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Pedotransfer functions for extended hydraulic models using high resolution soil hydraulic measurements

使用高分辨率土壤水力测量的扩展水力模型的 Pedotransfer 函数

基本信息

批准号：
404632386
负责人：
Dr. Andre Peters
金额：
--
依托单位：
Institut für Geoökologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2018
资助国家：
德国
起止时间：
2017-12-31 至 2021-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/404632386?language=en
关键词：
Pedotransfer functions extended hydraulic models

项目摘要

An appropriate knowledge of water transport in the soil-plant atmosphere system plays a major role for many topics regarding environmental and agricultural questions. For modeling water transport with the Richards equation, the soil hydraulic functions, i.e. the water retention and hydraulic conductivity function must be known. These functions are usually derived by elaborate measurements with subsequent fitting of appropriate models to the data. Pedotransfer functions (PTF) are often used if such data are not available and cannot be taken. These PTF derive by means of regression approaches parameters of the hydraulic functions from basic soil properties (texture, organic carbon content or bulk density), which are often available. This is especially important for distributed modeling of environmental processes on large scales, like hydrological modeling at the catchment scale or modeling of the soil surface moisture in meteorological models. In the past decades, many PTF have been derived for such purposes. Yet, comparison of such PTF showed that general PTF are not precise for local applications and therefore a special calibration for local and regional applications was required. In our proposal (i) we hypothesize that the hitherto developed PTF neglect essential features of hydraulic properties, like water conductivity in films, and thus lead to systematic errors in the estimated parameters. Furthermore, (ii) these PTF are based on data with limited resolution and moisture range. Due to modern measurement techniques, there exists a multitude of highly resolved hydraulic data in an extended moisture range. New extended and consistent hydraulic models have been developed based on these data. The aim of the project is to combine the new models with the new data to derive new improved PTF. A comparison with classic PTF will show if, and how much, the newly developed PTF lead to better estimates of soil hydraulic properties.

土壤-植物-大气系统中水分传输的适当知识对于环境和农业问题的许多主题起着重要作用。用理查兹方程模拟土壤水分运移时，必须知道土壤的水力学函数，即土壤的持水力和导水率函数。这些函数通常是通过精细的测量以及随后对数据进行适当模型的拟合而得出的。如果没有这样的数据，则通常使用土壤转移函数（PTF）。这些PTF通过回归方法从通常可用的基本土壤特性（质地、有机碳含量或体积密度）中获得水力功能参数。这对于大尺度环境过程的分布式建模尤其重要，例如流域尺度的水文建模或气象模型中的土壤表面水分建模。在过去的几十年中，许多PTF已经被用于这样的目的。然而，这种PTF的比较表明，一般的PTF是不精确的本地应用程序，因此，一个特殊的校准本地和区域的应用程序是必需的。在我们的建议（i）中，我们假设迄今开发的PTF忽略了水力特性的基本特征，如膜中的水电导率，从而导致估计参数的系统误差。此外，（ii）这些PTF是基于有限的分辨率和湿度范围的数据。由于现代测量技术，在扩展的湿度范围内存在大量高分辨率的水力数据。新的扩展和一致的水力模型已经开发出这些数据的基础上。该项目的目的是将新模型与新数据相结合，以获得新的改进PTF。与经典的PTF的比较将显示，如果，以及有多少，新开发的PTF导致更好的估计土壤水力特性。