Orbital-scale nonlinear response of East Asian summer monsoon to its potential driving forces in the late Quaternary

We conducted a statistical study to characterize the nonlinear response of the East Asian summer monsoon (EASM) to its potential forcing factors over the last 260 ka on orbital timescales. We find that both variation in solar insolation and global ice volume were responsible for the nonlinear forcing of orbital-scale monsoonal variations, accounting for similar to 80% of the total variance. Specifically, EASM records with dominated precession variance exhibit a more sensitive response to changes in solar insolation during intervals of enhanced monsoon strength, but are less sensitive during intervals of reduced monsoon strength. In the case of global ice volume with 100-ka variance, this difference is not one of sensitivity but rather a difference in baseline conditions, such as the relative areas of land and sea which affected the land-sea thermal gradient. We therefore suggest that EASM records with dominated precession variance recorded the signal of a shift in the location of the Inter-tropical Convergence Zone, and the associated changes in the incidence of torrential rainfall; while for proxies with dominated 100-ka variance, it recorded changes in the land-sea thermal gradient via its effects on non-torrential precipitation

The Establishment of Rapid Evaluating System for Surficial Inundations

Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv

RESILIENCE MANAGEMENT: FROM FUKUSHIMA DISASTER TO BOILING OCEANS AND NORTHWARD VIRAL SPREAD

We reviews the necessity of \u27resilience based on disaster management\u27 (Chroust, G., 2015). Firstly, it examines non-resilience, showing the current status of nuclear fuel debris, contaminated water and radioactive waste after the Fukushima Nuclear Disaster, since when radioactive contamination has damaged the local community and socio-economic systems. Secondly, it presents evidence of global spread of super-typhoons and unusual weather patterns, with the location of maximum typhoon intensity having moved northward by approximately 150-200 km compared to 1982, and at the same time expanded due to the \u27boiling ocean\u27 effect. Thirdly: it considers ir-resilience, \u27global ocean warming\u27 through the multiplier effects of hydrospheric and CO2 atmospheric warming. Finally: it discusses un-resilience, arising from the spread of infectious tropical diseases to the northern hemisphere caused by global ocean warming, as part of the irreversible environmental change caused by our artificial systems, which will increase the risk and crisis of disasters for all human beings. Re-consideration of our living systems is therefore necessary to create awareness of the \u27five functions of resilience management\u27 for all-round sustainability.Proceedings of the 61st Annual Meeting of the ISSS - 2017 Vienna, Austriahttp://journals.isss.org/index.php/proceedings61st/article/view/319

The Variation of Riverbed Material due to Tropical Storms in Shi-Wen River, Taiwan

Taiwan, because of its location, is a flood prone region and is characterised by typhoons which brings about two-thirds to three quarters of the annual rainfall amount. Consequently, enormous flows result in rivers and entrain some fractions of the grains that constitute the riverbed. Hence, the purpose of the study is to quantify the impacts of these enormous flows on the distribution of grain size in riverbeds. The characteristics of riverbed material prior to and after the typhoon season are compared in Shi-Wen River located at southern Taiwan. These include grain size variation, bimodality, and roughness coefficient. A decrease (65%) and increase (50%) in geometric mean size of grains were observed for subsurface and surface bed material, respectively. Geometric standard deviation decreased in all sites after typhoon. Subsurface material was bimodal prior to typhoons and polymodal after. For surface material, modal class is in the gravel class, while after typhoons it shifts towards cobble class. The reduction in geometric mean resulted to a decrease in roughness coefficient by up to 30%. Finally, the relationship of Shields and Froude numbers are studied and a change in the bed form to antidunes and transition form is observed, respectively

Characteristics of rainfall during tropical cyclone periods in Taiwan

Due to the Central Mountain Range with an elevation up to about 4 km, the amount and distribution of rainfall in Taiwan associated with typhoons or tropical cyclones (TCs) depends not only on the distribution of convection within the TCs (internal structure) and influences from monsoon-scale environmental flow, but also on the orographic effect. This study analyzes the spatial and temporal characteristics of rainfall associated with 62 TC cases that affected Taiwan by using observations from the 371 automatic rain stations available in the period 1989–2002. It is found from the climatology maps that highly different rainfall distributions occurred for TCs that approached the Taiwan area from different directions. By performing objective clustering analysis of the rainfall time series of all the rain gauges, several characteristic temporal rainfall profiles are obtained. The geographic distribution of rain gauges that possess a particular temporal profile is also consistent with the possible TC track types that bring maximum rain to the Taiwan area at different times. <br><br> Based on data in the 1989–2002 period, the development of a TC rainfall climatology-persistence (CLIPER) model is described. CLIPER is an optimized combination of climatology and persistence with different relative weighting for different forecast periods. Independent cases (other than the model development database) during 2003–2004 are used to validate the model. Objective measures like equitable threat score and bias score show that CLIPER's skill is acceptable for practical applications for 24-h rain threshold below 100 mm. However, the underestimation bias for more heavy rainfall is serious and CLIPER seems to have better performance for the northwestern Taiwan than for the other locations. Future directions for improvement of the CLIPER model are discussed

