Nowadays, in literature there are a lot of indices and factors designed to assess drought periods and water needs. Indices are presented in different spatial and temporal scale, from regional to global and chiefly are dedicated to agriculture and economy for making decision. Their application mainly depends on target and data availability. Such application imposes methodological approach; it means that obtained results should be comparable for different regions. Therefore drought indices are express as single number related to selected region. Some of them, especially the ones that are simple to calculate, are based only on one feature - precipitation for instance as a difference between total precipitation from investigated period and established norm from multiyear data. Others indices are based on more features as temperature, snow-cover, surface water and groundwater supply etc. Although it is hard to select a prori which index is the most effective, for each region the one that matches the best local environment and climatic conditions should be appointed. The paper presents a survey of indices for drought assessment and the results obtained for selected indices in Nysa Klodzka basin. ...
