Khammouane Province Research Articles

Study on the Water Use at the Tailwater of Nam Theun 2 Hydropower Station through the Canal of the 3rd Water Gate (Case study: Nongping and Boungbao villages) Nhommalath District, Khammounce Province

Water management is managed through the Nam Theun 2 hydroelectric project. The project has released water in two parts: 1) Water gates and channels release water into natural streams about 30 km long and can drain 1,200 m3/s; and 2) Releasing through the newly constructed regulating dam to the Xe Bang Fai River directly, with a length of about 27 km, can drain 330 m3/s. According to the length of the channel, there is a built water gate for 5 irrigations. Currently, only 3 water gates have been opened to supply water for production in 9 villages that depend on Nhommalath district, Khammouane province. In order to make the use of water through the channel to the maximum benefit, it can operate together between electricity generation and the actual use of water by the community. In this chapter, we have studied the amount of water flow according to the season through Regulating Dam during the past 11 years. Since 2012 to 2022, we have studied the participation of farmers in the management and use of water within the scope of agricultural land. Through comparing the amount of water flow during the past 11 years, from 2012 to 2022, The amount of water flow through the channel with the lowest flow in December 2022 is equal to 0.0 cubic meters per second caused by the stoppage of the company's electricity production to do various repairs, and the highest flow rate in November 2016 was 318.18 cubic meters per second. The reason is that the project has full production capacity to respond to the electricity buyers. Among them, the annual average flow volume with the lowest value in 2022 is equal to 153.06 cubic meters per second, and the annual average flow volume with the highest value in 2017 is equal to 239.11 cubic meters per second. At the time the company stopped production, it used a backup pump with a suction power equal to 0.083 m3/s, which was installed at 2 points to pump water into the irrigation channel for the people. The company is responsible for all costs, such as fuel for the pump, maintenance of the pump, and the water system from the pump to the channel. Assessment of farmers' participation in water management with topics such as survey participation and data collection, participation in the implementation of four seasonal plans, participation in monitoring and evaluation, and participation in the review of all outputs is at a very satisfactory level ( = 3-3.8), except for the topic of participation in determining water use regulations within the channel, and the flood problems are evaluated at a moderate level ( = 2.4). Because of management, the municipality has appointed a committee and has specific management rules. There has never been a natural disaster in the area in the past, such as a drought or flood.

Comprehensive evaluation of malaria reactive surveillance and response strategies in Lao People’s Democratic Republic: a mixed-methods study

ObjectivesTo achieve malaria elimination by 2030, the Lao People’s Democratic Republic (PDR) adopted a reactive surveillance and response (RASR) strategy of malaria case notification within 1 day, case investigation and...

A new genus and new species of sucking louse (Phthiraptera: Anoplura: Enderleinellidae) from the particoloured flying squirrel (Hylopetes alboniger) in Laos, and an updated identification key to enderleinellid genera.

Hylophthirus spinosus, new genus and new species (Phthiraptera: Anoplura: Enderleinellidae), is described from specimens collected from the particoloured flying squirrel, Hylopetes alboniger in Khammouane Province, Laos (Lao Peoples Democratic Republic). Both sexes of the new louse are illustrated with stacked microphotographs, scanning electron micrographs and line drawings. An updated morphological identification key to the six genera (Atopophthirus, Enderleinellus, Hylophthirus, Microphthirus, Phthirunculus and Werneckia) now recognised within the family Enderleinellidae is presented. The new genus is unique within the Enderleinellidae in having massive spines (modified setae) on some abdominal sternites, partially bulbous 5th antennal segments, mesothoracic spiracles borne on protuberances and the morphology of the genitalia of both sexes. Tables showing all genera of sucking lice that include species parasitising sciurids (squirrels, chipmunks, susliks and marmots), and all known species of enderleinellids, with their known host associations and geographical distributions are included and briefly discussed in relation to the new genus and species.

