Long-Term Effects Of River Bed Variations Downstream Of The Shihmen Reservoir Due To Climate Change

Most rivers in Taiwan are suffered from serious sedimentation problems due to extreme weather in recent years. In order to decrease sediment trap in Shihmen Reservoir, the reservoir sediment was effluent into downstream river during flood period. The river sediment deposition and erosion would be thus more violent. The quasi-two dimensional model, NETSTARS, was applied to investigate hydraulic characteristics and corresponding river sedimentation behavior in Da-Han basin. The model was calibrated and verified with field survey data and then was utilized to predict the spatial and temporal variations of downstream suspended solid concentration. Through investigating the change of suspended solid concentration at Yuan-Shan Dam- which is one of the most important water supply facility in Taipei metropolitan area- the success of lowing the suspended solid concentration was certain. The water level and bed elevation movement in typhoon events were investigated via the numerical model at different river reaches. The joint operation of Shihmen sluice gate and Yuan-Shan weir was also discussed for Long-term effects due to climate change

Frequency Dependent Alterations in Regional Homogeneity of Baseline Brain Activity in Schizophrenia

Low frequency oscillations are essential in cognitive function impairment in schizophrenia. While functional connectivity can reveal the synchronization between distant brain regions, the regional abnormalities in task-independent baseline brain activity are less clear, especially in specific frequency bands. Here, we used a regional homogeneity (ReHo) method combined with resting-state functional magnetic resonance imaging to investigate low frequency spontaneous neural activity in the three different frequency bands (slow-5:0.01–0.027 Hz; slow-4:0.027–0.08 Hz; and typical band: 0.01–0.08 Hz) in 69 patients with schizophrenia and 62 healthy controls. Compared with controls, schizophrenia patients exhibited decreased ReHo in the precentral gyrus, middle occipital gyrus, and posterior insula, whereas increased ReHo in the medial prefrontal cortex and anterior insula. Significant differences in ReHo between the two bands were found in fusiform gyrus and superior frontal gyrus (slow-4> slow-5), and in basal ganglia, parahippocampus, and dorsal middle prefrontal gyrus (slow-5> slow-4). Importantly, we identified significant interaction between frequency bands and groups in the inferior occipital gyrus and caudate body. This study demonstrates that ReHo changes in schizophrenia are widespread and frequency dependent

Effect Of Sediment Releasing Operation From Reservoir Outlets On The Water Treatment Plant Downstream

With steep slope and strong rainfall intensity, landslide and debris flow could generate huge amount of sediment yield from the watershed, typically during typhoon floods in Taiwan. As such huge amount of sediment moved into a reservoir, serious sedimentation problem reduced storage of reservoir due to decrease of flow velocity and without sufficient sediment releasing bottom outlet. As a result, using flood discharge to release sediment during Typhoon or rain fall duration is very important. This study adopts the data of field observation from outlet structures of the Shihmen reservoir to establish the operational strategies of sediment releasing rule and keep water sustained supply at downstream river intake. Based on the numerical simulation by using 1-D and 2-D models, the relationship of sediment concentration between the Shihmen reservoir and downstream withdraw intake at the YuanShan weir can be established. The sediment concentration reduction ratio is calculated to be 89% from the Shihmen reservoir to the YuanShan weir. This study also focuses on the sediment concentration mitigation influence of tunnel spillway due to the high sediment concentration releasing from bottom outlet. From simulated results, when the extra discharge of tunnel spillway reaches 830m3/s for specific event, the influence of reducing sediment concentration to downstream river by tunnel spillway can maintain water supply of downstream withdraw intake at YuanShan weir. In practice, when using the extra discharge of tunnel spillway to reduce sediment concentration during Typhoon Haitang and Typhoon Wipha, the sediment concentration at YuanShan weir can reduce water turbidity lower than 6000NTU that water treatment plant can deal with

Adaptive management on the wintering habitat of common teals (Anas crecca) in Hwajiang estuarine wetland

