Developing a geomorphic approach for ranking watersheds for rehabilitation, Zuni Indian Reservation, New Mexico

摘要: Abstract As a result of past erosion problems on the Zuni Indian Reservation in western New Mexico, US Congress 1990 authorized Tribe to begin program for watershed rehabilitation. This paper describes an approach rank most appropriate watersheds rehabilitation Reservation. The was based data collected during 3-year study geomorphic and anthropogenic characteristics Rio Nutria Watershed, including (i) arroyo cross-sectional changes, (ii) erosion-control structures, (iii) sheetwash erosion. Results this indicated that 61 85 channel cross-sections aggraded channels with lower width-to-depth ratios eroded. assessment some dating back 1930s, 60% earthen dams 22% rock-and-brush structures were breached or flanked Watershed. Sheetwash measured five land-cover sites (sagebrush, pasture, chained pinon juniper, unchained ponderosa pine) juniper pasture had highest volume-weighted sediment concentrations 13,000 9970 ppm, respectively. Based interpretations two-stage developed In first stage, reservation divided into eight major watersheds, which ranked according potential second sub-basins, Quantitative qualitative information physical factors used at each stage watersheds. included headcut density, percentage bare ground, area, ratio, change density from 1934 1988, rates. Qualitative rankings main channels, tributaries, entire basins. Anthropogenic dirt roads condition structures. A community survey agricultural acreage also selection process. analysis resulted Watershed as 15 sub-basins; priority sub-basins Benny Draw, Coal Mine Canyon Garcia Draw. Many projects have been conducted southwestern United States since 1930s lack documentation select treatment areas. demonstrates by using logical ranking can be developed.