Enhancing child dietary diversity through cooking demonstration and nutritional education in rural Lao PDR

BackgroundEfforts to prevent malnutrition in children under five are crucial for both short-term and long-term impact, especially in resource-constrained low- and middle-income countries, where ensuring minimal food diversity remains an urgent challenge. Our organization implemented initiatives to improve dietary diversity among children under five in rural areas of Lao People’s Democratic Republic (Lao PDR).MethodsWe carried out educational and awareness programs directed at caregivers of children aged 6–59 months. These programs were delivered by healthcare professionals and trained community volunteers in specific areas of Xaybouathong District, Khammouane Province. To evaluate the impact of our interventions, we conducted surveys both at the beginning and end of the project. We designated the Individual Dietary Diversity Score IDDS as the objective variable, serving as an indicator of child dietary diversity. Using sociodemographic and economic indicators as explanatory variables, we assessed the impact of the intervention through multivariate analysis with a generalized linear model as well as a bivariate analysis.ResultsThe comparison between 210 children at baseline and 205 children at endline revealed a significant increase in IDDS among children aged 6–23 months (from 3.36 to 4.22) and children aged 24–59 months (from 3.29 to 3.83). Multivariate analysis indicated a significant association between the intervention effect (baseline vs. endline) and the village of residence. Furthermore, significant improvements were observed in each food group that constitute IDDS, including vegetables and fruits, eggs, and legumes and nuts.ConclusionsEven in resource-limited settings, such as rural areas of Lao PDR, it is possible to improve child dietary diversity through educational approaches that encourage the utilization of locally available foods.

Dalbergia calcarea, a new species of Dalbergia (Fabaceae: Dalbergieae) from Lao PDR

Dalbergia calcarea, a new species currently only known from the limestone mountains of Khammouan Province, central Laos, is described and illustrated. The key characters such as habit, colour and limb of standard, and number of ovules of the new species are discussed and compared with its closest relatives. A detailed description along with etymology, conservation status, illustrations and colour photographs are provided for a new species. This discovery increases the number of Laotian species in the genus Dalbergia to seventeen taxa.

Three new taxa and two noteworthy species of Peliosanthes (Asparagaceae, Convallarioideae) from Laos and Vietnam

Two new species, Peliosanthes annamensis and P. virescens from Dak Lak Province in southern Vietnam, are described and illustrated. The former is morphologically similar to P. crassicoronata, while the latter to P. argenteostriata. We also describe and illustrate one new variety, P. nivea var. acutiloba from Khammouane Province, central Laos. Peliosanthes divaricatanthera, formerly known from central Vietnam (Da Nang City) and SW China (Yunnan), was rediscovered in southern Vietnam (Dak Lak Province). Its illustrations and amended description based on new materials are provided. We also report P. micrantha, so far known from central and southernVietnam, as a new addition to the flora of Laos. Notes on their morphological and ecological aspects, taxonomic relationships to the respective congeners, and data on their habitats are provided as well.

Review of the pill millipede genus Hyperglomeris Silvestri, 1917 (Diplopoda, Glomerida, Glomeridae) with description of two new species from Laos.

The pill millipede genus Hyperglomeris Silvestri, 1917 is reported from Laos for the first time. Two new species, namely H.bicaudata Likhitrakarn, sp. nov. and H.inkhavilayi Likhitrakarn, sp. nov., from Houaphanh and Khammouane provinces, northern Laos, are described and illustrated based on morphological characters and molecular analyses. Sequences of COI gene were used as DNA barcoding markers, and successfully supported the accurate identification of other Glomeridae species. Interspecific divergence of the COI uncorrected p-distance between these new species and other Hyperglomeris species ranged from 7.84-13.07%, while the intraspecific divergence was 0.45% in H.inkhavilayisp. nov. and 5.3% in H.bicaudatasp. nov. The updated status of Hyperglomeris, a map of its distribution, and identification keys for all species are given.

Two new species of Dixonius from Vietnam and Laos with a discussion of the taxonomy of Dixonius (Squamata, Gekkonidae).

