Super Typhoon Research Articles

The Impact of Extreme Weather Events on Bacterial Communities and Opportunistic Pathogens in a Drinking Water Treatment Plant

Drinking water treatment processes are highly effective at improving water quality, but pathogens can still persist in treated water, especially after extreme weather events. To identify how extreme weather events affected bacterial populations in source and treated water, water samples were collected from the Yangtze River Delta area and a local full-scale drinking water treatment plant. Bacterial community structure and the occurrence of pathogens were investigated in samples using 16S rRNA sequencing and qPCR techniques. In this study, the results show that intense rainfall can significantly increase levels of bacteria and opportunistic pathogens in river and drinking water treatment processes (p < 0.05); in particular, the relative abundance of Cyanobacteria increased after a super typhoon event (p < 0.05). The biological activated carbon (BAC) tank was identified as a potential pathogen reservoir and was responsible for 52 ± 6% of the bacteria released downstream, according to Bayesian-based SourceTracker analysis. Our results provide an insight into the challenges faced by maintaining finished water quality under changing weather conditions.

Comparative Study of the Near-Surface Typhoon Wind Profile Fitting between Offshore and Onshore Areas

The study of typhoon wind profiles, especially offshore typhoon wind profiles, has been constrained by the scarcity of observational data. In this study, the Doppler wind lidar was used to observe the offshore wind profiles during Super Typhoon Mangkhut and onshore wind profiles during Super Typhoon Lekima. Four wind profile models, including the power law, logarithmic law, Deaves–Harris (D-H), and Gryning, were selected in the height range of 0–300 m to fit the wind profile. The variations in the power exponent with the mean wind speed and roughness length were also analyzed. The results showed that the wind profiles fitted by the four models were generally in good agreement with the observed wind profiles with correlation coefficients greater than 0.98 and root mean square deviations less than 0.5 m s−1. For the offshore case, the fitting degree of all wind profile models improved with increasing mean wind speed. Specifically, the D-H model had the highest fitting degree when the horizontal mean wind speed at 40 m was in the range of 8–25 m s−1, while the log-law model had the highest fitting degree when the wind speed exceeded 30 m s−1. For the onshore case, the fitting degree of the four wind profile models deteriorated with increasing mean wind speed, and the log-law model had the highest fitting degree in all wind speed intervals from 8 to 30 m s−1. For both offshore and onshore cases, the power exponent was less affected by mean wind speed and increased with increasing roughness length, and the logarithmic empirical model proposed in this study could well characterize the relationship between the power exponent and roughness length.

Status of Coral Reefs in Lagonoy Gulf, Eastern Bicol, Philippines with Emphasis on Marine Protected Areas

Status of coral reef health of 8 Marine Protected Areas (MPA), 6 adjacent MPA reefs and 5 regular reefs of Lagonoy Gulf were assessed from December 2017 to August 2018 and compared with previous gulf-wide assessment results in 1994 and 2004. Underwater photo transect (UPT) method was utilized to collect benthic lifeform information and coral point count with excel extensions (CPCe) was used to analyzed benthic data. Results showed that present live coral cover in MPAs are low with 26% as compared to adjacent MPA reef areas (30%) and regular reef stations (33%). A downtrend was noted from 1993 – 2004 with 10% decline of MPA reefs while from 2004 to 2018 decrease was almost 20% and from 1993 to 2018 an average fall of 25% was detected. Overall, Lagonoy Gulf reef health is declining and can be attributed to both natural and fisheries activities, as evidenced by almost 20 typhoons affecting the Region per year with a super typhoon at least every 5-10 years and the heavy dependence of fishing communities on reef fishes respectively. However, non-MPA reefs decline was observed to very minimal as compared for both MPA and adjacent MPA reefs ranging from 1% to 6%. With this, MPA management schemes should be revisited and amended to improve and strengthen MPA governance, direction and strategies.

