scholarly journals Impact of Flow Variation on Hydropower Projects in Budhigandaki River Basin of Nepal

2021 ◽  
Vol 26 (1) ◽  
pp. 89-98
Author(s):  
Suresh Marahatta ◽  
Laxmi Prasad Devkota ◽  
Deepak Aryal
Keyword(s):  
Annual Variation ◽  
Energy Generation ◽  
Dry Season ◽  
Wet Season ◽  
Flow Variation ◽  
Small Uncertainty ◽  
Average Loss ◽  
The Impact ◽  
Very High

Daily flow data from 1964 to 2015 of Budhigandaki River at Arughat were analyzed to assess the impact of flow variation at different time scales to the run of the river (RoR) type of hydropower projects. The data show very high inter-annual variation in daily, monthly and seasonal flows. The long term annual average flow at Arughat was 160 m3/s and varies from 120 to 210 m3/s. The long-term averages of loss in flow for both dry and wet seasons based on daily flows for three design discharges (Q90, Q60 and Q40) were found to be respectively -0.72, -1.76 and -1.54 m3/s for dry season and 0.0, -0.27 and -2.26 m3/s for wet season.  Although long-term average loss is small, uncertainty increases with the increase in design discharge. The long-term dry season power loss is about 3 % for the RoR projects of the basin however, its annual variation is large. There is a probability of losing the quantum of energy generation by nearly 40% in some years and gaining by about 30 % in some other years in dry season. The impact of flow variation on power production was negative in both dry and wet seasons for RoR projects of Budhigandaki basin. This study concludes that uncertainty arising from daily flow variation should be assessed while estimating energy generation in hydropower projects. Intra-annual flow variation is, thus, to be taken into consideration while calculating the power generated by the RoR plants; and it should be reflected in power purchase agreement.

scholarly journals Seasonal changes in water quality and macrophytes and the impact of cattle on tropical floodplain waterholes

2012 ◽  
Vol 63 (9) ◽  
pp. 788 ◽  
Author(s):  
N. E. Pettit ◽  
T. D. Jardine ◽  
S. K. Hamilton ◽  
V. Sinnamon ◽  
D. Valdez ◽  
...  
Keyword(s):  
Water Quality ◽  
Seasonal Changes ◽  
Aquatic Macrophyte ◽  
Plant Cover ◽  
Critical Role ◽  
Dry Season ◽  
Nutrient Concentrations ◽  
Wet Season ◽  
Dry Tropics ◽  
The Impact

The present study indicates the critical role of hydrologic connectivity in floodplain waterholes in the wet–dry tropics of northern Australia. These waterbodies provide dry-season refugia for plants and animals, are a hotspot of productivity, and are a critical part in the subsistence economy of many remote Aboriginal communities. We examined seasonal changes in water quality and aquatic plant cover of floodplain waterholes, and related changes to variation of waterhole depth and visitation by livestock. The waterholes showed declining water quality through the dry season, which was exacerbated by more frequent cattle usage as conditions became progressively drier, which also increased turbidity and nutrient concentrations. Aquatic macrophyte biomass was highest in the early dry season, and declined as the dry season progressed. Remaining macrophytes were flushed out by the first wet-season flows, although they quickly re-establish later during the wet season. Waterholes of greater depth were more resistant to the effects of cattle disturbance, and seasonal flushing of the waterholes with wet-season flooding homogenised the water quality and increased plant cover of previously disparate waterholes. Therefore, maintaining high levels of connectivity between the river and its floodplain is vital for the persistence of these waterholes.

scholarly journals Solute transport dynamics in small, shallow groundwater-dominated agricultural catchments: insights from a high-frequency, multisolute 10 yr-long monitoring study

2013 ◽  
Vol 17 (4) ◽  
pp. 1379-1391 ◽  
Author(s):  
A. H. Aubert ◽  
C. Gascuel-Odoux ◽  
G. Gruau ◽  
N. Akkal ◽  
M. Faucheux ◽  
...  
Keyword(s):  
High Frequency ◽  
Inorganic Carbon ◽  
Shallow Groundwater ◽  
Data Series ◽  
Wet Season ◽  
Transport Dynamics ◽  
Agricultural Catchments ◽  
Organic And Inorganic Carbon ◽  
The Impact

