Because global warming and water shortage are supposed to make a big problem in this generation (Charles et al., 2000), several mitigating ideas have been proposed. This study proposes an idea to solve these two with additional by-products. It is named the ice control. Firstly, the ice control can conserve a big amount of water resources through the suppression of evaporation. Secondly, because the increased ice by the ice control reflects more insolation, the global warming can be suppressed. Thirdly, through the ice control, water temperature can be kept low and its quality can be kept from aggravation. Fourthly, no harmful side effect of the ice control has been founded yet. The technical ideas to make ice form earlier, thicken more and sustain longer are investigated. Any preceding studies on these topics are hard to find. However, the expected benefits of the ice control are expected to be very big.

2. Mechanism of evaporation.

Cho (1969) set up an equation supposing the evaporation amount by simple meteorological elements after Penman (1948). Han and Lee (2005) upgraded it as (1) by the comparison with the observed data. E= (0.0146+0.0063 *U) (ew-ea), - (1) where E is evaporation (Unit is mm/h), U is wind speed(m/s) over 1 m altitude, ew is the saturated vapor pressure of the air that has the same temperature with water, ea is the vapor pressure (hPa) of the air over 1 m high that can be calculated by the dew point temperature.

3. Mechanism of freezing and melting.

3.1. Start of freezing.

By using thermodynamic equations, the amount of ice made by cold air can be calculated. From the numerical experiments, it is clear that in the starting stage of freezing, the most important factor for freezing is Cw-a and one against freezing is Cw-w.

3.2. Freezing over ice plate.

It is found that freezing over the ice plate is faster than the one without ice plate. But, unfortunately, no pre-studies on this process are found.

3.3. Freezing under ice plate.

Because the cold of the free air can penetrate into the water under the ice plate only after the ice plate cooled down, the thicker the ice is, the harder the cold penetrate into. Then the thicker the ice plate is, the harder it grows. On this process, only Turri (2004) is found as a pre-study. It verified that in the cave of the Swiss Alps, to thicken the ice plate 1 m more under the ice plate, 3 months of duration, 12C difference of temperature between ice and air, and continuous snow fall are supposed to be needed.

4. The principle of the ice control.

4.1. Early freezing (EF).

By this method the starting day of the freezing can be pushed three or five weeks ahead.

4.2. Forced thickening of ice (FTI).

The process of the FTI is the cyclic repeat of the four stages. The loading-up stage is the first. In the second stage, the water to be frozen is spreading on the ice plate. In the third stage, the water freezes by the cold wind in nature. In the fourth stage, the ice plate should be maintained without water over it during the time when solar radiation exists. Along the topography, many styles of FTI are possible. FTI is available in summer also though there are no ices or snows.

4.3. Delayed melting (DM).

Slow melting of ice is harder and more important than thickening. Then the places where ice is sustained to summer are investigated. Two ice valleys in Korea and in Mongolia, and one ice-lake in Russia are selected. The common 5 characteristics of the three areas denote the method to make snow and ice persist long. The first artificial method that is the most general method to apply to the every reservoir is to make the Ice Hill (IH). IH must be located at the higher place than reservoir. The second artificial method is the flow control (FC). If the water flow into the reservoir is permitted only in the morning, it can suppress the ice melting, the water temperature rising, consequently the evaporation.

5. The expected results of the ice control.

5.1. Additional water resources.

On the reservoir with the surface area of 1 km X 1 km, the water level of 5m equals to the 5 million tons of water. In case of the Daechung-Dam with 73 km**2 of surface area, by the ice control, 365 million tons of water can be conserved from evaporation.

5.2. The conservation of water quality.

Because the ice control keeps water as a solid state for a long time, it keeps water quantity from contamination and pollution.

5.3. Suppression of the global warming.

By the ice control, a great deal of global warming effect can be suppressed because ice reflects insolation directly. To reduce the energy accumulation, the earth surface area of 4.8 X 10**6 km**2 should be covered more by ice. This is about 40% of the total area above 35 degree latitude. Over the floating ice and/or over the ice plate, ships sprinkle and/or flow the sea water. That is the work needed. After the ice covered area widened enough, the positive feedback mechanism of the ice cover will widen the ice covered area for itself. However the scale of work is so big that international organizations should be prepared to carry it out. When they are launched, weather modification and climate control may be able to be experimented together. Therefore, the earth environmental sciences will advance together in a great deal.

6. By-products and the adverse reactions.

Many benefits are known as by products. As the adverse reactions, nothing has known yet.