Comparing Peasants' Perceptions Of

Earth Syst. Dynam., 7, 499–515, 2016 www.earth-syst-dynam.net/7/499/2016/ doi:10.5194/esd-7-499-2016 © Author(s) 2016. CC Attribution 3.0 License. Comparing peasants’ perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru Wolfgang Gurgiser1, Irmgard Juen1, Katrin Singer2, Martina Neuburger2, Simone Schauwecker3,4, Marlis Hofer1, and Georg Kaser1 1Institute of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria 2Institute of Geography, University of Hamburg, Hamburg, Germany 3Institute of Geography, University of Zurich, Zurich, Switzerland 4Meteodat GmbH, Zurich, Switzerland Correspondence to: W. Gurgiser ([email protected]) Received: 19 August 2015 – Published in Earth Syst. Dynam. Discuss.: 9 October 2015 Revised: 25 April 2016 – Accepted: 6 May 2016 – Published: 26 May 2016 Abstract. Pronounced hygric seasonality determines the regional climate and, thus, the characteristics of rain- fed agriculture in the Peruvian Callejón de Huaylas (Cordillera Blanca). Peasants in the Cuenca Auqui on the eastern slopes above the city of Huaraz attribute recently experienced challenges in agricultural production mainly to perceived changes in precipitation patterns. Statistical analyses of daily precipitation records at nearby Recuay (1964 to 2013) and Huaraz (1996 to 2013) stations do not corroborate the perceived changes. Ei- ther insufficient temporal resolution of available precipitation records or other environmental and sociopolitical factors impacting traditional farming methods may be the reason for the lack of concordance between the two information sources investigated in this study. 1 Introduction – considering different perspectives terized by single-peaked hygric seasonality. Precipitation in- on a complex problem creases from August towards the October to April core wet season and is close to nil during June and July (e.g., Bury Scientific evidence of climate warming and of projected re- et al., 2010; Kaser and Osmaston, 2002; Mark et al., 2010; sulting impacts can provide the basis for a responsible and Schauwecker et al., 2014). Dry season runoff, and thus water efficient adaptation strategy if implemented in a timely and supply, is comprised of up to two thirds glacial melt water careful fashion, but can also be misused to legitimize partic- from the Cordillera Blanca (e.g., Baraer et al., 2012; Kaser ular interests (Arnall et al., 2014; Dietz, 2011; Neuburger, et al., 2010; Mark and Seltzer, 2003, 2005). They smooth the 2008). While the physical aspects of climate change are, seasonal runoff to a degree that varies with the proportion of though complex, of relatively straightforward nature, soci- sub-catchments that are covered by glaciers (e.g., Kaser et etal processes in reaction to them are contingent upon and al., 2003; Mark and Seltzer, 2003). While the highest glacier characterized by the different interests, positions and vulner- cover of up to 41 % is found in the northern Cordillera Blanca abilities of affected groups (Postigo et al., 2008; Sietz, 2014; valleys, rivers draining the western Cordillera Negra are lack- Zimmerer, 1993). ing in glacier contribution (e.g., Kaser et al., 2003). A region of specific interest is the Callejón de Huaylas (the Glacier contribution definitely has a considerable effect on valley drained by the Río Santa) in Peru, where water avail- the runoff of the Río Santa during the dry season (Bury et ability is determined by particular climate and topographi- al., 2013; Carey et al., 2014) and even more so on the tribu- cal settings (e.g., Kaser et al., 2003). While the tropical at- taries draining the Cordillera Blanca. Both ancient and mod- mosphere is thermally homogeneous, the region is charac- ern channel systems have witnessed the sophisticated use of Published by Copernicus Publications on behalf of the European Geosciences Union. 500 W. Gurgiser et al.: Comparing peasants’ perceptions of precipitation change with precipitation records river water for agriculture and other needs (Bury et al., 2013; Río Auqui (crop types used, seasonal cycle of sowing, grow- Gelles, 2001). Many studies were dedicated to the impact of ing and harvesting) and presenting and evaluating the peas- glaciers on runoff and water availability in the region (Baraer ants accounts of changes, (ii) analyzing available information et al., 2012; Carey et al., 2014; Mark et al., 2010). The in- on local precipitation, and (iii) touching on potential effects creasing knowledge of human-caused climate warming and on small-scale farming as far as possible from available data. resulting impacts has attracted much attention in the region Aspects of climate change impacts not investigated in this up to now (Baraer et al., 2012; Bury et al., 2013; Carey, 2010; study and potential other disturbances of agricultural perfor- Carey et al., 2014; Chevallier et al., 2011; Juen et al., 2007; mance will be briefly referred to in the discussion section. Mark et al., 2010; Vuille et al., 2008) and, among other inter- The outcome of this study may shed light on other peas- ests, our interdisciplinary research