ABSTRACT

Agriculture in the Aconcagua Basin is both vital to Chile’s economy and critically dependent on water resources from snow and glaciers. Expanding croplands, a growing population, and a changing climate are all expected to exacerbate water scarcity in this arid region where agriculture requires 7.1 × 10⁸ m³ of water for irrigation annually. We investigate agricultural water resources in the Aconcagua Basin by examining the drivers of and trends in river discharge, calculating approximate crop water demand, and assessing the potential for future water scarcity given discharge rates and agricultural demand. We find that growing-season (October to March) discharge is significantly correlated with austral winter precipitation and the El Niño-Southern Oscillation. Austral winter precipitation provides snow that melts during the growing season, supplying water for agricultural irrigation. Time series analysis shows that temperature increased by 0.23°C per decade between 1965 and 2017, and snow cover frequency decreased 2.7% per decade over the relatively short time period of 2000 to 2017. Based on historical discharge data and our assessment of current agricultural water demand, we show that the Aconcagua Basin is already water-scarce, experiencing demand exceeding supply approximately three out of every 10 years.

摘要

阿空加瓜盆地的农业对智利的经济至关重要，而且严重依赖雪和冰川的水资源。在这个农业需要 7.1 × 10 ⁸  m ^{3 的}干旱地区，扩大农田、不断增长的人口和不断变化的气候都将加剧水资源短缺每年灌溉用水。我们通过检查河流排放的驱动因素和趋势、计算大致的作物需水量以及评估给定排放率和农业需求的未来水资源短缺的可能性来调查阿空加瓜盆地的农业水资源。我们发现生长季节（10 月至 3 月）的流量与南方冬季降水和厄尔尼诺-南方涛动显着相关。南方冬季降水提供在生长季节融化的雪，为农业灌溉提供水。时间序列分析表明，1965 年至 2017 年间气温每十年升高 0.23°C，而积雪频率在 2000 年至 2017 年相对较短的时间内每十年减少 2.7%。