Evaluation of Biogeochemical Watershed Models: How Do We Know When A Model is Wrong?

由于缺乏可用的评估工具，生物地球化学流域模型已经与严格的假设检验脱节，从而限制了这些模型的有用性。我建议通过使用最近开发的多准则校准技术开发改进的假设检验技术来提高生物地球化学流域模型的实用性。本文将讨论三个问题：(1)分布式集水区生物地球化学模型的好处是什么？(2)我们如何将多个通量和状态变量纳入我们对模型执行情况的判断中？(3)我们如何使用不同类型的数据来评估模型的问题？多媒体方法的初步结果在解决生物地球化学流域模型的假设检验挑战方面显示出希望。我将通过教育和对这些技术的基础研究来促进这些方法的发展。我将为我所教授的普通水文学课程开发一个关于流域物质平衡模型的创新小组项目。该项目的研究生教育部分将包括讲座和小组集体学习，使用流域过程的简单桶模型。小组项目将带领学生从模型构建的基础到集总和分布式水文模型的模型校准和模型评估的可用工具。本课程将为我希望创建的生物地球化学流域建模小组奠定基础。我建议的研究重点是开发多过程生物地球化学流域模型的多标准模型校准和评估工具。建议的工作包括使用“true”（参数唯一性和识别性测试）和使用可用的多标准评估工具的真实数据集来测试翡翠湖流域的AHM模型。将对几个场景进行模型校准，比较空间聚集水平、时间序列持续时间和可用数据种类（流出时间序列以及土壤条件的空间数据）。这些研究将探讨分布式生物地球化学流域模型的效用，以及需要什么样的数据来适当地参数化和评估这些模型。我还将在一位农业工程专业的博士后助理的帮助下，用农业非点源模型进行类似的建模研究。最后，我将在圣地亚哥实验森林建立一个生物地球化学流域过程现场。

0094312MeixnerBiogeochemical watershed models have become disconnected from rigorous hypothesis testing due to a lack of available evaluation tools, thereby limiting the usefulness of these models. I propose to improve the utilitty of biogeochemical watershed models by developing improved techniques of hypothesis testing using recently developed multi-criteria calibration techniques. Three questions will be addressed: (1) What are the benefits of distributed models of catchment biogeochemistry? (2) How do we incorporate multiple fluxes and state variables into our judgment of how well a model is performing? (3) How do we use different types of data in evaluating what is wrong with a model? Preliminary results with multi-media methods have shown promise in solving the hypothesis-testing challenge of biogeochemical watershed models. I will foster the development of these methods through both education and fundamental research into these techniques. I will develop an innovative group project on watershed mass balance models for the general hydrology course I teach. The graduate education portion of the project will involve lecture and collective learning in small groups using a simple bucket model of watershed processes. The group project will take the students from the rudiments of model construction to the tools available for model calibration and model evaluation of lumped as well as distributed hydrologic models. This course will form the foundation for the biogeochemical watershed modeling group I hope to create. The research I propose will focus on the development of multi-criteria model calibration and evaluation tools for multi-process biogeochemical watershed models. The proposed work includes testing the AHM model of the Emerald Lake watershed using "true" (testing for parameter uniqueness and identification) and real data sets using the available multi-criteria evaluation tools. Model calibration will be conducted for several scenarios comparing the level of spatial aggregation, time series duration, and the kinds of data available (outflow time series in addition to spatial data of soil conditions). These studies will investigate the utility of distributed biogeochemical watershed models and what sort of data is needed to properly parameterize and evaluate these models. I will also conduct similar modeling studies with agricultural non-point source models with the assistance of a post-doctoral associate trained in agricultural engineering. Finally, I will establish a biogeochemical watershed processes field site at the San Diego Experimental Forest.