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

Landslides Triggered by Typhoon Morakot in Taiwan

Landslides are general geomorphic erosion processes on hillslopes and can usually cause severe threats to human life and property due to their unexpected occurrence and fast traveling. Typhoon Morakot (in 2009) released more than 2000 mm rainfall during 6 days at the beginning of August 5 in Taiwan, leading to a large number of landslides, especially in southern Taiwan. Here we significantly devote this chapter to address the causes and effects of landslides in Cishan River watershed accompanied with the primary factors of landslide triggering such as the geologic and topographic settings and rainfall characteristics. We evaluate the devastation of landslides caused by Typhoon Morakot and its aftermath, and also assess the present status of landslide hazards mitigation strategies in Taiwan

Soil-Water Conservation, Erosion, and Landslide

The predicted climate change is likely to cause extreme storm events and, subsequently, catastrophic disasters, including soil erosion, debris and landslide formation, loss of life, etc. In the decade from 1976, natural disasters affected less than a billion lives. These numbers have surged in the last decade alone. It is said that natural disasters have affected over 3 billion lives, killed on average 750,000 people, and cost more than 600 billion US dollars. Of these numbers, a greater proportion are due to sediment-related disasters, and these numbers are an indication of the amount of work still to be done in the field of soil erosion, conservation, and landslides. Scientists, engineers, and planners are all under immense pressure to develop and improve existing scientific tools to model erosion and landslides and, in the process, better conserve the soil. Therefore, the purpose of this Special Issue is to improve our knowledge on the processes and mechanics of soil erosion and landslides. In turn, these will be crucial in developing the right tools and models for soil and water conservation, disaster mitigation, and early warning systems

The effect of tropical cyclones on the carbon cycle

Tropical cyclones influence processes within the carbon cycle on different time-scales. Forested ecosystems suffer windfall and long-term impacts from tropical cyclones, leading to the release of CO2 to the atmosphere. The coarse woody debris created by extreme wind speeds and landslides brought on by tropical cyclones can leave a forested ecosystem via riverine channels and end up in the ocean, where it is unclear whether it is buried or slowly decomposed. Particulate organic carbon is flushed out of terrestrial ecosystems along with the coarse woody debris. Furthermore, air-sea fluxes of CO2 are influenced and local levels can be altered significantly by the passage of a tropical cyclone. Mixing induced in the euphotic zone of the oceans leads to increases in primary production in the wake of tropical cyclones, which could be an important factor in the global carbon balance. Global warming has led and will lead to changes in the frequency and intensity of tropical cyclones, and therefore the importance of these processes will shift in the future. In this review, the effect of tropical cyclones on tree mortality, terrestrial carbon transport, ocean primary production and air-sea co2 fluxes were singled out and researched. Factors playing into these processes and the speculated impact of the changing climate were analysed. Case studies on each of these processes were examined and their impact and importance was quantified. As tropical cyclones mainly impact the oceans and make landfall between 45° north and 45° south of the equator, these areas were focused on. Both modelled and observed methods of research were considered and reviewed.Tropical cyclones are known for their devastating effect on coastal communities, and the loss of lives and economic damage they cause. An aspect that has traditionally not received a lot of attention is how tropical cyclones interact with nature itself, and more specifically, the carbon cycle. The carbon cycle is a term used for processes involving the storage and transport of carbon around the globe. The amount of carbon stored in and released by ecosystems is used as an indicator for its effect on greenhouse global warming, and measuring these values is therefore very important. It may not be immediately apparent how tropical cyclones affect the carbon cycle. Some examples of these effects are easily recognized and understood. Windfall is caused as extreme wind speeds strike a forest. The immense amounts of precipitation that occur during a tropical cyclone cause elevated levels of erosion and can lead to landslides on sloped areas. However, it is not apparent how large the effect of tropical cyclones on these processes is and what happens to the carbon stored inside the soils and trees that are affected. There are also many unknowns as to how tropical cyclones impact processes involving carbon in the oceans. The upper layers of the oceans are exposed to sunlight, and the phytoplankton found here photosynthesizes and takes up carbon dioxide. Phytoplankton blooms have been observed in the wake of tropical cyclones. Lastly, fluxes of carbon between the oceans and the atmosphere are heightened during tropical cyclones. All these processes were examined and their effects on and interactions with the carbon cycle were discussed. As tropical cyclones obstruct measurements due to the violent conditions found inside them, and because the cloud cover obscures certain wavelengths of light used in remote sensing, scientists have not been able to come to conclusive results in this field. My work finds that tropical cyclones indeed do have a strong effect on the carbon cycle through the processes described above, but it is unclear how much of an effect it is. As global warming is bound to have a strong effect on these extreme storms, determining just how important tropical cyclones are in respect to the carbon cycle is of great importance

Resilience Assessment of Mountain Settlements Isolation Effects in Extreme Climate Change

