreat and its impact on meltwater availability downstream) has emerged over the past decade, there is an increasing realization that the water demand side may be an equally, if not more, important aspect of this equation Drenkhan et al, 2015;Rasmussen, 2016;Carey et al, 2017). Buytaert and de Bievre (2012) for example analyzed future water supply and demand for four large cities in the Andes (Bogota, Quito, Lima, La Paz), of which one (La Paz) receives a significant water supply contribution from glacier melt, under a range of future scenarios.…”

“…To anticipate these issues and identify hotspots of water shortage and potential conflict, it is essential to understand the spatiotemporal patterns of water demand and how they interact with a changing supply. Within this context, political constellations as well as economic and marketdriven aspects will largely determine priorities for water allocation (Drenkhan et al, 2015). Water rights are distributed based on historical practices and trends, but also based on political conditions, economic agendas, institutional capacity, laws and legal structures, and cultural values.…”

“…The same is true for agriculture that is reliant on irrigation. Large irrigation projects for export-oriented agriculture along the Peruvian coastal deserts (Chavimochic and Chinecas, for example) have led to a rapidly increasing water demand from the Rio Santa that drains the Cordillera Blanca (Bury et al, 2013;Carey et al, 2014;Drenkhan et al, 2015). In Peru subsistence farming based on crops such as alfalfa, barely or potatoes is increasingly being replaced by export crops (asparagus, rice, avocado) grown in these large coastal desert irrigation projects.…”

“…Hydropower constitutes a major component of the power mix in many Andean countries (Vergara et al, 2007). In Peru, for example, it accounts for 54% of the energy production (Drenkhan et al, 2015). With the energy demand in Peru currently increasing at a rate of 5.4% per year (Drenkhan et al, 2015), this capacity is projected to grow rapidly (Finer and Jenkins, 2012).…”

“…In Peru, for example, it accounts for 54% of the energy production (Drenkhan et al, 2015). With the energy demand in Peru currently increasing at a rate of 5.4% per year (Drenkhan et al, 2015), this capacity is projected to grow rapidly (Finer and Jenkins, 2012). Yet glacier retreat might at least in some regions, such as the Cordillera Blanca, Peru, have a negative impact on hydropower production, because of the likely decrease in river discharge during the dry season (Mark et al, 2010;Chevallier et al, 2011;Baraer et al, 2012;Condom et al, 2012;).…”