本研究整合生態學與水利學觀點，以棲地適合度指標模式（HSI model）量化小水鴨喜好之度冬棲地條件，建置一套適用於感潮濕地之小水鴨度冬棲地適應性管理模式。華江濕地為東亞小水鴨重要度冬棲地之一，惟近年來受到自然營力及人為干擾，環境劇烈變遷。河床大幅回淤，植被面積也隨之快速擴增，使小水鴨喜好之灘地及水域面積大量減少。因此小水鴨度冬棲地復育及管理，為當前極為重要且迫切之課題。 本研究於2008年10月至2009年3月在華江濕地三個固定位置，進行22次小水鴨數量及棲息位置調查，共紀錄小水鴨3615隻次。同時調查高程、坡度及距植被最短距離等環境因子，以地理資訊系統記錄於5m×5m之數值地形網格。接著以單位努力收穫量的概念，繪製網格內單次調查小水鴨最大數量與環境因子關係之包絡線，作為各環境因子之適合度指標（SI）。以最小值法整合三個環境因子之適合度指標，建置棲地適合度指標（HSI）模式。分析結果顯示，小水鴨喜好低緩坡度、高低潮位間之高程及鄰近植被邊緣之棲地環境，其棲地之最適坡度介於0.7%至1.4%間，最適地表高程介於EL. 0.3m至EL. 0.7m間，最適距植被最短距離則為0 m至4m。另以網格內小水鴨最大數量與棲地適合度指標進行驗證，兩者成高度顯著相關，顯示本研究建立之小水鴨度冬棲地適合度指標模式具高度可靠性及實用性。本研究依據棲地適合度指標將本區之環境品質分為不良（0 -0.25）、普通（0.25-0.50）、良好（0.50-0.75）及最佳（0.75-1.0）等4個等級，最佳棲地的比例在新潮池、內河道及次潮溝分別為41.9%、17.4%及26.4%。 本研究以小水鴨度冬棲地適合度指標及量化之棲地特性研擬棲地復育原則，主要為坡度小於1.5%、高程於EL. 0.0m至EL. 0.5m間、在灘地營造潮池或潮溝，退潮時仍保有水域、距植被最短距離不超過25m、復育棲地寬度至少100m及長度至少250m、復育地點儘量於小水鴨主要棲息地附近，以增加適合棲地之連續性。規劃三個華江濕地復育方案，僅以復育地點為操縱變因，再以CCHE2D模式進行數值實驗，以分析不同復育地點之優劣。主要考量為造床流量條件下之減淤效益，模擬結果進一步計算水流底床剪應力分布，並假設水流底床剪應力愈大、淤積潛勢愈低、復育效果愈佳。分析結果顯示，位於華江濕地上游側之復育地點淤積趨勢相對較低，為較佳之復育地點。 本研究引用適應性管理之架構，以棲地適合度指標模式作為量化評估工具，建置華江濕地小水鴨度冬棲地適應性管理模式。此模式包括監測、評估及決策三部分，可作為華江濕地小水鴨度冬棲地復育及管理參考使用，並可供其他類似濕地之復育及永續管理參考。This study aimed at constructing an adaptive management model for wintering habitat of Common Teal (Anas crecca) in Hwajiang Wetland. A habitat suitability index (HSI) was developed to quantify the physical environments of the Teals’ preferred habitat. The Hwajiang wetland is an important wintering site for migratory Common Teal, whose population has dramatically declined in recent years, due most likely to the persistent degradation of habitats in this wetland. Due to river morphology, the changes of sediment deposition and vegetation expansion, have reduced the available habitat for the wintering Teal. Therefore, the rehabilitation of the Teals’ habitat is urgently needed for a sustainable management in this wetland. Point-count surveys of the Common Teal were conducted at a tidal pool, an inner channel and a tidal creek in Hwajiang Wetland and Teals’ positions were recorded from October 2008 to March 2009. Twenty-two sets of data and 3615 counted individuals were collected. Three habitat variables, including slope, elevation and the distance to the nearest vegetation, were displayed on 5 m × 5 m grid cells and analyzed with GIS software. Suitability index (SI) values of habitat variables were determined using the envelop curve of maximum abundance of common teals versus the habitat variables. The results showed that Common Teal preferred habitats with gentle slopes, median elevations and areas close to vegetation. The abundance of the Common Teal was highest in the grid cells with slopes ranging from 0.7 to 1.4%, bed elevation varying from 0.3 to 0.7 m above the mean sea level, and distance to the nearest vegetation shorter than 4 m. The HSI model was constructed by calculating the minimum value of the three SIs, and the suitability map of wintering common teals was generated to represent an integrated map of habitat quality in the area. A simple regression analysis indicated that the HSI model is a reliable indicator as the maximum numbers of the Common Teal in each grid cell increased significantly with the HSI values. Four types of habitat conditions, poor, fair, good and excellent, were determined based on the HSI values. The proportions of excellent habitat were 41.9%, 17.4% and 26.4% in the tidal pool, the inner channel and the tidal creek, respectively. A principle of rehabilitation was derived from the HSI model, with slopes smaller than 1.5%, elevations between 0.0m and 0.5m, and distance of less 25 m to the nearest vegetation. The rehabilitation area should be larger than 100 m in width and 250 m in length and adjacent to the existing Teal habitat. Three rehabilitation scenarios were simulated and characterized based on field survey and the HSI model. In addition, a horizontal two dimension numerical model, CCHE2D, was employed to simulate bank-full flow characteristics such as water surface elevation, flow velocity, shear stress and so on. The bathymetry and vegetation cover were assumed the same while the location was different. The shear stress evaluation indicated that the rehabilitation of the most upstream location is the best scenario because it has the lowest sediment deposition rate and represents a minimum maintenance effort needed in the future. This study provided a foundation for determining potential habitats and information on how to mitigate a degraded wetland for the Common Teal. It encompassed the aspects of monitoring, evaluation, and decision making that would benefit future management plans directed toward the Common Teal and other waterfowl species in Taiwan. It also provided an adaptive management model for application to similar projects of wetland rehabilitation and sustainable management

