Meteorological and Climate Indices for Assessing the Effects of Weather Events on Agriculture
Posted on 28 Mar 2018
By: Olga Makarova,
PR Manager, OpenWeather
During the entirety of their lifecycle, crops are affected by a whole range of factors, the greatest influence being exerted by weather events. These have a significant and occasionally decisive effect on the size, quality, and timeliness of a harvest and, consequently, on its value.
There exist a large number of indices for assessing this effect, including both direct measurements and the results of calculations.
Currently, the main source of information is complex weather models based on the mathematical processing of large amounts of data collected from tens of thousands of stations around the world as well as the data received from satellites.
The main meteorological indices affecting agricultural productivity are: temperature, air pressure and humidity, wind speed and direction, cloud cover, precipitation, and the intensity of solar radiation.These indices are in constant flux and vary considerably. Some of these variations are periodic in character (diurnal and annual variations) and are determined by the rotation of the Earth on its axis and around the Sun. These variations are the easiest to predict. The other variations (nonperiodic), based in particular on the shifting of air masses, have no less effect on weather conditions and often substantially disrupt the normal course of events.
Essential for agriculture is not only data that reflects current and past weather conditions but forecasts too.
Forecasts are split into long-term and short-term. Long-term forecasts help the most in the planning of agricultural production and in organizing the main aspects of farming operations. Short-term forecasts give warning of potential severe meteorological phenomena and allow the damage caused by them to be reduced.
As well as meteorological information, there are such things as agrometeorological parameters, which include essential indices such as soil temperature, frost and thaw penetration, moisture on the soil surface and in its inner levels, and the amount of snow cover.
The perennial weather pattern for a specific area is called a climate. To properly organize agricultural production, it is very important to be able to match the climate resources for a given locality with the specific requirements of crop cultivation. The indices that enable this to be done are called agroclimatic.
These refer to such indices as the cumulative temperature sum (accumulated temperature), critical temperatures, etc. These indices, based on historical weather data, help to assess the heat requirements for crops in the growing season and the lifecycles of pests and beneficial insects. The agroclimatic indices that refer to crop moisture requirements are sums of cumulative precipitation, their distribution by month or other selected time periods, various soil moistening indices, and those critical soil moisture values that can bring about crop damage or destruction.
These agrometeorological and agroclimatic observations can also be used to compile forecasts. Of these, the most important are forecasts for agrometeorological conditions (the heat provided in the growing season, timeframes for soil thaw and frost penetration, productive soil moisture reserves, and so on); phenological forecasts (times for beginning spring field work, times for the main stages when crops and their pests develop); yield and quality forecasts for staple crops; forecasts for conditions for autumn sown crops, and fruit trees during the wintertime.
Recently, satellite monitoring has been making an increasingly greater contribution to the management of agricultural processes.
Satellite images and other spatial datasets can be used in agricultural planning, the forecasting and assessment of crop yield and grazing conditions, mapping irrigated and non-irrigated vegetation, and the monitoring of seasonal and climatic variations.
Using combined analysis of meteorological, agrometeorological, agroclimatic, and satellite observations, it is possible to assess the effect of weather events on the whole agricultural cycle and carry out shrewd planning of both purely agricultural, as well as economic, elements.