Productions of Initial and Boundary Condition for Mesoscale Model - Construction of Taiwan Surface Roughness Dateset and the Soil Moisture from Remote Sensing Data

Land is the major component of the climate system, but it inclusion in climate models isstill relatively simplistic. More realistic treatments of land processes and a fuller appropriatedataset are current research objectives. Some Land surface scheme (LSS) parameters, such asalbedo, fraction of vegetated cover, leaf area index, etc., can be measured (estimated) at boththe patch scale and the large scale (via remote sensing), and the relationship between theirarea-averaged values at patch and large scales is linear. However, other parameters such assoil hydraulic conductivity, stomatal resistance, aerodynamic resistance, etc., are not easilymeasured at the relevant scales, and their relationship at different scales is less simple.The main work in this project will be divided into five items and completed within threeyears: 1) Construction of NCHU flux tower over urban areas to observe the fluxes betweenthe atmosphere and the underlying surface and the meteorological data , 2) Derivation of landcharacteristics, including roughness length for heat, albedo, surface emissivity, area heatcapacity, canopy resistance and Bowen ratio using the observed data of N. Tongyen Mt.,NHCU and TFRI, 3) Development of a 1-km resolution dataset of roughness length formomentum and heat based on observations and its relationship to landuse types, andImplementation the roughness dataset for use in WRF under the cooperation with CWB, 4)Construction of long-term observation sites for soil moisture and development of hydrologicalrunoff model applied to the complex terrain in Taiwan, and 5) Development of a localizedland surface scheme (LSS) for use in WRF based on observation in Taiwan.地表真實值的觀測(例如各能量通量與土壤函水率等)及地表參數的表現在氣候及氣象模式中極為重要。在國外所提供之氣動粗糙度一般過小，造成風速模擬過快(Tsuang etal., 2003; Tsai and Tsuang, 2005)。計畫申請人過去5 年，已發表了相關研究期刊論文達3篇，利用繫留氣球、渦流協變性系統等觀測資料，或反演等方法求取中部地區等參數(Tsaiand Tsuang 2005; Tsai et al., 2007; Tsuang et al., 2008; Tsuang et al., 2009; Tsai et al.,2010a)。本計畫主要目的是希望能建立全台灣之動量粗糙度及熱粗糙度資料庫和台灣地區地表阻抗及土壤含水率在時間、空間上的分布，進而整合入WRF 區域氣象模式。此研究計畫將有以下四個工作方向。第一、收集地面觀測氣象資料並推導不同地貌的動量粗糙度(z0m)，並搭配過去成果(Tsuang et al., 2003; Tsai and Tsuang, 2005; Tsai etal., 2010a)及本計畫資料建立台灣地區動量粗糙度資料庫。第二、利用水稻田及森林地觀測資料推導熱粗糙度。第三、利用遙測資料推導台灣地區地表阻抗及土壤含水率時間、空間上的分布，以提供初始及邊界場予中尺度氣象模式使用。第四、將所得之初始及邊界資料應用於WRF 模式比較其是否改善地面風場及各能量通量模擬的模式表現。本計畫預定主要工作人力為計畫申請人本人，並搭配共同主持人所提供之地面觀測資料及衛星遙測資料來進行研究。希望三年內可以完整建立台灣地區重要大氣陸地下邊界之參數化過程包含觀測，並整合入WRF 之模式中，方便台灣之研究團隊及氣象單位使用

Service Platform of Common Database for Atmopheric Science (II)-Taiwan Fluxnet Data Center (Atmospheric Science Devision)

