Blocky Hillslopes: From Outcrops to Flatirons

地球陆地表面的大部分由山坡组成，但是目前山坡演变的数学模型未能捕捉到真实景观的许多关键要素。大多数山坡，特别是在山区和干旱地区，都是崎岖不平的。该项目的目标是推进对这些常见岩石山坡如何随时间演变的认识。科罗拉多州博尔德附近的景观，作为一个自然实验，几个岩石地貌可以用来测试岩石山坡演变的概念和定量模型。该项目将测试一个假设，即所有山坡特征都可以通过基于连接块体的裂缝密度和方向差异的数值模型来模拟。这个项目将通过认识被侵蚀的岩石类型和岩石破碎程度所起的作用，增加对普通景观如何演变的认识。这些特性在评估对滑坡和其他边坡运动的控制方面很重要，并有助于评估自然灾害的风险。该项目具有很强的教育和推广成分，将为各种受众（包括本科生、科学教师和普通公众）开发主题。项目的技术描述当前的景观演变模型未能捕捉到真实景观的关键要素。该项目旨在测试使用相同规则集的单一模型在多大程度上可以再现各种岩石类型和方向的特征。这套新的模型将阐明岩石地形中的侵蚀山坡过程，并允许定量探索这些模式是如何产生的。研究将包括实地考察和数值模拟。裂缝分布、露头块体边缘的几何形状、距骨块的大小以及能够撬出块体的树木的位置将被记录在现场和数字高程模型的图像上。宇宙成因同位素分析将限制当地的侵蚀速率。将建立一个数值模型的层次结构，并受实地测量的约束。该项目建立在与科罗拉多大学继续教育部门“科学发现”的长期合作伙伴关系的基础上。现有的侧重于溪流的课程将增加一些说明当地山坡及其演变的材料。这些教材还将在每年夏天向参加为期一周的教师培训讲习班的中学教师展示。通过在博尔德举行的每月晚上“青少年咖啡馆”系列活动，还将为对科学感兴趣的青少年和当地退休社区设计演讲。通过该项目发现的更广泛的景观演变历史将与当地居民从窗户看到的博尔德地区标志性地貌的演变相结合。

A nontechnical description of the project that explains the signficance and importanceThe majority of earth's land surface consists of hillslopes, but current mathematical models of hillslope evolution fail to capture many of the key elements of real landscapes. Most hillslopes, especially in mountainous and arid terrain, are rough and rocky. The goal of this project is to advance knowledge of how such common rocky hillslopes evolve through time. The landscape near Boulder, Colorado, serves as a natural experiment in which several rocky landforms can be used to test conceptual and quantitative models of rocky hillslope evolution. This project will test the hypothesis that all hillslope features can be simulated by numerical model that is based upon the differences in the density and orientations of the fractures that bound the blocks. This project will increase knowledge of how common landscapes evolve by acknowledging the roles played by the type of rock being eroded and the degree of fracturing of that rock. These qualities are important in evaluating the controls on landslides and other slope movements and can help in the evaluating risks from natural hazards. The project has a very strong education and outreach component that will develop the topic for various audiences, including undergraduate students, science teachers, and the general public.A technical description of the projectCurrent models of landscape evolution fail to capture the key elements of real landscapes. This project is designed to test to what degree a single model utilizing the same rule set can reproduce the features of various rock types and orientations. This new suite of models will illuminate erosional hillslope processes in rocky terrain, and allow quantitative exploration of how these patterns arise. Research will include both fieldwork and numerical modeling. Fracture distributions, geometry of block edges in outcrop, block sizes in talus, and locations of trees capable of prying out blocks will be documented in the field and on imagery from digital elevation models. Cosmogenic isotope analyses will constrain local rates of erosion. A hierarchy of numerical models will be developed and constrained by the field measurements. The project builds upon a long-standing partnership with the education outreach program of the University of Colorado Division of Continuing Education, "Science Discovery." An existing curriculum that focuses on streams will be augmented by materials that illustrate local hillslopes and their evolution. These curricular materials will also be demonstrated to middle school teachers who participate in a week-long teacher training workshop each summer. Presentations will be also designed for teenagers interested in science through a monthly evening "Teen Cafe" series held in Boulder, and for local retirement communities. The broader history of landscape evolution discovered through this project will be meshed with evolution of the iconic landforms of the Boulder area that local residents see out their windows.