and their relation to climatic factors. Streamflow is generally stochastic highlighting the importance of factoring in temporal flow variability in water resources planning. There is no clear evidence that changes in climatic variables are related to streamflow
Classification and regression tree (CART) analyses were undertaken to test the usefulness of including vegetation variables in mountain permafrost distribution models for 5 widely spaced study areas in the Yukon. Digital elevation model (DEM
)-derived variables, field-derived vegetation variables and satellite imagery-derived vegetation variables were employed individually to classify sites into permafrost probable, permafrost improbable and permafrost ‘uncertain’ categories. The vegetation
variables were subsequently combined with the DEM-derived set to see if they could improve the latter's accuracy. CART analyses appear useful for predicting permafrost distribution because they can incorporate non-linear relationships between independent
Air temperature variability in Illinois based on weather station records and the North American Regional Reanalysis from 1979 to 2006
Air temperature ; Climatic change ; Climatic data ; Climatic variability ; Illinois ; Regional analysis ; Rural area ; Temperature ; United States of America ; Urban area
Spatial and temporal near-surface air temperature variabilities and trends were analyzed for 30 locations in Illinois based on annual data derived from station records and the North American Regional Reanalysis (NARR) dataset from 1979 to 2006
. A high correlation was found between the two datasets for interannual variability at most locations. Temperatures were generally higher at urban stations than non-urban stations, while non-urban NARR data points showed higher temperatures than urban data
Short-term versus medium-term monitoring for detecting gully-erosion variability in a Mediterranean environment
The AA. investigate how medium-term gully-development data differ from short-term data, and which factors influence their spatial and temporal variability at 9 selected actively retreating bank gullies situated in 4 Spanish basin landscapes. Results
show a high variability of annual gully retreat rates both between gullies and between observation periods. The varying influences of land use and human activities on runoff production and connectivity play a dominant role in these study areas, both
for short-term variability and medium-term difference in gully development. The study proves the value of capturing spatially continuous, high-resolution three-dimensional data using small-format aerial photography for detailed gully monitoring. Results
Straw coverage alleviates seasonal variability of the topsoil microbial biomass and activity
Agricultural practice ; Agropedology ; China ; Cultivated land ; Experiment plot ; Maize ; Micro-organism ; Mulching ; North-Eastern China ; Seasonal variability ; Soil properties ; Soil temperature
Seasonal variability of microbial biomass carbon (MBC) and basal respiration (BR) in surface soil was compared between conventional straw removal (SR) and straw coverage (SC) in a maize field experiment, Northeast China. The straw coverage treatment
variability of MBC and BR. These results demonstrate that straw coverage contributes to stabilizing soil microbial characteristics in season.
Spatiotemporal drought variability in northwestern Africa over the last nine centuries
Africa ; Climate ; Climate reconstruction ; Climatic index ; Climatic variability ; Dendrology ; Drought ; North-West Africa ; Palaeoclimate ; Space time ; Twelfth Century ; Twentieth Century
Atmospheric circulation ; Central Europe ; Discharge ; Elbe ; Europe ; Fluvial hydrology ; Interannual variability ; Ocean atmosphere interaction ; Periodicity ; Teleconnection ; Temperature ; Time series ; Twentieth Century
, mainly related to local-regional climate variability. On the long trend at the millennial scale, a more coherent pattern of glacier advance/retreat phases is emerging, if not worldwide at least at the hemispheric level. - (NF)
Des variables aléatoires d’ordre supérieur de l’élévation de la surface de la mer
L’article présente la fluctuation des variables aléatoires de 5ème et 6ème ordre de l’élévation de la surface marine. La recherche est basée sur les données des enregistrements de la houle, effectués dans les conditions naturelles. Il est démontré
que les variables aléatoires de 5ème ordre sont en faible corrélation avec les variations de l’inclinaison moyenne de la surface de la mer, créée par les vagues dominantes. Les variations des variables aléatoires de 6ème ordre ne sont pas corrélées