Influence d’un double barrage sur la dynamique saisonnière des communautés de phytoplancton et de microphytobenthos

International audienc

Influence d’un double barrage sur la dynamique saisonnière des communautés de phytoplancton et de microphytobenthos

International audienc

Alternatives Analysis of Residential Users Choosing Demand Response Electricity Rates with Smart Meters

本文針對住宅用戶觀點，模擬七種時間電價相關方案之電費支出水準，及利用參與者檢定(Participant Cost Test, PCT)，評估用戶參與各種電價方案前之成本效益，最後對研究變數中之智慧電表成本及折現率作敏感度分析。從各電價方案對用戶電費支出實證結果顯示，選用現行二段式時間電價方案其電費最高，其次為二段式時間電價A-1方案，最低者為即時電價C方案。用戶改選用不同電價方案後，參與者檢定結果顯示：以現行非時間電價方案為基準，多數用戶益本比未達1，僅用戶甲夏月及用戶戊選用即時電價方案有通過檢定，以現行二段式時間電價方案為基準：益本比大小依序為即時電價C、二段式時間電價A-2、三段式時間電價B、二段式時間電價A-1。 由智慧電表成本及折現率為變數之敏感度分析結果顯示：以現行非時間電價方案為基準，在不同折現率情境下，多數用戶益本比未通過檢定，僅有用戶甲夏月與用戶戊在智慧電表成本為3000 元及6000元時選用即時電價C方案，益本比會大於1。以現行二段式時間電價方案為基準：智慧電表成本為3000元~9000元時，益本比多數大於1，通過成本效益檢定，當智慧電表成本達15000元時，多數用戶益本比則小於1。此隱示智慧電表成本之高低，將會影響住宅用戶採用各種需求面管理方案之意願。This article aims at looking from the residential users' perspective. It simulates seven electricity rate programs pertaining to time-of-use rate or non-time-of-use rate, utilizing Participant Cost Test (PCT) to assess those residential customers' programs and the cost-benefit analysis. The costs and the discount rate of the smart meter are also artificially varied in this study for sensitive analysis. For each of the tariff programs, the electricity expenditure for the users are compared and shows the following results: those users selecting the present two-tier time-of-use rate program has the highest expenditures, followed by the two-tier time-of-use rate scheme A-1. Those with the lowest expenditures were those who chose the Real-Time Pricing program. When those who have taken the Participant Cost Test for the cost-benefit analysis, taking the existing non-time-of-use program as a benchmark, most of the ratio are less than 1, only the userU1 in a summer month and userU5 selecting the Real-Time Pricing have passed the PCT test. Using the present two-tier time-of-use rate scheme as a benchmark: the cost benefit ratio is highest for Real-Time Pricing, followed by Two-tier Time-of-Use, Three-tier Time-of-Use and the Two-tire Time-of-Use A-1. The cost of the smart meter and the discount rate for sensitive analysis. With existing non-time-of-use rate program as a benchmark and the discount rate with different scenarios, most users' cost benefit ratio cannot pass the PCT test. Only user U1 in a summer month and user U5 choosing Real-Time Pricing with smart meters costing betweenNT$3000 to NT$6000, then the cost benefit ratio will be greater than1. Taking the present two-tier time-of-use rate program as a benchmark, when the smart meter costs between NT$3000 to NT$9000, the ratio for the majority of users will be greater than 1, thus passing the Participant Cost Test. However, when the smart meter reaches NT$15000, then most users benefit cost ratio will plummet to less than 1. This implies that the cost of the smart meter does matter to the adoption willingness of the demand-side management programs for residential users.目次 第一章 緒論 1 第一節 研究動機 1 第二節 研究目的 3 第三節 研究架構 4 第二章 智慧電表發展概況與文獻探討 6 第一節 國內智慧電表發展概況 6 第二節 需量反應文獻回顧 7 第三節 成本效益分析文獻回顧 15 第三章 研究方法與資料說明 19 第一節 參與者檢定 19 第二節 實證資料 20 第四章 實證結果分析 21 第一節 電費支出水準 21 第二節 成本效益分析之結果 33 第三節 敏感度分析 37 第五章 結論與建議 47 第一節 結論 47 第二節 未來研究建議 49 參考文獻 5

Daily Monitoring of Shallow and Fine-Grained Water Patterns in Wet Grasslands Combining Aerial LiDAR Data and In Situ Piezometric Measurements

The real-time monitoring of hydrodynamics in wetlands at fine spatial and temporal scales is crucial for understanding ecological and hydrological processes. The key interest of light detection and ranging (LiDAR) data is its ability to accurately detect microtopography. However, how such data may account for subtle wetland flooding changes in both space and time still needs to be tested, even though the degree to which these changes impact biodiversity patterns is of upmost importance. This study assesses the use of 1 m × 1 m resolution aerial LiDAR data in combination with in situ piezometric measurements in order to predict the flooded areas at a daily scale along a one-year hydrological period. The simulation was applied over 663 ha of wet grasslands distributed on six sites across the Marais Poitevin (France). A set of seven remote sensing images was used as the reference data in order to validate the simulation and provide a high overall accuracy (76–94%). The best results were observed in areas where the ditch density was low, whereas the highly drained sites showed a discrepancy with the predicted flooded areas. The landscape proportion index was calculated for the daily steps. The results highlighted the spatiotemporal dynamics of the shallow flooded areas. We showed that the differences in the flooding durations among the years were mainly related to a narrow contrast in topography (40 cm), and occurred over a short period of time (two months)

Rooted floating-leaf macrophytes structure the coexistence of different phytoplankton assemblages within a shallow lake

International audienceAquatic macrophytes in shallow lakes control habitats through local turbulence, water transparency, nutrients and oxygen concentrations. As engineer species, they structure these ecosystems, increasing the biodiversity. While many studies focused on submerged macrophyte, research on habitats created by rooted floating-leaf macrophytes is scarcer. Macrophytes, such as water lilies, should have the similar ecological consequences as submerged macrophytes, but with greater shading. In this study, we showed how macrophytes structure phytoplankton assemblages and allow the coexistence of different assemblages in the same shallow lake. During summer 2018, we characterized the phytoplankton assemblages in 9 stations covered by water lilies and 6 stations in open water, in a large shallow water lake. The lake is colonized on a third of its surface by water lilies from April to October. We showed an effect of waterlilies on temperature, oxygen, pH, turbidity, phosphates and dissolved silicon. Many taxa of phytoplankton from almost all classes were in higher abundance in stations covered by macrophytes, while cyanobacteria showed a higher biomass and richness in open water. Unicellular mixotrophic flagellates predominated in macrophytes habitat, with all representatives of the classes Euglenophyceae and Cryptophyceae