Fire-Induced Changes of Soil Structure: Implications for Soil Hydraulic Properties and Coupled Erosion by Water and Wind

快速：火灾引起的土壤结构变化：土壤水力特性和水和风耦合侵蚀的影响David Shafer，水文科学部副研究教授，DRIMichael Young，水文科学部副研究教授，DRIDave DuBois，大气科学部副研究教授，DRIMarkus Berli，水文科学部助理研究教授，DRIScott泰勒，该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。 项目摘要：在内华达州的伊利附近进行的格里森控制燃烧提供了一个机会，可以量化火灾对土壤结构的影响，并通过在燃烧前后收集相同地点的数据，测试关于火灾引起的土壤结构变化如何导致水和风蚀的假设。焚烧将于2009年8月由美国土地管理局进行。因为烧伤是一个计划好的事件，所以可以在预先确定的地点进行烧伤前和烧伤后的测量。 由NSF提供的资金，沿着来自DRI的内部资金，将用于收集一组火灾前的测量结果。 在格里森大火中燃烧的地区在未燃烧的地区具有强烈发育的、粗糙破碎的土壤结构。 然而，在附近进行了其他控制燃烧的地方，这个结构已经坍塌成无结构的土壤，富含极有可能受到侵蚀的细颗粒。火灾前的测量将包括土壤形态和结构、水分渗透、空气渗透性和引起土壤颗粒风成输送所需的风切变。 假设包括：1）火灾将破坏土壤结构，增加土壤容重，降低土壤导水率和空气渗透率，这一系列条件将增加由于降水输入而造成的土壤水侵蚀的可能性; 2）土壤结构的丧失将使土壤物质分解，与燃烧前的条件相比，在较低风速下，土壤物质更容易被风悬浮。 大多数关于火灾后影响的研究缺乏与火灾前条件的真正比较。这项研究将允许土壤结构的变化进行定量描述，并与火灾后的水力和风沙运输特性，强烈影响火灾后土壤侵蚀的敏感性。 虽然范围有限，但这项研究将提供火灾后比较所需的数据，并允许测试一些现场和实验室方法，研究人员将建议在向NSF提交的关于火灾前和火灾后土壤特性和侵蚀潜力的更全面建议中使用这些方法。 后续提案将包括收集格里森火灾后的数据。

RAPID: Fire-Induced Changes of Soil Structure: Implications for Soil Hydraulic Properties and Coupled Erosion by Water and WindDavid Shafer, Associate Research Professor, Division of Hydrologic Sciences, DRIMichael Young, Associate Research Professor, Division of Hydrologic Sciences, DRIDave DuBois, Associate Research Professor, Division of Atmospheric Sciences, DRIMarkus Berli, Assistant Research Professor, Division of Hydrologic Sciences, DRIScott Tyler, Research Professor, Department of Geological Sciences and Engineering, UNRThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). Project Abstract: The Gleason Controlled Burn, to be conducted near Ely, Nevada, provides an opportunity to quantify the effects of fire on soil structure, and to test hypotheses on how fire-induced changes in soil structure can lead to coupled water and wind erosion by collecting data at the same locations prior to and after the burn. The burn will be conducted by the U.S. Bureau of Land Management in August 2009. Because the burn is a planned event, pre- and post-burn measurements can be conducted on pre-determined sites. The funding awarded by NSF, along with internal funds from DRI, will be used to collect a set of pre-fire measurements. The area to be burned in the Gleason Fire has strongly-developed, coarse crumbled, soil structure in unburned areas. However, where other controlled burns have been done nearby, this structure has collapsed into a structureless soil, rich in fine particles that are most likely prone to erosion. Pre-fire measurements will include soil morphology and structure, water infiltration, air permeability, and wind-shear required to induce aeolian transport of soil particles. Hypotheses include: 1) the fire will destroy soil structure, increasing soil bulk density, and decreasing soil hydraulic conductivity and air permeability, a set of conditions that would increase the potential for soil erosion by water due to precipitation input; and, 2) the loss of soil structure will disaggregate soil material that would be more prone to suspension by wind at lower wind velocities, when compared to pre-burn conditions. Most studies on post-fire effects lack a true comparison to pre-fire conditions. This research will allow changes in soil structure to be quantitatively described and linked to post-fire hydraulic and aeolian transport properties that strongly influence the susceptibility of post-fire soil erosion. Although limited in scope, this research will provide the data needed for post-fire comparisons, and allow testing of some of the field and laboratory methods that the researchers will propose to use in a more comprehensive proposal to NSF on pre- and post-fire soil properties and erosion potential. The follow-on proposal will include collection of post-fire data from the Gleason Fire.