Assessment of mangroves affected by super typhoon Pablo in Barangay Lucod, Baganga, Davao Oriental

This study investigates the impact of super typhoon Pablo on mangrove forests in Barangay Lucod, Baganga, Davao Oriental. The mangroves in this area were severely affected by the typhoon, causing damage to individual trees and altering the overall ecosystem structure. The study aimed to assess the damaged and recovered mangroves in the affected area by measuring various parameters such as tree height, canopy branch length, and density. The study also assessed the density, relative density, frequency, and relative frequency of mangrove species, providing insights into their distribution patterns and abundance within the study area. Mangrove measurements were conducted using standard quadrat sampling methods, with four quadrats established within the study area. The results showed that the mangrove of quadrat 2 had the tallest tree which reached 8.5 m. among all quadrats. In canopy branch length, quadrats 3 and 4 have plants with longer branches (5.26 m and 3.6 m). In terms of density, Rhizophora apiculata and Rhizophora stylosa have (0.4 Ind/m2) including Xylocarpus granatum (0.4 Ind/m2). Additionally, the percentage of recovered (55%) and damaged mangroves (45%) in the different quadrats highlighted the ongoing recovery process following the super typhoon. The study contributes valuable information for understanding the impact of natural disasters on mangrove ecosystems and assessing their resilience and recovery mechanisms. The findings can aid in the development of effective conservation and rehabilitation strategies for mangrove forests in typhoon-prone regions in the Philippines.

Interpreting the water use strategies of plantation tree species by canopy stomatal conductance and its sensitivity to vapor pressure deficit in South China

Stomatal regulation controls tree transpiration rate and is central to plant function. However, most previous studies that investigated the stomatal regulation of forest trees mainly focused on arid and semi-arid zones, uncertainty remains about how trees adjust their stomatal response to the changing environment in subtropical moist areas. In this study, we investigated the tree transpiration (El), canopy stomatal conductance (Gs), and Gs sensitivity to vapor pressure deficit (VPD) of four typical plantation tree species (Schima wallichii, Acacia mangium, Eucalyptus urophylla, and Cunninghamia lanceolata) in hilly lands of South China. Datasets including the continuously measured sap flow and meteorological parameters, as well as the physiological traits of the four species, were collected during the year of 2018. Our results showed that the coniferous C. lanceolata had significantly lower El, Gs, and weak sensitivity to VPD than the other three broadleaved species. We attributed the different water use and stomatal behavior to the various species-specific traits. The three broadleaved species generally possessed higher leaf area, specific leaf area (SLA), the ratio of sapwood area (As) to leaf area (Al), and deeper root depth, facilitating their transpiration and gas exchange. During the experimental period, a super typhoon “Mangkhut” hit the research site and caused substantial decline in leaf area, while the whole tree transpiration experienced slighter decrease, indicating the rapid compensatory effect of stomatal regulation. Moreover, the increased Gs sensitivity to VPD (m values) and reference Gs for the introduced A. mangium and E. urophylla in the dry season highlighted their ability to function well even under the much drier condition with no strict stomatal control. Our analyses on the response of Gs to the changing environment for typical species in the subtropical moist forests will provide important insights for forest management and ecosystem stability under future climate changes.

Investigation of time-varying structural dynamic properties of high-rise buildings under typhoon conditions

This paper investigates the time-varying structural dynamic properties of high-rise buildings under typhoon conditions via the covariance-driven stochastic subspace identification (SSI–COV) method. Firstly, a numerical simulation study on a three-degree-of-freedom model is conducted, and the results prove that the SSI–COV method can provide accurate identification of the time-varying structural dynamic properties. Then, based on field measurements on a 420-m-tall high-rise building during Super Typhoon Mangkhut (No. 1822), the time-varying structural dynamic properties of the skyscraper are presented and discussed. The results indicate that the structural natural frequencies exhibited a trend of first decreasing and then increasing, while the damping ratios and modal directions basically remained unchanged during the typhoon process. Moreover, the variation of structural dynamic properties of the fundamental sway modes of the monitored building during 16 typhoons is investigated. The results show that the degree of variation in structural natural frequencies generally increased with the peak acceleration response of the building or the maximum 10-min-mean wind speed atop the building during a typhoon. While the damping ratios of the fundamental sway modes did not vary significantly during these 16 typhoons, which were around 0.64%. This paper aims to further the understanding of structural dynamic properties of high-rise buildings during typhoons.

A Method Based on Numerical Wind Field and Extreme Learning Machine for Typhoon Wind Speed Prediction of Wind Farm

Typhoon wind speed prediction is of great significance for it can help prevent wind farms from damages caused by frequent typhoon disasters in coastal areas. However, most researches on wind forecast are either for meteorological application or for normal weather. Therefore, this paper proposes a systematic method based on numerical wind field and extreme learning machine for typhoon wind speed prediction of wind farms. The proposed method mainly consists of three parts, IGA-YanMeng typhoon numerical simulation model, typhoon status prediction model, and wind speed simulation model based on an extreme learning machine. The IGA-YanMeng typhoon numerical simulation model can greatly enrich typhoon wind speed data according to historical typhoon parameters. The typhoon status prediction model can predict the status of typhoons studied in the next few hours. And wind speed simulation model simulates the average wind speed magnitude/direction at 10 m height of each turbine in the farm according to the predicted status. The end of this paper presents a case study on a wind farm located in Guangdong province that suffered from the super typhoon Mangkhut landed in 2018. The results verified the feasibility and effectiveness of the proposed method.

