Desalinization Mechanism in a Soil Mass with a Large Crack

Positive studies on the salt behayior and salt exclusion in Kasaoka bay polder (IV)

Abstract

From the observations of the Kasaoka bay polder after land draining, we found that the muddy soil surface was subdivided into a soil mass (column) of a tortoise shell pattern by a widely advanced large crack, the mass of which became the fundamental unit of the subsequent salt and water behavior in the soil layer. Based on the above mention, we first investigated the actual conditions of the crack development which was thought to decide the character of the early polder having occurred two times in the summer and winter using a lysimeter. Next, the yearly change in the salt behavior in the soil mass with a large crack was thoroughly investigated.
Consequently, we were able to clarify the importance of the crack which governed the conditions of the salt behavior up to this time and which is expected to control salt exclusion. Then, we classified and adjusted the movement of the salt in the soil mass based on the fundamental idea of salt exclusion, which was thought to be able to describe the actual conditions of the salt behavior under the time scale after land draining.