Search results for "Watershed"

Critical analysis of thermal inertia approaches for surface soil water content retrieval

2013

The “thermal inertia” method to retrieve surface soil water content maps on bare or sparsely-vegetated soils is analysed. The study area is a small experimental watershed, where optical and thermal images (in day and night time) and in situ data were simultaneously acquired. The sensitivity of thermal inertia to the phase difference between incoming radiation and soil temperature is demonstrated. Thus, to obtain an accurate value of the phase difference, the temporal distance between thermographs using a three-temperature approach is evaluated. We highlight when a cosine correction of the temperature needs to be applied, depending on whether the thermal inertia formulation includes two gene…

Influence of anthropogenic activity on the lead isotope signature of Thau Lake sediments (southern France): origin and temporal evolution

2000

Lead concentrations and isotopic compositions were determined on both bulk sediments deposited in the Thau lake in southern France during the last 200 years, and leachates derived from a series of sequential leachings of the sediments, making it possible to identify the sources, natural (i.e. indigenous lithologic) or anthropogenic, and to quantify the different inputs of Pb. Two distinct inputs of Pb could be distinguished. One of these corresponds to the terrigenous material entering the basin, representative of the local natural Pb ‘background’. Its supply remained steady most of the time with 206Pb/207Pb ratios of 1.200±0.003, except at the time of heavy storms producing voluminous and …

Sur la présence de matières organiques mésocénozoïques dans des humus actuels (bassin de Chaillexon, Doubs, France)

1998

Abstract The optical analysis in the Chaillexon watershed (Doubs, France), of the present soils' humus layers' organic matter points out the contribution of Meso-Cenozoic organic matter in addition to the one produced by vegetal cover. Their relative occurrence varies in each layer: in the reverse of that of vegetal organic matter, the relative amount of Meso-Cenozoic organic matter increases according to the depth. That result shows that the total organic matter amounts in soils (and its evaluation) do not only depend on the net primary production and that geological formations have to be taken into account. Moreover, it suggests that present and past detrital supplies are concerned with ‘…

Effects of morphology on watershed actual evapotranspiration estimation by means of SEBAL model

2008

Upper Caraş River (Danube watershed) fish populations fragmentation – technical rehabilitation proposal

2017

Abstract We propose a technical solution for fish movement based on the flow of water over a spill threshold. Such barriers are common in the Danube system. The proposed system has a range of operating components which are easily detachable from the spill threshold, are resistant to corrosion and will not harm the fish. In fact, if designed to complement swimming abilities of target fish, it should provide adequate passage for both adults and juveniles. If implemented correctly, the design may offer a solution to help displaced fish recolonize upstream habitats.

Human Impact Effects on Târnava River Basin Aquatic Biodiversity (Transylvania, Romania)

2020

Today the following categories of human impact are present in the Tarnava Watershed: hydrotechnical works, insufficiently treated/cleaned sewage, river substratum mineral exploitation/over-exploitation, manure leakage, artificial standing water, industry, river embankment, deforestation, pouching, etc., the first three of these inducing the highest impact on the lotic systems habitats and biodiversity.

Des particules charbonneuses, t�moins des variations de l'�rosion chimique d'un bassin versant calcaire durant l'holoc�ne (bassin de chaillexon, doub…

1999

Matter fluxes result from chemical and mechanical weathering that vary as a function of climate, relief, lithology and human activities. The aim of this paper is to characterize chemical weathering variations in the past using coaly particles found in both the geological substratum and the Holocene lacustrine sediments of a calcareous basin (Chaillexon lake, Doubs, France). Results point out that chemical weathering was the predominant erosional process in the watershed, which may be due to the calcareous nature of the bedrock. The significant variability of this process relative to mechanical weathering during the Holocene period can be interpreted as a consequence of the development of th…

Comparing Physical Quality of Forest and Pasture Soils in a Sicilian Watershed

2011

Forest and pasture soils should have differing properties due, for example, to differing root characteristics or livestock trampling rates, but contradictory results are reported in the literature. The surface soil physical and hydraulic properties of five forest and pasture sites were determined in a Sicilian watershed. In general, forest soils had a significantly lower bulk density, b (by 17 to 35%), and a higher field saturated hydraulic conductivity, Kfs (by a factor of 3.4-11.5) than pasture soils. Differences between water retention characteristics of forest and pasture soils were low when high levels of organic matter, OM, content (> 7.1%) were detected for both land uses. The mean …

Enceintes néolithiques de Bourgogne

2002

L'article fait le point sur les enceintes néolithiques identifiées dans les départements bourguignons, principalement Yonne et Côte d'Or. On dénombre ainsi environ 180 sites aménagés défensivement. En plaine, les enceintes privilégient l'installation le long des cours d'eau principaux (Yonne, Armançon, Serein, cours amont de la Saône), à la confluence avec un ru de moindre importance dont le bassin versant s'ouvre sur un "arrière pays" qui offre des opportunités d'échanges. Ainsi s'esquisse un modèle d'occupation du territoire qui débute avec le Cerny et qui évolue jusqu'au Néolithique récent.

Comparing the monitoring and evaluation systems of watershed management related development projects in Amhara, Ethiopia

2012

Natural resource degradation is both a cause and a result of poverty in Ethiopia. Therefore it is important to include watershed management into efforts to reduce poverty and food insecurity in the country. In order to see if different interventions are effective in restoring the degraded environment, it is important to have a functioning monitoring and evaluation system that includes natural resource degradation and other environmental factors. This study compares the monitoring and evaluation systems used by five different projects involved in watershed management in the Amhara region, Ethiopia. The objective is to find out whether these systems are providing adequate and scientifically v…