Abstract. High-frequency, long-term and multisolute measurements are required to assess the impact of human pressures on water quality due to (i) the high temporal and spatial variability of climate and human activity and (ii) the fact that chemical solutes combine short- and long-term dynamics. Such data series are scarce. This study, based on an original and unpublished time series from the Kervidy-Naizin headwater catchment (Brittany, France), aims to determine solute transfer processes and dynamics that characterise this strongly human-impacted catchment. The Kervidy-Naizin catchment is a temperate, intensive agricultural catchment, hydrologically controlled by shallow groundwater. Over 10 yr, five solutes (nitrate, sulphate, chloride, and dissolved organic and inorganic carbon) were monitored daily at the catchment outlet and roughly every four months in the shallow groundwater. The concentrations of all five solutes showed seasonal variations but the patterns of the variations differed from one solute to another. Nitrate and chloride exhibit rather smooth variations. In contrast, sulphate as well as organic and inorganic carbon is dominated by flood flushes. The observed nitrate and chloride patterns are typical of an intensive agricultural catchment hydrologically controlled by shallow groundwater. Nitrate and chloride originating mainly from organic fertilisers accumulated over several years in the shallow groundwater. They are seasonally exported when upland groundwater connects with the stream during the wet season. Conversely, sulphate as well as organic and inorganic carbon patterns are not specific to agricultural catchments. These solutes do not come from fertilisers and do not accumulate in soil or shallow groundwater; instead, they are biogeochemically produced in the catchment. The results allowed development of a generic classification system based on the specific temporal patterns and source locations of each solute. It also considers the stocking period and the dominant process that limits transport to the stream, i.e. the connectivity of the stocking compartment. This mechanistic classification can be applied to any chemical solute to help assess its origin, storage or production location and transfer mechanism in similar catchments.

scholarly journals The chemical signature of a livestock farming catchment: synthesis from a high-frequency multi-element long term monitoring

2012 ◽  
Vol 9 (8) ◽  
pp. 9715-9741 ◽  
Author(s):  
A. H. Aubert ◽  
C. Gascuel-Odoux ◽  
G. Gruau ◽  
J. Molénat ◽  
M. Faucheux ◽  
...  
Keyword(s):  
High Frequency ◽  
Inorganic Carbon ◽  
Shallow Groundwater ◽  
Wet Season ◽  
Livestock Farming ◽  
Agricultural Catchments ◽  
Organic And Inorganic Carbon ◽  
Five Elements ◽  
The Impact

Abstract. Assessing the impact of human pressures on water quality is difficult. First, there is a high temporal and spatial variability of climate and human activity. Second, chemical elements have their own characteristics mixing short and long term dynamics. High frequency, long-term and multi-element measurements are required. But, such data series are scarce. This paper aims at determining what the hydro-chemical particularities of a livestock farming catchment are in a temperate climatic context. It is based on an original and never published time series, from Kervidy-Naizin headwater catchment. Stream chemistry was monitored daily and shallow groundwater roughly every four month, for 10 yr and five elements (nitrate, sulphate, chloride, and dissolved organic and inorganic carbon). The five elements present strong but different seasonal patterns. Nitrate and chloride present a seasonal flush, all along or at the beginning of the wet season, respectively. Sulphate, organic and inorganic carbon present storm flushes, with constant or decreasing peaks throughout the wet season. These depicted nitrate and chloride patterns are typical of a livestock farming catchment. There, nitrate and chloride coming from organic fertilisation have been accumulating over years in the shallow groundwater. They are seasonally flushed when the groundwater connects to the stream. Sulphate, organic and inorganic carbon patterns do not seem specific to agricultural catchments. These elements are produced each year and flushed by storms. Finally, a generic classification of temporal patterns and elements is established for agricultural catchments. It is based on the distance of the source component to the stream and the dominant controlling process (accumulation versus production). This classification could be applied to any chemical element and help assessing the level of water disturbances.

