SSF FORCING - Temporal dynamics and land use effects of SSF - Irrigation experiments combined with ERT measurements

我们的重点是实验和数值评估的影响，不同的强迫地下暴雨径流（SSF）在小区尺度，这将支持SSF的山坡和集水尺度的建模。该图被视为在这些不同尺度上评估SFF的最小公分母。我们解决不同的初始和边界条件，以及不同的土壤和土地利用特性，影响的生成和时间动态的SFF。目的是得到阈值，从而参数化来描述的过程动态。我们将通过分析来自人工降雨模拟（ARS）和本项目内进行的ARS的现有数据来实现这些目标。试验内容包括四个不同特征的研究集水区的定量流量测量以及通量和状态的定性评估，具体研究问题包括：（1）如何在样地尺度上检测垂直和横向SSF流分量的通量和路径？哪些示踪剂和测量方法（例如TDR、稳定同位素、ERT）可用于识别它们？(2)事件间动态如何影响地表径流和SSF之间的比例？(3)土地利用和覆被的季节变化如何影响SSF？前提条件的时间动态性如何影响SSF？(4)在地块比例尺上启动SSF的阈值是多少？阈值在不同地点和集水区之间的可变性和可转移性如何（与其他集水区/地点的联系）？(5)如何以及我们可以检测到的空间变异的优惠SSF使用稳定的水同位素或ERT期间和之后的自然降雨事件？影响SSF的空间范围（面积/流动长度）是多少？该工作计划的重点是SSF的驱动力和识别对SSF时间动态的影响，将创新的喷洒实验与涉及不同示踪剂方法的永久性和基于生物学的测量相结合。WP 1和WP 2包含小区规模的喷洒实验，计划并应用于沟渠小区，研究不同初始和边界条件（如降雨、径流或地下入流）的影响。灌溉试验将与不同的示踪方法（项目A、C、D、F）、安装的土壤湿度测量（项目A、H）、ERT测量（项目A、B）和UHF雷达（分机号）的应用相结合。coop. A）在所有四个测试点。WP 3处理分析、评估和不确定性评估，WP 1和WP 2的输出被结合起来，以建立强迫、边界条件和SSF动力学之间的联系。WP 4涉及模拟的区域化问题，涉及驱动力在地块尺度和子流域一级的分布，以便更好地确定用于改进模拟的参数设置。在WP 5中，使用不同复杂性的模型对地块尺度上的过程进行数值模拟。

We are focusing on the experimental and numerical assessment of the effects of different forcing on subsurface stormflow (SSF) at the plot scale, which will support the modeling of SSF on the hillslope and catchment scales. The plot is seen as the least common denominator to assess SFF over these different scales. We address varying initial and boundary conditions as well as different soil and land use characteristics which affect the generation and the temporal dynamics of SFF.Aims are to derive thresholds and consequently a parameterization to describe the process dynamics. We will reach these aims by means of analysis of pre-existing data from artificial rainfall simulations (ARS) and from ARS conducted within this project. The planned tests will comprise quantitative flow measurements as well as qualitative assessment of fluxes and states in four research catchments with different characteristics.Specific research questions include: (1) How can fluxes and pathways of vertical and lateral SSF flow components be detected at the plot scale? Which tracers and measurement methods (e.g. TDR, stable isotopes, ERT) can be used to identify them? (2) How are inter-event dynamics affecting the proportion between surface runoff and SSF? (3) How are seasonal changes of land use and cover affecting SSF? How do temporal dynamics of precondition affect SSF? (4) What are the thresholds to initiate SSF on the plot scale? How variable and transferable are thresholds among sites and catchments (link to other catchments/sites)? (5) How well can we detect the spatial variability of preferential SSF using stable water isotopes or ERT during and after natural rainfall events? What is the spatial extent (area/flow length) contributing to SSF?The work program focuses on the driving forces of SSF and the identification of impacts on SSF temporal dynamics combining innovative sprinkling experiments with permanent, and campaign-based measurements involving different tracer methods. WP1 and WP2 contain the plot scale sprinkling experiments, planned and applied at the trenched plots studying the effect of different initial and boundary conditions such as rainfall, runon or subsurface inflow. The irrigation experiments will be combined with the application of different tracer methods (projects A, C, D, F), installed soil moisture measurements (projects A, H), ERT measurements (projects A, B), and UHF radar (ext. coop. project A) in all four test sites. WP3 deals with the analysis, evaluation and the uncertainty assessment, were the outputs of WP 1 and 2 are combined to establish links between forcing, boundary conditions and SSF dynamics. WP4 addresses regionalization for modelling dealing with the distribution of driving forces among plot scales and at sub catchment level, in order to better identify parameter settings used for an improved modelling. In WP 5, numerical modeling of the processes on the plot scale is performed with models of different complexity.