a primary limiting factor to agricultural development in many arid and semi
arid regions. In these regions, a large fraction of the annual rainfall is a result
of a few intensive convective storms during which only a small fraction of the
precipitation is absorbed by the soil. The fraction that is not absorbed by the
soil flows to the lower laying parts of the land and is thus lost for plant
production. The techniques of collecting runoff and conveying it to areas in
which it can be ponded, is known collectively as runoff harvesting and
microcatchments are one of the most popular systems. . In this system, runoff
water is collected close to the area in which it was generated and conveyed to
small dyke-surrounded plots in which trees/shrubs are planted and rely on the
stored water in order to overcome the next dry season. The main objective of
the work present herein was to estimate the effect the geometry of the
collection area (shallow basin vs. deep trench) has on the efficiency of
study was carried out during two years. During the first year one large runoff
event was simulated and in the second year four small runoff events were simulated.
ET and transpiration were monitored during both seasons. Evaporation was
estimated as the difference between evapotranspiration obtained from soil water
content monitoring and transpiration estimated by sap flow measurement.
Evaporation from micro-catchments was significantly higher than evaporation
from trenches for both seasons.