Integrated analyses using maximum likelihood (ML), Bayesian inference (BI), principal component analysis (PCA), discriminate analysis of principal components (DAPC), multiple factor analysis (MFA), and analysis of variance (ANOVA) recovered two new diagnosable species of gekkonid lizards in the genus Dixonius, one from the Central Highlands, Gia Lai Province, Vietnam and another from the Vientiane Province, Laos. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs showed that Dixoniusgialaiensissp. nov. is the sister species of D.minhlei from Dong Nai Province, Vietnam and is nested within a clade that also includes the sister species D.siamensis and D.somchanhae. Dixoniusmuangfuangensissp. nov. is the sister species to D.lao from Khammouane Province, Laos and is embedded in a clade with D.vietnamensis, D.taoi, and undescribed species from Thailand. Multivariate (PCA, DAPC, and MFA) and univariate (ANOVA) analyses using combinations of 15 meristic (scale counts), six morphometric (measurements), and five categorical (color pattern and morphology) characters from 44 specimens encompassing all eight species of Dixonius from Vietnam and Laos clearly illustrate Dixoniusgialaiensissp. nov. and Dixoniusmuangfuangensissp. nov. are statistically different and discretely diagnosable from all closely related species of Dixonius. These integrative analyses also highlight additional taxonomic issues that remain unresolved within Dixonius and the need for additional studies. The discovery of these new species further emphasizes the underappreciated herpetological diversity of the genus Dixonius and illustrates the continued need for field work in these regions.

Combination of 2D-Electrical Resistivity Imaging and Seismic Refraction Tomography methods for groundwater potential assessments: A case study of Khammouane province, Laos

2D Electrical Resistivity Imaging (2D-ERI) and Seismic Refraction Tomography (SRT) are non-destructive techniques widely used for numerous geophysical investigations, namely, structural geology mapping, archaeological, engineering, and groundwater investigations. The present study aims to define potential groundwater zones in the Thakhek district of Khammouane Province, Laos, by 2D-ERI and SRT methods; due to the limitation of groundwater potential information, monitoring and evaluation activities regarding groundwater quantity and quality have not been conducted in this study area. The 2D-ERI measurement is based on the Wenner configuration with an electrode spacing of 10-160 m. In contrast, SRT uses a 6.5 kg sledgehammer for a seismic source with a 4 m geophone interval. The results indicate moderate resistivity values ranging from 18.8-71 Ohm-m, and seismic velocities ranging from 1220-2140 m/s were found at 12-30 m in the study region, illustrating the existence of a groundwater/aquifer at this depth. These results correlate well with drilling results from the borehole measurements in the Thakhek district, where the water levels were found at a depth of 12 m for borehole 1 and 15 m for borehole 2. The present study also demonstrates the correlation between 2D-ERI and SRT techniques. The adopted methods favor groundwater identification in the study region and other areas with similar geology formations.

Ethnobotanical Study on the utilized of medicinal plants by the Phouthai Ethnic Group in Khammouan Province, Lao PDR

Background: Plants have been a part of rural areas’ people's life from birth to die since prehistoric times and their utilization is an important traditional culture in the worldwide. However, this is a lack of ethnobotanical study in Laos. The aim of the study is to record the plants' species and explore their medical utilization in Nakeu village, Hinboon district, Khammouan province, middle part Laos. Methods: Ethnobotanical survey was conducted from August 2018 to July 2019. One hundred and fifty key information (81 males and 69 females). Ethnomedicinal data were collected through semi-structured interviews with key informants. Results: The total 79 plant species belong to 46 families were recorded as wild medicinal important. Life form importance value (LIV) was highest in tree 52%, followed by shrub 29%, liana 14%, grass 4%. The medicinal plants are used for stomach problems, heart disease, kidney problems, fever, and others, respectively. Used value (UV) was highest in Ocimum americanum (0.93). This knowledge will support primary health care providers and policymakers in decision-making on the utilization of medicinal plants. Conclusion: In Hinboon district, Khammouane province, Lao PDR, are some of the richest in species of medicinal plants in developing countries, and indeed in Asia. It is worth pointing out the exceptional long list of medicinal plants which are used for traditional medicine and documented as used in the treatment of different common sicknesses. Health policies have to promote the utilization of medicinal plants as part of a strategy to improve the basic health and livelihoods of rural communities throughout the country. Further exploration is needed on the bioactive compound and chemical factor contents of medicinal plants.

Hiding on jagged karst pinnacles: A new microendemic genus and species of a limestone-dwelling agamid lizard (Squamata: Agamidae: Draconinae) from Khammouan Province, Laos.