Harnessing the power of sport for disaster recovery

ABSTRACT This paper contributes to the discourse on sport for development from the psychosocial lens by examining the case of the 3R sport-based intervention for the Filipino survivors of super typhoon Haiyan in the Philippines. Using the five essential principles of effective psychosocial interventions to frame the design, pilot implementation, and preliminary assessment of 3R, it presents a theory-informed post-disaster sport initiative. It also demonstrates how the principles of safety, calmness, connectedness, efficacy, and hope are operationalised in the context of sport outcomes. Fifty-two PE teachers and 39 students, all survivors of Haiyan, participated in the study. Results provided empirical support to the interrelated components of psychosocial care and illustrated how sport interventions could facilitate disaster recovery through the innovative, holistic, inclusive, and culturally nuanced application of effective psychosocial mechanisms. Ultimately, this case study confirms that post-disaster sport interventions are not merely about sport but more about the tangential and vital social processes that occur through the channel of sport.

Control performance of active tuned mass damper for mitigating wind-induced vibrations of a 600-m-tall skyscraper

Based on the field measurements on a 600-m-tall skyscraper equiped with an active tuned mass damper (ATMD) system, this paper investigates the control performance of the world's largest ATMD system to suppress the building vibrations. On-site forced vibration tests on the skyscraper were first conducted and the results showed that the ATMD system can increase the damping ratios of the fundamental sway modes up to about 11 times. Accordingly, ambient vibration tests on the building during Super Typhoon Hato were carried out, and the measured building acceleration responses showed that the ATMD system can effectively suppress the wind-induced vibrations of the skyscraper. Moreover, the structural damping ratios of the building with and without the operation of the ATMD system were identified, which showed that the ATMD system can significantly boost the damping ratios of the fundamental sway modes of the building for suppressing wind-induced vibrations, while it had limited effects on higher modal responses. The paper aims to provide useful information for the design of active vibration control systems and the wind-resistant design of high-rise buildings.

Evaluation of the Simulation of Typhoon Lekima (2019) Based on Different Physical Parameterization Schemes and FY-3D Satellite’s MWHS-2 Data Assimilation

In this study, the case of super typhoon Lekima, which landed in Jiangsu and Zhejiang Province on 4 August 2019, is numerically simulated. Based on the Weather Research and Forecasting (WRF) model, the sensitivity experiments are carried out with different combinations of physical parameterization schemes. The results show that microphysical schemes have obvious impacts on the simulation of the typhoon’s track, while the intensity of the simulated typhoon is more sensitive to surface physical schemes. Based on the results of the typhoon’s track and intensity simulation, one parameterization scheme was further selected to provide the background field for the following data assimilation experiments. Using the three-dimensional variational (3DVar) data assimilation method, the Microwave Humidity Sounder-2 (MWHS-2) radiance data onboard the Fengyun-3D satellite (FY-3D) were assimilated for this case. It was found that the assimilation of the FY-3D MWHS-2 radiance data was able to optimize the initial field of the numerical model in terms of the model variables, especially for the humidity. Finally, by the inspection of the typhoon’s track and intensity forecast, it was found that the assimilation of FY-3D MWHS-2 radiance data improved the skill of the prediction for both the typhoon’s track and intensity.

Observations of wind and turbulence structures of Super Typhoons Hato and Mangkhut over land from a 356 m high meteorological tower

Knowledge of tropical cyclone (TC, or typhoon, hurricane) boundary layer over land is of vital importance to a variety of applications such as track and intensity forecasts of TCs and design of civil structures and infrastructures. On the basis of the 356-m-high Shenzhen Meteorological Gradient Tower which is the tallest of its kind in Asia, this paper presents an observational study of wind and turbulence structure of two Super Typhoons, namely Hato in 2017 and Mangkhut in 2018. First, the mean wind speed profiles, momentum flux, and drag coefficient are analyzed, and their correlations with upwind terrain and wind speed are discussed. Then, the characteristics of wind spectra are investigated and compared with existing spectral models. Subsequently, wind speed variances and turbulent kinetic energy (TKE) are inspected, and their variations with height are examined. Last, the characteristics and vertical profiles of TKE budget are explored. The outcome of this study is expected to enhance the understanding of TC boundary layer over land, provide useful information for the design of civil structures and infrastructures, benefit the numerical simulation of landfalling TCs, and facilitate the TC hazard prevention in coastal regions.

