Interpolación geoestadística de datos topográficos para obtener un MED de una pequeña cuenca forestal en el noroeste de España

[Abstract] This article gives an example of the elaboration of a digital elevation model (DEM) with the aid of geostatistics, using the case of a small experimental catchment near Arcos de la Condesa in Galicia, Spain. A DEM is a necessary tool in present-day erosion and landscape modelling. The geostatistical method of DEM construction involves six steps, starting with the removal of the drift and ending with the final interpolation. The drift was almost completely eliminated by a first order trend surface. After it had been confirmed that no heteroscedacity is present in the data set, the resulting experimental variogram was fitted by an anisotropic Gaussian variogram model, which is the variogram model that is generally used for DEM interpolation. Cross validation was used to determine the optimal number of data points to be used in interpolation. The interpolation results were found to be satisfactory and the interpolation standard deviations are below the data set standard deviation. It is yet noted that this uncertainty in the DEM – although small – may influence its derivatives and subsequent model results. However, when compared to other methods of DEM elaboration, the method as used here is an easy, adequate and relatively fast method, that has the major advantage of providing interpolation errors, enabling an evaluation of the interpolation result

Polítiques de cooperació per a la pau. Anàlisi comparada de les polítiques públiques catalanes i valencianes (2009-2019)

La seguretat mundial s'ha deteriorat en aquesta darrera dècada. Aquesta recerca vol comprendre com la política pública ha respost a aquesta degradació de la seguretat mitjançant l'anàlisi del que anomenem cooperació per a la pau. Definim cooperació per a la pau com la política pública vinculada a la cooperació internacional que es du a terme en contextos de tensió, conflicte armat, o incideix en les causes o impactes d'aquests. Les polítiques de cooperació de pau s'observen a partir de: i) Definició d'accions de construcció de pau; ii) Identificació d'accions de sensibilitat al conflicte; iii) Anàlisi de la incorporació de dones i joves en iniciatives de pau i seguretat, així com de les mesures que afecten persones refugiades i desplaçades. S'exploren dues preguntes principals: Com han evolucionat les polítiques de cooperació de pau en el període 2015-2019? En quina mesura s'han adaptat als nous contextos interns i internacionals? Per a fer-ho utilitza una metodologia de política comparada. Així, s'estudien dos contextos de política municipal (Barcelona i València) i dos de regionals (Catalunya i País Valencià) que experimenten canvis de govern significatius en el 2015. La combinació de mètodes emprats inclou l'anàlisi documental i pressupostària, entrevistes semi-estructurades i grups de discussió. Els resultats indiquen que els governs estudiats destinen cada vegada més recursos públics a contextos en conflicte armat o tensió, (entre el 85% i el 99% de la cooperació a altres països, en funció de l'actor). Malgrat això, el grau de definició i incorporació de perspectives de sensibilitat al conflicte i comprensió de processos de construcció de pau no queda prou reflectit en instruments de cooperació. A la vegada, es mostra com els governs adapten la seva actuació a crisis amb impacte mediàtic, com ara l'emergència del desplaçament forçat i que es visibilitza a Europa el 2015

Factors associated with sexual quality of life among men living with HIV

Introduction This study aims to assess the prevalence of sexual difficulties and identify factors associated with the Sexual Quality of Life (SQoL) among people living with HIV (PLWHA). Methods The study included 107 heterosexual men and 474 men who have sex with men (MSM) from five countries. Participants self-reported variables related to physical and mental health, as well as HIV-related parameters. Erectile or ejaculation difficulty, as well as low sexual desire, were investigated. SQoL was measured using the PROQOL-SexLife questionnaire. Results Most of participants reported low sexual desire, predominantly among MSM. Among MSM, living with a partner and healthcare satisfaction were associated with SQoL scores in POP dimension, while consistent condom use, cardiovascular complications, and being single were associated with SQoL scores in STI dimension. Viagra use, anti-cholesterol treatment, and living with a partner were associated with SQoL scores in DIS dimension. Among heterosexual men, employment and African origin were associated with SQoL scores in the POP dimension. Alcohol consumption was associated with SQoL scores in STI dimension. Conclusion This study underscores the importance of non-clinical determinants when assessing SQoL among PLWHA, emphasizing psychological factors and the perceived quality of healthcare. Tailored interventions should incorporate these findings to enhance overall SQoL outcomes

The effect of skiing on soil, hydrology and erosion hazard in the ski area of Sölden, Tyrol, Austria

