Hydrologic Change and Accelerated Erosion in Mountainous Tropical Watersheds: The Impact of Rural Roads

9614259吉安贝卢卡未铺设道路在改变近地表水文反应以及随后在温带流域加速土壤侵蚀方面发挥了重要作用。在热带地区，与公路有关的影响也特别令人关切，因为这些地区的农业做法往往是侵蚀和沉积问题的罪魁祸首。这项研究的重点是展示不断扩大的公路网如何改变泰国北部一个热带山区流域的水文和侵蚀过程。其主要目标是：(1)确定道路对热带流域水文过程的干扰程度--这一信息稍后可与温带流域道路中断的已知情况进行比较；(2)确定与农业区有关的道路在引发水文变化和加速侵蚀方面的重要性；通过这样做，详细了解在路面上和与路面相邻的侵蚀过程；以及(3)评估几种与道路管理有关的假设假设情景的保护价值。建议的研究策略可分为四部分：(1)全面的实地研究，以建立水文、侵蚀和土壤-植被-大气转移信息数据库；(2)深入分析由于土地覆盖变化，特别是道路扩建引起的水文和侵蚀过程的变化；(3)确定与道路相关的重要径流过程，以便选择合适的一个或多个模型来模拟由于路网扩张而产生的水文变化和侵蚀；以及(4)使用模型(S)来模拟几种管理情景的影响。这项研究将提高我们对热带流域在经历土地利用急剧变化时的水文和地貌过程的了解；有助于确定与农业实践相比，道路在促进累积流域影响方面的重要性；有助于热带山区流域的未来管理；并为改善农村道路的设计、路线选择、维护和使用提供洞察力。

9614259 Giambelluca Unpaved roads play a significant role in altering near-surface hydrologic response and subsequently accelerating soil erosion in temperate drainage basins. Road-related impacts are also of particular concern in tropical areas where agriculture practices are most often blamed for erosion and sedimentation problems. The focus of this study is to show how an expanding road network changes the hydrological and erosion processes of a mountainous tropical watershed in northern Thailand. The major objective are to (1) determine the degree to which hydrologic processes in tropical watersheds are disrupted by roads--this information can later be compared with what is known about road disruption in temperate watershed; (2) establish the importance of roads in relation to agricultural areas in initiating hydrologic change and contributing to accelerated erosion; and in so doing, obtain a detailed understanding of erosion processes operating on and adjacent to road surfaces; and (3) evaluate the conservation value of several road management-related what if scenarios. The proposed research strategy can be represented by four components: (1) a comprehensive field study to build a database of hydrological, erosional, and soil-vegetation-atmosphere-transfer (SVAT) information; (2) in-depth analysis of changes in hydrologic and erosion processes due to land-cover change, especially changes due to road expansion; (3) determination of the important road-related runoff processes in order to select the appropriate model or models to simulate hydrologic change and erosion resulting from the expansion of road networks; and (4) use of model(s) to simulate the effects of several management scenarios. This research will improve our knowledge of hydrologic and geomorphic processes operating in tropical watersheds undergoing dramatic landuse changes; help determine the importance of roads, as compared with agricultural practices, in contributing to cumulative watershed impacts; aid in the fut ure management of tropical mountainous watersheds; and provide insight into improving the design, routing, maintenance, and usage of rural roads.