Hydrological functioning of cattle ranching impoundments in the Dry Chaco rangelands of Argentina

MAGLIANO, PATRICIO N.; MINDHAM, D; TYCH, W; MURRAY, F; NOSETTO, M D; JOBBÁGY, E G; NIBORSKY, M J; RUFINO, M; CHAPPELL, N A

HYDROLOGY RESEARCH

I W A PUBLISHING

Año: 2019

0029-1277

Water provision for livestock in Dry Chaco rangelands rely mostly on artificial impoundments that capture infiltration-excess overland flow. Based on field data and modelling, we explored the water balance (water gains and losses) and water temporal dynamics of two impoundments: one subject to trampling and consumption by cattle (?cattle?) and another one protected from cattle (?control?). During the 421 days of measurements, water harvested approached 10,690 and 6,630 m3 in cattle and control impoundment, respectively. In cattle impoundment, evaporation (43%) and consumption (42%) were the main water losses, while infiltration represented a minor component (15%). In the control impoundment, infiltration became the dominant water loss (65%) followed by evaporation (35%). The cattle impoundment had more rainfall events that harvest water (16 vs. 13) than the control impoundment and it also harvested more water in the whole analysed period. On the contrary, the control impoundment lost water at a rate twice as high as the cattle impoundment. These results highlighted the key role of cattle trampling at the bottom of impoundment reducing infiltration losses, and suggested that cattle transit on the surroundings of the landscape compacts soil surface and increases runoff generation, enhancing rainwater harvesting events.