Doctoral Dissertation Research: Conservation Engineering and Cross-Slope Terracing in Mexico

University Of Texas At Austin, Austin TX

Investigators

Abstract

Imitating the works of ancient and native peoples, federal conservation agencies in Mexico build earthen terraces on mountain slopes to capture surface runoff, inhibit erosion, and improve water infiltration into agricultural soils. Doctoral student Matthew LaFevor under the guidance of Professor William Doolittle in the Department of Geography at the University of Texas at Austin will investigate one of these terracing methods, zanja-bordo, for its effectiveness at conserving water and increasing soil moisture levels in agricultural fields of northern Tlaxcala. The impetus for the research is to better understand the mechanics of, and investments in, indigenous water management technologies as mitigation strategies at times of freshwater deficits in the context of climate change. This study will entail volumetric soil moisture sampling and mapping of zanja-bordo terraces, as well as semi-structured interviews with terrace farmers and federal conservation officials. Estimating the moisture levels of both zanja-bordo and control plots, over specific spatial scales, will provide valuable data that will be used to test existing assumptions over their hydrological benefits. Spatial measurements of zanja-bordo terraces in the field will allow for their comparison with the architectural forms specified in the federal design templates used to build them. Variations between these more theoretical design models and actual field measurements would have implications for the long-term effectiveness of terracing projects. Finally, interviews with terrace builders and conservation officials will lend insight into the labor demands, required maintenance and sustainability of zanja-bordo terracing projects. This field study will provide a critical assessment of one of Mexico's major environmental development initiatives. If shown to be effective, zanja-bordo techniques could be used to conserve freshwater resources, increase agricultural productivity, and improve the livelihoods of smallholder farmers in arid and semi-arid regions around the world. More globally, this research will offer a critical perspective on the effectiveness of using indigenous agricultural technologies for modern conservation practices, and it will advance knowledge about water harvesting techniques and the rain-fed agricultural systems upon which many subsistence communities depend. Results of this study will could improve governmental terracing projects that directly affect over 750,000 farmers in rural areas of Mexico by providing critical information and direction for environmental policy-making. The project?s collaborative focus will serve as a conduit for increased communication between conservation officials and local communities, many of which are composed of indigenous groups. Finally, the publication of findings in both U.S. and international journals will broaden interest in human-environment geography.