Landscape-Scale Determinants of the Hydrological and Hydrochemical Responses of Mountainous Catchments

山区流域水文和水化学响应的景观尺度决定因素

• 批准号: 9304794
• 负责人: George Hornberger
• 金额: $ 33.35万
• 依托单位: University of Virginia Main Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-07-15 至 1997-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9304794&HistoricalAwards=false
• 关键词: Landscape; Scale; Determinants; Hydrological; Hydrochemical

A quantitative understanding of the hydrochemical response of upland catchments is a fundamental goal of hydrologists and environmental chemists. Such knowledge is needed to ascertain the potential and realized effects, for example, of atmospheric deposition of acids and agricultural chemicals on the catchment (terrestrial and aquatic) ecosystems, of changes of climate on water quality, and of the role of hydrology in the transport of heavy metals and other trace contaminants. In particular, an improved understanding of the factors controlling the variation of dissolved organic carbon (DOC) in headwater streams is of scientific concern for at least two reasons. First, the overall carbon budget of lotic systems is of primary interest to aquatic ecologists seeking a fundamental scientific understanding of these systems. Second, DOC interacts strongly with other dissolved substances (heavy metals in particular) and therefore plays an important role in the transport of contaminants in streams. Heterogeneities in the amount of precipitation delivered to the surface of a catchment, in soil properties and vegetation coverage, and in incident solar radiation can pay an important role in the hydrological response of mountainous catchments. These heterogeneities may be particularly important in influencing how chemicals (e.g., DOC) are delivered from the terrestrial catchment to the stream. Complete characterization of heterogeneities over a catchment is essentially impossible, but is likely to be unnecessary for descriptions of hydrochemical dynamics at the scale of a whole catchment. A possibly fruitful hypothesis is that the heterogeneities that dominate the catchment response are relatively large scale and hence can be identified from readily available data--topography, aerial photography, and satellite imagery -- in conjunction with a modest data-collection program in the field. The proposed work will explore this idea. The effects of spatial patterns in topography, vegetation cover, snow accumulation and melt, and soil transmissivity on the hydrochemical response of the Snake River in Summit County, Colorado will be determined. Spatial data will be analyzed using techniques embodied within geographic information systems (GIS) and synthesized in the context of a hydrological model (TOPMODEL) that will be modified to take into account the identified landscape-scale heterogeneities. Field data on precipitation, flow, hydraulic conductivity, and dissolved constituents (sulfate and DOC, in particular) will be used to evaluate the working hypothesis of the links between large-scale heterogeneity, hydrology, and hydrochemical response.

定量了解水化学响应的 高地集水区是水文学家的基本目标， 环境化学家 需要这些知识来确定 潜在的和已实现的影响，例如， 酸和农业化学品在集水区的沉积 （陆地和水生）生态系统、气候变化对 水文学在水污染物输送中的作用 重金属和其他微量污染物。 尤其是 更好地了解控制变化的因素， 溶解有机碳（DOC）在源头流是 科学的关注至少有两个原因。 一是整体 湖泊系统的碳收支是水生生物的主要兴趣， 生态学家寻求对这些问题的基本科学理解， 系统. 其次，DOC与其他溶解的 物质（特别是重金属），因此， 在河流中污染物的运输中起着重要作用。 降水量的不均匀性 集水区表面，土壤特性和植被覆盖， 在入射太阳辐射中， 山区集水区水文响应 这些 异质性可能在影响 化学品（例如，DOC）从陆地集水区输送 去小溪 上非均匀性的完全刻画 集水基本上是不可能的，但很可能是 在尺度上描述水化学动力学是不必要的 一个完整的集水区。一个可能富有成效的假设是， 主导集水区响应的异质性相对 大规模，因此可以从现成的 数据-地形，航空摄影和卫星图像-在 结合实地的适度数据收集程序。 拟议的工作将探讨这一想法。 空间的影响 地形、植被覆盖、积雪和 融化和土壤transmittance对水化学的响应， 科罗拉多州首脑会议县的蛇河将被确定。 空间 数据将使用地理信息系统中包含的技术进行分析。 信息系统（GIS）的概念，并结合 水文模型（TOPMODEL），将被修改，以考虑到 考虑到已识别的非均匀性。 场数据 对降水、水流、导水率和溶解性的影响 成分（特别是硫酸盐和DOC）将用于 评估大规模之间联系的工作假设 异质性、水文学和水化学响应。