In order to make cst more practical and easier to popularize , it is essential and urgent to keep on studying and developing cst at lower unit level to establish basic soil classification units of cst 發(fā)生分類到系統(tǒng)分類的參比關(guān)系復雜,參比難度大,原因在于它們的分類體系和劃分標準是完全不同的。
1 . 4 based on the attribute db , the soil classification graphic db is set up by using arc / info cis . the soil order , suborder sketchs and basic classification unit ( series ) sample maps , make the distribution of soil in hubei province clear at a glance 4在屬性數(shù)據(jù)庫的基礎(chǔ)上,利用arc infogis建立了湖北省土壤分類圖形數(shù)據(jù)庫(空間數(shù)據(jù)庫) ,運用計算機編制和輸出了全省土壤系統(tǒng)分類土綱、亞綱概圖和基層分類單元(土系)樣塊圖,使全省土壤分布狀況一目了然。
Primarily there are two aspects : 1 ) the calculation model of the value of land classifying units - - model of time distance attenuation . in the calculation model of the value of land classifying units , author brings forward the model of time distance attenuation . in this model adopting the network analysis , and by establishing the road network , and proceeding path analysis , computing the time distance , then proceed the exponential attenuation or straight line attenuation on time distance , get the value of influence factor of the land classification unit 主要有兩個方面: 1 、定級單元分值計算模型? ?時間距離衰減模型在定級單元分值的求取模塊中,提出了時間距離衰減模型,模型中采用網(wǎng)絡(luò)分析的方法,通過建立道路網(wǎng)絡(luò),進行路徑分析,求取時間距離,進而按時間距離進行指數(shù)衰減或直線衰減,得到定級單元因素因子影響分值。