A contextual learning model for developing interactive e-books to improve students’ performances of learning the analects of Confucius

[[abstract]]The Analects of Confucius has been identified as an important and influential philosophy around the globe. However, in traditional instruction, it is difficult to express the spirit of this philosophy. Therefore, many students consider it as a big challenge to study the Analects of Confucius. To cope with this problem, in this study, an interactive e-book system has been developed based on the contextual learning model to interpret the Analects of Confucius in an interactive way. A quasi-experiment was conducted to evaluate the performance of the proposed approach. The participants were 38 fifth graders from 2 classes in an elementary school located in northern Taiwan, who were divided into an experimental and a control group. The experimental group used an interactive e-book learning mode to learn the Analects of Confucius course while the control group used a conventional technology enhanced teaching mode. The results showed that adopting the interactive e-book teaching mode to study the Analects of Confucius in the elementary school course can promote students’ learning achievement and motive. It was also found that the interactive e-book learning mode can trigger learners’ deep motive, and hence promote their learning achievement

The development of habitat suitability models for fiddler crabs residing in subtropical tidal flats

Fiddler crabs are deposit feeders that play critical roles as ecological engineers in tidal flats. Recently, anthropogenic disturbances have led to fiddler crab habitat loss and/or degradation; therefore, we developed a mathematically derived habitat suitability index (HSI) model to aid in habitat assessments of fiddler crabs. Based on what is known about the life histories of fiddler crabs, the variables of an HSI model included submersion time, interstitial salinity, and soil 1) grain size, 2) organic matter content, and 3) heat capacity. We acquired density data from four fiddler crab species—Xeruca formosensis, Tubuca arcuata, Austruca lactea, and Gelasimus borealis— at five sites on the western coast of Taiwan to develop the HSI models. Significant positive correlations existed between the HSI output and fiddler crab density for all target species except for those X. formosensis inhabiting the topsoil layer (0–20 cm). For the deep burrowers X. formosensis, however, a positive linear relationship was documented when only those data from the 40–60 cm layers were considered and if the habitat was a sand-covered mudflat. Mapping for each species was conducted using the HSI models with the highest reliability, and four classification levels were established for the habitat suitability of each species at one of the study sites. Based on this field test of a fiddler crab HSI model, we have developed a platform for the proactive conservation of fiddler crabs inhabiting subtropical tidal flats