NOAA/WDS Paleoclimatology - Pederson - Frick Creek - LITU - ITRDB GA011

The depth of the 2006-9 drought in the humid, southeastern US left several metropolitan areas with only a 60-120 day water supply. To put the region's recent drought variability in a long-term perspective, a dense and diverse tree-ring network-including the first records throughout the Apalachicola-Chattahoochee-Flint river basin - is used to reconstruct drought from 1665 to 2010 CE. The network accounts for up to 58.1% of the annual variance in warm-season drought during the 20th century and captures wet eras during the middle to late 20th century. The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665. Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come.

2006至2009年发生于美国东南部湿润地区的干旱烈度极高，致使多个大都市区的可供水储备仅能维持60至120天。为从长期维度审视该区域近期的干旱变异性，研究团队依托一套高密度且多样性丰富的树木年轮网络（涵盖阿巴拉契科拉-查特胡奇-弗林特河流域（Apalachicola-Chattahoochee-Flint river basin）的首批树木年轮记录），重建了公元1665年至2010年的干旱序列。该树木年轮网络对20世纪暖季干旱年际变异的解释量最高可达58.1%，且能够捕捉到20世纪中后期的湿润时段。重建结果显示，近346年来，此次区域性干旱事件并非史无前例。事实上，1696年至1820年间，持续时长更长的干旱事件发生频率显著更高。研究结果表明，当地及州级供水政策的制定时期，以及该政策所依托的器测数据时段，均为至少自1665年以来最为湿润的时期之一。鉴于美国东南部地区人口持续增长，叠加后续工业、农业与城市用水需求的攀升，基于古水文气候记录的研究结论提示，未来数十年内，该区域水相关冲突的风险或将进一步加剧。