圖書典藏及影音數位平台

河川為全民寶貴的資產，河川的開發利用，從過去單純的灌溉供水、農業生產、農村需求等逐漸演變到休閒遊憩、景觀與環境生態等。隨著經濟發展及社會的變遷，河川區域內之使用行為也日趨複雜，以本署各河川局有限之人力欲有效監控河川區域內違法之行為，有其實際之困難，尤其盜濫採砂石、毀損河防建造物、棄置廢土廢棄物等動態違規行為，更加困難。另中央管河川區域內違法行為一般係由轄管河川局巡防人員於查獲當時告發，唯因河川區域內地形地貌常隨水位變易產生極大之變化，或因缺乏客觀事實之比對，導致相關執法人員與違法行為者發生極多之衝突，亦對河川局執行取締業務產生諸多困擾。 爰此，如何透過一套完善的監測機制，以客觀、有效的方法掌握河川區域內地形地貌的現況及變遷的資訊，遂成為提昇河川管理成效重要的課題之一。近年來，由於遙測技術具有大地區的空間涵蓋特性，可以提供詳實且長時間的紀錄，並具有極佳的觀察能力，是快速獲取全面性最新國土資訊的調查及監測工具。尤其是93年5月21日我國自主衛星華衛二號成功發射之後，華衛二號衛星影像以其具有自主性高、影像解析度高、資料獲取週期短、價格較便宜等特性，可用以迅速掌握地表改變狀況以做為全面性的土地利用監測工具。 本計畫將引入此一先進而成熟的遙測科學技術對中央管河川（含淡水河及磺溪水系）流域進行長期的監測，期望藉由其高時效與大範圍監測的特性，週期性地進行河川區域內之監測，並針對每一前、後期的遙測監測資料進行比對，將發現有異之區域分析結果，透過網路通報機制提供本署各河川局該變異點的座標及現場查證的相關輔助圖資，俾利進行實地的查核，減少河川局第一線工作同仁巡防取締之工作人力及壓力，提高河川巡防取締及管理成效並落實現代化之河川管理。

The monitoring of river area is a crucial work in the management of water resources in Taiwan. However, the illegal land-use in river area has become rampant over the past years. It appears that the monitoring of whole river area will be extremely difficult if the task is only conducted by limited human resource. Therefore, it is important to use advanced remote sensing technology to monitor river areas on a regular basis. With high efficiency and large scale monitoring, we use remote sensing satellite images to regularly detect the change spots surrounding the river areas which are supervised by Central Government (including Danshui and Huang River). Any changes on the spots will later be delivered to the local patrol units via the Internet. They are required to perform field investigations based on the change spots. Thereafter, the results and the field photographs will be uploaded and integrated into a web-based database management system after their investigation. In this project, we proceed the automatic change detection. Manual interpretation procedure is also involving in assist to select the change spots with high possibility of illegal use. The project has been carried out from 6th September, 2011 to 5th September, 2012. 33 change spot notifications and investigations are completed and 883 change spots are detected. In the project, the majority of image sources are obtained from FORMOSAT-2 and some from SPOT-5. Therefore, the amount of the images not only provides the total coverage over the study areas, but also keeps the project management on schedule. In addition, we plan to establish Web-based Image Interactive Change and Detection (WIICAD) to integrate various periods of satellite images and map data analysis results in particular cases; thus we can meet the needs of various co-ordination departments. We have also sketched river channels from 2008-2012 by using Arc GIS to provide reference to co-ordination departments accordingly. The Water Resources Agency has requested 17 emergency cases during the period of this project. The satellite images as well as the related analysis are able to provide valuable information to various situations. It is essential to collect illegal sandstone quarrying and waste dumping cases in the river area so that we can use them for spatially analysis at the same time. The results of the project indicate the efficiency of how the river patrols can apply temporal satellite images to regular detection of the changes in river areas. It is certainly a great assistance to have a better understanding in the management of the surrounding lands near the river banks, too.