Investigation of the Atmospheric Boundary Layer Height Using Radio Occultation: A Case Study during Twelve Super Typhoons over the Northwest Pacific

This study investigated the relationship between variations in the atmospheric boundary layer height (ABLH) and typhoons over the Northwest Pacific using global navigation satellite system (GNSS) radio occultation (RO) data during the local summer typhoon season (July–October in the Northern Hemisphere) from 2007 to 2020. The minimum gradient of refractivity derived from COSMIC and COSMIC-2 was used to determine the ABLH. The RO profiles were co-located with the position of a typhoon track base within a 600 km space window and different time windows. ABLH climatology with a 2.5° × 2.5° horizontal resolution was developed, which can be used to obtain the interpolated mean ABLH at any target position. The mean ABLH at the central typhoon position in a specific year was compared with the results interpolated from the climatology of the same location (excluding the year in which the investigated typhoon occurred). In this paper, the results indicate that the ABLH is lower in the vicinity of typhoons relative to the undisturbed atmosphere by a significant amount, and that the reduction in ABLH ranges from 0.13 km to 0.39 km. It was also found that the ABLH was negatively correlated with wind speed, and that the mean correlation coefficient was −0.607. Moreover, similar results can be obtained via the RO water vapor partial pressure profile compared to the refractivity results.

Spatiotemporal Evolution of the Online Social Network after a Natural Disaster

Social media has been a vital channel for communicating and broadcasting disaster-related information. However, the global spatiotemporal patterns of social media users’ activities, interactions, and connections after a natural disaster remain unclear. Hence, we integrated geocoding, geovisualization, and complex network methods to illustrate and analyze the online social network’s spatiotemporal evolution. Taking the super typhoon Haiyan as a case, we constructed a retweeting network and mapped this network according to the tweets’ location information. The results show that (1) the distribution of in-degree and out-degree follow power-law and retweeting networks are scale-free. (2) A local catastrophe could attract significant global interest but with strong geographical heterogeneity. The super typhoon Haiyan especially attracted attention from the United States, Europe, and Australia, in which users are more active in posting and forwarding disaster-related tweets than other regions (except the Philippines). (3) The users’ interactions and connections are also significantly different between countries and regions. Connections and interactions between the Philippines and the United States, Europe, and Australia were much closer than in other regions. Therefore, the agencies and platforms should also pay attention to other countries and regions outside the disaster area to provide more valuable information for the local people.

Mangroves As Coastal Bio-Shield: A Review of Mangroves Performance in Wave Attenuation

Mangroves have been recognized as soft structures that provide coastline protection. The capability of dampening waves helps minimize destruction from catastrophic events including erosive wave attacks, torrential storms, and tsunamis. Mangroves act as the first line of coastal defense in natural tragedies such as during the Super Typhoon Haiyan 2013 and Indian Ocean Tsunami 2004, whereby the leeward mangrove area encountered less damage than the unprotected area. This has further brought the attention of researchers to study the attenuation performance of these coastal vegetations. Based on an extensive literature review, this paper discusses the attenuation mechanism of mangroves, the factors influencing the dissipation performance, studies on mangrove dissipation via different approaches, the dissipation efficiency, mangrove conservation and rehabilitation efforts in Malaysia and implementation of mangrove as coastal bio-shield in other countries. The study highlights that mangrove parameters (such as species, width, density etc.) and wave parameters (such as wave period and incident wave height) are among the contributing factors in mangroves-induced wave attenuation, with different efficiency rates performed by different mangroves and waves parameters. Towards that end, several improvements are proposed for future research such as to incorporate all influencing dissipation factors with specific analysis for each species of mangroves, to perform validation on the studied mangroves attenuation capacity in different settings and circumstances, as well as to address the extent of protection by the rehabilitated mangroves. A systematic and effective management strategy incorporating ecological, forestry, and coastal engineering knowledge should be considered to ensure a sustainable mangroves ecosystem and promising coastline protection by mangroves. Doi: 10.28991/cej-2021-03091772 Full Text: PDF