scholarly journals Impact of community-led local development on territorial prosperity

2021 ◽  
Vol 120 ◽  
pp. 01015
Author(s):  
Stoyanka Tsacheva ◽  
Violetka Zheleva
Keyword(s):  
Development Policy ◽  
Local Development ◽  
Statistical Processing ◽  
Expert Assessment ◽  
Territorial Development ◽  
Development Approach ◽  
Programming Period ◽  
The Impact ◽  
Very High

Community-led local development is an approach that is increasingly applied in traditional territorial development policy. In this method, management is left in the “hands of local people”, who receive long-term funding, which they distribute according to the needs of the region. The aim of the study is to examine the impact and participation in the development of the territory through CLLD measures. The expert assessment and recommendations of the surveyed LAG leaders and specialists regarding the contribution of the community-led local development approach have been sought. The applied research methods in the present study are theoretical and empirical, incl. analysis, synthesis, comparison, survey, statistical processing. The results of the survey show that the majority of respondents are satisfied with the implementation of CLLD and have clear and concrete proposals for improving the approach in the next programming period. In conclusion it is necessary to note that despite all difficulties, the interest in CLLD on the part of local communities is very high, because the approach provides many opportunities to solve problems related to local development. Key words: community-led local development, LEADER program, LAG, territorial prosperity.

scholarly journals Diurnal, Seasonal and Annual Variation of Microwave Radio Refractivity Gradient over Akure, South West Nigeria

2019 ◽  
pp. 1-11
Author(s):  
Adekunle Titus Adediji ◽  
Joseph Babatunde Dada ◽  
Moses Oludare Ajewole
Keyword(s):  
Rainy Season ◽  
Annual Variation ◽  
Ground Surface ◽  
Local Effect ◽  
Dry Season ◽  
Radio Link ◽  
Wet Season ◽  
Annual Variations ◽  
Microwave Radio

In this study, four years in-situ measurements of atmospheric parameters (pressure, temperature and relative humidity) were carried out. The measurement was by placing an automatic weather station at five different heights: ground surface, 50, 100, 150 and 200 m respectively on a 220 m Nigeria Television Authority TV tower in Akure, South Western Nigeria. The four years Data collected (January 2007 to December 2009 and January to December 2011) were used to compute radio refractivity and its gradient. The local effect of a location/ region cannot but looked into when designing effective radio link, hence the diurnal, seasonal and annual variations of the radio refractivity gradient were studied. Results showed that refractivity gradient steadily increases inthe hour of 8:30 and 9:30 to 18:00 during dry season throughout the years investigated, and decreases two hours in the rainy season than the dry season. The record shows that at 50 m altitude, the maximum and minimum values are 158 N-unit/km around 14:30 and - 286 N-unit/km around 13:30 to 14:00 hrs, LT during the dry and rainy season respectively. Seasonally, refractivity gradient is steeper with greater variability in the dry season months than in the wet season months.

scholarly journals Capital Structure and Firms’ Performance: Evidence from Vietnam’s Stock Exchange

2015 ◽  
Vol 7 (12) ◽  
pp. 1 ◽  
Author(s):  
Tristan Nguyen ◽  
Huy-Cuong Nguyen
Keyword(s):  
Capital Structure ◽  
Stock Exchange ◽  
Debt Maturity ◽  
Management Process ◽  
Short Term ◽  
Fixed Assets ◽  
Two Factors ◽  
The Impact ◽  
Very High

<p>Our paper examines what impact capital structure has on firms’ performance in selected firms listed on HCMC Stock Exchange. The data is collected from 147 listed companies during the period from 2006 to 2014. The study not only checks the impact the level of leverage has on firms’ performance, which is found to be negative in this study, but it also uses the short-term and long-term debt ratios to see the effect of debt maturity. However, there is no difference whether it is short-term or long-term. Tangibility is found to be negative with a very high proportion on average. With the suggestion that companies might invest too much in fixed assets and there is a lack of efficiency, this could be the alert for firms to improve their management process. Size and growth are found to be positive, since larger firms have lower costs of bankruptcy and higher growth rates associate with higher performance. Moreover, the study also adds the effects of industry and macroeconomics, and the result shows a correlation between the two factors and firms’ performance.</p>

scholarly journals A Comparative Frequency Analysis of Maximum Daily Rainfall for a SE Asian Region under Current and Future Climate Conditions

