- 期刊
遙測與GIS結合應用於水稻田辨識
Combined Remote Sensing and GIS Data for Rice Paddy Landuse Interpretation
摘要
本研究利用多時SPOT衛星影像，判釋以垣塊為單元的水稻田分佈'進而更新農地垣塊土地利用GIS資料。方法是以鹿港一帶為先期研究區，採用單一時期與多時段組合影像，利用非監督式（unsupervised）及監督式（supervised）分類方法，藉由逐像元（pixel-by-pixel）及區塊（parcel-based）單元分類方式，以改良式的垣塊網格化資料（網格大小2.5X2.5m^2）對應相對的SPOT影像進行區塊分額。比較水稻田判釋分類優劣後，選擇最佳分顯精度與k指標的NDVI指數差值影像之監督式區塊單元分類法，施行彰化地區南、北端兩個地區的測試;證實可行後，再推展到較大範圍同一期水稻的分顯判釋。推廣應用結果，彰化全區1997年二期稻以相同判釋準則分類的全體精度為88.71%，k指標為0.77 :考慮生長條件不同，調整北、中、南三區的判釋標準後，全區分類精度為89.01%，k指標為0.78。另以同樣的判釋方法及判釋規則庫設定條件，分析1999年一期稻的水稻分佈後，相同判釋標準的全體精度為85 . 64%，k指標為0 .71 :微調北、中、南區判釋區間後，全體精度提昇至86 .4 4%，k指標昇為0.73。因此，結合GIS資料的遙測影像水稻田分類與快速更新農地坵塊GIS資訊，可供實際應用參考。
並列摘要
Multi-temporal images and cadastral parcels were combined in a pilot study for detecting rice crops and updating the GIS database of landuse parcels. Both unsupervised and supervised classification scheme in a pixel-by-pixel mode and a parcel-based mode that using a single time or combined multi-temporal images were adopted in Lu-Kang study area. Cadastral parcels were rasterized into a 2.5m grid for the classification. It is shown that the best result was obtained by applying the parcel-based supervised classification with NDVI difference images, evaluated on basis of classification accuracy and k index.Images from two other test areas in Chang-Hwa County are analyzed using this method for verifying the possibilities of adopting common criteria. Results include: (1) A classification accuracy of 88.71 % with k 0.77 can be achieved for the 2nd crop period in 1997. An accuracy of 89.01% with k 0.78 was obtained if the interpreted criteria was adjusted according to the growing period of North, Middle, South area of Chang-Hwa. (2) The classification accuracy was 85 .64% with k 0.71 for the 1st crop period in l999 using the same classification method. A improvement of accuracy of 0.8% was obtained by using three different interpreted creteria.