Remobilization of Sediments in Gully Pots During High Intensity Precipitation Events

2018 ◽  
pp. 993-996
Author(s):  
Tone Merete Muthanna ◽  
Maria Viklander
Keyword(s):  
High Intensity ◽  
Precipitation Events

More exposed but also more vulnerable? Climate change, high intensity precipitation events and flooding in Mediterranean Spain

2020 ◽  
Vol 29 (3) ◽  
pp. 229-248 ◽  
Author(s):  
Anna Ribas ◽  
Jorge Olcina ◽  
David Sauri
Keyword(s):  
High Intensity ◽  
Urban Areas ◽  
Design Methodology ◽  
Urban Drainage ◽  
Content Type ◽  
Linear Approach ◽  
Changing Patterns ◽  
Flood Flows ◽  
Precipitation Events

Purpose The purpose of this paper is to examine the role of high intensity precipitation events in increasing the vulnerability to floods in Mediterranean Spain. Precipitation intensity in this area appears to have augmented in the last two decades in association with warming trends of the Mediterranean Sea. At the same time, intense urbanization processes, occupying and transforming flood prone land, have produced an important increase in exposure. The main objective is to assess whether higher intensity precipitation and changing patterns in exposure aggravate vulnerability to floods. Design/methodology/approach In this paper, vulnerability is understood as the result of the interrelationships between exposure, sensitivity, impacts and adaptive capacity. Consequently, methods used involved the compilation and analysis of published and unpublished precipitation data, population and land use data, data on insurance claims, and media sources related to those variables. Findings Changes toward episodes of more intense precipitation in the expanding urban areas of Mediterranean Spain increase exposure but not necessarily vulnerability, at least in terms of human deaths. However, adaptative capacity needs to be formulated. Actions that attempt to absorb and eventually reuse flood flows (as the flood park in Alicante) appear to be more effective than traditional hydraulic solutions (as in Majorca). Originality/value The paper provides a systematic and coherent approach to vulnerability analysis taking into account the changing dynamics of its components. Especially, it signals the limits of current adaptive approaches to flooding and advocates for changes toward a more circular and less linear approach to urban drainage.

scholarly journals Tracking the error sources of spatiotemporal differences in TRMM accuracy using error decomposition method

2018 ◽  
Vol 49 (6) ◽  
pp. 1960-1976 ◽  
Author(s):  
Jialing Wang ◽  
Hua Chen ◽  
Chong-Yu Xu ◽  
Qiang Zeng ◽  
Qingjing Wang ◽  
...  
Keyword(s):  
High Intensity ◽  
Decomposition Method ◽  
High Elevation ◽  
Precipitation Intensity ◽  
Xiangjiang River ◽  
Satellite Precipitation ◽  
Low Intensity ◽  
Error Components ◽  
Error Decomposition ◽  
Precipitation Events

Abstract Tropical Rainfall Measuring Mission (TRMM) products are widely utilized, but the causes of the differences in their spatiotemporal accuracy require further investigation to improve satellite precipitation estimation. In this study, the spatiotemporal accuracy of TRMM 3B42 V7 data was systematically evaluated using the rain gauge data of the densely gauged Xiangjiang River basin, a humid region in South China. The effects of the precipitation intensity and elevation on different error components derived from the error decomposition method were analysed to reveal the causes of spatiotemporal differences of the data errors. The results showed the following. (1) TRMM performs better in the wet season than in the dry season, and it underestimates precipitation in winter and in high-elevation areas. (2) Precipitation intensity directly influences the occurrence and magnitude of error components. Most of the missed precipitation (precipitation detected only by rain-gauged data) and false precipitation (precipitation detected only by TRMM data) occur in low-intensity precipitation events. Hit events (precipitation detected by both TRMM and rain-gauged data) tend to overestimate low-intensity precipitation and underestimate high-intensity precipitation. Elevation has no direct relation with daily bias, but affects the distribution of occurrence and intensity of precipitation events. (3) Missed precipitation is the main contributing source of error in winter. The negative error increases in high-elevation areas, which is contributed by the larger proportion of high intensity hit precipitation and the missed events. This study is not only beneficial for understanding the effect of topography and climate factors on the accuracy of TRMM precipitation data but also provides a reference for the application and error improvement of satellite precipitation products.

