A Large-Area, Lightweight Rainshelter with Programmable Control

ABSTRACT IN order to implement water stress studies in the field where the probability of rain is significant, some type of rain excluding device must be used to assure the timeliness and intensity of plant water deficits. A rainshelter facility, which covers 0.13 ha (0.33 acres), has been constructed at the Kellogg Biological Station of Michigan State University for the study of plant growth response to soil water deficit. The facility consists of two buildings which run on a single drive system. The buildings are located at opposite ends of a set of tracks and move toward each other during rainfall. The ends of the buildings which face one another are open so that when the buildings meet in the center, they enclose the entire test plot. Once the buildings cover the plot, ventilation is provided by openings at the base of the walls and by a 17.8 cm (7 in.) wide lateral opening that runs the full length of the ridge of each building's roof. A programmable controller governs the movement of the buildings and performs constant checks on the system's status. This facility incorporates many features from other rainshelter designs that have performed satisfactorily. To our knowledge, it covers a larger area than any other previously constructed.