Application of different drought indicators as a background for investigation of forest growth influence on runoff conditions in small mountainous catchment

Código

I-EBHE0139

Autores

Vaclav David

Tema

WG 1.14: Droughts in Mountain Regions

Resumo

Due to climate change droughts has been becoming a more important issue in recent decades in the area of Central Europe as well as in other regions worldwide. It is related to both surface and subsurface hydrological processes. Thus, it is crucial to describe drought well when investigating such processes in detail to correctly interpret the results of such investigation. Jizera mountains in the northern part of the Czech Republic is an intriguing area for the research of the influence of reforestation on hydrologic process. The reason is, that the forests there were destroyed by acid rains before nineties of 20th century and after that reforestation started from the very beginning and continues till presence as the forest is already about 30 years old. The influence of a forest growth can be investigated in many ways. One of them consists in the assessment of trend in the values of for example runoff coefficient or reservoir constant when approximating a catchment by a linear or other reservoir. However, both can be strongly affected by drought conditions. In this study, the investigation on the suitability of different probability distributions used in standardization process when calculating different drought indexes such SPI or SDI is presented. The results show that it is important to pay attention to a proper selection of a probability distribution which is different for station precipitation data, areal precipitation data or discharge data.