Contents page 1 — “We need farmers earlier on page 2, warn,” — “It is important to keep track of severe weather warnings” On a page
It is: in 2018, in terms of the weather, a year of records. Never since records began, the sun has shone for so many hours, it rained so little and it was so many days, extremely hot. With extreme consequences: farmers and their Crops, the inland waterway came to a Standstill, petrol, fruit and vegetables were more expensive in the Winter, the drought damage in forests, meadows, and cultivated Fields visible. lost Forecasters say We will have to in the course of climate change. The German weather service (DWD) has therefore developed a new prediction model of ground sage wet for the farmers. How this works is explained by Paul Becker. The meteorologist is Vice-President of the DWD.
TIME ONLINE: In the past year, the consequences of the ongoing drought dramatically for the agricultural sector. Were surprised the farmers of the drought?
Paul Becker: A period of drought builds slowly, but the farmers can not expect a priori that a year is extremely dry or wet. This is because the weather can be said for up to two weeks in advance.
Zeit ONLINE: you have now presented a model that the soil moisture for a period of six weeks. What exactly is the soil moisture?
Becker: The soil humidity describes how much water is in the soil available. This percentage is also referred to as stick water, since he remains against the force of gravity in the upper layers of soil, instead of in the deeper layers to sink in. It was important for us to look at the area from which the plants draw their water. This is just under the surface of the earth. To find out how wet is the reason, we consider the soil and its properties: for example, whether it is coarse or fine-grained. Once we know this, we can determine how much water it can absorb. We then calculate how many litres fell per square metre and how much of it evaporates.
TIME ONLINE: Well it’s True, Yes, but also devices with which the water content in the soil to measure …
Becker:, Lysimeter allow it to capture the soil moisture. However, the measurement is often error-prone and time-consuming. Accordingly, it is preferable to calculate the soil moisture. For our forecasts we have looked at us on a regular basis as adverse weather conditions – the weather conditions in a certain period of time – and with our soil water balance model is coupled.
TIME ONLINE: The calculation model has been around longer. Why have meteorolog inside and meteorologists, it is not used?
to Paul Becker is a meteorologist and Vice-President of the German weather service. © DWD
Becker: the coupling of the soil moisture model with a classic weather forecast of about two weeks, only a very small gain in knowledge. It was only when a coupling with longer-term weather observations became possible for four to six weeks – could be relevant to the soil moisture fluctuations are calculated. In addition, extensive testing was necessary to ensure the quality of the prediction estimate. For this purpose, we have attributed to 20 years.
TIME ONLINE: now, If the DWD predicts that the soil is moist in the coming weeks, slimming, what they can do to farmers?
Becker: The agricultural sector can reduce future crop damage and Yield losses in a targeted and resource-use taxes. For example, by applying fertilizer and then, if enough moisture for its uptake in the soil is present. Another example is the targeted use of plant protection measures, which related to the weather, can be adapted to the situation.