Please use this identifier to cite or link to this item:
Hydrogen and Oxygen isotopic studies of rivers in Wuchi watershed, Nan-Tou
|關鍵字:||Wu-Chi watershed;烏溪流域;Tao-Zhi typhoon;Hydrogen and Oxygen isotopic;hydrological characteristics;桃芝颱風;氫氧同位素;水文特性||出版社:||土壤環境科學系||摘要:||
River provides the most important source for Taiwan water resources. Due to the establishment limitation of hydrological stations, many essential hydrological phenomena cannot get a better understanding in the upper part of a watershed. Because of geographical convenience, this study chose the Wuchi as the target to study the upper-stream hydrological characteristics of its watersheds by stable isotope compositions complementing with the traditional hydrological parameters. Wuchi is the fourth largest river in terms of area (2025km2) in Taiwan. It has many tributaries, and four watersheds (Peikangchi, Nankangchi, Maolochi and Talichi) with relatively less anthropogenic activities in the upper-stream parts. In addition, Typhoon Toraji occurred during the study period. A hydrological separation analysis was conducted for the particular typhoon event. The aims were to trace the effect of typhoon precipitation on the watersheds and evaluate their water-retaining capacities.
Stable isotope compositions for water samples collected from spots spreading over major tributaries showed that Maolochi exhibited large variations during the dry period, indicating an unstable state for its watershed, probably due to a relatively high degree of anthropogenic activity. Nankangchi is comprised of many small tributaries, but isotopic variations showed a homogeneous pattern from upper to lower stream parts for both wet and dry periods, suggesting its watershed is relatively stable. Peikangchi has a simple source of stream flow, and displayed also very little variations in isotopic compositions, implying its stable nature of the watershed. Talichi has been engineering regulated and showed distinct isotopic compositions with other watersheds of Wuchi. The water sources of Talichi may be derived from Tachiachi. Isotopic separation analysis showed that there are three types with regards to water-retaining capacities. Maolochi represents the low type with a capacity value less than 40%. The Meichi of Nankangchi has the capacity larger than 60% and can be classified as the high type. All others belong to the intermediate type with values between 40 and 60%. This study demonstrates that stable isotopes with traditional hydrological parameters can further understand upper-stream hydrological characteristics. The analytical results are valuable in landslide prevention and land management.
|Appears in Collections:||土壤環境科學系|
Show full item record
TAIR Related Article
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.