农业工程学报
農業工程學報
농업공정학보
2014年
18期
151-158
,共8页
模型%土壤%土地利用%圆盘入渗仪%计算方法%吸渗率
模型%土壤%土地利用%圓盤入滲儀%計算方法%吸滲率
모형%토양%토지이용%원반입삼의%계산방법%흡삼솔
models%soils%land use%disc infiltrometer%calculation methods%soil sorptivity
探讨利用圆盘入渗仪测定不同利用类型土壤吸渗率的适用性,该文选用盘径分别为10和20 cm的圆盘入渗仪对3种利用土壤(菜地、草地和茶园)在0、-3、-6、-9 cm 4个压力水头下的吸渗过程进行测定。研究以Vandervaere法为参考方法,对Philip法、Haverkamp 三维吸渗法、Haverkamp 三维吸渗改进法的适用性进行比较分析。结果表明:吸渗率的不同计算公式所适应的吸渗过程时间尺度不同,且Haverkamp三维吸渗法所得吸渗率值与参考方法最接近。盘径对吸渗率测定差异的影响不显著。除0 cm压力水头外,不同利用类型土壤吸渗率差异显著,且不同压力水头下测得3种土壤吸渗率大小排序不同。当压力水头为-9和-6 cm时,菜地吸渗率(0.0104和0.0119 cm/s0.5)显著高于茶园(0.0017和0.0025 cm/s0.5)(P<0.05);当压力水头为-3 cm时,茶园吸渗率(0.0370 cm/s0.5)显著高于菜地和草地(0.0147和0.0132 cm/s0.5)(P<0.05)。该研究可为南方丘陵区土壤水力参数的测定提供理论依据。
探討利用圓盤入滲儀測定不同利用類型土壤吸滲率的適用性,該文選用盤徑分彆為10和20 cm的圓盤入滲儀對3種利用土壤(菜地、草地和茶園)在0、-3、-6、-9 cm 4箇壓力水頭下的吸滲過程進行測定。研究以Vandervaere法為參攷方法,對Philip法、Haverkamp 三維吸滲法、Haverkamp 三維吸滲改進法的適用性進行比較分析。結果錶明:吸滲率的不同計算公式所適應的吸滲過程時間呎度不同,且Haverkamp三維吸滲法所得吸滲率值與參攷方法最接近。盤徑對吸滲率測定差異的影響不顯著。除0 cm壓力水頭外,不同利用類型土壤吸滲率差異顯著,且不同壓力水頭下測得3種土壤吸滲率大小排序不同。噹壓力水頭為-9和-6 cm時,菜地吸滲率(0.0104和0.0119 cm/s0.5)顯著高于茶園(0.0017和0.0025 cm/s0.5)(P<0.05);噹壓力水頭為-3 cm時,茶園吸滲率(0.0370 cm/s0.5)顯著高于菜地和草地(0.0147和0.0132 cm/s0.5)(P<0.05)。該研究可為南方丘陵區土壤水力參數的測定提供理論依據。
탐토이용원반입삼의측정불동이용류형토양흡삼솔적괄용성,해문선용반경분별위10화20 cm적원반입삼의대3충이용토양(채지、초지화다완)재0、-3、-6、-9 cm 4개압력수두하적흡삼과정진행측정。연구이Vandervaere법위삼고방법,대Philip법、Haverkamp 삼유흡삼법、Haverkamp 삼유흡삼개진법적괄용성진행비교분석。결과표명:흡삼솔적불동계산공식소괄응적흡삼과정시간척도불동,차Haverkamp삼유흡삼법소득흡삼솔치여삼고방법최접근。반경대흡삼솔측정차이적영향불현저。제0 cm압력수두외,불동이용류형토양흡삼솔차이현저,차불동압력수두하측득3충토양흡삼솔대소배서불동。당압력수두위-9화-6 cm시,채지흡삼솔(0.0104화0.0119 cm/s0.5)현저고우다완(0.0017화0.0025 cm/s0.5)(P<0.05);당압력수두위-3 cm시,다완흡삼솔(0.0370 cm/s0.5)현저고우채지화초지(0.0147화0.0132 cm/s0.5)(P<0.05)。해연구가위남방구릉구토양수력삼수적측정제공이론의거。
Soil sorptivity is one of the most important soil hydraulic parameters, representing the capacity of soil to absorb and release the soil solution by capillary force. Quantifying soil sorptivity is essential for describing and modeling hydrological and biological processes, and promoting the theoretical research of the unsaturated soil water movement processes, as well as for the determination of rational irrigation and drainage technology parameters. However, obtaining sufficient and reliable soil sorptivity data is expensive and time consuming. Since the measurement is fast and good for the in-site measurement in fields, the disc infiltration method has been paid more attention gradually. The objective of this study was to assess the feasibility of using a disc infiltrometer to determine soil sorptivity in 3 soils with different land uses (vegetable field, grass land and tea garden) and contrasting soil textures. For this purpose, a series of 3-D infiltration experiments were conducted using 2 sizes (in diameter of 10 and 20 cm) of disc infiltrometer under 4 pressure heads (-9, -6, -3, and 0 cm). The performances of Philip, Haverkamp 3-D infiltration and modified Haverkamp 3-D infiltration method were assessed by setting the Vandervaere method as the control. The results showed that the optimum infiltration time (OIT) for sorptivity calculation differed with methods. Among the 4 methods, the optimum infiltration time for Philip method was the shortest, being 30 s. The OIT for the modified Haverkamp 3-D infiltration method was about 240 s, but the whole infiltration process was required to get a reasonable sorptivity value for the Haverkamp 3-D infiltration method. The Haverkamp method was better than the other 2 methods because that the Haverkamp 3-D infiltration method resulted in sorptivity values closest to that of the Vandervaere method. No significant difference in the soil sorptivity determined by infiltrometers was found between different diameter discs. This may indicate that sorptivity measurement is not affected by the disc size. Small disc is thus recommended for the field application considering that small disc is in better contact with soil surface and a smaller quantity of water is required for the measurement. Pressure heads and land use types had interaction on sorptivity rate. The sorptivity rate under 4 pressure heads was not significant at vegetable field (P>0.05), but significant at tea garden and grass land (P<0.05). Except for the pressure head of 0 cm, soil sorptivity was significantly different in the 3 land use types (P<0.05), and the order of measured soil sorptivity among the 3 land uses differed with pressure heads. The soil sorptivity of vegetable field was highest under lower pressure heads (-9 and -6 cm), while that of tea garden and grass land was higher than that of vegetable field under higher pressure heads (-3 cm). This indicated that the difference of soil pore distribution is obvious in different land use types. This study may be instructive in estimating soil hydraulic parameters by disc infiltrometer in hilly area of South China.