Numerous researchers discuss of the collapse of civilizations in response to abrupt climate change in the Mediterranean region. The period between 6500 and 5000 cal yr BP is one of the least studied episodes of rapid climate change at the end of the Late Neolithic. This period is characterized by a dramatic decline in settlement and a cultural break in the Balkans. High-resolution paleoenvironmental proxy data obtained in the Lower Angitis Valley enables an examination of the societal responses to rapid climatic change in Greece. Development of a lasting fluvio-lacustrine environment followed by enhanced fluvial activity is evident from 6000 cal yr BP. Paleoecological data show a succession of dry events at 5800–5700, 5450 and 5000–4900 cal yr BP. These events correspond to incursion of cold air masses to the eastern Mediterranean, confirming the climatic instability of the middle Holocene climate transition. Two periods with farming and pastural activities (6300–5600 and 5100–4700 cal BP) are evident. The intervening period is marked by environmental changes, but the continuous occurrence of anthropogenic taxa suggests the persistence of human activities despite the absence of archaeological evidence. The environmental factors alone were not sufficient to trigger the observed societal changes.

The morpho-genetic evolution of the upper Aller valley (Weser basin, North Germany) was reconstructed using geological and géomorphologie data integrated within a numerical process model framework (FLUVER-2). The current relief was shaped by Pre-Elsterian fluvial processes, Elsterian and Saalian ice sheets, followed by Weichselian fluvial processes. Structural analysis based on subsurface data and morphological interpretations were used to reconstruct uplift/subsidence rates. A detailed analysis led to the hypothesis that we are dealing with either a NNW-SSE or a WSW-ENE oriented compression leading to uplift in the upper Aller valley. It is also hypothesised that the NNW-SSE compression might have caused strike-slip deformation leading to differential block movement and tilt. Two different uplift rate scenarios were reconstructed and used as a variable parameter in numerical modelling scenarios simulating the Late Quaternary longitudinal dynamics of the Aller. Each different scenario was run for 150.000 years and calibrated to the actual setting. The resulting model settings were consequently evaluated for their plausibility and validity. Subsequently, regional semi-3D simulations of valley development were made to test the two tectonic stress hypotheses. Differential tectonic uplift and regional tilt seems to have played an important role in shaping the current valley morphology in the upper Aller. Unfortunately, due to the uncertainties involved, we were unable to discriminate between the two postulated tectonic stress scenarios.

Human occupation and development of alluvial river floodplains are adversely affected by river channel lateral migration, which may range as high as several hundred metres per year. Reservoirs that reduce the frequency and duration of high flows typically reduce lateral migration rates by factors of 3 to 6. The ecology of riverine corridors is dependent upon the processes of erosion and sedimentation, which lead to lateral migration. Multiple-objective use of floodplains adjacent to active rivers therefore requires tools for assessing the probability and magnitude of channel movements. Existing approaches for predicting river channel movement may be classified as empirical or mechanistic, and are inadequate for widespread application. The Missouri River downstream from Fort Peck Dam in Montana, a major alluvial river with flow highly perturbed by regulation, was selected for case study. Maps and aerial photographs were available before and after dam construction. This imagery was analysed by digitizing channel centrelines at successive coverages under pre-dam and post-dam conditions, and mean migration rates were computed by bend and by reach. The mean rate of channel centreline migration fell from 6.6 m yr-1 to 1.8 m yr-1 after impoundment. Bend-mean channel activity rates were only weakly correlated with variables describing channel form and geometry. Results indicate that flow regulation for flood control and hydropower production typical of the study reach had profound effects on river corridor dynamism, with implications for habitat type distribution and ecosystem integrity.