This paper addresses droughts in the Czech Lands in the 1090–2012 AD period, basing its findings on documentary evidence and instrumental records. Various documentary sources were employed for the selection of drought events, which were then interpreted at a monthly level. While the data on droughts before 1500 AD are scarce, the analysis concentrated mainly on droughts after this time. A dry year in 1501–1804 period (i.e. pre-instrumental times) was defined as a calendar year in the course of which dry patterns occurred on at least two consecutive months. Using this definition, 129 dry years were identified (an average of one drought per 2.4 yr). From the 16th to the 18th centuries these figures become 41, 36 and 49 yr respectively, with the prevailing occurrence of dry months from April to September (73.7%). Drought indices – SPEI-1, Z-index and PDSI – calculated for the Czech Lands for April–September describe drought patterns between 1805 and 2012 (the instrumental period). N-year recurrence intervals were calculated for each of the three indices. Using N ≥ 5 yr, SPEI-1 indicates 40 drought years, Z-index 39 yr and PDSI 47 yr. SPEI-1 and Z-index recorded 100 yr drought in 1834, 1842, 1868, 1947 and 2003 (50 yr drought in 1992). PDSI as an indicator of long-term drought disclosed two important drought periods: 1863–1874 and 2004–2012. The first period was related to a lack of precipitation, the other may be attributed to recent temperature increases without significant changes in precipitation. Droughts from the pre-instrumental and instrumental period were used to compile a long-term chronology for the Czech Lands. The number of years with drought has fluctuated between 26 in 1951–2000 and 16 in 1651–1700. Only nine drought years were recorded between 1641 and 1680, while between 1981 and 2012 the figure was 22 yr. A number of past severe droughts are described in detail: in 1540, 1590, 1616, 1718 and 1719. A discussion of the results centres around the uncertainty problem, the spatial variability of droughts, comparison with tree-ring reconstructions from southern Moravia, and the broader central European context

This contribution employs documentary-based precipitation indices and long homogenized series of precipitation totals for quantitative reconstruction of seasonal and annual precipitation in the Czech Lands (now the Czech Republic) from AD 1501. Final calibration is based on linear regression using fully independent indices and data measured during the 1804-1854 overlap period, with subsequent variance scaling. Correlation analysis demonstrates that Czech documentary indices explain a significant amount of precipitation variability in all months and seasons of the entire overlapping period. Reconstruction results are best for annual values and for autumn (SON), for which proxy and target data share 36% of common variability. The coefficient of determination for summer (June-July-August -JJA) is 35%, for spring (March-April-May -MAM) 33%, while for winter (December-January-February -DJF) it is only 26%. Verification statistics [reduction of error (RE), coefficient of efficiency (CE)] computed for early (1804-1829) and late (1830-1854) overlapping periods indicate acceptable reconstruction skill for precipitation indices in JJA and annual values. However, for the other seasons they failed in the early or late calibration period, indicating possible chronological instability of reconstruction results in MAM, SON (September-October-November), and DJF seasons. The final reconstructions are complemented with uncertainty estimates. Reconstructed Czech precipitation series do not indicate long-term trends but reveal quite high inter-annual and inter-decadal variability. Smoothed reconstructed DJF and JJA precipitation totals show the highest values in the second part of the 16th century, while the driest 30-year period occurred during the 18th century in DJF, MAM, JJA, and in annual series. Direct comparisons with two other reconstructions (tree-ring-based for southern Moravia and gridded multi-proxy for Central Europe) not only show significant correlations for a substantial part of the common period, but also disclose several periods with loss of coherence. Finally, uncertainties in reconstructions are discussed.

This study addresses the reconstruction of 4 slightly different drought indices in the Czech Lands (now the Czech Republic) back to 1501 AD. Reconstructed monthly temperatures for Central Europe that are representative for the Czech territory, together with reconstructed seasonal precipitation totals from the same area, are used to calculate monthly, seasonal and annual drought indices (SPI, SPEI, Z-index, and scPDSI). The resulting time series reflect interannual to multi-decadal drought variability. The driest episodes cluster around the beginning and end of the 18th century, while 1540 emerges as a particularly dry extreme year. The temperature-driven dryness of the past 3 decades is well captured by SPEI, Z-index and scPDSI, whereas precipitation totals show no significant trend during this period (as reflected in SPI). Data and methodological uncertainty associated with Czech drought indices, as well as their position in a greater European context, are critically outlined. Comparison with fir tree-rings from southern Moravia and a spatial subset of the 'Old World Drought Atlas' (OWDA) reveals statistically significant correlation coefficients, of around 0.40 and 0.50, respectively. This study introduces a new documentary-based approach for the robust extension of standardised drought indices back into pre-instrumental times, which we also believe has great potential in other parts of the world where high-resolution paleoclimatic insight remains limited.

Floods from the middle part of the River Morava (eastern Czech Republic) are considered over the course of the past three centuries, the study being based on data derived from documentary evidence (1691-1880), measured peak water stages, H k (1881-1920) and peak discharges, Q k , evaluated with respect to their N-year return period (H N and Q N ). Changes in land use and water management (water reservoirs, channel modifications) are discussed, as are factors influencing runoff conditions in the Morava catchment. Decadal synthesis of flood series identifies the highest flood activity in the decades of

5Czech Hydrometeorological Institute, Brno Regional Office, Kroftova 43, 616 67 Brno, Czech Republic 6