Search

The study proposed a Standardized Precipitation Index (SPI) drought forecasting model based on singular spectrum analysis (SSA) and single least square support vector machine (LSSVM) with a twofold investigation: (Beguería et al. Int J Climatol, 34(10): 3001–3023, 2014) the forecasting performance of the LSSVM-based model with or without coupling SSA and (Belayneh et al. J Hydrol, 508: 418–429, 2014) the model performances by using different inputs (i.e., antecedent SPIs and antecedent accumulated monthly rainfall) preprocessed by SSA. For the first part investigation, the LSSVM-based model using antecedent SPI as input (LSSVM1) and the LSSVM-based model coupling with SSA using antecedent SPI as input (SSA-LSSVM2) were developed. For the second part of investigation, the SSA-LSSVM-based model using antecedent accumulated monthly rainfall as input (SSA-LSSVM3) was developed and compared to SSA-LSSVM2. The drought indices (SPI3 and SPI6) were chosen as the outputs of the SPI drought forecasting models. The Tseng-Wen reservoir catchment in southern Taiwan was selected to test the aforementioned models. The results show that the forecasting performance of SSA-LSSVM2 is better than that of LSSVM1, which means the input data preprocessed by SSA can significantly increase the accuracy of the SPI drought forecasting. In addition, the performance comparison between SSA-LSSVM2 and SSA-LSSVM3 indicates that using antecedent accumulated monthly rainfalls (i.e., 3-month and 6-month accumulated rainfalls) as input of SSA-LSSVM3 are much better than using antecedent SPIs (i.e., SPI3 and SPI6) as input of SSA-LSSVM2. SSA-LSSVM3 is found to be the most appropriate model for SPI drought forecasting in the case study. [ABSTRACT FROM AUTHOR]

Background: Dominant mutations in MYO7A may lead to nonsyndromic deafness DFNA11. A p.R206C variant in MYO7A has previously been reported in a small deaf family from Taiwan but with ambiguous pathogenicity and inheritance pattern.Aims/objectives: Our study aims to clarify the pathogenicity of this variant by clinical characterization and genetic analysis of a separate autosomal dominant deaf family harboring this variant in mainland China.Materials and Methods: Auditory features of hearing loss were characterized in representative affected family members. Mutation screening was performed by targeted next-generation sequencing of 138 known deafness genes in the proband. Candidate pathogenic mutations were confirmed by Sanger sequencing in family members and ethnically matched controls.Results: Consistent with typical DFNA11 phenotype, the affected family members in this study showed delayed-onset, progressive hearing loss affecting mostly high frequencies. Targeted next-generation sequencing identified a p.R206C mutation in MYO7A as the only candidate pathogenic mutation cosegregating with the hearing phenotype. This mutation is not seen in 200 Chinese Han normal-hearing controls.Conclusions and Significance: The recurrent p.R206C variant in MYO7A is pathogenic and is likely in a mutation hot spot or due to a founder effect. Reports of such rare variants in multiple patients or families may facilitate exploitation of its pathogenicity. [ABSTRACT FROM AUTHOR]

Monthly rainfall forecasts can be translated into monthly runoff predictions that could support water resources planning and management activities. Therefore, development of monthly rainfall forecasting models in reservoir watersheds is essential for generating future rainfall amounts as an input to a water-resources-system simulation model to predict water shortage conditions. This research aims to examine the reliability of linking a data preprocessing method (singular spectrum analysis, SSA) with machine learning, least-squares support vector regression (LS-SVR), and random forest (RF), for monthly rainfall forecasting in two reservoir watersheds (Deji and Shihmen reservoir watersheds) located in Taiwan. Merging SSA with LS-SVR and RF, the hybrid models (SSA-LSSVR and SSA-RF) were developed and compared with the standard models (LS-SVR and RF). The proposed models were calibrated and validated using the watersheds' observed areal monthly rainfalls separated into 70 percent of data for calibration and 30 percent of data for validation. Model performances were evaluated using two accuracy measures, root mean square error (RMSE) and Nash–Sutcliffe efficiency (NSE). Results show that the hybrid models could efficiently forecast monthly rainfalls. Nonetheless, the performances of the hybrid models vary in both watersheds which suggests that prior knowledge about the watershed's hydrological behavior would be helpful to implement the appropriate model. Overall, the hybrid models significantly surpass the standard models for the two studied watersheds, which indicates that the proposed models are a prudent modeling approach that could be employed in the current research regions for monthly rainfall forecasting. [ABSTRACT FROM AUTHOR]

