Modeling Regime Shifts in the Logone floodplain (MORSL)

This interdisciplinary research project focused on the impact of human activities and climate change on African floodplains. African floodplains are an excellent example of coupled human-natural systems because they exhibit strong interactions among multiple social, ecological, and hydrological systems. The intra-annual and inter-annual variations in the area, depth, and duration of seasonal flooding have direct and indirect impacts on ecosystems and human lives and livelihoods. The goal was to develop an integrated computer model that simulates the dynamic couplings among social, ecological and hydrological systems of the Logone floodplain in Cameroon. The model will allow us to simulate the impacts of climate change scenarios and human modifications of the landscape on the social, ecological, and hydrological systems. Fishermen in the Logone floodplain have been modifying the floodplain's hydrology by constructing thousands of individually owned fish canals. The cumulative effect of these canals may equal the impact of large-scale dams.

The devastating impact of large-scale dams on African floodplains has been well documented, but what is less clear is how smaller, slower changes like the fish canals may result in regime shifts that have equally disastrous consequences. If the floodplain is characterized by critical transitions, the gradual increase in fish canals may result in a sudden and catastrophic transition equivalent to the impact of large-scale dams. The integrated computer model will enable researchers to examine the nature of the regime shift. The project brought together a team of researchers from a broad range of disciplines and used a transdisciplinary approach to investigate coupled human and natural systems using a combination of field research, remote sensing analysis, and modeling.

The project will hopefully contribute to the sustainable management of African floodplains, which are of enormous ecological and economic importance, by developing an integrated computer model that will permit stakeholders to evaluate the impact of different human activities and climate change scenarios. The project trained graduate and undergraduate students at the Ohio State University and at Maroua University in Cameroon in quantitative and qualitative, transdisciplinary approaches to the study and management of coupled human and natural systems. This project was supported by the NSF Dynamics of Coupled Natural and Human Systems (CNH) Program and the NSF Office of International Science and Engineering (BCS-1211986).

本跨学科研究项目聚焦人类活动与气候变化对非洲泛滥平原（African floodplains）的影响。非洲泛滥平原是耦合人-自然系统（coupled human-natural systems）的典型范例，因其在多重社会、生态与水文系统之间存在强烈的相互作用。季节性洪水的面积、深度与持续时间的年内及年际变化，会对生态系统、人类生活与生计造成直接与间接影响。本项目的目标是开发一款集成计算机模型，用以模拟喀麦隆洛贡泛滥平原（Logone floodplain）社会、生态与水文系统之间的动态耦合关系。该模型可用于模拟气候变化情景与人类景观改造对社会、生态及水文系统的影响。洛贡泛滥平原的渔民通过修建数千条私人所有的鱼渠，改变了该区域的水文状况。这些鱼渠的累积效应或许可与大型水坝的影响相匹敌。

大型水坝对非洲泛滥平原的破坏性影响已有充分文献记载，但尚不明确的是，诸如鱼渠这类规模更小、进展更缓慢的改变，会如何引发状态转变（regime shifts）并带来同等灾难性的后果。若该泛滥平原存在临界转换（critical transitions）特征，那么鱼渠数量的逐步增加或许会引发一场突发性灾难性转变，其影响堪比大型水坝。这款集成计算机模型将帮助研究者探究这类状态转变的本质。本项目汇集了来自多个不同学科的研究团队，采用超学科研究方法（transdisciplinary approach），结合实地研究、遥感分析与模型构建，对耦合人-自然系统展开研究。

本项目旨在通过开发集成计算机模型，助力利益相关方评估不同人类活动与气候变化情景的影响，从而为非洲泛滥平原的可持续管理提供支持——该平原兼具极高的生态与经济价值。本项目为美国俄亥俄州立大学（Ohio State University）与喀麦隆马鲁阿大学（Maroua University）的研究生与本科生提供了定量、定性及超学科研究方法的培训，以用于耦合人-自然系统的研究与管理。本项目由美国国家科学基金会（NSF）耦合自然与人类系统动力学（CNH）计划，以及美国国家科学基金会国际科学与工程局（资助编号BCS-1211986）资助。