Reconstructing a late Neolithic extreme storm event on the southern Yangtze coast, East China, based on sedimentary records and numerical modeling

Using geological evidence to extend the history of typhoon activity beyond the instrumental period and understand the possible linkage between future climate change and increasing storm intensity is of great significance in preparing for coastal risks in a warming world. In this study, an extreme storm event that occurred on the southern Yangtze coast, East China, during the latter stage of Neolithic Liangzhu Culture were estimated based on sedimentary records and numerical modeling. We first investigated the spatial distribution of peat layers formed during the time of the Liangzhu Culture to produce a high-resolution map of the paleo-coastline of the Ningbo Plain. Inverse modeling using the grain size of storm deposits recovered at the end of Liangzhu Culture at the Neolithic Yushan site was applied to calculate the instantaneous water level including wave run-up and storm surge caused by the extreme event. Numerical simulations of multiple typhoon scenarios combined with precipitation and sea-level rise constrained by the paleo-coastline and paleo-topography were then used to estimate the storm surge and inundation on the coast of Hangzhou Bay. Through comparison of results between the inverse model and numerical simulations, we infer that the intensity of the storm recorded at the Yushan site was likely greater than any typhoon in the local instrumental records and that the storm deposits were formed by a Super Typhoon, which moved close to or made landfall directly on the southeast coast of Hangzhou Bay. Our modeling further suggests that the extreme storm event was coupled with an abrupt relative sea-level rise at ca. 4.5 cal kyr BP, which indicates a warmer west Pacific Ocean at that time.

Observation of vertical eddy diffusivity and mixing length during landfalling Super Typhoons

Understanding the vertical turbulent mixing processes in the planetary boundary layer (PBL) of tropical cyclones (TCs, or typhoons, hurricanes) and improving the PBL parameterization in numerical models of TCs is of paramount importance for TC modeling and forecasting. Based on the multi-level, high-resolution observations from Asia's tallest meteorological tower, the 356-m-high Shenzhen Meteorological Gradient Tower, this paper investigates the characteristics and vertical profiles of vertical eddy diffusivity and mixing length during two landfalling typhoons, namely Super Typhoons Mangkhut and Hato. The observed vertical eddy diffusivity and mixing length are compared with several widely-used parametrization schemes to assess the performance of the schemes. The results demonstrate that the K-profile parameterization scheme with the coefficient α = 1.5 satisfactorily portrays the magnitude and vertical distribution of the vertical eddy diffusivity. Moreover, a novel parametrization for mixing length is proposed, which is shown effective in reproducing the vertical mixing when used in conjunction with the Mellor–Yamada scheme. This study aims to enhance the understanding of vertical turbulent mixing in TC boundary layer and facilitate the numerical simulation of TCs over land.

Monitoring Forest Resilience Dynamics from Very High-Resolution Satellite Images in Case of Multi-Hazard Disaster

Typhoons strongly impact the structure and functioning of the forests, especially in the coastal areas in which typhoon-induced flooding imposes additional stress on the ecosystem via physical destruction and rising soil salinity. The impact of typhoons on forest ecosystems is becoming even more significant in the changing climate, which triggers atmospheric mechanisms that increase their frequency and intensity. This study investigates the resiliency of the Philippines’ forest areas (i.e., two selected forestry areas in Tacloban and Guiuan) in the aftermath of Super Typhoon Haiyan, which was followed by coastal flooding, as well as changes in ecosystem and biomass content using remote sensing. For this, we first evaluated the sensitivity of the normalized difference vegetation index (NDVI), green normalized difference vegetation index (GNDVI), and enhanced vegetation index (EVI) in detecting temporal changes in biomass content using very high-resolution satellite images. Then, employing three resilience concepts: amplitude, malleability, and elasticity, the most sensitive biomass index (i.e., NDVI) and digital elevation model (DEM) data were used to measure the resiliency of the Guiuan and Tacloban sites. We also applied a mean-variance analysis to extract and illustrate the shifts in the ecosystem status. The results show that despite a considerable biomass loss (57% in Guiuan and 46% in Tacloban), the Guiuan and Tacloban sites regained 80% and 70% of their initial biomass content within a year after the typhoon, respectively. However, the presence of canopy gaps in the Tacloban site makes it vulnerable to external stressors. Furthermore, the findings demonstrate that the study areas return to their initial states within two years. This indicates the high resiliency of those areas according to elasticity results. Moreover, the evaluation of typhoon impacts according to the elevation demonstrates that the elevation had a substantial impact on both damage severity and biomass recovery.

