Development of models to predict land-use-induced soil pore-space changes and their hydrological impacts

随着对农产品需求的增加和极端天气情况的发生，资源土壤和水更多地受到公众的吸引。因此，适应性土地利用作为水土保持的预防性要素变得重要。适应战略的规划往往基于数字模型的应用。利用这些模型，可以估计和评价在最近和不断变化的气候条件下土地利用的假设变化对植物生长和水平衡组成部分的影响。作为一个先决条件，在现有的模型中，土壤水力特性被认为是在时间上恒定的。然而，以往的研究表明，土壤结构，并与它的土壤水分保持和水力传导功能的变化显着的土地利用的结果。如果忽略土结构的动力学，模型结果的不确定性增加。这可能导致不正确的规划和更多的资源消耗的土地使用。因此，本研究的目标是：a）测量土地利用引起的土壤结构和土壤水力特性的变化，以及B）将结果应用于水文模型，使用数学方程量化变化。这些方程描述了不同土地利用实践（例如，土壤耕作、作物轮作、植树造林）。为了得出土地利用对水文相关土壤性质的影响的一般原则，我们将分析从勃兰登堡到施蒂里亚州的气候样带沿着类似土壤的可比土地利用实践。为了确定土壤水力特性的特性，将把实地方法（罩式渗透计和染料示踪实验）与实验室方法（瞬时蒸发实验）结合起来。这种方法可以更好地区分大孔隙和基质流域，这可能是基本的功能描述土地利用引起的土壤孔隙空间的变化的发展。我们预计，不同的土地利用措施将有较大的影响，大孔隙。该研究将增加我们对不同土地利用方式下土壤孔隙空间变化的认识。基于对所涉及过程的更好理解，我们将开发能够量化适应性土地利用对土壤水力特性，水循环组成部分（土壤水容量，地下水补给，水质）以及生物质生产的影响的方法和模型。这将是发展和评估可持续土地利用系统的基础。

As the demand for agricultural products and the occurrence of extreme weather conditions increase, the resources soil and water are more attracted by the public. Therefore, an adaptive land use as a preventative element for soil and water conservation gains in importance. Planning of adaptation strategies are often based on the application of numerical models. With these models, the impact of hypothetical changes in land useunder recent and changing climatic conditions on plant growth and water balance components can be estimated and evaluated. As a pre-requisite in existing models, soil hydraulic properties are seen to be temporally constant. However, previous studies have shown that soil structure and with it the soil water retention and hydraulic conductivity functions change significantly as a result of land use. If the dynamics of soil structure are neglected, the uncertainty of the model results increases. This could lead to incorrectplanning and a more resources-consuming land use. Therefore, the objectives of this study are a) to measure landuse-induced changes in soil structure and in the soil hydraulic properties and b) the implementation of the results into hydrological models that quantify the changes using mathematical equations. These equations describe temporal changes of soil water retention and hydraulic conductivity based on the evolution in the soilpore-size distribution for different land use pratices (e.g., soil tillage, crop rotation, afforestation). To derive general principles for the influence of land use on hydrologically relevant soil properties, we will analyze comparable land use practices with similar soils along a climatic transect from Brandenburg to Styria. For the characterization of the soil hydraulic properties, field methods (hood infiltrometer and dye tracer experiments) will be combined with laboratory methods (transient evaporation experiments). This approach allows a better differentiation between macropore and matrix flow domains, which may be fundamental for the development of functions describing land use-induced changes of the soil pore space. We expect that the different land use measures will have a stronger influence on the macropores. The study will increase our knowledge about soil pore space changes under different land use pratices. Basing on a better understanding of the involved processes we will develop methods and models that are able to quantify the impact of an adaptive land use on the soil hydraulic properties, on components of the water cycle (soil water capacity, groundwater recharge, water quality), and on the production of biomass. This will be the basis for the development and assessment ofsustainable land use systems.