Adsorption of Cd(2+) on two types of Egyptian soils: clay (alluvial) and sandy loam (calcareous), was studied. Effect of changing the matrix electrolyte type and concentration was used to mimic the natural soil salts. Kinetics and thermodynamic parameters of the adsorption were calculated at two different electrolyte concentrations: 0.05 N and 0.15 N. The adsorption was described by Langmuir an...

Spotlight surveys were conducted from 1992 to 1997 to determine the population status of Morelet's crocodile, Crocodylus moreletii, in northern Belize. A total of 754 crocodiles were observed and 481.9 km surveyed (1.55/km). Encounter rates were highest in non-alluvial (8.20/km) and alluvial (6.11/km) lagoons, and considerably lower in most rivers and creeks (0.95/km), and coastal mangrove habi...

A process-based landscape and channel classification is proposed as a framework for assessing watershed response to natural and anthropogenic environmental change. Our proposed classification is based on a hierarchy of process-regimes at several spatial scales: i) geomorphic province, ii) watershed, iii) valley segment, iv) channel reach, and v) channel unit. The geomorphic province level ident...

Internally oscillating cycles of cutting and filling occur naturally in many coupled geomorphic systems. As a demonstration, we have modeled stream entrenchment and backfilling where alluvial systems couple to uplifting mountain blocks. This simple model tracks bedrock stream erosion and transport of alluvium to base level. Internal oscillations arise from coupling of a kinematic wave model for...

The diversion of natural river courses and subsequent filling by alluvial deposits or anthropic intervention has been hidden by urban development in the majority of the cities. The research we conducted involved monitoring the evolution of a river course and reconnaissance of the original morphology of the fluvial systems. Our research was applied to the section of the River Beiro that flows th...

Buried sedimentary aggradational sections deposited between 800 ka and 600 ka in the Tiber River coastal alluvial plain have been studied using borecores from around Rome. Ar/Ar ages on sanidine and/or leucite from intercalated tephra layers and paleomagnetic investigation of clay sections provide geochronologic constraints on the timing of aggradation of two alluvial sections, demonstrating th...

Middle Miocene alluvial fans in the intramontane Fohnsdorf Basin of the Eastern Alps originated along normal faults and linked strike-slip faults in a continental half-graben setting. The fans display considerable facies differences. Debris flows of the Rachau fan are characterized by a sandy matrix and large boulders, whereas debris flows of the Apfelberg fan are characterized by higher silt a...

Introduction: Impact crater degradation provides a powerful tool to analyze past Martian hydrological evolution. Previous studies concluded that large impact craters were strongly degraded during early Martian history, whereas younger craters are only weakly degraded [1]. Degraded craters are therefore one of the main lines of evidence for a warmer climate on early Mars. Global altimetry and re...