LTREB: Emergent Landscape Patterns in Stream Ecosystem Processes Resulting from Groundwater/Surface Water Interactions

LTREB：地下水/地表水相互作用导致的河流生态系统过程中的新兴景观模式

• 批准号: 0545463
• 负责人: Catherine Pringle
• 金额: $ 41.5万
• 依托单位: University of Georgia Research Foundation Inc
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-03-15 至 2012-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0545463&HistoricalAwards=false
• 关键词: LTREB; Emergent; Landscape; Patterns; Stream

The overall scientific objective of this study is to understand how groundwater, supplied to rivers via inter-basin transfers (i.e., from outside the immediate watershed), affects how tropical streams function in the long term (25 yrs). The project is based in lowland Costa Rica, where solute-rich groundwater account for over half of stream discharge in the dry season. This groundwater is naturally-rich in nutrients such as phosphorus (P), with levels higher than those typically found below sewage treatment plants. Prior research has shown that landscape patterns in stream chemistry (resulting from variation in solute-rich groundwater inputs) reflect rates of primary production and decomposition. This project continues to build a long-term (1988-present) data set on stream solute chemistry, which is the only one for lowland primary rainforests of Central America. The investigators are relating long-term trends in stream chemistry to large-scale climatic phenomena: solute-rich groundwater (also rich in bicarbonates) buffer receiving streams against increases in acidity during periods following El Nino-related droughts, while those streams that do not receive solute-rich groundwater experience dramatic increases in acidity. An outgrowth of the project is the development of an environmental outreach program that focuses on water quality and quantity issues in tropical regions.

这项研究的总体科学目标是了解通过流域间转移（即，从直接流域外），影响热带气流如何长期（25年）运作。 该项目位于哥斯达黎加的低地，那里富含溶质的地下水占旱季河流排放量的一半以上。 这种地下水天然富含磷（P）等营养物质，其水平高于污水处理厂下方通常发现的水平。 先前的研究表明，景观格局在流化学（由于溶质丰富的地下水输入的变化）反映了初级生产和分解率。 这个项目继续建立一个关于溪流溶质化学的长期（1988年至今）数据集，这是中美洲低地原始雨林的唯一数据集。 研究人员正在将溪流化学的长期趋势与大规模气候现象联系起来：富含溶质的地下水（也富含碳酸氢盐）在厄尔尼诺相关干旱期间缓冲了接收溪流的酸度增加，而那些没有接收富含溶质的地下水的溪流酸度急剧增加。该项目的一个成果是制定了一个环境外联方案，重点是热带地区的水质和水量问题。