[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...

Kenya has a large population of multifunctional tree species like Moringa oleifera (Lamark). Two provenances from areas Gede and Machakos were used in study to examine how Negarim micro catchment affects their growth survival traits under various spacings. An experiment was set up Randomised Complete Block Design with three replicates. Root collar diameter, branches development, rate increase h...

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...

one of the major sectors of water loss is the loss of rain runoff. kirkby (2001) the effect of soil surface characteristics in the production of runoff in time and space scales concluded that soil properties such as undulating, soil texture and structure on the amount and spatial pattern of runoff are effective. in this research that was conducted in the latian watershed, twenty experimental pl...

[ 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 ...