Method and system for water distribution and soil moisture determination

An apparatus comprising:

• a soil moisture determination system to spatially derive soil moisture at a selected location within an irrigation district to be irrigated, said s soil moisture determination system comprising:
• a networked computer system connected to a plurality of weather stations within said irrigation district, wherein the networked computer system is configured and arranged- to:
• measure a selection from:
• solar radiation spectrum, wind speed, rainfall, temperature, humidity, barometric pressure, and energy measurement from solar panels at each of a plurality of representative locations, said networked computer system having data access to crop factor, soil type, and irrigation historical data at said representative locations;
• use system identification techniques to produce an algorithm for evapotranspiration based on a predetermined selection from the weather station measurements and the data access to crop factor, soil type, and irrigation historical data at said representative locations;
• calibrate said algorithm by direct measurement of the moisture in the soil at each of said representative locations by respective soil moisture sensors;
• use measured parameters of rainfall, soil type, irrigation historical data and crop factor in combination with said algorithm to derive or interpolate soil moisture at said selected location within said irrigation district;
• and
• an irrigation management system configured to irrigate predetermined areas of said irrigation district based on the derived or interpolated soil moisture for said predetermined areas, an availability of irrigation water, and requests for timed irrigation from end users.

A method of controlling a water distribution system, the system having at least one at-least-predominantly-free-surface flow-path from which water is deliverable to soil, the method comprising:

• spatially deriving soil moisture at a selected location within an irrigation district to be irrigated comprising:
• using system identification techniques to produce an algorithm for evapotranspiration based on at least one of the following measured parameters:
• solar radiation spectrum, wind speed, temperature, humidity, crop factor, soil type, barometric pressure, irrigation historical data, and energy measurement from solar panels at each of a plurality of representative locations;
• calibrating said algorithm by direct measurement of the moisture in the soil at each of said representative locations by respective soil moisture sensors;
• using measured parameters of rainfall, soil type, irrigation historical data and crop factor in combination with said algorithm to derive or interpolate soil moisture at said selected location within said irrigation district;
• and
• irrigating the predetermined areas of said irrigation district with an irrigation management system using the water based on the derived or interpolated soil moisture for said predetermined areas, an availability of water, and requests for timed irrigation from end users,
• wherein
• the availability of water includes at least one supply indicator, the at least one supply indicator being an indicator of at least one of at least one volume of water in the system, an inflow of water to the system, and a future inflow of water to the system.