In July and August 1999, we investigated the influence of skiing on the catchment hydrology and soil (erosion) in the surroundings of Sölden, Tyrol, Austria. Sölden is a ski village located in the Ötztal valley in between the Ötztaler and Stubaier Alps. During this research, we conducted 122 rainfall simulations, often in combination with measurements of the most important edaphic parameters. Also, continuous discharge measurements were carried out in three headwaters. We analyzed the output data, subjected them to statistical investigations in order to reveal differences and relationships and, if necessary, interpolated. With the interpolated data and the erosion- and runoff model EUROSEM we investigated where the soil is sensitive to rill erosion. It appears from the analyses that skiing only indirectly leads to compaction of the soil (via vegetation damage) but directly leads to a lowering of the soil moisture content, which may cause vegetation stress and damage. The vertical conductivity and the porosity of the soil are not affected by skiing. However, skiing increases the chance of overland flow, which, under circumstances with low vegetation cover, can lead to soil erosion. This is supported by the model results and field observations, which show the artificial soils without vegetation cover to be vulnerable to soil erosion. We recommended that the vegetation cover should be kept sufficiently high as to protect the soil from compaction and to minimize the erosion hazard. When the present policy of the skiing companies in the area is maintained, they sufficiently secure sustainability

Thresholds for incipient rilling and particle entrainment

The most cited definition of a rill is "a microchannel (...) small enough to be removed by normal tillage operations" (FAO 1965, op. cit. Bryan 1987, op. cit. Selby 1993) although, according to Bryan (1987), a more precise definition of the term ‘rill’ would be useful. Its width and depth is normally measured in centimeters (Summerfield 1991; Carson & Kirkby 1972) or even in millimeters (Van Asch 1997) and its maximum depth is often arbitrarily chosen as half a meter. When a rill cannot be removed anymore by agricultural practice it has become a gully. The formation of gullies is quite different from the formation of rills, and will therefore not be treated here. Rill initiation by overland flow can be viewed in two ways (Kirkby 1980; Rauws 1987). The first view is that rill generation is caused by the lack of balance between the infilling of juvenile rills by inter-rill processes - such as splash and wash erosion - at one side, and widening and deepening of young rills by rill processes - such as small mass movements and headcutting - at the other side. This view was first proposed by Smith & Bretherton (1972) in a conceptual model

Impact of a changed inundation regime caused by climate change and floodplain rehabilitation on population viability of earthworms in a lower River Rhine floodplain

River floodplains are dynamic and fertile ecosystems where soil invertebrates such as earthworms can reach high population densities. Earthworms are an important food source for a wide range of organisms including species under conservation such as badgers. Flooding, however, reduces earthworm numbers. Populations recover from cocoons that survive floods. If the period between two floods is too short such that cocoons cannot develop into reproductive adults, populations cannot sustain themselves. Both climate change and floodplain rehabilitation change the flooding frequency affecting earthworm populations. The present paper estimates the influence of climate change and floodplain rehabilitation on the viability of earthworm populations in a Dutch floodplain; the Afferdensche and Deestsche Waarden along the River Waal. This floodplain will be part of major river rehabilitation plans of the Dutch government. In those plans, the floodplain will experience the construction of a secondary channel and the removal of part of its minor embankment. To estimate the impact of these plans and climate change, we used a dataset of daily discharges for 1900-2003 for the River Rhine at the Dutch-German border. We perturbed this dataset to obtain two new datasets under climate change scenarios for 2050 and 2100. From the original and two projected datasets we derived the frequency distributions for the annual periods without inundations for the studied floodplain. We subsequently compared the duration of these inundation-free (dry) periods with the maturation age distribution for L. rubellus as derived from a Dynamic Energy Budget model. This comparison yielded in which parts of our study area and under which climate conditions the populations would still be viable, be able to adapt or become extinct. The results show that climate change has almost no adverse effect on earthworm viability. This is because climate change reduces the flooding frequency during the earthworms growing season. Floodplain rehabilitation, on the other hand, reduces the part of the floodplain area where populations can sustain themselves. Before rehabilitation, only 12% of the floodplain area cannot sustain a viable earthworm population. After rehabilitation, this increases to 59%, 28% of which is due to more frequent flooding. Enhanced exposure to soil contaminants may further suppress earthworm viability. This could frustrate further nature development and the viability of earthworm-dependent species such as the badger (Meles meles) or little owl (Athene noctua vidalli species), which is an objective of the river rehabilitation plans in the Netherlands