This project will establish a databank to collect flux data from flux towers currentlymaintained by individual scientists in Taiwan. There are 14 stations in operations, and somenew stations will be established in the coming years. In addition, Taiwan Fluxnet (TwFlux)will be organized. Therefore, we should be able to work closely with international fluxnetcommunities. Nonetheless, most of the stations are located away from individual scientists'institutes. Some of them are in rural area, and some in remote mountain area. There is a needto transfer the data by modern telecommunication technique, in order to reduce the travelexpense for collecting data. Moreover, through the real-time monitoring system, the datacenter can be aware whether the operation of equipments at stations continues normal, so asto avoid loss of data. It also provides an opportunity to unify data formats at each individualstation, which is import for the following-up model simulations or the applications of otherresearches. In addition, processing procedures for data will be established, including theQA/QC of data, coordinate rotation, WPL correction and gap filling of CO2. In theatmospheric community, although the surface energy components can be measured, most ofscientists are not available to investigate the soil/vegetation characteristics at the flux towersites. This project will conduct such investigations at each site with helps from forest/soilscientists. Items include the soil thermodynamic conductivity, soil porosity, soil fieldcapacity, soil wilting point, leaf area index (LAI) . In conjunction with the flux database, thedatabank constructed by this study can be used for various purposes, such as forinitialization of the soil/land fields for regional weather and climate forecasts, for studyingthe impact of land-cover change, to quantify the rate of the ecosystem sink to CO2, and forremote sensing study. In addition, a parallel comparison between observations at a tower sitewith an additional set of measurement will be carried out. Recommendations to the towersite scientist will be made after the comparison. This comparison is important to reduce theinconsistency among tower sites.本計畫旨在建立台灣地區通量觀測站資料庫，以收集目前運作中的14 座通量觀測站以及未來新增設之觀測站的資料。因各觀測站分布於本島不同區域，又或位於野外及高山上，預定利用無線網路技術將資料即時傳輸至資料庫中，並藉由即時資料來判斷觀測儀器是否持續正常運作，以免漏失觀測資料，亦藉此機會統一資料庫資料格式以利後續模式或其他研究所使用。另外藉由討論會議制定資料後處理程序，包括觀測資料的真實性、座標轉換、水氣密度干擾修正及缺值填入。同時針對觀測站生態環境記錄植被變動(例如農田播種、休耕及農作物種類)、測定土壤性質等基本資料，並逐月進行葉面積指數的調查。以利未來可以利用此作土地變遷對氣象影響之量化研究。儀器性能平行比對在本計畫中亦會選取嘉義農業氣象站進行，利用第二套的觀測系統來推估不同系統間之差異，以為後續研究分析及模式所使用。本計畫冀望後續能跟隨國際趨勢，成立台灣通量觀測網(Taiwan Fluxnet) (TwFlux) ，以提升台灣在相關領域之地位和能見度。