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Velautham Daksiya ◽  
Pradeep Mandapaka ◽  
Edmond Y. M. Lo
Keyword(s):  
General Circulation ◽  
Daily Rainfall ◽  
Circulation Model ◽  
Dry Season ◽  
Wet Season ◽  
Climate Conditions ◽  
Rainfall Extremes ◽  
Annual Maximum Daily Rainfall ◽  
The Impact ◽  
Maximum Daily Rainfall

The impact of changing climate on the frequency of daily rainfall extremes in Jakarta, Indonesia, is analysed and quantified. The study used three different models to assess the changes in rainfall characteristics. The first method involves the use of the weather generator LARS-WG to quantify changes between historical and future daily rainfall maxima. The second approach consists of statistically downscaling general circulation model (GCM) output based on historical empirical relationships between GCM output and station rainfall. Lastly, the study employed recent statistically downscaled global gridded rainfall projections to characterize climate change impact rainfall structure. Both annual and seasonal rainfall extremes are studied. The results show significant changes in annual maximum daily rainfall, with an average increase as high as 20% in the 100-year return period daily rainfall. The uncertainty arising from the use of different GCMs was found to be much larger than the uncertainty from the emission scenarios. Furthermore, the annual and wet seasonal analyses exhibit similar behaviors with increased future rainfall, but the dry season is not consistent across the models. The GCM uncertainty is larger in the dry season compared to annual and wet season.

scholarly journals Seasonal Variation of Phthalate Esters in Urban River Sediments: A Case Study of Fengshan River System in Taiwan

2021 ◽  
Vol 14 (1) ◽  
pp. 347
Author(s):  
Kuan-Nan Lin ◽  
Chiu-Wen Chen ◽  
Chih-Feng Chen ◽  
Yee Cheng Lim ◽  
Chih-Ming Kao ◽  
...  
Keyword(s):  
Phthalate Esters ◽  
River Sediments ◽  
Aquatic Organisms ◽  
River System ◽  
Dry Season ◽  
Ecological Risks ◽  
Total Risk ◽  
Wet Season ◽  
Potential Risks ◽  
The Impact

The Fengshan River system is one of the major rivers in Kaohsiung City, Taiwan. This study investigated the concentration of eight phthalate esters (PAEs) in sediments of the river and the impact of potential ecological risks during the dry and wet seasons. The potential risk assessment of sediment PAEs was evaluated by adopting the total risk quotient (TRQ) method. The total PAEs concentrations (∑PAEs) in the sediments of the Fengshan River system are between 490–40,190 ng/g dw, with an average of 8418 ± 11,812 ng/g dw. Diisononyl phthalate (38.1%), bis(2-ethylhexyl) phthalate (36.9%) and di-isodecyl phthalate (24.3%) accounted for more than 99.3% of ∑PAEs. The concentration of ∑PAEs in sediments at the river channel stations is higher during the wet season (616–15,281 ng/g dw) than that during the dry season (490–1535 ng/g dw). However, in the downstream and estuary stations, the wet season (3975–6768 ng/g dw) is lower than the dry season (20,216–40,190 ng/g dw). The PAEs in sediments of the Fengshan River may have low to moderate potential risks to aquatic organisms. The TQR of PAEs in sediments at the downstream and estuary (TQR = 0.13) is higher than that in the upstream (TQR = 0.04). In addition, during the wet season, rainfall transported a large amount of land-sourced PAEs to rivers, leading to increased PAEs concentration and potential ecological risks in the upper reaches of the river.

scholarly journals IMPACT OF COVID-19 EVENT ON AIR POLLUTANTS OF PM2.5 AND PM10 IN JAKARTA, INDONESIA

