Age of Lake Malawi (Nyasa) and water level fluctuations
facteur d'instabilité. Le bassin tectonique a commencé à se former au Miocène tardif (8,6 Ma) mais le lac n'est devenu profond que vers 4,3 Ma. Il s'est asséché complètement au début du Pléistocène (1,6-1,0 Ma). Nouvelles régression entre 0,42 et 0,26 Ma
Regime of subsurface water resources in shallow groundwater agricultural fields
Agroclimatology ; China ; Evapotranspiration ; Groundwater ; Irrigation ; Shandong ; Soil water ; Sustainable development ; Water ; Water regime
In shallow groundwater agricultural fields, water exchanges between groundwater and soil water happen frequently and intensively. This paper analyzes the regime of subsurface water during the growing period of winter wheat from October 1998 to June
1999 in Yucheng area. The results showed that a significant proportion of field evapotranspiration was supplied by groundwater evaporation, whereas the role of groundwater evaporation was not considered during irrigation, leading to soil water
percolation into groundwater. In order to improve water use efficiency of crops, some measures were put forward in the paper.
Wydmy barchanopodobne w obnizeniu Ma ej Panwi. (Dunes ressemblant à des barkhanes dans la dépression de Ma a Panew)
Barkhane ; Dune ; Eolien ; Géographie de l'Europe ; Géomorphogenèse ; Géomorphologie ; Kalety région ; Ma a Panew ; Pologne
Caractéristique morphologique des dunes ayant les caractéristiques de barkhanes apparaissant dans la dépression de Ma a Panew aux environs de Kalety. Description de la structure, des caractéristiques de granulométrie et de polissage du matériau qui
Arid area ; China ; Cluster analysis ; Desert ; Hydrochemistry ; Infiltration ; Lake ; North-Western China ; Precipitation ; Spatial variation ; Underground water ; Water
Based on the analysis of ion chemical composition of lake water and shallow groundwater in the Badain Jaran Desert, this paper discussed the characteristics of ion chemical composition, spatial variation of lake water, and possible supply sources
of lake water and groundwater in the desert areas. The results show that the pH, salinity, TDS and electrical conductivity of the lake water are greater than those of groundwater. The ion chemical composition of the lake water reveals that the flow
direction of lake water is from southeast to northwest in the Badain Jaran Desert. The ion chemical composition, moisture content of sand layer water level height and hierarchical cluster analysis of the lake water and groundwater demonstrate that the lake
water is mainly supplied by local rainfall and infiltration of precipitation in Yabulai Mountains and Heishantou Mountain.
Les lacs à déstratificateur thermique et le cas de Mas Chaban (Charente, France)
Charente ; Eutrophication ; France ; Hydrosystem ; Lake ; Limnology ; Poitou-Charentes ; Scale ; Temperature ; Water temperature ; Watershed
Dans le bassin de la haute Charente, les lacs de Lavaud et Mas Chaban, l'un de fonctionnement libre, l'autre muni d'un déstratificateur thermique, ont pour but de soutenir l'étiage du fleuve. La qualité de l'eau lacustre et fluviale est suivie grâce
Hydraulic properties of biological crusts on sand dunes studied by 13C-CP/MAS-NMR : A comparison between an arid and a temperate site
Arid area ; Biogenic process ; Brandenburg ; Comparative study ; Dune ; Duricrust ; Geochemistry ; Germany ; Infiltration ; Israel ; Negev ; Porosity ; Repellency ; Sand ; Soil ; Soil properties ; Soil water ; Temperate zone
Using principal component analysis (PCA), the AA. studied the relationships between hydraulic properties and 13C-CP/MAS-NMR shift regions of biological soil crusts (BSCs) on sand dunes under arid and temperate conditions. The arid study site
and water holding capacities (WHCs) were higher in Nizzana, whereas surface wettability was reduced in Lieberose. At both sites, BSCs caused extra WHC compared to the mineral substrate. Infiltration kinetics was attributed to polysaccharide hydration
compounds mainly dominated by carbohydrates and physical surface properties related to texture, porosity and water holding capacity.
Explotaciones agrarias de les Valls de'Alcoi : El mas, la empresa familiar y el agricultor alternante (Exploitations agricoles de la vallée de l'Alcoi : le mas, l'entreprise familiale et l'agriculteur à temps partiel)
vignes. Le mas est une exploitation moyenne ou grande à l'échelle locale. - (JLG)
Esophageal cancer spatial and correlation analyses : Water pollution, mortality rates, and safe buffer distances in China
Cancer ; China ; Geographical information system ; Health ; Lake ; Mortality ; Pollution ; Risk factor ; Spatial analysis ; Stream ; Water quality
This study applied spatial analysis to ascertain the relationship between water pollution and esophageal cancer mortality rates nationwide. The AA. employed 2 datasets, including a national investigation of esophageal cancer rates and distribution
, and national water quality grades in China's primary rivers and lakes. Esophageal cancer data were grouped based on different water quality grades, which included a scaled buffer distance from rivers and lakes. The results revealed a significant positive
correlation between widespread water pollution and esophageal cancer mortality nationwide; and a significant negative correlation between esophageal cancer mortality, and buffer distance from rivers and lakes.
Applied geomorphology ; China ; Geophysics ; Groundwater ; Northern China ; Palaeogeomorphology ; Plain ; Stream ; Thematic mapping ; Water resources
On the North China Plain, the shallow-buried palaeochannels have significance to both practical and theoretical geomorphology: water supply and potential problems related to construction projects. The 4 methods used in compiling the shallow-buried