[1] In this study we investigate an event-scale transit time distribution (TTD) for a catchment located in the Santa Catalina Mountains northeast of downtown Tucson, Arizona, USA, during a series of extreme rainfall events. Traditionally, TTD studies look at the long time response of a catchment to an input variation in tracer concentration. Few studies have determined the TTD at the scale of a...

In the past few decades, the quantitative computation of surface roughness has received increasing attention due to its importance in numerical surface study. In this paper, concepts of mathematical morphology are employed to compute and characterize the surface roughness of catchments extracted from a simulated digital elevation model (DEM). Morphological smoothing is implemented on the simula...

OBJECTIVE To illustrate the use of a new method for defining the catchment areas of health-care facilities based on their utilization. METHODS The catchment areas of six health-care facilities in Uganda were determined using the cumulative case ratio: the ratio of the observed to expected utilization of a facility for a particular condition by patients from small administrative areas. The cum...

Abstract This study aims to calculate the water balance, interaction with irrigation inflow, and hydrodynamics of Lake Beseka by a spreadsheet-based model using climatic, hydrological, multi-temporal satellite images, groundwater, lake chemistry data. The rainfall for catchment was estimated as 558.4 mm/year, whereas mean evaporation computed 2,214 mm/year Penman method. annual direct contribut...

The structural framework for a parametric catchment erosion model is proposed. A parameter optimization technique that provides a rational basis for the calibration of the model is developed. The adequacy of the model in representing a natural catchment is investigated.

Riparian zones can provide a protective buffer between streams and adjacent land-based activities by removing nitrate from shallow groundwater flowing through them. Catchment-scale waterquality models are useful tools for predicting catchment behaviour under various climatic conditions and land-use scenarios. In this paper, we use the Riparian Nitrate Model (RNM) to investigate the potential ro...

[ I ] This study uses time series analysis to examine long-term stream water nitrate concentration records from a pair of forested catchments at the Coweeta Hydrologic Laboratory, North Carolina, USA. Monthly average concentrations were available from 1970 through 1997 for two forested catchments, one of which was clear-felled in 1977 and the other maintained as a control. The time series were ...

Catchment management requires modelling for compliance, investigation, understanding, knowledge capture, and informing decisions. The nature of the problems is variable, ranging across scales both temporally and spatially, including discrete events, long term averages, daily and seasonal dynamics, point and spatial estimates and total catchment outputs. These requirements have spawned a variety...

Spatial changes in the dietary regime of Ruditapes philippinarum from intertidal sediments of Arcachon Bay were depicted by analyzing stable isotope ratios in both its adductor muscles and potential trophic sources. Manila clams were collected from 50 sites in May to June 2006. Dietary reconstruction was based on the IsoSource mixing model, considering trophic enrichments of 3.5‰ for carbon and...