The Impact of Sowbug (Hemilepistus hirazi Schuttz) on Infiltration Ratein a Arid Region, Iran

Desertification control through Floodwater Spreading (FWS) mainly for the Artificial Recharge of Groundwater (ARG) is comprehensive study that is being implemented since, Jan. 1983 in the Gareh Bygone Plain (GBP) in Southern of Iran. Eight ARG systems with a total area of 1365 ha were constructed during the 1983-1987 period on the debris cone and alluvial fan formed by the Bisheh Zard river, an ephemeral stream that supplies floodwater to the GBP from none to 8 times a year. The inevitable Malthusian dilemma however may be delayed through the application of the artificial recharge of groundwater methods using the turbid floodwaters that abound in most deserts. While soil building is a highly desirable outcome of the ARG activities, formation of a hard crust that substantially decreases infiltrability of sedimentation basins and recharge ponds is a negative attribute of using turbid waters for the ARG. This problem was delicately solved by nature when a population of sowbug (Hemilepistus shirazi Schuttz) invaded the ARG systems in the Gareh Bygone plain in Southern Iran. The burrows made by this crustacean have a circular opening 7 mm in diameter and reach a depth of 80 cm. The infiltration rate of the areas punctured by the burrows as determined by the double ring method had increased 4.2 fold in some plots, in comparison with control. Statistical investigation shows that there is a significant difference between sowbug and control. This difference was significant at the 1% level. Cautious introduction of plants attractive to this useful organism is an environmentally sound and a financially viable method of lengthening the economic life of the ARG system.