Chronofunctions of Heilu soil developed from Loess in Luochuan, on the chinese Loess plateau

Soil chronofunctions are an alternative for the quantification of soil-forming processes and underlie the modeling of soil genesis. To establish soil chronofunctions of a Heilu soil profile on Loess in Luochuan, selected soil properties and the 14C ages in the Holocene were studied. Linear, logarithmic, and third-order polynomial functions were selected to fit the relationships between soil properties and ages. The results indicated that third-order polynomial function fit best for the relationships between clay (< 0.002 mm), silt (0.002-0.02 mm), sand (0.02-2 mm) and soil ages, and a trend of an Ah horizon ocurrence in the profile. The logarithmic function indicated mainly variations of soil organic carbon and pH with time (soil age). The variation in CaCO3 content, Mn/Zr, Fe/Zr, K/Zr, Mg/Zr, Ca/Zr, P/Zr, and Na/Zr ratios with soil age were best described by three-order polynomial functions, in which the trend line showed migration of CaCO3 and some elements.

Effects of erosion and deposition on particle size distribution of deposited farmland soils on the chinese loess plateau

Particle size distribution (PSD) in the soil profile is strongly related to erosion, deposition, and physical and chemical processes. Water cycling and plant growth are also affected by PSD. Material sedimented upstream of the dam constructions formed large areas of deposited farmland (DF) soils on the Chinese Loess Plateau (CLP), which has been the site of the most severe soil erosion in the world. Two DFs without tillage on the CLP were chosen to study the combined effect of erosion and check dams on PSD. Eighty-eight layers (each 10 cm thick) of filled deposited farmland (FDF) soils and 22 layers of silting deposited farmland (SDF) soils of each studied soil profile were collected and 932 soil samples were investigated using laser granulometry. The particle sizes were stratified in both DFs based on soil properties and erosion resistance. The obtained results of clay and silt fractions showed similar horizontal distribution, indicating parallel characteristics of erosion and deposition processes. Fine sand represented the largest fraction, suggesting the preferential detachment of this fraction. The most erodible range of particle sizes was 0.25-0.5 mm, followed by 0.2-0.25 mm in the studied soil profiles. The correlation between particle size and soil water contents tended to increase with increasing water contents in FDF. Due to the abundant shallow groundwater, the relationship between particle size and soil water content in SDF was lost. Further studies on PSD in the DF area are needed to enhance the conservation management of soil and water resources in this region.

La régulation des interdépendances entre la forêt et l'eau potable en France : études de cas sur le site du Mont Forchat : les cas des captages de Ramble et des Moises (projet Alpeau)

Ce working paper traite des règles prévues en France pour gérer les usages des forêts et de l'eau souterraine ainsi que leur interdépendance. En deuxième partie, deux études de cas (sur le Mont Forchat, Haute Savoie) montrent de quelle manière les règles prédéfinies sont mises en oeuvre et parviennent (ou pas) à protéger les captages d'eau souterraine. En troisième partie, une application du cadre d'analyse des régimes institutionnels des ressources (RIR) permet de discuter en profondeur des mécanismes institutionnels en oeuvre et des enjeux en présence dans le contexte français.

Audit report on Clay Central/Everly Community School District in Royal, Iowa for the year ended June 30, 2011

Audit report on Clay Central/Everly Community School District in Royal, Iowa for the year ended June 30, 2011

[Phot. d'un avion ayant atterri sur le Mont-Blanc, envoi dédicacé au prince Roland Bonaparte, 3 juillet 1921, des collections de ce dernier]

Donateur : Bonaparte, Roland (1858-1924)

[14 juillet 1919, foule place du Palais Royal, les Grands magasins du Louvre décorés et illuminés] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54993

[14 juillet 1919, foule place du Palais Royal, les Grands magasins du Louvre décorés et illuminés] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54994

[14 juillet 1919, foule place du Palais Royal, les Grands magasins du Louvre décorés et illuminés] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54995

[14 juillet 1919, foule place du Palais Royal, les Grands magasins du Louvre décorés et illuminés] : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 54995 bis