Flow dynamics and age of groundwater within a humid equatorial active volcano (Mount Cameroon) deduced by δD, δ18O, 3H and chlorofluorocarbons (CFCs)

被引：15

作者：

Ako, Andrew Ako ^{[1
]}

Shimada, Jun ^{[2
]}

Hosono, Takahiro ^{[3
]}

Kagabu, Makoto ^{[2
]}

Richard, Akoachere ^{[4
]}

Nkeng, George Elambo ^{[5
]}

Tongwa, Aka Festus ^{[6
]}

Ono, Masahiko ^{[2
]}

Eyong, Gloria Eneke Takem ^{[1
]}

Tandia, Beatrice Ketchemen ^{[7
]}

Mouncherou, Oumar Farouk ^{[1
]}

机构：

[1] Hydrol Res Ctr, Yaounde, Cameroon

[2] Kumamoto Univ Japan, Grad Sch Sci & Technol, Kumamoto 8608555, Japan

[3] Kumamoto Univ, Prior Org Innovat & Excellence, Kumamoto 8608555, Japan

[4] Univ Buea, Dept Geol, Buea, Cameroon

[5] Natl Adv Sch Publ Works, Yaounde, Cameroon

[6] Inst Geol & Min Res IRGM, Yaounde, Cameroon

[7] Univ Douala, Dept Earth Sci, Douala, Cameroon

来源：

JOURNAL OF HYDROLOGY | 2013年 / 502卷

关键词：

Recharge elevation; Apparent age; Groundwater flow; Environmental tracers; Mount Cameroon; Cameroon; STABLE-ISOTOPE RATIOS; WATER; TRANSPORT; BASIN; PRECIPITATION; SPRINGS;

D O I：

10.1016/j.jhydrol.2013.08.032

中图分类号：

TU [建筑科学];

学科分类号：

0813 ;

摘要：

We used environmental tracers (delta D, delta O-18, H-3 and chlorofluorocarbons (CFCs)) to establish the groundwater flow system within the Mount Cameroon area: a 4090 m high active entirely alkaline volcano located within a humid equatorial region. Seventy-five ground and surface water samples (68 spring samples, 6 borehole samples and 1 stream sample) were collected around the volcano during the wet (October-November 2010) and dry seasons Uanuary-February 2010) as well as 10 rain samples in June-September 2010 in order to establish recharge elevations, apparent ages (residence times) and groundwater flow system in the fractured volcanic (basaltic) aquifers. The 8180 and 61) composition of rainwater and groundwater in the Mount Cameroon area fit the Douala Local Meteoric Water Line (DLMWL). The recharge elevations of the individual springs were calculated from their 3180-values and the equation of the altitude gradient (-0.16%., delta O-18/100 m) of precipitation on the mountain. For springs sampled during the two seasons, dry season samples have higher recharge elevations than rainy season samples. Seasonal variation exists in the tritium values as rainy season samples systemically are higher than those of the dry season samples. This implies the input of new water from the rain causing the groundwater system to rejuvenate. Apparent ages for the Mount Cameroon springs calculated from CFCs based on the Piston Flow model range from 10 to approximately 57 years. CFC apparent ages for rainy season samples are systemically younger than those of dry season samples. There is seasonal variation in groundwater flow system in the Mount Cameroon area and also along the different flanks of the volcano. The groundwater flow system is conceptualized by 2 models; a Bypass/piston flow model for the flow system during the rainy season and a binary mixing/piston flow model characterizes the flow system during the dry season. (C) 2013 Elsevier B.V. All rights reserved.

引用

页码：156 / 176

页数：21

共 69 条

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