|Wainwright, John - KING'S COLLEGE|
|Parsons, Anthony - UNIVERSITY OF LEICESTER|
Submitted to: Chihuahuan Desert Symposium
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2004
Publication Date: October 15, 2004
Citation: Rango, A., Tartowski, S.L., Wainwright, J., Parsons, A. 2004. Factors influencing the spatial variability of runoff at differing scales in the Jornada Basin [abstract]. Sixth Symposium on the Natural Resources of the Chihuahuan Desert Region, October 14-17, 2004, Alpine, Texas. p. 39. Technical Abstract: Numerous factors influence runoff generation in arid climates such as the Jornada basin of southern New Mexico. The overall result is a spatially heterogeneous distribution of surface water, erosion, vegetation, soil moisture, and productivity. Factors that cause the high spatial variability of water include precipitation, soil, physiographic, and vegetation characteristics. Because of the limited precipitation input at the Jornada (247 mm annually, 53% occurring in July-September), it is critical that a significant spatial heterogeneous distribution of water exists to create islands of hydrologically enhanced productivity. These productive islands can be observed at all scales from plots through large catchments. The inherent heterogeneity of these arid lands causes areas of runoff and run-on at the individual plant scale as well as in large area patterns of banded vegetation and drainage networks where beaded areas of run-on and infiltration occur along the stream channels. Areas of extreme aridity typically contain closed drainage systems. At the Jornada, playas occur in the flat and lower portions of the basin and small playas, or playettes, occur in clusters in upland areas. It is wise to try to mimic nature when attempting to rehabilitate degraded rangelands by diverting water to target areas to provide islands of high productivity or installing structures, such as water ponding dikes, to promote change in the landscape that would resemble banded vegetation patterns or beaded drainage networks. There have been several successful attempts in the Jornada Basin which established spatial discontinuities of water, soil, and vegetation similar to naturally occurring patterns.