team also focuses on this ant communities in the region whose economy is based on issue. rain-fed agriculture and, more generally, on mountain re- Yet, by gradually deciphering natural components of wa- gions with similarly vulnerable communities and with simi- ter availability, societal practices of water use, and emerging larly poor availability of information. It also takes account of trends of water conflicts, we have identified important non- potential complications caused by the different approaches of glacial aspects of the question of water supply in our study scientific groups in an interdisciplinary setting and by bring- region. Even on the slopes of the heavily glaciated Cordillera ing together epistemologies represented by Western scien- Blanca many small-scale farmers have no access to nearby tific knowledge with peasants’ local knowledge (e.g., Boe- glacier-fed river runoff due to unequal land and water distri- lens, 2014; Escobar, 2008; Klein et al., 2014; Lennox and bution systems. Gowdy, 2014). We emphasize that this study only concen- Accounts from local peasants suggest that changes in pre- trates on one variable (precipitation) out of a series of poten- cipitation patterns, e.g., during the onset of the wetter season tially interrelated variables explaining perceived changes. It (August–September), the traditional period for ground prepa- will, therefore, rather point out open questions then provide ration and first seeding, have caused detrimental effects on conclusive answers to the complex problem. In fact we con- the crops’ growth and, thus, on overall agricultural produc- sider the outcome of our methodical experiments at the in- tion. However, human perception can often fail to accurately terface of the, by their nature, explicitly different knowledge determine the drivers of concern (e.g., precipitation, solar systems as a major result. We therefore provide the details of radiation, temperature, deforestation, changes in seed types the approaches taken from both sides for providing insight to etc.) for the experienced impacts (changing soil moisture, readers from different scientific disciplines. problems with seedlings and harvests). A full range analysis of crop yield and precipitation data, of forest degradation, soil erosion, changing seeds, cultivating methods, develop- 2 Study site ment and/or liberalization of agricultural markets, political programs and dominant discourses etc. would lead to a most Our study site (here called Cuenca Auqui) stretches from comprehensive answer to whether and why crop yields may the city of Huaraz along the slopes south of the Río Auqui have changed and how counter measures could be applied. up to the highest settlements close to Río Shallap and in- Yet sustainability farming is rarely accompanied by system- cludes five main villages with about 1500 inhabitants in to- atic data collection and change monitoring, hindering a com- tal: Los Pinos, Ichoca, Collyur, Paquishka and Jancu (Fig. 1). prehensive analysis of drivers of alterations in crop growing. The narrow bottom of the valley is well-defined by steep General statistics on agricultural production changes for the slopes reaching altitudes up to 4500 m a.s.l. that become gen- entire Department of Ancash do not allow for the derivation tler towards the crests. Aside from some houses at the valley of local information and understanding the complexities of flanks, all settlements are located close to the road at an al- changes (Bury et al., 2013). titude of 3200 m a.s.l. (Los Pinos) to 3800 m a.s.l. (Jancu). Also, precipitation data in the Callejón de Huaylas have The cultivation area in the Cuenca Auqui is naturally con- been recorded more from the perspective of hydropower use centrated towards the valley bottom but also extends to the than of agriculture, and thus long-term measurements with adjacent slopes. Irrigation is currently only available for rel- high temporal resolution (at least daily values) as required atively small areas close to the river (Fig. 1). The irriga- for analyzing potential impacts on crop yields are rare. Nev- tion channel along the upper slopes has never been in op- ertheless, for this study we were able to assemble time se- eration yet. Since 2014 it is under reconstruction to improve ries of daily precipitation totals for two sites in the Southern the urban water supply. From a hydrological viewpoint the Cordillera Blanca, for the periods 1964 to 2013 and 1996 to Cuenca Auqui stretches from the Río Santa into the heavily 2013 respectively. These data allow us to examine one po- glaciated Cordillera Blanca, which together with the ice-free tentially powerful (and the most blamed) driver of the expe- Cordillera Negra in the West, defines the Callejón de Huay- rienced changes in rain-fed agriculture. las. In this study we examine the issue by (i) characterizing With the implementation of the agrarian reform in 1969, agricultural practices of Andean peasant families along the four former haciendas (colonial large-scale farms) at the Earth Syst.

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