scholarly journals The large-scale spatio-temporal variability of precipitation over Sweden observed from the weather radar network

2013 ◽  
Vol 6 (6) ◽  
pp. 10699-10730
Author(s):  
A. Devasthale ◽  
L. Norin
Keyword(s):  
Temporal Variability ◽  
High Intensity ◽  
Large Scale ◽  
Weather Radar ◽  
Radar Data ◽  
The Arctic ◽  
Northern Sweden ◽  
Late Night ◽  
Spatio Temporal ◽  
Precipitation Events

Abstract. Using measurements from the national network of 12 weather radar stations for the last decade (2000–2010), we investigate the large-scale spatio-temporal variability of precipitation over Sweden. These statistics provide useful information to evaluate regional climate models as well as for hydrology and energy applications. A strict quality control is applied to filter out noise and artifacts from the radar data. We focus on investigating four distinct aspects namely, the diurnal cycle of precipitation and its seasonality, the dominant time scale (diurnal vs. seasonal) of variability, precipitation response to different wind directions, and the correlation of precipitation events with the North Atlantic Oscillation (NAO) and the Arctic Oscillation (AO). When classified based on their intensity, moderate to high intensity events (precipitation > 0.34 mm (3 h)−1) peak distinctly during late afternoon over the majority of radar stations in summer and during late night or early morning in winter. Precipitation variability is highest over the southwestern parts of Sweden. It is shown that the high intensity events (precipitation > 1.7mm (3 h)−1) are positively correlated with NAO and AO (esp. over northern Sweden), while the low intensity events are negatively correlated (esp. over southeastern parts). It is further observed that southeasterly winds often lead to intense precipitation events over central and northern Sweden, while southwesterly winds contribute most to the total accumulated precipitation for all radar stations. Apart from its operational applications, the present study demonstrates the potential of the weather radar data set for studying climatic features of precipitation over Sweden.

scholarly journals Projected Changes in the Annual Cycle of High-Intensity Precipitation Events over West Africa for the Late Twenty-First Century*

2015 ◽  
Vol 28 (16) ◽  
pp. 6475-6488 ◽  
Author(s):  
Mouhamadou Bamba Sylla ◽  
Filippo Giorgi ◽  
Jeremy S. Pal ◽  
Peter Gibba ◽  
Ibourahima Kebe ◽  
...  
Keyword(s):  
West Africa ◽  
Annual Cycle ◽  
High Intensity ◽  
Daily Precipitation ◽  
Monsoon Season ◽  
First Century ◽  
Increased Risk ◽  
Twenty First Century ◽  
Projected Changes ◽  
Precipitation Events

Abstract In this study, the response of the annual cycle of high-intensity daily precipitation events over West Africa to anthropogenic greenhouse gas for the late twenty-first century is investigated using an ensemble of high-resolution regional climate model experiments. For the present day, the RCM ensemble substantially improves the simulation of the annual cycle for various precipitation statistics compared to the driving Earth system models. The late-twenty-first-century projected changes in mean precipitation exhibit a delay of the monsoon season, consistent with previous studies. In addition, these projections indicate a prevailing decrease in frequency but increase in intensity of very wet events, particularly in the premonsoon and early mature monsoon stages, more pronounced over the Sahel and in RCP8.5 than the Gulf of Guinea and in RCP4.5. This is due to the presence of stronger moisture convergence in the boundary layer that sustains intense precipitation once convection is initiated. The premonsoon season experiences the largest changes in daily precipitation statistics, particularly toward an increased risk of drought associated with a decrease in mean precipitation and frequency of wet days and an increased risk of flood associated with very wet events. Both of these features can produce significant stresses on important sectors such as agriculture and water resources at a time of the year (e.g., the monsoon onset) where such stresses can have stronger impacts. The results thus point toward the importance of analyzing changes of precipitation characteristics as a function of the regional seasonal and subseasonal cycles of rainfall.

