Search Results (7)

This work identifies and analyses, from a synoptic point of view, episodes of torrential rainfall (equal to or greater than 200 mm in a single day) that occurred in the Canary Islands between 1950 and 2020. For this purpose, all daily rainfall series available in different databases were used, with a final selection, after applying various filters for the detection of errors, of 88 days on which 200 mm was exceeded. Subsequently, the isobaric configurations at the surface and at 500 hPa were analysed by applying the following two classification methods: the automatic one of Jenkinson and Collinson (1977) and the subjective one of Jorge Olcina (1994). Most of the selected days (63.4%) corresponded to high-altitude isolated depressions (known by their initials in Spanish as DANAs), as well as troughs showing the advection of polar air of different origins (36.5%). According to the Jenkinson and Collinson classification, half of the days were classified as cyclonic or hybrid cyclonic and 37.5% as pure advective or directional (37.5%), with five days classified as undetermined. On only one day, 23 November 1954, was a tropical disturbance observed, with cloud fronts moving from the south of the Canary Islands along the west coast of Africa. Full article

Semi-arid and arid regions are characterized by their water scarcity, which leads territories to seek ways of increasing the water resources available to meet their demands (urban, agricultural, industrial, leisure and tourism, etc.). For this reason, this article proposes the term “wastewater use basin”; the concept of the “wastewater use basin” is presented as a working unit of a smaller scale than traditional river basins, which allows for a better management of the water collected in the sewerage network and rainwater of urban agglomerations. It is a geographically-focused proposal for the integrated management of wastewater and stormwater that ends up in a wastewater treatment plant for treatment and reuse. The study area is located in the southeast of the Iberian Peninsula, Spain; specifically, the Campo of Cartagena-Mar Menor district (Murcia) and Vega Baja district (Alicante). The results show the trend behaviour of rainfall in the Segura river basin in recent episodes of torrential rainfall. There is a clear tendency for these episodes to occur in the coastal and pre-coastal areas, so that the water does not reach the headwaters where the reservoirs are located. For this reason, the proposed concept includes the area of the basin that would be formed by the wastewater and rainwater collectors which, in short, are intended to be treated in a treatment plant for subsequent reuse. The calculations made on the basis of the capacity of the environmental tanks executed and projected amount to four cubic hectometers which could be added to the hydrological planning of the Segura basin. In conclusion, the collection of rainwater allows the incorporation of an additional volume of water that complements and increases the resources offered by the treatment plants in the hydrological planning. It also serves as a measure of adaptation to climatic extremes (droughts and floods) and to the effects of climate change, supporting a circular management of the use of resources. Full article

It has been scientifically proven that climate change is a reality. In subarid Mediterranean limates, this fact is observed in the irregular distribution of rainfall, resulting in alternating periods of more or less prolonged drought with episodes of torrential rains concentrated in short periods of time. We have selected 11 natural areas in southern Spain, where we will observe these circumstances and where a series of ecosystems composed of vegetation covers of a high ecological value are found. We start from the question of whether these climatic circumstances are really deteriorating them. For this study, we propose a method that combines three analysis techniques: the design of the time series, the application of vegetation indices, and the use of techniques analysis of changes in land use. From the combination of these techniques in the period from 1997 to 2021, we have observed that there have been a dynamic of changes in land use that has maintained its original characteristics by more than 70%, so it is possible to affirm that the adaptation of ecosystems to climatic conditions has occurred satisfactorily. However, this general statement shows some particularities which are those that we will show in this work. Full article

Climate change scenarios are predicting an increase in temperature as well as more scarce and torrential rainfall episodes. Due to this, an imbalance between grape technological and phenolic maturity is being observed, which detrimentally affects the grapes’ composition. In semi-arid areas, irrigation management is a main field practice used to influence grape ripening. The goal of the present study was to investigate the influence of vine irrigation on the aroma composition and sensory characteristics of La Mancha Chelva wines. Volatile compounds were studied by gas chromatography–mass spectrometry (GC/MS). A total of 75 aroma compounds were identified and quantified in Chelva wines elaborated with grapes of irrigated and non-irrigated vines. The results show that the application of irrigation during vine cultivation produced small changes in the concentration of wine volatile compounds. Nevertheless, it increased, in general, the intensity of the attributes of the main aroma sensory profile of the wines. According to the results, the vine irrigation of Chelva cultivated in the La Mancha region can be used as a method to increase the aroma of wines. Full article