Full and partial posttraumatic stress disorders in adults exposed to super typhoon Lekima: a cross-sectional investigation

BackgroundSuper typhoon Lekima had a maximum wind force of 16 (52 m/s) and hit Wenling city, Zhejiang province in China on August 10, 2019. The typhoon left many victims showing symptoms of posttraumatic stress disorder (PTSD).ObjectiveThis study aimed to assess the prevalence of full and partial PTSD to inform targeted interventions for adult victims.MethodIn total, four thousand seven hundred and forty-six adults who are parents of students in local primary and middle schools were recruited to participate in this study. Participants completed a trauma exposure scale and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition PTSD Checklist. Logistic regression analysis was used to examine the factors of full and partial PTSD.ResultsNine hundred and ten (19.2%) adults had full PTSD and 1775 (37.4%) had partial PTSD. Adults with a monthly income > 10,000 RMB (about 1530 dollars) and a high education level (bachelor’s degree or above) were less likely to have full or partial PTSD than those with lower income and lower education levels. In addition, married adults were less likely to have full PTSD than divorced or widowed ones. Higher rates of PTSD were observed among those aged ≥40 years, who were injured/trapped, whose family members/friends were injured/trapped, and who lost property.ConclusionsPartial and full PTSD were common among adults following super typhoon Lekima, and high income, high education level, and married status were protective factors, whereas trauma exposure was a risk factor of PTSD. Target psychological intervention should be provided to these victims who are in low income and education level, divorced and widowed, and experienced more serious trauma.

Variability of dissolved organic matter in two coastal wetlands along the Changjiang River Estuary: Responses to tidal cycles, seasons, and degradation processes

Dissolved organic matter (DOM) in the coastal tidal marsh–estuary systems are complex mixtures with different source materials that vary with hydrological regimes, seasons, and environmental conditions and are modified by removal processes including photochemical and microbial degradations. Here, monthly surveys of DOM and its optical properties (i.e., absorbance and fluorescence of DOM) covering a complete semi-diurnal tidal cycle were conducted in two coastal marshes with distinct hydrological regimes (i.e., one freshwater and one brackish marsh) in the Changjiang River Estuary (CRE). Four fluorescent components were identified by excitation–emission matrix fluoresces combined with parallel factor analysis (EEMs–PARAFAC) as two terrestrial humic-like components and two autochthonous protein-like components. Results indicated that ebbing waters draining the marshes were consistently enriched with highly absorbing, more humic and highly aromatic DOM compared to the flood tidewaters. On a seasonal basis, DOM dynamics were largely modulated by the marsh productivity and the seasonal Changjiang runoff. Protein-like fluorophores, however, demonstrated a constant, less variable pattern on both the tidal and seasonal timescales. Onsite water incubation experiments with photochemical and microbial alterations revealed that photochemistry was primarily responsible for the removal of optically active components in the marsh DOM pools whereas the impact of microbes was minor. Principal component analysis (PCA) illustrated the processes regulating the DOM dynamics at the marsh–estuarine interface and allowed a clear distinction of samples between the two marshes, in addition to the samples under the influence of episodic weather events (i.e., Super Typhoon Lekima in summer 2009 and the basin-wide severe flood event occurred in summer 2020). This study underscores the importance of world large-rivers such as Changjiang on estuarine marsh DOM dynamics and also highlights the substantial heterogeneity of the marsh DOM across a river-dominated estuary.

Shelterbelt Structure and Crop Protection from Increased Typhoon Activity in Northeast China

Global warming has led to increases in the frequency and intensity of typhoons. In recent years, super typhoons have had a greater impact on agriculture in the black soil farmland of Northeast China, posing serious threats to crop growth. Planting trees as windbreaks and to reduce erosion is common in this region, but their protective effects against crop damage from typhoons is still unknown. This paper studied the protective effect of different shelterbelt structures on crops that encountered a super typhoon. The results show that the distance between shelterbelt rows and shelterbelt porosity have significant influences on the starting lodging distance of crops behind the shelterbelt. Increasing the shelterbelt distance between shelterbelt rows or reducing shelterbelt porosity can enhance their protective effects on crops. Among the main crops, rice has the strongest lodging resistance, followed by soybeans, with maize being the least resistant. The protective effect of mixed tree and shrub shelterbelts is better than that of single tree species shelterbelts. Dead or missing trees reduce the shelterbelt protective effect. These results provide strategies for reducing the impact of more intense and frequent super typhoons.