It’s been a while since people have awareness of the environmental impact of climate change, especially in mountain settelements of Taiwan. Extreme heavy precipitation event was very rare in the past, we rarely saw a disaster occurrence that affect the daily life of human beings. However, due to the impact of climate change, the occurs of extremely heavy precipitation events in Taiwan are more and more frequent in the past 20 years. From once every few years to nearly a dozen times a year, including heavy rain and typhoon every summer and autumn. Taiwan has special geographical factors: narrow land, densely populated, and a high density of streams. If the slope is greater than 5 degrees or the elevation is greater than 100m, the region is regarded as a mountain area. Such an area occupies about 70% lands of Taiwan, and there are many old settlements and aboriginal tribes living here. The best-known disaster event was the typhoon Morakot in 2009, it caused serious flooding, mountain crashing, and landslides in many areas of Taiwan. These disasters in mountain settlements are the most serious, including road blockage, house inundation, water and food shortages, etc. After the typhoon Morakot, People refer to "the situation in which mountain settlements are blocked due to climate phenomena" as an "isolation effect" due to plenty of news reports. Mountain settlements that have an isolation effect are like inhabitants of isolated islands on the sea. It’s difficult for local residents to save themselves, and it is hard to obtain external rescue resources. Because of the natural landform and special socio-economic environment of mountain settlements, we need to pay attention to such problems occur. The collection of “isolation effect” data is from domestic news reports, from 2000 to October 2021. A total of 326 disasters had occurred in 151 villages(The level is larger than that of the settlement because the news media mostly reported the disaster situation in the village as a unit). The severity of the disaster ranges from mild to severe, there were also many villages where the isolation effect had repeatedly occurred in different years. This study attempts to integrate and analyze the weights of the isolation effect from past studies, at this stage, the historic isolation effect villages have been split into 270 historic isolation effect settlements. The indicators include general isolation effect, hazard, exposure, and vulnerability. Then, the weight of the analyzed indicators is used to determine the other 360 mountain settlements in Taiwan. Looking forward to clarifying the potential degree of isolation effect that may occur in the future, and providing it to the public. It is hoped that such a demonstration will allow the government to carry out more disaster reduction measures for mountain settlements, and local residents can also have considerable disaster awareness in their homes. In the future, climate change will be more abrupt, but mountain settlement residents can also live and work in peace

Case-Based Reasoning of Man-Made Geohazards Induced by Rainfall on Transportation Systems

Due to global warming and environmental change, disastrous natural events have increased in scale and impact, e.g., Typhoon Morakot, in 2009 and 2011 Tōhoku earthquake and resulting tsunami in Japan. Hazard management is becoming increasingly important, making it a necessity to manage risk and fully understand critical scenarios. For example, the National Infrastructure Protection Plan of the United States emphasizes on lessons learned from past disasters. In this chapter, several selected cases of accidents caused by man-made geohazards in Taiwan are studied

Indigenous Resilience and Indigenous Knowledge Systems in the context of Climate Change

Indigenous peoples, in Taiwan and worldwide, need to come up with various ways to cope with and adapt to rapid environmental change. This edited book, which is a follow-up to a conference entitled “Climate Change, Indigenous Resilience and Local Knowledge Systems: Cross-time and Cross-boundary Perspectives” organized by the Research Institute for the Humanities and Social Sciences, Ministry of Science and Technology, presents 16 papers which explore the various dimensions of Indigenous resilience to climate change and disasters in Taiwan and other regions in the world. This book explores the interrelated themes of climate change and Indigenous knowledge-based responses, and Indigenous (community) resilience with specific reference to Typhoon Morakot and beyond. The goals of this book are to discuss the international experience with Indigenous resilience; to review Indigenous knowledge for adaptation to climate change and disasters; and to generate a conversation among scholars, Indigenous peoples, and policy-makers to move the agenda forward. This book focusses on Indigenous resilience, the ways in which cultural factors such as knowledge and learning, along with the broader political ecology, determine how local and Indigenous people understand, deal with, and adapt to environmental change

Climatology and Change of Extreme Precipitation Events in Taiwan Based on Weather Types

Taiwan\u27s most significant natural hazards are caused by hydrological extremes resulting from excessive precipitation. The threat of extreme precipitation is posed by several different types of weather patterns that affect Taiwan. This study examined the bi‐decadal changes in rainfall by defining an extreme precipitation occurrence (EPO) for a range of event durations from 1 to 24 hr. Three major weather types affecting EPO in Taiwan were identified from 1993 to 2015: the front type consisting of either a frontal zone or convective systems developing with an apparent Meiyu cloudband, diurnal rainfall events when no apparent synoptic features are present, and a tropical cyclone (TC) type according to the maximum sustained wind radius of a TC. Results show that TC‐type events have the greatest overall contribution to EPO at longer (\u3e6 hr) durations. Diurnal/afternoon convection events contribute most to the shorter (\u3c3 hr) duration EPO, while frontal/Meiyu systems prevail in the medium (3–6 hr) duration. EPO of almost all durations have experienced an increase, with the 3‐ and 12‐hr EPO having increased by 4.6 days each over the 23 years. However, apparent decadal‐scale variability exists in these EPO associated with the decreasing tendency of EPO after the mid‐2000s, particularly the longer duration (\u3e6 hr) EPO associated with the TC‐type events in summer. The distinction between EPO trends for the entire island of Taiwan and for the Taipei metropolitan area alone (northern Taiwan, population of 7 million) were compared, and an intriguing interannual variation is reported in the TC‐type EPO associated with the TC season 1 year to a year and half just before an El Niño–Southern Oscillation event. The analysis here provides refined statistical distributions of extreme rainfall, and these can contribute to the revision of governmental definitions for weather disasters that are used in mitigation and response strategies