Implementation of the Water Framework Directive calls for methodologies and tools to quantify nutrient losses from diffuse sources at a river basin district scale. Here, we examine the possibility of using a statistical model for source apportionment and retention of nutrients in a large transboundary drainage basin (44,000 km2). The model approach uses non-linear regression for simultaneous es...

tectonic processes are major factors controlling landform development in tectonically active areas. in order to evaluate quantitative measurement of tectonic activities in the alamarvdasht basin in the south of iran, six different morphological indices including stream-gradient index (sl), drainage basin asymmetry (af), hypsometric integral (hi), valley floor width-valley height ratio (vf), dra...

in central part of kopeh dagh there is an array of active right-lateral strike-slip faults that obliquely cut the range and produce offsets of several kilometers in the geomorphology and geological structure. geomorphic indices indicate the presence of differential uplifting in history of this area. tectonic activity of the study area is investigated by a large number of dem derived catchments ...

Intermontane basins in the Trans-Pecos region of westernmost Texas and northern Chihuahua, Mexico, are target areas for disposal of interstate municipal sludge and have been identified as possible disposal sites for low-level radioactive waste. Understanding ground water movement within and between these basins is needed to assess potential contaminant fate and movement. Four associated basin a...

the present study carried out to identify neo tectonic activity of the gorgan river basin in golestan province, in north of eastern alborz range is investigated by four geomorphic indices including the stream– gradient index (sl), drainage basin asymmetry (af), reveres symmetry of topography (t) and mountain front sinuosity (smf). result from the analysis is accumulated and expressed as an in...

Controlled tile drainage (CTD) can reduce pollutant loading. The Annualized Agricultural Nonpoint Source model (AnnAGNPS version 5.2) was used to examine changes in growing season discharge, sediment, nitrogen, and phosphorus loads due to CTD for a ∼3900-km agriculturally dominated river basin in Ontario, Canada. Two tile drain depth scenarios were examined in detail to mimic tile drainage cont...

We propose, as a testable hypothesis, a basin-scale approach for interpreting the abundance of in situ produced cosmogenic isotopes, an approach which considers explicitly both the isotope and sediment flux through a drainage basin. Unlike most existing models, which are appropriate for evaluating in situ produced cosmogenic isotope abundance at discrete points on Earth’s surface, our model is ...

Introduction: Valley network systems on Mars remain the most unequivocal evidence that water carved the surface of the planet in the distant past and the climate was different than today. Most of these systems date from the Noachian [1], the p eriod of heavy bombardment which is >3.7 Ga [2], although local or regional formation seems to have continued to more recent times [3]. The discovery of ...

Insect societies vary greatly in social organization, yet the relative roles of ecological and genetic factors in driving this variation remain poorly understood. Identifying how social structure varies along environmental gradients can provide insights into the ecological conditions favouring alternative social organizations. Here, we investigate how queen number variation is distributed along...