Timescales of Geochemical and Isotopic Transport in Natural Waters

0106925克里斯 一个新的溶质和同位素在自然沃茨中迁移的模型正在完善和测试中。 该模型可以量化的时间尺度的运输没有特别的假设，关于混合地下水和地表水成分。 根据扩散理论，风暴事件被视为“三角洲函数”，引起一系列复杂的地球化学和物理响应。 的传输方程很容易转化为线性版本的拦截准确retrodict风暴事件的时间，其斜率揭示了每个生物化学成分的运输的时间常数。 其基本概念是研究具有自然过程提供的扰动的自然系统。 获得的关于地表溪流和泉水对风暴事件的地球化学和同位素反应的信息将确定复杂自然反应的时间尺度。 项目第一阶段收集的数据表明，不同参数（离子浓度、总溶解有机物、营养盐、沉积物、氧同位素等）有一个定性相似的方式，解释的模型，但时间尺度变化很大的参数，共同定义的自然系统的响应。该模型将进行严格的测试与地球化学和同位素数据收集的几个地点内的一个unimpeded流域（Meramec盆地，东部密苏里州）。这项奋进将由安装在华盛顿大学泰森研究中心岩溶泉的自动采样器和附近梅拉梅克河上的新自动采样器来推动。 这些可编程设备将允许密集的采样，以准确地解决时间尺度，并将允许详细比较同时地下水和河流对降水事件的反应。有关来源、反应（溶解性、离子交换、吸附、生物吸收等）的关键问题，将探讨污染物和病原体通过地表和近地表环境迁移的路径和时间尺度。 新的方法似乎适用于不同的地球化学，物理和同位素成分。 它具有利用自然事件解决自然系统复杂性的独特潜力。

0106925Criss A new model of solute and isotopic transport in natural waters is being refined and tested. This model can quantiy the timescales of transport without ad hoc assumptions, about ixing groundwater and surface water components. Based on diffusion theory, storm events are treated as "delta functions" that induce a complex series of geochemical and physical responses. The transport equations are readily transformed into linear versions whose intercepts accurately retrodict the timing of the storm events, and whose slopes reveal the time constants for transport of each creochemical constituent. The basic concept is to study the natural system with perturbations provided by natural processes. Information gained onthe geochemical and isotopic response of surface streams and springs to storm events would determine the timescales of complex natural responses. Data colllected in the first stage of this project show that different parameters (ionic concentraions, total dissolved organic compounds, nutrients, sediment, oxygen isotopes, etc.) have in a qualitatively similar manner, explicable by the model, but that the timescales vary greatly among the parameters that collectively define the response of the natural system. Rigorous tests of this model will be conducted withgeochemical and isotopic data collected from several sites within an unimpounded river basin (the Meramec Basin, eastem Missouri). This endeavor will be facilitated by an autosamplerinstalled a karst spring at Washington University's Tyson Research Center, and a new autosampler nearby on the Meramec River. These programmable devices will allow intensive sampling to resolve timescales accurately, and will permit detailed comparisons of simultaneous groundwater and riverine responses to precipitation events. Key questions concerning the sources, the reactions (solubility, ion exchange, adsorption, biological uptake, etc.), the migration paths, and the timescales of pollutant and pathogen transport through surface and near-surface environments will be explored. The new approach appears to be applicable to diverse geochemical, physical, and isotopic constituents. It has the unique potential to resolve the complexity of natural systems using natural events.