Geomorphological and environmental responses to rapid hydrological changes in the Atlas Mountains (Morocco) during the last 30,000 years

西地中海和北非沙漠边缘是全球变暖的热点地区，可能包括热应力增加、降水减少和更频繁的干旱。全新世和末次冰期档案表明，西地中海水文气候的百年至千年尺度的变化，虽然测年不准确，敏感，但不同的环境响应机制的调查参数，本项目的主要目的是了解西地中海地区的环境敏感性和对气候变化的响应，撒哈拉过渡。后续项目将扩大对全新世以外的古水文学、古生态学和尘埃动力学的了解，包括晚冰期和末次盛冰期。我们的目标是恢复连续和良好的解决湖泊序列跨越过去30万年。我们将提高对全新世快速气候变化（例如LIA，4.2和8.2 ka），全新世-晚冰期过渡和LGM冷却事件在百年至千年时间尺度上的突发环境响应的理解。我们将建立从亚湿润东北到半干旱西南的中到高阿特拉斯山地沙漠边缘的空间焦点。作为沙漠边缘，该区域对降水变化高度敏感，这反映在环境系统的动态中。这是第一次，我们将采用水文气候梯度的方法与一套相同的多代理技术在百年尺度分辨率。我们的目标是：O 1：检索和日期新的湖泊沉积物岩心沿着水文气候梯度。我们将重点关注两个湖泊：半湿润的中阿特拉斯湖的西迪阿里湖和半干旱的高阿特拉斯湖的提斯利特湖。我们将应用210铅测年，14 C花粉和宏体化石测年，发光测年技术和贝叶斯年龄建模。O2：约束过去的降雨和蒸发制度。我们将使用生物（介形虫，水生花粉）和地球化学参数，包括TOC，碳酸盐和介形虫上的δ 13 C/δ 18 O来确定湖泊水位和水文气候代用指标。O3：量化撒哈拉沙尘供应的过去变化。我们将应用粒度端元建模，元素和微量同位素分析。O 4：记录流域尺度的响应（植被，火灾，侵蚀）快速气候变化。我们将通过开发新的花粉和颗粒炭记录来限制植物有效水分和区域温度的变化。硅碎屑参数将被用作土壤侵蚀的替代指标。O 5：首次应用水文气候梯度方法。我们将使用多代理统计检测的时间和空间变化的环境和风成响应沿着北撒哈拉沙漠边缘。

The Western Mediterranean and the North African desert margin are hotspots of global warming that is likely to include increased heat stress, reduced precipitation and more frequent occurrence of droughts. Holocene and Last Glacial archives indicate centennial to millennial-scale changes of the Western Mediterranean hydro-climate, although dating inaccuracies, sensitive but different environmental response mechanisms of investigated parameters, and insufficient chronological resolution lead to many uncertainties.The major aim of our project is to develop the understanding of environmental sensitivities and responses to climatic variability in the zone of the Western Mediterranean-Saharan transition. The follow-up project will extend knowledge of palaeohydrology, palaeoecology and dust dynamics beyond the Holocene, including the Late Glacial and Last Glacial Maximum (LGM). We aim to recover continuous and well-resolved lacustrine sequences spanning the last 30 ka. We will improve understanding of abrupt environmental responses during Holocene Rapid Climate Changes (e.g. LIA, 4.2 and 8.2 ka), the Holocene-Late Glacial transition and LGM cooling events at centennial to millennial time-scales.We will establish a spatial focus on the Middle to High Atlas mountainous desert margin from the sub-humid Northeast to the semiarid Southwest. As a desert margin this zone is highly sensitive to precipitation changes as reflected in the dynamics of environmental systems. For the first time, we will apply a hydro-climatic gradient approach with an identical suite of multi-proxy techniques at centennial-scale resolution. Our objectives are:O1: to retrieve and date new lake sediment cores along the hydro-climatic gradient. We will focus on two lakes: Sidi Ali in the sub-humid Middle Atlas and Tislit in the semiarid High Atlas. We will apply 210Pb dating, 14C pollen and macrofossil dating, luminescence dating techniques and Bayesian age modelling.O2: to constrain past rainfall and evaporation regimes. We will identify lake level and hydro-climatic proxies using biological (ostracods, aquatic pollen) and biogeochemical parameters including TOC, carbonates and δ13C/δ18O on ostracods.O3: to quantify past variability in Saharan dust supply. We will apply grain size end-member modelling, element and trace isotopes analyses.O4: to document catchment-scale responses (vegetation, fire, erosion) to rapid climate changes. We will constrain shifts in plant available moisture and regional temperature through the development of new pollen and particulate charcoal records. Silici-clastic parameters will be used as proxies for soil erosion.O5: to apply for the first time a hydro-climatic gradient approach. We will use multi-proxy statistics for the detection of temporal and spatial variability in environmental and aeolian responses along the North Saharan desert margin.