2021 ◽  
Vol 56 (4) ◽  
pp. 117-140
Author(s):  
Nora Idiawati ◽  
Sepridawati Siregar
Keyword(s):  
Air Quality ◽  
Control Strategies ◽  
Dry Season ◽  
Capital City ◽  
Future Research ◽  
Air Pollution Control ◽  
Wet Season ◽  
Two Cities ◽  
Pm2.5 And Pm10 ◽  
The Impact

As the capital city of Indonesia, the Province of Jakarta encounter a problem seriously of decreasing air quality. This study analyzes the air quality of two cities in Jakarta Province, Central Jakarta and South Jakarta, from March to June 2016–2020, and the impact of COVID-19 epidemic prevention and control actions on air quality. The combined air quality index (AQI) for two cities from 2016–2019, in the wet season, indicated that it has the lowest AQI with an average of 79, and the highest AQI occurred in the dry season with averaged 118. The distribution of the six AQI classes for two cities in dry season were 2%, 24%, 63%, 11%, 0%, and 0%, and in wet season, they were 10%, 48%, 39%, 3%, 0%, and 0%, respectively. The concentrations for PM2.5 and PM10 in March, April, May, and June 2016–2019 and those for 2020 were also analyzed in this study. Based on the data from the two cities, during March, April, May, and June 2020, the average PM2.5 decreased by 23.6%, 39.5%, 41.5%, and 13.3%, respectively, and the average PM10 decreased by 22.2%, 29.9%, 36.9%, and 29.8%, respectively, compared with that in March, April, May, and June 2016–2019. It is obvious that air quality greatly improved during the COVID-19 epidemic. This study presents beneficial information to policymakers for developing scientific air pollution control strategies and is a useful reference for future research in improving urban air quality.

scholarly journals Long-Term historical and Projected Herbivore Population Dynamics in Ngorongoro Crater, Tanzania

2019 ◽  
Author(s):  
Joseph O. Ogutu ◽  
Patricia D Moehlman ◽  
Hans-Peter Piepho ◽  
Victor A Runyoro ◽  
Michael B Coughenour ◽  
...  
Keyword(s):  
Population Dynamics ◽  
Population Size ◽  
Dry Season ◽  
Climate Change Scenarios ◽  
Wet Season ◽  
Large Herbivore ◽  
Herbivore Species ◽  
Dry Seasons ◽  
Wet And Dry Seasons

The Ngorongoro Crater is an intact caldera with an area of approximately 310 km2. Long term records on herbivore populations, vegetation and rainfall made it possible to analyze historic and project future herbivore population dynamics. In 1974 there was a perturbation in that resident Maasai and their livestock were removed from the Crater. Vegetation structure changed in 1967 from predominately short grassland to mid and tall grasses dominating in 1995. Even with a change in grassland structure, total herbivore biomass remained relatively stable from 1963 to 2012, implying that the crater has a stable multi-herbivore community. However, in 1974, Maasai pastoralists were removed from the Ngorongoro Crater and there were significant changes in population trends for some herbivore species. Buffalo, elephant and ostrich numbers increased significantly during 1974-2012. The zebra population was stable from 1963 to 2012 whereas numbers of other eight species declined substantially between 1974 and 2012 relative to their peak numbers during 1974-1976. Numbers of Grant’s and Thomson’s gazelles, eland, kongoni, waterbuck (wet season only) declined significantly in the Crater in both seasons after 1974. Wildebeest numbers decreased in the Crater between 1974 and 2012 but this decrease was not statistically significant. In addition, some herbivore species were consistently more abundant inside the Crater during the wet than the dry season. This pattern was most evident for the large herbivore species requiring bulk forage, comprising buffalo, eland, and elephant. Analyses of rainfall indicated that there was a persistent annual cycle of 4.83 years. Herbivore population size was correlated with rainfall in both the wet and dry seasons. The relationships established between the time series of historic animal counts in the wet and dry seasons and lagged wet and dry season rainfall series were used to forecast the likely future trajectories of the wet and dry season population size for each species under three alternative climate change scenarios.

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