4,500 years of Hydrologic Variability from Zaca Lake, close to the Santa Barbara Basin

提供资金用于从加利福尼亚州圣巴巴拉县扎卡湖的沉积物中开发跨越过去4000年的高分辨率(十年或更高)、多指标气候记录。研究人员使用了一套方法，包括分子同位素分析(即水生和陆地生物标志物中的D/H比率)、生物分析(包括木炭计数)和物理沉积物分析(包括颗粒大小)。目标是重建气候变化(干旱和暴雨)的性质和频率、洪水事件地层以及在气候变化下降水和集水区水文学的变化。利用扎卡湖记录与区域和全球气候记录和强迫的相关性来探索驱动这些变化的机制。特别是，扎卡湖靠近圣巴巴拉盆地，这使得这一新的高分辨率陆地记录可以在50公里内与高分辨率海洋记录进行比较。更广泛的影响包括南加州大学和加州州立大学富勒顿分校(授予少数族裔学生的学士学位数量在全国排名第五)之间的跨机构合作，对一名新的女性研究人员的支持，以及在两所大学培训两名研究生和多名本科生。扎卡湖在原本缺乏湖泊的南加州提供了一个难得的机会，可以重建历史时期以外的过去洪水和干旱的频率和严重程度，研究结果与这个水资源紧张和人口稠密地区的灾害和水管理决策相关。

Funding is provided to develop a high-resolution (decadal or better), multi-proxy climate record spanning the past 4 millennia from the sediments of Zaca Lake, Santa Barbara County, California. The researchers use a suite of approaches including molecular isotopic analyses (i.e. D/H ratios in aquatic and terrestrial biomarkers), biological analyses (including charcoal counts), and physical sediment analyses (including grain size). The goals are to reconstruct the nature and frequency of climate variability (droughts and pluvials), flood event stratigraphy and changes in precipitation and catchment hydrology under changing climate. Correlation of the Zaca Lake record to regional and global climate records and forcings are used to explore the mechanisms driving these changes. In particular, the proximity of Zaca Lake to the Santa Barbara Basin enables comparison of this new high-resolution terrestrial record to a high-resolution marine record within 50km.The broader impacts include cross-institutional collaboration between University of Southern California and California State University at Fullerton (#5 in the nation for the number of bachelor's degrees awarded to minority students), support for a new female researcher, and the training of two graduate students and multiple undergraduate students at both institutions. Zaca Lake provides a rare opportunity in otherwise lake-poor Southern California to reconstruct the frequency and severity of past floods and droughts beyond the historical period, with findings of relevance to hazard and water management decisions in this water-stressed and highly populous region.