We describe a unique new species and genus of agamid lizard from the karstic massifs of Khammouan Province, central Laos. Laodracon carsticola Gen. et sp. nov. is an elusive medium-sized lizard (maximum snout-vent length 101 mm) specifically adapted to life on limestone rocks and pinnacles. To assess the phylogenetic position of the new genus amongst other agamids, we generated DNA sequences from two mitochondrial gene fragments (16S rRNA and ND2) and three nuclear loci ( BDNF, RAG1 and c-mos), with a final alignment comprising 7 418 base pairs for 64 agamid species. Phylogenetic analyses unambiguously place the new genus in the mainland Asia subfamily Draconinae, where it forms a clade sister to the genus Diploderma from East Asia and the northern part of Southeast Asia. Morphologically, the new genus is distinguished from all other genera in Draconinae by possessing a notably swollen tail base with enlarged scales on its dorsal and ventral surfaces. Our work provides further evidence that limestone regions of Indochina represent unique "arks of biodiversity" and harbor numerous relict lineages. To date, Laodracon carsticola Gen. et sp. nov. is known from only two adult male specimens and its distribution seems to be restricted to a narrow limestone massif on the border of Khammouan and Bolikhamxai provinces of Laos. Additional studies are required to understand its life history, distribution, and conservation status.

Molecular assessment of pitviper populations (genus trimeresurus) in Laos and Vietnam reveals new country record and overlooked diversity

Vietnam is home to at least ten species of the genus Trimeresurus (Asian green pitvipers) and at minimum five members are found in Laos. The number has been increasing in recent years because of new species descriptions, e.g., Trimeresurus guoi, and new records of recently discovered taxa, such as T. cardamomensis. However, the genus has still been poorly studied in Laos and Vietnam as many areas in the two countries have not been sufficiently surveyed. In addition, the taxonomic status of several populations in the two countries has not been thoroughly investigated. In this study, we sequenced 18 new samples of the Asian green pitvipers collected from various sites in Vietnam and from Khammouane province in Laos. Our analyses based on a short fragment of the mitochondrial COI gene confirm the occurrence of T. stejnegeri in Laos and thus increase the species richness in the country to at least six, but more study needs to be undertaken to better understand the diversity of the species group. Two other populations from Khammouane province potentially constitute cryptic species, although further investigation is warranted. In Vietnam, T. albolabris is broadly distributed and divided into two clades with unknown taxonomic status. Moreover, T. gumprechti is discovered in two new localities from the Northeastern provinces of Bac Giang and Cao Bang. It is apparent that this species might represent a species complex, which requires more detailed taxonomic treatment.

A new species of the Gekko japonicus group (Squamata: Gekkonidae) from Khammouane Province, central Laos.

A new species of the Gekko (Japonigekko) japonicus group from Khammouane Province, central Laos is described based on morphological characters and molecular evidence. Morphologically, Gekko khunkhamensis sp. nov. can be distinguished from the remaining congeners by a combination of the following characters: size moderate (SVL 69.775.2 mm); nares in contact with rostral; internasals absent; postmentals enlarged; interorbital scales between anterior corners of the eyes 31 or 32; dorsal tubercles absent; ventrals between mental and cloacal slit 181185; midbody scales 127138; ventral scales 4245; subdigital lamellae on first toe 13 or 14, on fourth toe 14 or 15; tubercles on upper surface of fore and hind limbs absent; precloacal pores absent in the male and females; postcloacal tubercles 2; tubercles absent on dorsal surface of tail base; subcaudals distinctly enlarged; dorsal surface of body with five dark grey bands, which become irregular posteriorly. Genetically, the new species is placed in a clade, consisting of G. bonkowskii, G. nadenensis, G. scientiadventura, G. sengchanthavongi, and G. thakhekensis and differs from other congeners by at least 13% in terms of pairwise distance based on a fragment of the mitochondrial ND2 gene.

