喀斯特小流域土壤厚度的影響因素

摘要：在貴州普定縣后寨河小流域75km2面積內，采用150m×150m的網格布點方式，挖設2755個土壤剖面，研究了土壤厚度在小流域內的分布及其影響因素，并對喀斯特小流域土壤概念進行了探討，結果表明從流域尺度來看，當前研究的熱點問題中存在的一個新詞匯即喀斯特土壤，需要定義為由喀斯特巖石發育形成的土壤，而不應該理解為分布在喀斯特區域內的土壤，否則極易導致理解差異而形成誤解。流域尺度下土壤的分布特征表現為8度以下坡度條件下多分布厚度大的土層，而隨著坡度的增加土層厚度減小；喀斯特與非喀斯特的土壤厚度存在差別，海拔條件下的土壤厚度與地貌特征關聯度較大；而人為作用則由于主動選擇的結果，人為影響大的土壤厚度較大；小流域內土壤厚度的影響因素主要與水動力條件相關，表現在坡度、坡位的主要影響方面，因此小流域土壤的利用需要考慮到土壤厚度的分布特征，即土壤厚度大的區域可以進行利用，但土層薄的區域則需要加強保護，尤其是坡度較大的區域；而石漠化區域則需要進行治理并加強保護。

關鍵詞：喀斯特小流域； 喀斯特土壤；土壤厚度；分布特征；利用與保護

中圖分類號：S1522

文獻標識碼：A

文章編號：1008-0457（2017）03-0001-05國際DOI編碼：10.15958/j.cnki.sdnyswxb.2017.03.001

Abstract：2755 profiles were dug according grid of 150m×150m 75km2 area of small watershed of Houzhaihe，Puding，Guizhou provinceInfluencing factors of soil thickness distribution were studied，and the concept of karst soil was discussed，the results showed as follow，currently，karst soil，a new word of extremely used，is difficult to understand for the meanings’ confusion，which needed to be defined exactly to be developed from the karst rocks and to be distinguished from the soil distributed in karst areaSoil was thicker when slope was lower than 8 degree，but thinner as the slope increasedThe thickness of karst soil thinner than non-karst soil，soil thickness was increased with the decrease of altitude about sea level in the small watershedSoil was thicker owing to the selection of humanFrom about，soil thickness was controlled by hydrodynamic force such as degree of slope and position of slopeIt is needed to consider soil thickness while utilizing of soil in the small watershed，which means soil can be used while soil thickness is larger，but need to be protected while soil thickness is thinner，especially area of larger slope degreeThe area of karst rocky desertification is needed to be managed and strengthened protection

Key words：karst small watershed；karst soils；soil thickness；distributional characteristics；utilization and protection

喀斯特地區由于特殊的二元水文結構以及復雜的峰叢、峰林、洼地和漏斗等地貌形態，成土速率慢，土層淺薄且不連續[1]。受成土母質地形氣候植被等成土因素及人為干擾活動影響，喀斯特土壤具有復雜性和高度的空間變異性 [2，3]。……