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A Case Study of Long-Term Field Performance of Check-Dams In Environ Geol (2009) 58:897–911 DOI 10.1007/s00254-008-1570-z ORIGINAL ARTICLE A case study of long-term field performance of check-dams in mitigation of soil erosion in Jiangjia stream, China Q. L. Zeng Æ Z. Q. Yue Æ Z. F. Yang Æ X. J. Zhang Received: 2 April 2008 / Accepted: 22 September 2008 / Published online: 16 October 2008 Ó Springer-Verlag 2008 Abstract This paper examines the long-term field perfor- erosion; and (d) vegetations on bank slopes. The field data mance of the check-dams in mitigation of soil erosion in the demonstrate that the check-dams have had the following Duozhao catchment of Jiangjia stream, southwest China. good functions for mitigation of soil erosion: (1) restricting Since their construction between 1979 and 1982, the check- the channel depth and lateral erosions, (2) protecting the dams have been functioning effectively. The examination is channel erosion base, (3) reducing the bed gradients of made via comparisons between the environmental condi- debris-flow channels, (4) fixing the channel bed, (5) stabi- tions of the Duozhao catchment with its adjacent Menqian lizing the bank slopes, as well as (6) facilitating the growth of catchment in the stream, because no check dams were con- vegetations. structed in the Menqian catchment. The examination is based on recent field investigations and aerial photograph analyses, Keywords Check-dam Á Debris flow Á Soil erosion Á and covers four aspects: (a) bed gradients of catchment Environmental management Á Jiangjia stream Á Case studies channels; (b) stability of bank slopes; (c) rates of land Introduction Electronic supplementary material The online version of this Soil erosion is a common natural phenomenon in moun- article (doi:10.1007/s00254-008-1570-z) contains supplementary tainous regions. It can change the ground geomorphology material, which is available to authorized users. and induce debris flows and landslides. Debris flows and Q. L. Zeng Á Z. F. Yang landslides can cause casualties to human beings and damages Key Laboratory of Engineering Geomechanics, to civil infrastructures (Takahashi 1991; Armanini 1997). Institute of Geology and Geophysics, For many years, people have developed various mitigation or Chinese Academy of Sciences, P.O. Box 9825, preventive measures to control soil erosions. Check-dam is Chaoyang Area, 100029 Beijing, China e-mail: [email protected] one of the simple and effective engineering measures. A check-dam can be defined as a dam constructed across a Z. F. Yang drainage channel to mitigate and reduce soil erosion (Hudson e-mail: [email protected] 1981; Morgan 1986; Chanson 2004). This structural measure Z. Q. Yue (&) is commonly used to reduce stream speed and to capture Department of Civil Engineering, sediments. It can be made of various materials including University of Hong Kong, Pokfulam Road, woods, boulders, and concrete blocks. It can be close or open Hong Kong, China for preventing or allowing water flow through itself, e-mail: [email protected] respectively. It can be used to permanently store their sedi- X. J. Zhang ments in the channel. Or it can be used to temporarily store Institute of Geomechanics, their sediments. Once its above space is full of sediments, the Chinese Academy of Geosciences, sediments will be removed so that its above space can store 11 Minzhuxueyuan Nanlu, Haidian Area, 100081 Beijing, China new sediments again (VanDine 1996; Armanini 1997; Jaeggi e-mail: [email protected] and Pellandini 1997; Chanson 2004). 123 898 Environ Geol (2009) 58:897–911 Check-dam has a long history of development and uti- Jiangjia stream and its soil erosion lization. Check-dams were built in the mountain of Alps in the fourteenth century and became popular there in the Jiangjia stream is located about 200 km north of Kunming nineteenth century. They were constructed in the Loess city, Yunnan Province, Southwestern China (Fig. 1). It Plateau, China in the sixteenth century. They were used in occupies a plane area of 48.6 km2 and is a tributary Japan in the early twentieth century. More details on the watershed of the Xiaojiang River, a branch of Jinsha check-dam history can be found in Wu (1990), Jaeggi and River of the Yangtze River. The stream is about 13.9 km Pellandini (1997), Shun et al. (1997), Mizuyama et al. long. (2000), Chanson (2004), and Xu et al. (2004). Jiangjia stream is known for its severe soil erosions and This paper presents an investigation on the long-term debris flows. During the wet season in each year, many field performance of masonry check-dams in mitigation of rainstorm induced debris-flows