1. a United States Department of Agriculture—Agricultural Research Service , 3810 4th Street, Lubbock , TX , 79415 , USA E-mail:
2. b Department of Geological Sciences , University of Texas at El Paso , 500 West University Avenue, El Paso , TX , 79968 , USA
3. e Environmental Science and Engineering Program , University of Texas at El Paso , 500 West University Avenue, El Paso , TX , 79968 , USA
4. c Department of Geography , University of Loughborough , Loughborough, Leicestershire , LE11 3TU , UK
5. d Departamento de Ingenieria Civil , Universidad Autonoma de Ciudad Juarez , 450 N. Avenida del Charro, Ciudad Juarez, Chihuahua , 32315 , Mexico