Rainfall-runoff relationships for a small semiarid watershed, western flank San Andres Mountains, New Mexico
— William J. Stone and Daniel R. Brown

Geomorphologic and paleohydrologic studies in the Southwest require an appreciation of modern rainfall-runoff relationships on the semiarid piedmont slopes typical of the region. Much information on the hydrology of such watersheds has been derived from research conducted by the Southwest Watershed Research Center of the Agricultural Research Service at their Walnut Gulch Experimental Watershed, Tomb-stone, Arizona (Renard, 1970). Although Walnut Gulch drains an area of about 60 sq mi, many arroyos on piedmont slopes are smaller than this, draining areas of less than 10 sq mi. These small watersheds have received less attention and little is known of their hydrology. The purpose of this paper is to present and interpret hydrologic data for such a watershed in Dona Ana County, New Mexico.

 

The data presented were collected during the period June 1972 to December 1973 in conjunction with a research project of the U.S. Army Atmospheric Sciences Laboratory, White Sands Missile Range, directed by the senior author. The project objectives, study area, and results were described in greater detail by Stone (1973) and Miers and Oey (1975). In that project two watersheds were instrumented: Cottonwood Draw and Ropes Draw. Because runoff rating curves were only obtained for Ropes Draw, this paper is restricted to a discussion of data from that watershed. Ropes Draw is located about 25 mi northeast of Las Cruces and lies in the portion of the missile range occupied by the Agricultural Research Service's Jornada Experimental Range and the San Andres Wildlife Refuge (Fig. 1). The western flank of the San Andres Mountains was selected as the study area for reasons of easy access, availability of useful previous works, abundance of water wells, backlog of hydrometeorologic data, and suitable regional setting.