Permit Water Move at www.japanese-home-gardens.com

Permeable rocks have pores sufficiently large and interconnected to permit water move water to move through them by the force of gravity. If such permeable rocks are saturated, they are called aquifers (water-bearers). Aquifers yield water to springs, streams, and lakes, and to the wells dug by man. Many of them have been formed in layers. When the layers are horizontal or nearly so, a succession of them can be tested for water simply by drilling a vertical hole, but the search is more complicated if the layers have been tilted or folded.

The flow of water in rivers is turbulent, meaning that water particles move in more or less erratic fashion; although the general path is downstream, a particle may move forward, backward, and sideways. Turbulence is of great importance because it makes possible erosion and movement of rock debris. Such debris (gravel, sand, mud) is called sediment.

Certain shores of the Great Lakes have been found especially favorable for fruit growing, in part, because of the modifying and equalizing effect of large bodies of water. One acre of such land may prove to be worth several acres elsewhere. Elevation becomes important where it is impossible to depend on the moderating effect of a body of water. Air currents, like water, move down hill so that fruit plantations located on an upper slope possess a definite advantage, since the cold air remaining at night near the surface of the ground may move out from under the warmer layer which extends upward to treetop height.