Project Overview

Statement of Problem: 110 community-based governing bodies, on the 65,000 km2 Navajo Nation, are in the process of developing land-use plans that require information on geologic hazards, water availability, soils, plant habitats, topography, environmentally and culturally sensitive areas. Information is desperately needed for planning urban development, highways, buildings, bridges, and domestic septic and landfill systems. Even so, most of the Navajo Nation has only cursory geologic mapping available, conducted before a topographic base existed (Cooley, 1969). Soft, erodible bedrock lithologies dominate the region making it sensitive to fluctuations in precipitation intensity, percent vegetation cover, and local land use practices. Land use, drainage patterns, and periods of human occupation coincide with changes in surficial and bedrock geology. Limited, shallow water resources in the region are controlled by fluctuations in climate and over utilization. Limited water availability in this arid region, limits economic growth, and lowers the quality of life (including basic sanitation and drinking water availability). Water quality is often significantly affected by the local geology or local system contamination. Bedrock and surficial geologic deposits contribute uranium, arsenic, and other contaminants to groundwater resources and springs. These findings underscore the need for more accurate and detailed mapping of bedrock, surficial deposits, landforms, and geologic structures. Arid to semi-arid conditions on the Navajo Nation, combined with a landscape that includes extensive eolian deposits, makes this region especially vulnerable to sand and dust mobility from drought and climate change. Geologic mapping is required in order to establish local conditions of landscape mobility and stability, and their relation to local environmental conditions. The mapping in this study will also serve to document the baseline conditions against which to measure expected future landscape changes. Specific sites for detailed study will be selected during the mapping process, to address landscape relations to ecosystem function. Work will include documenting changes in alluvial systems, conditions of eolian sand movement, and land use impacts that will be added to the foundation of geologic setting.

Objectives: The Navajo Nation (roughly the size of West Virginia) has the largest land base and reservation population of all tribes in the United States. In addition, half of the population is currently under the age of 23 (Census, 2000). To provide for the growing needs of this burgeoning population, information is desperately needed for planning urban development and infrastructure. Basic surficial and bedrock geologic mapping will provide data for land-use planning, where rapid population growth may surpass carrying capacity of lands upon which people are dependent for their livelihood. Research conducted with participating members of the Navajo Nation will foster community-based land-use planning and science education for Native Americans. Our objectives will be to accomplish the following goals:

• Provide the geologic framework for the Navajo Nation that is needed to determine the present baseline of landscape conditions for land use planning and natural resource management.
• Document landscape change to provide a foundation for evaluating geologic hazards such as flash floods and dust storms, surface processes related to climate variability and ecosystem function, including plant ecology and landscape mobility. Specific sites for detailed study are selected during the mapping process, such as outlining flood hazards from the Little Colorado River, to be evaluated through mapping from temporal series air photos.
• Determine drought impacts on sand dune activity through combined meteorological monitoring and field evaluation of dunes and vegetation at key sites.
• Evaluate conditions that may exacerbate or mitigate drought effects, by comparing satellite imagery showing landscape conditions of the current drought, to maps of the spatial distribution of climatic variables that are factors in dune mobility and Navajo and Hopi rangeland health.

• land use planning
• Native plants and invasive species
• Geologic controls on groundwater
• Geologic hazards - sand and dust storms, flash floods, and earthquakes
• Education - knowledge of Earth, ecosystem, and the role of native people
• A Better understanding of ecosystem responses to land use and global warming
  
  See Maps of the 4 Corners Region including Navajo, Hopi, and other regional tribal lands. Maps include regional landscape features, water resources, climate, land use, and more!
  
  
  Tsezhin Bii', the name of this area in the Navajo language means "within black rocks". The black rocks, a result of past volcanic activity, are less resistant to erosion than the surrounding sedimentary layers that have weathered away.