scholarly journals Changes in high-intensity precipitation on the northern Apennines (Italy) as revealed by multidisciplinary data over the last 9000 years

2020 ◽  
Vol 16 (4) ◽  
pp. 1547-1564
Author(s):  
Stefano Segadelli ◽  
Federico Grazzini ◽  
Veronica Rossi ◽  
Margherita Aguzzi ◽  
Silvia Marvelli ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
High Intensity ◽  
Debris Flows ◽  
Northern Apennines ◽  
Coarse Grained ◽  
Precipitation Event ◽  
Peat Bog ◽  
Field Campaign ◽  
The Past ◽  
Precipitation Events

Abstract. Several record-breaking precipitation events have struck the mountainous area of the Emilia–Romagna region (northern Apennines, Italy) over the last 10 years. As a consequence, severe geomorphological processes such as debris avalanches and debris flows, shallow landslides, and overbank flooding have affected the territory, causing severe damage to human-made structures. The unusual intensity of these phenomena prompted an investigation into their frequency in the past, beyond instrumental time. In the quest for an understanding of whether these phenomena are unprecedented in the region, peat bog and lake deposits were analyzed to infer the frequency of extreme precipitation events that may have occurred in the past. We present the results of a dedicated field campaign performed in summer 2017 at Lake Moo in the northern Apennines, a 0.15 km2 peat bog located at an altitude of 1130 m a.s.l. During the extreme precipitation event of 13–14 September 2015, several debris flows generated by small streams affected the Lake Moo plain. In such a small drainage basin (<2 km2), high-density floods can be triggered only by high-intensity precipitation events. The sedimentary succession (ca. 13 m thick) was studied through the drilling of two cores and one trench. The sequence, characterized by clusters of coarse-grained alluvial deposits interbedded with organic-rich silty clays and peat layers, was analyzed by combining sedimentological, pollen, microanthracological and pedological data with radiocarbon dating (AMS 14C) in an innovative multidisciplinary approach for this area. Original data acquired during the field campaign were also correlated with other specific paleoclimatic proxies available in the literature for the northern Apennines area. We discover that the increase in extreme paleoflooding, associated with coarse-grained deposits similar to the ones observed recently, correlates well with the warm phases of the Holocene Thermal Maximum and with the ongoing warming trend observed that started at the beginning of the last century.

scholarly journals Characterizing the properties of daily precipitation concentration in Amur River Basin of northeast China

2019 ◽  
Vol 117 ◽  
pp. 00003
Author(s):  
Yousheng Wang ◽  
Jianzhao Guan ◽  
Xiaoming Zhang ◽  
Pengfei Du ◽  
Lei Zhang ◽  
...  
Keyword(s):  
River Basin ◽  
High Intensity ◽  
Northeast China ◽  
Precipitation Amount ◽  
Amur River Basin ◽  
Amur River ◽  
Precipitation Concentration ◽  
The Amur River ◽  
Rainy Days ◽  
Precipitation Events

The Amur River Basin is one of the most sensitive areas to the effects of climate change. In this study, spatial and temporal analysis of concentration index over the Amur River Basin in northeast China was presented. Precipitation data from 71 meteorological stations for the time series 1980-2018 on daily scale was employed in the study. The results indicated that precipitation events of low-intensity accounted for 28.59 % of rainy days, however, the proportion of rain amount was 1.33 %. On the contrary, high-and very high-intensity events accounted for 40.34 % of rainy days and as high as 90.53 % of annual precipitation amount. Precipitation concentration explain the cause of why some regions are prone to be influenced by high intensity precipitation events, spatial distribution of different intensities can be partly interpreted by daily rainfall heterogeneity and regional geomorphology. Furthermore, a significant change toward a stronger precipitation concentration was demonstrated over some regions, and this need concern from the administration.

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