Rainfall and Landslide Correlation Analysis and Prediction of Future Rainfall Base on Climate Change

The aim of this study is to analyze the quantitative relationship between the volume of rainfall and landslide occurrence in South Korea. To predict future rainfall, a future climate scenario was developed by downscaling the regional climate model (RCM) from the global climate model (GCM) based on the Intergovernmental Panel on Climate Change (IPCC) A1B scenario. In this study, for a quantitative analysis of correlation between rainfall and landslides occurrence, data on rainfall and landslides in Korea in the 2000s was analyzed using the correlation between the occurrence of landslides and rainfall volume (daily and accumulated) and the maximum hourly intensity of rainfall. Daily rainfalls exceeding 164.5 mm is categorized as high risk for landslide. A rainfall that continued for 3 days was found to affect the occurrence of landslide in Korea in the 2000s more than any other number of days during which rainfall lasted. The research area for the future climate change scenarios (A1B) covers the entire area of South Korea. Annual average rainfall had increased by 271.23 mm during 1971–2100. The development of downscaling method using GIS and verification with observed data could reduce the uncertainty of future climate change projection

Hazardousness of place : a new comparative approach to the Filipino past

© Ateneo de Manila University. The historiography of the Philippines has been largely bounded by the nation-state, which has defined how its past has been conceived and to whom its peoples are mainly compared. A more transnational environmental history, however, seeks to situate the archipelago within the context of the daily threats that its peoples have to face. This article focuses on the hazardous nature of living in the islands and explores the ways in which Filipinos have adapted to natural hazards as a frequent life experience over time

Resistance and resilience of social–ecological systems to recurrent typhoon disturbance on a subtropical island: Taiwan

Tropical cyclones (TCs) have major effects on ecological and social systems. However, studies integrating the effects of TCs on both social and ecological systems are rare, especially in the northwest Pacific, where the frequency of TCs (locally named typhoons) is the highest in the world. We synthesized studies of effects of recurrent typhoons on social and ecological systems in Taiwan over the last several decades. Many responses to TCs are comparable between social and ecological systems. High forest ecosystem resistance, evident from tree mortality below 2% even following multiple strong typhoons, is comparable with resistance of social systems, including the only 4% destruction of river embankments following a typhoon that brought nearly 3000 mm rainfall in three days. High resilience as reflected by quick returns of leaf area index, mostly in one year, and streamwater chemistry, one to several weeks to pre‐typhoon levels of ecosystems, are comparable to quick repair of the power grid within one to several days and returns of vegetable price within several weeks to pre‐typhoon levels of the social systems. Landslides associated with intense typhoons have buried mountain villages and transported large quantities of woody debris to the coast, affecting the coastal plains and reefs, illustrating a ridge‐to‐reef link between ecological and societal systems. Metrics of both social and ecological function showed large fluctuations in response to typhoons but quickly returned to pre‐disturbance levels, except when multiple intense typhoons occurred within a single season. Our synthesis illustrates that the social–ecological systems in Taiwan are highly dynamic and responsive to frequent typhoon disturbance, with extraordinarily high resistance and resilience. For ecosystems, the efficient responsiveness results from the selective force of TCs on ecosystem structure and processes. For social systems, it is the result of the effects of TCs on planning and decision making by individuals (e.g., farmers), management sectors, and ultimately the government. In regions with frequent TCs, the social–ecological systems are inevitably highly dynamic and rapid responses are fundamental to system resistance and resilience which in turn is key to maintaining structure and function of the social–ecological systems

Climatological Relationship between Warm Season Atmospheric Rivers and Heavy Rainfall over East Asia

Eddy transport of atmospheric water vapor from the tropics is important for rainfall and related natural disasters in the middle latitudes. Atmospheric rivers (ARs), intense moisture plumes that are typically associated with extratropical cyclones, often produce heavy precipitation upon encountering topography on the west coasts of mid-latitude North America and Europe. ARs also occur over the northwestern Pacific and sometimes cause floods and landslides over East Asia, but the climatological relationship between ARs and heavy rainfall in this region remains unclear. Here we evaluate the contribution of ARs to the hydrological cycle over East Asia using high-resolution daily rainfall observations and an atmospheric reanalysis during 1958-2007. Despite their low occurrence, ARs account for 14-44 % of the total rainfall and 20-90 % of extreme heavy-rainfall events during spring, summer, and autumn. AR-related extreme rainfall is especially pronounced over western-to-southeastern slopes of terrains over the Korean Peninsula and Japan, owing to strong orographic effects and a stable direction of low-level moisture flows. A strong relationship between warm-season AR heavy rainfall and preceding-winter El Niño is identified since the 1970s, suggesting the potential of predicting heavy-rainfall risk over Korea and Japan at seasonal leads