Economic feasibility of a sustainable production forest management system in Xaibouathong forest management area, Khammouan province, Lao PDR

Sustainable Production Forest Management is a priority forest policy in Laos in which forest management plans need to be produced for each Production Forest Area (PFA). The forest management plan is very important for the sustainable use of forest resources in a PFA. It determines harvesting rotation cycles, annually allowed sustainable cuts of timber for each compartment, and identifies areas for conservation, restoration and rehabilitation in each PFA. This study examines the economic feasibility of the implementation of forest management operations in Xaibouathong Forest Management Area (FMA) in Khammouan Province with a 15-year cutting cycle. Data and information on Government cost norms, fees, and timber prices associated with the development and implementation of forest management plans, volumes and timber species harvested from three sub-forest management areas (Sivilai, Kengchone, and Phakong) of Xaibouathong FMA were collected and analyzed by using benefit-cost analysis. The results of this study showed that the current production forest management operation in Xaibouathong FMA is not economically feasible. Most of the sub-forest management areas costs outweigh its benefits because most of commercial tree species harvested in the three Sub-FMAs are lesser use species with low market price. Further study is needed to identify the real costs associated with the development and implementation of forest management plans when the Government permits logging operations in other production forest areas.

Natural radionuclides and assessment of radiological hazards in different geological formations in Khammouan province, Laos

Natural radionuclides and assessment of radiological hazards in different geological formations in Khammouan province, Laos

Ecology and Conservation of the Laotian langur Trachypithecus laotum in a Protected Area of Laos (Southeast Asia)

Terrestrial species from the Lao People’s Democratic Republic (PDR) are under high threat due to deforestation and overhunting. Previous studies have even defined these forests as subjected to an “empty forest syndrome”, a condition in which forests that are apparently well preserved are instead almost deprived of vertebrate faunas due to extreme exploitation by local communities. Forest specialists, including several primates, are among the most threatened species in the country. The Laotian langur (Trachypithecus laotum) is endemic to Lao PDR, is listed as Endangered by the IUCN Red List, and it is one of the least studied species in the region. A survey on the local distribution, life history and conservation status of the Laotian langur was carried out in Phou Hin Poun National Protected Area, Khammouane Province of Lao PDR. The survey consisted of an initial phase with interviews to select key informants on the Laotian langur and the other primate species of the area. Then, a phase of field surveys along forest transects, totaling 64.1 km of 21 transects, yielded a record of 35 individuals in 9 groups. The highest encounter/detection rate of the Laotian langur was 1 group per km at one sector of the park. In contrast, it was much lower (0.18–0.34 groups/km) in the rest of the protected area. The group sizes were much lower than those observed in the same area between 1994 and 2010, thus suggesting a decline in the population size of langurs. This decline may be linked to habitat loss (timber extraction and mining). Still, also overhunting, as signs of poaching were observed during our field surveys. This was also supported by the reports of our interviewees. Laotian langurs were observed to be sympatric and interact while foraging with the Assamese macaque (Macaca assamensis). In the cases of sympatric occurrence between the two species, we observed that subtle mechanisms of niche partitioning may occur to reduce interspecific competition for food. Further research on the population and ecology of this endangered langur should be conducted to understand the species and aid its conservation.

Integrated mapping of water-related disasters using the analytical hierarchy process under land use change and climate change issues in Laos

Abstract. In the past few decades, various natural hazards have occurred in Laos. To lower the consequences and losses caused by hazardous events, it is important to understand the magnitude of each hazard and the potential impact area. The main objective of this study was to propose a new approach to integrating hazard maps to detect hazardous areas on a national scale, for which area-limited data are available. The integrated hazard maps were based on a merging of five hazard maps: floods, land use changes, landslides, climate change impacts on floods, and climate change impacts on landslides. The integrated hazard map consists of six maps under three representative concentration pathway (RCP) scenarios and two time periods (near future and far future). The analytical hierarchy process (AHP) was used as a tool to combine the different hazard maps into an integrated hazard map. From the results, comparing the increase in the very high hazard area between the integrated hazard maps of the far future under the RCP2.6 and RCP4.5 scenarios, Khammouan Province has the highest increase (16.45 %). Additionally, the very high hazard area in Khammouan Province increased by approximately 12.47 % between the integrated hazard maps under the RCP4.5 and RCP8.5 scenarios of the far future. The integrated hazard maps can pinpoint the dangerous area through the whole country, and the map can be used as primary data for selected future development areas. There are some limitations of the AHP methodology, which supposes linear independence of alternatives and criteria.