Background/purpose: Heavy metal pollution in farm soils is a problem in some parts of Taiwan. Copper can be a factor associated with increased disease activities of rheumatoid arthritis (RA). Thus, the aim of this study was to investigate whether copper pollution in farm soils is associated with worsened RA.Methods: Clinical parameters from 122 RA patients were collected from a medical center in central Taiwan. Levels of heavy metals in the blood were measured using inductively coupled plasma mass spectrometry. Levels of copper in farm soils were retrieved from a national survey. These data were analyzed to find the factors related to RA disease activities.Results: RA patients living where farm soils contained high levels of copper had increased white blood cell counts, erythrocyte sedimentation rate, and disease activity score 28, compared with patients living where copper levels were low. Among the nine types of heavy metal measured in the study, blood levels of copper and nickel correlated with erythrocyte sedimentation rate.Conclusion: Our cross-sectional data suggest a correlation between RA disease activity and the level of copper at township farm soils samples. Further longitudinal studies using more rigorous methodologies are warranted to examine whether this correlation is causal. [ABSTRACT FROM AUTHOR]

This study proposed a stochastic approach to forecast water-shortage probabilities for the coming three months in central Taiwan. Monte Carlo method is used to repeat random sampling from the seasonal weather outlook. For each Monte Carlo trial, the monthly rainfalls and monthly mean temperatures for one to three months ahead in eleven upstream catchments of central Taiwan can be obtained. Further, the disaggregation model is used to convert the monthly values into daily rainfall and temperature series. The HBV-based hydrological model uses the daily series to simulate daily inflows for each catchment as the input of system dynamic model for simulating the water budget of water resources system. After all the Monte Carlo trails, the monthly water-shortage probabilities for one to three months ahead can be calculated. The results reveal that the proposed approach can reasonably forecast the water-shortage conditions for one to three months ahead, which are beneficial for regional drought warning and decision support of drought-disaster prevention. [ABSTRACT FROM AUTHOR]

The study compared the performances of three weather generators (WGs), including a parametric model and two non-parametric models, in producing synthetic daily rainfall time series for multiple sites. The observed daily rainfalls of six raingauges during 1979~2008 in the catchment of Tseng-Wen Reservoir in Southern Taiwan were used as the data set. The generated results reveal that the k-nearest neighbor WG with a fixed window (i.e., a non-parametric model) is the best for daily rainfall generation at each site and performs well in preserving spatial correlation of rainfall among sites. The best WG was further applied to assess the impact of climate change on rainfall temporal characteristics (i.e., annual number of wet day, annual maximum number of continuous wet days and annual maximum number of continuous dry days) by using the downscaling results of 24 GCMs under the A1B emission scenario during 2020~2039. It is found that the rainfall temporal characteristics will change in the future which may make Southern Taiwan tend to face a longer period with no rain. [ABSTRACT FROM AUTHOR]

Flow duration curves (FDCs) are useful tools for many water resource development and management purposes. Many water resource projects are located at ungauged sites, however, for which FDCs are required but unavailable due to the lack of observed flow records. Both the polynomial and area-index methods are introduced herein to synthesize FDCs at ungauged sites and estimate their uncertainties for the upper catchments of the Cho-Shuei Creek in Taiwan. The major difference between these two methods is that the area-index method only uses drainage area to explain regional variation, whereas the polynomial method uses annual rainfall, altitude, and drainage area. Results obtained by using cross validation at 15 stations indicate that the polynomial method produces better estimates of synthetic FDCs at ungauged sites than the area-index method. Furthermore, uncertainty analysis through bootstrap resampling reveals that the polynomial method has less uncertainty in synthesizing FDCs than the area-index method. [ABSTRACT FROM AUTHOR]