The coastal regions of South Ecuador and Peru belong to the areas experiencing the strongest impact of the El Niño Southern Oscillation phenomenon. However, the impact and dynamic development of weather patterns during those events are not well understood, due to the sparse observational networks. In spite of neutral to cold conditions after the decaying 2015/16 El Niño in the central Pacific, the coastal region was hit by torrential rainfall in 2017 causing floods, erosion and landslides with many fatalities and significant damages to infrastructure. A new network of X-band weather radar systems in South Ecuador and North Peru allowed, for the first time, the spatio-temporally high-resolution monitoring of rainfall dynamics, also covering the 2017 event. Here, we compare this episode to the period 2014–2018 to point out the specific atmospheric process dynamics of this event. We found that isolated warming of the Niño 1 and 2 region sea surface temperature was the initial driver of the strong rainfall, but local weather patterns were modified by topography interacting with the synoptic situation. The high resolution radar data, for the first time, allowed to monitor previously unknown local spots of heavy rainfall during ENSO-related extreme events, associated with dynamic flow convergence initiated by low-level thermal breezes. Altogether, the coastal El Niño of 2017, at the same time, caused positive rainfall anomalies in the coastal plain and on the eastern slopes of the Andes, the latter normally associated only with La Niña events. Thus, the 2017 event must be attributed to the La Niña Modoki type. Full article

Rivers link terrestrial and marine ecosystems, not only transporting numerous substances downstream but also shaping landscapes and fostering aquatic ecosystems through physical interactions and biogeochemical processes with numerous agents. On the other hand, hydraulic facilities, such as reservoirs, hydropower plants, and banks are deployed to utilize water resources for sustaining human society. In the river network systems, rainstorms, as episodic/periodic strong triggers, can induce mass wasting from hillslopes, accelerating nutrient transport, which causes sequential effects. In recent decades, global warming has been accelerating water cycling via thermodynamics, and thus, the frequency and intensity of extreme rainstorms are increasing in intensity. In the West Pacific, typhoons (alias tropical cyclones in Asia) characterized by strong wind and torrential rainfall are evidenced to be getting stronger. The intensified typhoons inevitably stimulate the response of river systems through sediment and nutrient transport and threaten the safe operation of the hydraulic facilities and even coastal communities through storm surge flooding. These strong impacts on river systems should be comprehensively explored. This issue aims to improve the understanding of typhoon effects in river systems. Inter- and cross-disciplinary studies on different watershed scales, linking ecosystem services and watershed management, are particularly addressed. Full article

Soil quality indexes (SQIs) are very useful in assessing the status and edaphic health of soils. This is particularly the case in the Mediterranean area, where successive torrential rainfall episodes give rise to erosion and soil degradation processes; these are being exacerbated by the current climate crisis. The objective of this study was to analyze the soil quality in two contrasting Mediterranean watersheds in the province of Malaga (Spain): the middle and upper watersheds of the Rio Grande (sub-humid conditions) and the Benamargosa River (semi-arid conditions). Field soil sampling was carried out at representative sites, and the soils were subsequently analyzed for various edaphic properties in the laboratory. From the resulting data, the mean values have been grouped and reclassified, and, based on a multicriteria evaluation, an SQI for the study region was generated. The results show that there are major differences between the two watersheds, with optimal soil quality values being found in the Rio Grande watershed (very high soil quality—34.26%), but more unfavorable values occurring throughout most of the Benamargosa River watershed (very low soil quality—63.33%). Thus, these results have been subjected to a validation process in the field. Full article