RUI: Measurement and modeling of rainfall interception loss from Georgia Southern University's urban forest.

RUI：佐治亚南方大学城市森林降雨拦截损失的测量和建模。

• 批准号: 1518726
• 负责人: John Van Stan
• 金额: $ 21.46万
• 依托单位: Georgia Southern University Research and Service Foundation, Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-15 至 2018-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1518726&HistoricalAwards=false
• 关键词: RUI; Measurement; modeling; rainfall; interception

Forest canopy can reduce precipitation reaching the ground by up to 50% through interception, storage, and evaporation of droplets from leaf and bark surfaces. This process, called "interception loss," impacts run-off, recharge, flood flashiness, erosion, etc., and cost of stormwater management. It is not well understood how canopy structure affects interception loss, particularly in urban forests. This research addresses this by monitoring interception loss variables for a common SE US tree species (the loblolly pine) across a natural-to-urban gradient in forest structure. Interception loss variables monitored include rainwater stored in and evaporated from the canopy, passing through the canopy (throughfall), and draining down the stem (stemflow) as well as air temperature, humidity, wind speed/direction, pressure, and incoming solar radiation during and after rainfall. These measurements will be related to new, high-resolution, non-destructive laser-scanning (LiDAR) techniques to address 2 questions: 1) how do stand structural changes ranging from natural conditions to common urban conditions affect interception loss processes; and 2) Will LiDAR-measured canopy structures and interception loss processes improve estimation and prediction of hydrologic processes and, thereby, improve water management and planning? The hypothesis is that, because tree stand conditions affect branching and leaf structures, interception loss and its underlying variables will vary in response to storm conditions. Inclusion of these responses in common models will have predictive value for water management concerning shifts in storm conditions . This is an RUI (Research at Undergraduate Institutions) project that will train undergraduate students in cutting-edge hydrologic science and be incorporated into educational outreach efforts reaching thousands of K-12 students, undergraduate students, high school teachers, and community members. Georgia Southern University (GSU) has a substantial African American student population (25.7% and 26.4% of undergraduates in 2012 and 2013), so the project will provide research experiences to underrepresented groups. Project data will be used to develop management practices on the GSU campus. Forest canopy rainfall interception loss (I) is documented to exert significant influence on run-off, recharge, flood flashiness, erosion and the cost of stormwater management infrastructure. However, it is not well understood how the forest canopy structure controls the components of I (storage, S, and evaporation, E), particularly in urban forests. No existing study has: 1) compared S and E behavior along a natural-urban forest continuum of differing canopy architecture or 2) incorporated terrestrial LiDAR (TLiDAR) measured canopy structures and the interaction of these structures with S and E dynamics into common I models. This study will do this along a natural-to-urban forest structure gradient on the Georgia Southern University (GSU) campus using a regionally dominant species (Pinus taeda, loblolly pine). The study will couple existing biometeorological monitoring methods (meteorological, stemflow, and throughfall measurements) with novel terrestrial LiDAR techniques (LaserBark and L-Architect) to compare S and E in urban forests with directly, non-destructively measured canopy structural metrics. This addresses two questions: 1) how do across- and within-storm dynamics of S and E vary for 2 urban forest structures, and how does this compare to natural tree stands, and 2) to what extent can inclusion of directly-measured canopy structures in urban stands alter I outputs, parameters, and even parameterizations for the most commonly used models (i.e., the Gash- and Rutter-type)? These findings will advance nearly all hydrologic models that simulate or include forest interception processes. Six undergraduates supported by this proposal will receive substantial research experiences spanning the breadth of research activities (including field instrument training, installation, and maintenance; data collection and processing; modeling and model evaluation; manuscript preparation; and presentation at national meetings) in a timely and critical subfield of water resource management. Data will also be used to improve: 1) the L-Architect model, which is being incorporated into Computree, a tool used by the Office National des Forêts (France) for national improvement of forest inventories; and 2) the sustainable irrigation practices currently employed on the GSU campus.

森林冠层通过截留、储存和蒸发叶子和树皮表面的水滴，可减少到达地面的降水量高达 50%，这一过程称为“截留损失”，会影响径流、补给、洪泛、侵蚀等。 .，以及雨水管理的成本尚不清楚树冠结构如何影响拦截损失，特别是在城市森林中，这项研究通过监测美国东南部常见树种（火炬松）的拦截损失变量来解决这个问题。森林结构中自然到城市的梯度监测包括储存在树冠中和从树冠蒸发的雨水、穿过树冠的雨水（径流）和从树干排出的雨水（茎流）以及气温、湿度、风速。 /降雨期间和之后的方向、压力和入射太阳辐射这些测量将与新的高分辨率、无损激光扫描 (LiDAR) 技术相关，以解决两个问题：1) 如何测量。从自然条件到常见城市条件的结构变化是否会影响截留损失过程；2）激光雷达测量的冠层结构和截留损失过程是否会改善水文过程的估计和预测，从而改善水管理和规划？由于树位条件影响分枝和叶子结构，拦截损失及其基本变量将根据风暴条件而变化，将这些响应纳入通用模型将对有关风暴条件变化的水管理具有预测价值。 （研究于佐治亚南方大学 (GSU) 拥有大量非裔美国学生（2012 年和 2013 年占本科生的 25.7% 和 26.4%），因此该项目将为代表性不足的群体提供研究经验。项目数据将用于开发 GSU 的管理实践。校园。据记载，森林冠层降雨拦截损失 (I) 对径流、补给、洪水闪现、侵蚀和雨水管理基础设施的成本产生重大影响。然而，人们尚不清楚森林冠层结构如何控制 I 的组成部分。 （储存，S 和蒸发，E），特别是在城市森林中，目前还没有研究：1）比较不同树冠结构的自然-城市森林连续体的 S 和 E 行为，或 2）纳入陆地。 LiDAR (TLiDAR) 测量了树冠结构以及这些结构与 S 和 E 动力学的相互作用，并将其纳入通用 I 模型中。本研究将使用区域性方法，沿着佐治亚南方大学 (GSU) 校园的自然到城市森林结构梯度进行测量。该研究将现有的生物气象监测方法（气象、茎流和径流测量）与新型地面激光雷达技术相结合。 （LaserBark 和 L-Architect）将城市森林中的 S 和 E 与直接、非破坏性测量的树冠结构指标进行比较，这解决了两个问题：1）S 和 E 的跨风暴和风暴内动态如何随两个城市的变化而变化。森林结构，以及与自然林分相比如何，2）城市林分中直接测量的树冠结构会在多大程度上改变输出、参数，甚至最常用模型的参数化（即， Gash 型和 Rutter 型）？这些发现将推动几乎所有模拟或包括森林拦截过程的水文模型。该提案支持的六名本科生将获得广泛的研究活动（包括现场仪器培训、安装和研究）。水资源管理的及时和关键子领域的数据收集和处理；建模和模型评估；手稿准备和演示）。进入Computree，一个使用的工具由国家森林办公室（法国）负责改善国家森林资源；2) GSU 校园目前采用的可持续灌溉方法。