occur in the stream (Li soil erosions in a stream where many debris flows had et al. 1983; Takahashi 1991; Zhang 1993; Corominas 1995; occurred. This stream is the Jiangjia stream near Kunming Lan et al. 2004). Since 1961, tremendous data on the debris in southwest China (Fig. 1). The stream has two major flows and their characteristics have been collected and catchments. One is named Duozhao and the other Menqian. documented by researchers. The occurrence rate of debris The masonry check-dams were constructed between 1979 flows in the stream is about 15 times per year. Solid and 1982 for mitigating and reducing soil erosion in the materials of about 3 9 106 m3 per year in the stream are Duozhao catchment only. Therefore, the investigation is transported into Xiaojiang River and then Yangtze River carried out by comparing the current geomorphologic (Xu 2008). The recorded peak values for the discharge, features of the Duozhao catchment with those of the velocity, head depth, and wet unit weight of the debris Menqian catchment. The comparison covers four aspects: flows are 2,820 m3/s, 15 m/s, 5.5 m and 23.7 kN/m3, (a) the bed gradients of the catchment channels, (b) the respectively (Wu 1990; Li et al. 2003). bank slope stabilities of the two catchments, (c) the soil The stream catchment soil is the core of a tectonic uplift. erosion rates of the two catchments and (d) the vegetation The original hillside slopes comprise mainly the Lower cover in the bank slopes of the two catchments. The Proterozoic thin bedded slate with NE 60°–70° in strike examination has shown that the check-dams have effec- and 40°–50° in dip, and slightly the Sinian medium-thick tively mitigated the severe soil erosions in Douzhao bedded dolomite. Due to strongly regional neotectonic catchment. Consequently, the soil surfaces in Duozhao activities and uplifts, the slate is strongly deformed and catchment are more stable and covered with much more fractured. Table 1 presents the physical and mechanical vegetation and trees than those in Menqian catchment. properties of the slate and dolomite in the stream (Li 1993). Fig. 1 Location plan of Jiangjia 103° 05′ 103° 10′ 26° stream and its vicinities in 17′ China. The names of water 20 24km N o system of different ranks are ° na S 48 ha l a s e c a n defined as follows: the primary n n h M a j h a i c n a as stream, like Jiangjia stream; n c e u l n Dad the first as ravine, like Menqian r i ch e an ann iv ng el and Duozhao ravine; the second li l R e ng ne g in So an and third and fourth as channel, n av ch ia R j n like Daqishu channel o ia ia q X en 45° Jiangjia stream M D ch hu annel uo is R z iz Observation Station a ha e vin o M e D el al n iek an an h D c aq is hu nnel 80° 90° 100° 110° 120° 130° cha 40° 46° 26° 30° 15′ Beijing Jiangjia Watershed of JiangjiaGully ° Stratum dip direction and dip angle 20° stream 45 10° Kunming Menqian subcatchment Duozhao subcatchment 1st 3rd 2 0 nd Water system 123 Environ Geol (2009) 58:897–911 899 The fractured slate belongs to the type of loose and frac- tured structural rocks (Gu 1979). Besides the bedrocks, the stream has abundant and loose deposits of recent and old Poisson’s ratio debris flows and landslides (Li et al. 2003). As shown in Fig. 2, Duozhao and Menqian are the two major catchments of Jiangjia stream. They occupy the plane areas of 13.2 and 14.8 km2, respectively (Wu 1990; Static elastic modulus (GPa) Hu and Zhong 2002). They have eight and nine tributary ) ° U ( debris-flow channels, respectively. Table 2 shows the features of these tributary debris-flow channels. The lon- gitudinal profiles of the two catchments are shown in Shear strength (MPa) Fig. 3. In the paper, the stream system is ranked as fol- lows: the primary stream is the Jiangjia stream; the first streams are the Menqian ravine and the Duozhao ravine; the second and third and fourth streams are named as Softening coefficient channels. Check-dams and performance in Jiangjia stream General introduction Saturated compression strength ) Due to the facts that the debris flows in Jiangjia stream had severe destruction to the civil infrastructure and farmland, 1993 some mitigation measures had been planed and imple- mented since 1960s. Dry compression strength Dry packed random rubble check-dams Between 1965 and 1967, 117 check-dams were made with dry packed random rubbles and constructed. The dams Saturated water absorption were 1.0–2.5 m high, about 1 m wide at the top surface, and less than 1:0.5 for the gradient of the dam down- stream slope. Dolomite boulders were directly built on the channel beds without disposal of dam foundation and Water absorption abutment.
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