In most cases, local meteorological factors should be considered. From mountainous areas to coastal areas, the meteorological conditions of different project areas are different.
The following meteorological factors must be considered in the design of irrigation system:
1.Evaporation Capacity
Evaporation affects irrigation water requirement. Evapotranspiration should be calculated to calculate crop water demand.
Principle of evaporation sensor: the weight of liquid in evaporation dish is measured by high-precision weighing principle, and then the liquid level height is calculated. Therefore, it can be used in a variety of environments, such as liquid or ice, which solves the disadvantages of using ultrasonic principle to measure the height of liquid level (1. Inaccurate measurement when ice is frozen; 2. Easy to damage the sensor when there is no water; 3. Low accuracy)
2.Wind Speed and Wind Direction
According to the wind speed and direction, the nozzle selection and layout spacing.
Wind speed, wind direction sensor is used to measure the wind speed and direction of the environment.
3.Precipitation
Effective rainfall must be considered when using water balance method to calculate irrigation demand, so rainfall sensor is needed.
Rainfall sensor: used to measure precipitation, precipitation intensity and precipitation time.
4.Crop Growing Season
The length of irrigation season is related to the days of frost free period. The number of days of irrigation season should be known when calculating the annual irrigation water demand. The actual operation of irrigation system is greatly affected by the weather, water source and other accidental factors, so it must be corrected according to the weather, soil and crop conditions at that time.
5.Frost
Spray irrigation can be used to prevent frost in some areas. The demand of frost prevention should be considered in irrigation design. For example, some crop areas of some farms need frost protection design, and golf course greens in some areas should pay special attention to frost protection.
6.Meteorological Peak Value
In order to meet the water requirement of plants under the most unfavorable conditions, the design parameters should be determined by the historical meteorological peak.
7. Compact Weather Sation
The meteorological parameters in some areas are different from those in large areas. This is related to the shading conditions, ventilation conditions, light conditions, heat reflection, heat conduction and so on in local areas. The difference of micrometeorology in agriculture is not big, but that in garden is big. Small weather stations meet the needs of users.