This study investigates the impact of climate change on water resources in southern Taiwan. The upstream catchment of Shin-Fa Bridge station in the Kao-Pen Creek basin was the study area chosen herein. The historical trends of meteorological variables, such as mean daily temperature, mean daily precipitation on wet days, monthly wet days, and the transition probabilities of daily precipitation occurrence in each month, at the Kao-Hsiung meteorological station, near the catchments were detected using a non-parametric statistical test. The trends of these meteorological variables were then employed to generate runoff in future climatic conditions using a continuous rainfall–runoff model. The analytical results indicate that the transition probabilities of daily precipitation occurrence significantly influence precipitation generation, and generated runoff for future climatic conditions in southern Taiwan was found to rise during the wet season and decline during the dry season. [Copyright &y& Elsevier]

In this work, the Pliocene dolomitic carbonate concretions and pipes from Chiahsien of the Western Foothills, southwestern Taiwan were studied. We conducted a synthetical analysis of stable carbon and oxygen isotopes, rare earth element (REE) contents, and Sr and Nd isotopes, to trace the compositions and sources of pore fluids from which carbonates have precipitated and reconstruct the carbonate formation processes. The carbonates with low δ13C values (as low as −48.6‰) are promoted by the anaerobic oxidation of biogenic methane. The 87Sr/86Sr ratios of samples reflect the mixing of coeval bottom seawater and seep fluid enriched in 87Sr. The Nd isotopic signatures of studied carbonates indicate multiple Nd sources, including detrital components, Fe–Mn oxyhydroxides, organic matter, and seawater. The MREE-bulge patterns in samples are typical of anoxic conditions, which are supported by Ce anomalies. Our results demonstrate that the seepage intensity played a key role in the formation processes of concretions and pipes by controlling the depth of the sulfate-methane transition zone (SMTZ). The concretions characterized by the lowest δ13C values formed at a deeper depth in sediments under low methane flux, which suffered no/less influence of seawater. The representative pipe with obvious concentric lamination grew in a rim-to-core pattern. In the early stage, the variable flux of highly channelized seepage caused the fluctuation of carbon and oxygen isotopes. During the later stage, the modification of isotopic compositions in the core part were resulted from meteoric alteration. Our work provides insights into the formation process related to seepage evolution in ancient cold seeps on Taiwan Island. • Sr–Nd isotopes of cold seep carbonates from the Western Foothills of Taiwan Island are firsly reported. • C–Sr–Nd isotopes and REE indicate multiple sources of pore waters. • Seepage intensity plays a controlling role in the formation of seep carbonates. [ABSTRACT FROM AUTHOR]

Exposed in the Coastal Range of eastern Taiwan is a portion of the Luzon volcanic arc that has collided with the South China continent since 6 Ma, as well as syn-orogenic sedimentary rocks deposited on the arc and subsequently intensely folded and thrusted. This study sampled syn-orogenic mudstones for the measurement of anisotropy of magnetic susceptibility (AMS) at four sites on the sides of the range. The AMS fabrics reveal a contribution from burial compaction and, less significantly, tectonic shortening which varies slightly across the range. This lateral variation is considered as, for simplicity, a result of two-phase deformation because these rocks were involved in an eastward propagating back thrust system on the colliding arc. A new strain analysis method is developed to estimate the overall tectonic strain by unstraining the pseudo-strains with respect to the AMS measurements at each site with the knowledge about the distribution of the susceptibility ellipsoids in the unstrained state. Strain results reveal that shortening phases occurred before and after the folding, with a shortening ratio of 0.177–0.195 and 0.181–0.248, respectively. The post-folding shortening on the western side is sub-parallel to the range, and the pre-folding shortening on both sides is layer-parallel and nearly perpendicular to the range. Therefore, the mudstones underwent layer-parallel shortening, fold-related tilting and eventually orogen-parallel shortening after deposition. This sheds light on the complexity in deformation of the colliding Luzon arc. • Syn-orogenic mudstones in eastern Taiwan have composite magnetic fabrics. • A new method is developed to estimate strain from AMS data at a site. • Luzon arc mudstones underwent shortening before and after folding. [ABSTRACT FROM AUTHOR]