Monitoring System for Rice Growth and Environmental Conditions

「精準農業」經由合理的肥培、施藥等栽培管理手段, 可進行高效率的農業經營與管理, 並減少由農業所產生之非點源污染, 進而達到提高生產利潤, 保護生態環境的目標, 使農業得以永續發展.但首先必須能精確掌握氣候和土壤之時間與空間的變異, 以及其對農作物生育的影響.在精準農業體系中監測系統相當於”眼睛”的角色, 依管理需要進行觀測與監視農作物及環境的變異, 提供類同大腦之決策系統判別與辨識後做出決策, 再由擔任四肢的農機具系統實施處理達到精準管理目標.本計畫為水稻精準農業( 耕 )體系中之監測系統部分, 負責利用遙測技術, 快速且有效的提供共同試驗田區中有關水稻生育情形、病蟲害、產量、土壤特性與肥力之空間分佈圖.重要工作包括水稻生長、逆境( 病蟲害、雜草、旱害等 )及產量之監測與估測技術研究, 稻株氮營養狀態檢測技術研究, 近地面水稻光譜資料庫建置, 土壤性質及肥力狀態偵測技術研究等四大部分.計畫規劃期程共計五年, 於計畫結束時預期可以提供有關田間水稻生長、產量、氮營養狀態空間分佈之遙感監測與估測技術, 完成近地面水稻光譜資料庫, 以及有關田間土壤性質及肥力狀態空間分佈之偵測技術, 以供決策系統和農機具系統進行適時、適地、適量的精準管理.Precision agriculture, through proper fertilizer and pesticide managements, can make agricultural sustainable by not only raising the net profits due to efficient agricultural management practices, but also protecting the ecological environment due to reduced non-point pollution by agricultural activities.However, abilities to detect the influence of temporal and spatial variability of climate and soil to crop growth are requested.In precision agriculture, a monitoring system behaves just like eyes for a human.Obtained information regarding temporal and spatial variation of field crop growth will be sent to an expert system, like brains of a human, for identification and judgment.The decision will then be sent to machinery, like hands and feet of a human, for field operation.This project, the monitoring part of a rice precision agriculture system, is responsible for providing spatial maps of growth condition, pest and disease occurrence, and yields of rice and soil properties and fertility in the joint experimental farm.The work includes following four topics, ( 1 )studies on remote sensing techniques to estimate and monitor growth and yield of rice and its responses to stress conditions, ( 2 )detecting techniques for nitrogen content in rice plants, ( 3 )construction of near surface spectral reflectance database of rice, and ( 4 )detection techniques on soil properties and fertility situations.The project is designed to be completed in five years.When the project completes, it is expected to provide techniques for delineating growth condition, pest and disease occurrence, nitrogen status, and yields of rice by remote sensing, a reflectance database of rice, and express detection techniques for soil properties and fertility in the fields.Those monitoring techniques will enable timely and accurately decision making for the expert system and operation for farm machinery

A study on the use of satellite image to estimate evapotranspiration over crop fields

本研究嘗試以Roerink等人（2000）建立的衛星遙測估算旱作蒸發散量SEBI(Simplified Surface Energy Balance Index)模式，應用於估計美國SGP’97試區的熱通量和蒸發散量，應用時加上大氣校正模式，以及由衛星影像作土地利用分類。並對台中霧峰農試所2000 年一期作水稻田利用SPOT衛星多光譜資料測試估計效果。在SGP’97試區方面，利用地面實測資料和衛星觀測建立回歸關係推估的結果較良好；各項能量通量估計值與觀測值間的誤差，大部分源自地表參數的反演誤差，而後者又與大氣校正模式或回歸關係的誤差有關。在農試所水稻田試區方面，由於SPOT衛星影像缺乏熱紅外光波段，因此利用SPOT 觀測資料反演的NDVI，透過Landsat衛星影像資料建立的回歸關係推估地表溫度，進而推估能量通量。但因此反演的地表參數間具有某種相關性，且水田的所有反射率一溫度資料均落於蒸發散控制區，不能建立模式所需熱通量分配的圖形。本研究也利用DMSV-1空載多光譜資料分析模式對水稻田的可行性，熱通量分配圖沒有某種程度相關，初估結果合理，大氣影響較小，待未來有測量資料時作進一步的比對分析。 This work intends to implement the Simplified Surface Energy Balance Index (5-SEBI) model by Roerink et al.(2000) to estimate the heat fluxes during The Southern Great Plain (SGP’97 in short) Hydrological Experiment in 1997. Two additional features are added to the 5-SEBI model in the work, performing atmospheric correction by radiative transfer model and land-use classification. Results show that partitioning of heat fluxes is in accordance with the measurement. Main cause of discrepancy is due to inaccurate surface parameter estimates. To estimate evapo-transpiration in rice paddy, surface temperature retrieval is compulsory. Since SPOT image is lack of thermal channel, this work uses the Landsat data to construct the regression function between NDVI and surface temperature. However, it is found that the derived surface temperature is collinear with the SPOT retrieved reflectivity. Also, it is realized that all reflectivity-temperature data of rice paddy should fall in the evaporation-controlled region. Application of satellite data for evaporation estimation in rice paddy requires further research