Seroepidemiology of Foot and Mouth Disease using passive surveillance techniques in selected provinces of Lao PDR

Foot and Mouth Disease (FMD) is a high-impact, contagious transboundary animal disease that is endemic in Southeast Asia. Abattoir samples were routinely collected in six selected provinces between March and December 2019. A total of 1280 samples of abattoir animals were tested for FMD Non-Structural Protein (NSP) antibodies to indicate natural infections. Overall, 22.8% were seropositive for FMD NSP antibodies while seroprevalence of cattle (n = 469), buffalo (n = 214), and pigs (n = 597) were 44.6%, 35.0%, and 1.3%, respectively. The highest seroprevalence destination province was Xiengkhouang (35.3% of 272 samples), followed by Savannakhet (27.0% of 244 samples). Risk factors for evidence of natural infection identified by a multivariate logistic regression model included age groups (p-value = 0.02) and origin provinces (p-value = 2.8 × 10−5) of the animals. There were significant differences of FMD NSP seroprevalence between age groups and origin provinces of the animals. The odds ratio of a seropositive result in the less than 1 year old group was 2.5 (95% CI; 1.4, 4.4) when compared to the 3–4 years old group, while the odds ratios for animals that originated from Khammouane and Xiengkhouang provinces were 4.5 (95% CI; 1.1, 18.7) and 2.4 (95% CI; 1.4, 4.1), respectively, when compared to Champasak province. Serotype-specific antibody ELISA for 44 NSP antibody–positive samples revealed evidence of FMD serotypes O and A virus circulation in some provinces. Despite the passive abattoir survey providing useful information on FMD virus previous exposure and geographic locations of the animals, timely information on FMD virus circulation and distribution is also crucial to an effective control program. Alternative approaches to increase the cost-effectiveness of the surveillance network are also discussed.

High prevalence of opisthorchiasis in rural populations from Khammouane Province, central Lao PDR: serological screening using total IgG- and IgG4-based ELISA.

Human opisthorchiasis, caused by Opisthorchis viverrini, is a public health problem in Southeast Asia and a major risk factor for cholangiocarcinoma. In Lao PDR, seroprevalence and the relationship between the number of O. viverrini eggs in infected people and specific antibody responses are still unknown. We evaluated and compared parasitological and serological screening methods in the community in an endemic area of opisthorchiasis in Lao PDR. Seroprevalence of O. viverrini-specific total IgG and IgG4 antibodies and their relationships with O. viverrini egg intensities were evaluated in Khammouane Province, central Lao PDR, using ELISA and a modified formalin ethyl-acetate concentration technique (FECT). FECT stool examination revealed O. viverrini eggs in 70.3% (90/128) of individuals (95% CI 61.6 to 78.1%) while ELISA (based on total IgG and on IgG4 antibodies to O. viverrini) found 98.4% (95% CI 94.5 to 99.8%) and 89.8% (95% CI 83.3 to 94.5%) of sera, respectively. There was a positive and significant correlation between numbers of O. viverrini eggs per gram and levels of both IgG (R2=0.168, p<0.001) and IgG4 (R2=0.219, p<0.001) antibodies. A high prevalence of human opisthorchiasis in Lao PDR was found using a new platform, serological screening in the community. This points to a need for sustainable control of this liver fluke infection.

Rediscovery of Andrea's keelback, Hebius andreae (Ziegler & Le, 2006): First country record for Laos and phylogenetic placement

For more than a decade, the keelback snake Hebius andreae was only known from the holotype from the limestone forest in the central Truong Son (the Annamite Mountain Range) of Quang Binh Province in Vietnam. As the adult male was formaldehyde-fixed, the description was based on morphological characters only. During recent herpetological surveys in the karst forest of central Laos, opposite to the type locality of H. andreae on the other side of the Annamite Range, the Andrea's keelback is rediscovered. Based on a juvenile male from Bualapha District, Khammouane Province, within Hin Nam No National Protected Area, we herein report the first country record of this species from Laos, provide an expanded morphological definition, and for the first time recover the phylogenetic relationship of H. andreae, based on the sequences of four genes, including one mitochondrial, cytochrome b, and three nuclear markers, Cmos, NT3, and Rag1. The phylogenetic placement of H. andreae reveals it to be a member of Hebius, in fact the most basal representative of the genus. The rediscovery of the beautiful but still poorly known and obviously rare species underlines the conservation importance of the Annamite Mountain Range as habitat and refugium for the regional unique biodiversity, which only occurs in this karst massif.