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Ho Chi Minh City, Vietnam

Khoi D.N.,Yamanashi University | Khoi D.N.,University of Science Ho Chi Minh City | Suetsugi T.,Yamanashi University
Water and Environment Journal | Year: 2012

This paper focuses on the uncertainty in climate change impacts on streamflow in Be River Catchment. Uncertainty associated with GCM structure from a subset of CMIP3 (CCCMA CGCM3.1, CSIRO Mk30, IPSL CM4, MPI ECHAM5, NCAR CCSM3.0, UKMO HadGEM1, and UKMO HadCM3), SRES emission scenarios (A1B, A2, B1, and B2), and prescribed increases in global mean temperature (0.5°C to 6°C) using SWAT model is investigated. For prescribed warming scenarios using HadCM3, linear decreases in mean annual streamflow range from 3.1 to 16.7%. Differences in projected annual streamflow between SRES emission scenarios using HadCM3 are small (-5.6% to -4.6%). Under the A1B scenario and 2°C increase in global mean temperature using seven GCMs, there is substantial disparity, by -2.9-25.5% and -8.3-19.1%, respectively. It is generally reasonable to conclude that GCM structure-related uncertainty is greater than that associated with the emission scenarios and climate sensitivity. © 2012 The Authors. Water and Environment Journal © 2012 CIWEM.. Source


Khoi D.N.,Yamanashi University | Suetsugi T.,University of Science Ho Chi Minh City
Journal of Water and Climate Change | Year: 2012

The Be River Catchment was studied to quantify the potential impact of climate change on the streamflow using a multi-model ensemble approach. Climate change scenarios (A1B and B1) were developed from an ensemble of four GCMs (general circulation models) (CGCM3.1 (T63), CM2.0, CM2.1 and HadCM3) that showed good performance for the Be River Catchment through statistical evaluations between 15 GCM control simulations and the corresponding time series of observations at annual and monthly levels. The Soil and Water Assessment Tool (SWAT) was used to investigate the impact on streamflow under climate change scenarios. The model was calibrated and validated using daily streamflow records. The calibration and validation results indicated that the SWAT model was able to simulate the streamflow well, with Nash-Sutcliffe efficiency exceeding 0.78 for the Phuoc Long station and 0.65 for the Phuoc Hoa station, for both calibration and validation at daily and monthly steps. Their differences in simulating the streamflow under future climate scenarios were also investigated. The results indicate a 1.0-2.9 WC increase in annual temperature and a -4.0 to 0.7% change in annual precipitation corresponding to a change in streamflow of -6.0 to -0.4%. Large decreases in precipitation and runoff are observed in the dry season.© IWA Publishing 2012. Source


Rowley J.J.L.,College St | Le D.T.T.,University of Science Ho Chi Minh City | Hoang H.D.,University of Science Ho Chi Minh City | Dau V.Q.,Institute of Ecology and Biological Resources | Cao T.T.,Vinh University
Zootaxa | Year: 2011

Two new species of rhacophorid frogs in the genus Theloderma are described from high-elevation montane forest on the Kon Tum and Langbian Plateaus in Vietnam, on the basis of morphological and molecular evidence. Both new species are differentiated morphologically from their congeners by their small body size (<30 mm SVL); absence of vomerine teeth; rugose skin texture with minute, calcified dorsal asperities; no webbing on hands; brownish dorsum; and a bicoloured iris (pale gold in upper third and reddish brown in lower two-thirds). Molecular evidence supports that both new species are members of genus Theloderma, and are distinct from all congeners sampled (uncorrected sequence divergences at the 16S rRNA gene of >8.5% for all Theloderma for which homologous 16S rRNA sequences are available). The new species are differentiated from each other by dorsal pattern, extent of dorsal asperities, and by mitochondrial DNA. Copyright © 2011, Magnolia Press. Source


Rowley J.J.L.,College St | Le D.T.T.,University of Science Ho Chi Minh City | Tran D.T.A.,University of Bonn | Hoang H.D.,University of Science Ho Chi Minh City
Zootaxa | Year: 2011

We describe a new species of small megophryid frog from the Langbian Plateau in southern Vietnam, the southernmost record of Leptolalax from Vietnam. Leptolalax bidoupensis sp. nov. is distinguished from its congeners by a combination of a dark brownish red ventral surface with white speckling on entire ventral surface including throat, arms and legs, small size (23.6-24.6 mm in four adult males and 29.2-29.4 mm in two adult females), bicoloured iris (coppery red upper half, fading to pale silver ventrally), a mostly smooth skin texture with no skin ridges, and relatively short tibia (male TIB:SVL 0.44-0.46). The male advertisement call of the new species, consisting of 6-9 single-pulsed notes with a dominant frequency of 1.9-3.8 kHz, is also unique among Leptolalax species for which calls are known. From the morphologically similar L. applebyi and L. melicus, L. bidoupensis sp. nov. differs by 9.3% and 9.6% sequence divergence at the 16S mtDNA gene. At present, the new species is known from montane evergreen forest between 1620-1730 m elevation, within an area of 1 km2. We suggest the species should be considered Data Deficient following IUCN's Red List categories. © 2011 Magnolia Press. Source


Rowley J.J.L.,College St | Rowley J.J.L.,James Cook University | Hoang H.D.,University of Science Ho Chi Minh City | Dau V.Q.,Institute of Ecology and Biological Resources | And 2 more authors.
Zootaxa | Year: 2012

We describe a new species of Leptolalax from central Vietnam. Leptolalax firthi sp. nov. is distinguished from its congeners by a combination of the following characters: an absence of distinct dark brown or black dorsolateral markings; toes with rudimentary webbing and wide lateral dermal fringes in males and weak or absent lateral dermal fringes in females; most males with wide lateral dermal fringes on Finger II; medium size (26.4-29.2 mm in 21 adult males, 25.7-36.9 mm in 14 females); and near immaculate white chest and belly. The male advertisement call of the new species, consisting of 2-5 notes with a dominant frequency of 5.4-6.6 kHz (at 18.3-21.2° C) is also unique among Leptolalax species for which calls are known. Uncorrected sequence divergences between L. firthi and all homologous 16S rRNA sequences available were >10%. At present, the new species is known from montane evergreen forest between ∼860-1720 m elevation in Kon Tum and Quang Nam Provinces. The extreme sexual dimorphism observed in L. firthi in terms of lateral dermal fringing, a morphological character often used to distinguish Leptolalax species, highlights the importance of ensuring interspecific comparisons in the genus are performed separately for each sex. Copyright © 2012 · Magnolia Press. Source

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