Abstract
Water harvesting is the agriculture with the primitive irrigation which has been developed in arid region as middle East and north Africa. It is modified and arranged in Israel to the new modern arid agricultural thechnology which is called as runoff agriculture. It is expected to be the sustainable agricultural thechnology for developping contries due to low investment and unnecessity of high technoligy. In this paper it is pointed out that the water harvesting is also very important in humid region as Japan. Effective rainfall which is caught in root zone is decreased irrigation water require-ment, and the river discharge in drought period is released as groundwater from stored rain water in geological formation. The former is the rainfall caught is soil and the latter is the rainfall caught in geological formation. Both of them are caught by storage capacity in the watershed. It is concluded that Water harvesting concept is very important in irrigation plannig and water resourced develop-ment in the humid regeion.
