By reading, you can know the knowledge and things more, not only about what you get from people t... more By reading, you can know the knowledge and things more, not only about what you get from people to people. Book will be more trusted. As this climate change trends and instances of socio economic effects in nepal, it will really give you the good idea to be successful. It is not only for you to be success in certain life you can be successful in everything. The success can be started by knowing the basic knowledge and do actions.
(1997) Vörösmarty et al. Ambio. Read by researchers in: 100% Environmental Sciences. In this stud... more (1997) Vörösmarty et al. Ambio. Read by researchers in: 100% Environmental Sciences. In this study we analyze the scope and potential impact of reservoir construction on the world's river systems. Water storage behind the global population of large dams represents a 700% increase ...
The participation of the general public in the research design, data collection and interpretatio... more The participation of the general public in the research design, data collection and interpretation process together with scientists is often referred to as citizen science. While citizen science itself has existed since the start of scientific practice, developments in sensing technology, data processing and visualization, and communication of ideas and results, are creating a wide range of new opportunities for public participation in scientific research. This paper reviews the state of citizen science in a hydrological context and explores the potential of citizen science to complement more traditional ways of scientific data collection and knowledge generation for hydrological sciences and water resources management. Although hydrological data collection often involves advanced technology, the advent of robust, cheap, and low-maintenance sensing equipment provides unprecedented opportunities for data collection in a citizen science context. These data have a significant potential...
Twenty microsatellite primer pairs, previously developed in peach, were used to characterize and ... more Twenty microsatellite primer pairs, previously developed in peach, were used to characterize and to explore genetic relationships among 44 clones, representing three groups of rootstocks defined as: (1) Peach-based rootstocks (Prunus dulcis × P. persica, P. persica × P. ...
Hydro Nepal: Journal of Water, Energy and Environment, 2012
On average, South Asian river basins drain about 2,672 km3 of water to the oceans every year, whi... more On average, South Asian river basins drain about 2,672 km3 of water to the oceans every year, which is almost 6% of the global runoff. These rivers also contribute 15% to 20% of the global oceanward sediment flux. Retreating glaciers and decreasing flows during low flow seasons have already shown the signatures of global warming in the region. Temperature trends in the South Asian region range from -2.9°C per decade to +4.0°C per decade. Similarly, precipitation changes fall in the range of -8% to +18% during the period of available records. One of the major concerns regarding climatic change in the region is the tendency of decreasing low flows in several major river basins. Such alterations in river discharge may cause adverse impacts on available water supplies during critical periods. Besides, the region is subjected to high vulnerabilities of water resources because of population pressure, poverty and agriculture-based economy, strong temporal and spatial variation of precipita...
Land-use and climatic changes are of major concern in the Himalayan region because of their poten... more Land-use and climatic changes are of major concern in the Himalayan region because of their potential impacts on a predominantly agriculture-based economy and a regional hydrology dominated by strong seasonality. Such concerns are not limited to any particular basin but exist throughout the region including the downstream plain areas. As a representative basin of the Himalayas, we studied the Kosi basin (54,000 km2) located in the mountainous area of the central Himalayan region. We analyzed climatic and hydrologic information to assess the impacts of existing and potential future land-use and climatic changes over the basin. The assessment of anthropogenic inputs showed that the population grew at a compound growth rate of about one percent per annum over the basin during the last four decades. The comparison of land-use data based on the surveys made in the 1960s, and the surveys of 1978-79 did not reveal noticeable trends in land-use change. Analysis of meteorological and hydrological trends using parametric and nonparametric statistics for monthly data from 1947 to 1993 showed some increasing tendency for temperature and precipitation. Statistical tests of hydrological trends indicated an overall decrease of discharge along mainstem Kosi River and its major tributaries. The decreasing trends of streamflow were more significant during low-flow months. Statistical analysis of homogeneity showed that the climatological as well as the hydrological trends were more localized in nature lacking distinct basinwide significance. Statistical analysis of annual sediment time series, available for a single station on the Kosi River did not reveal a significant trend. We used water balance, statistical correlation, and distributed deterministic modeling approaches to analyze the hydrological sensitivity of the basin to possible land-use and climatic changes. The results indicated a stronger influence of basin characteristics compared to climatic characteristics on flow regime. Among the climatic variables, hydrologic response was much more sensitive to changes in precipitation, and the response was more significant in the drier areas of the basin. Rapid retreat of glaciers due to potential global warming was shown to be as important as projected deforestation scenarios in regulating sediment flux over the basin.
A framework for estimating global-scale impacts from reservoir construction on riverine sediment ... more A framework for estimating global-scale impacts from reservoir construction on riverine sediment transport to the ocean is presented. Framework results depict a large, global-scale, and growing impact from anthropogenic impoundment. This study analyzes data on 633 of the world’s largest reservoirs (LRs) (>= 0.5 km^3 maximum storage) and uses statistical inference to assess the impact of the remaining >44,000 smaller reservoirs (SRs). Information on the LRs was linked to a digitized river network at 30' (latitude x longitude) resolution. A residence time change BoxBox_R) for otherwise free-flowing river water is determined locally at each reservoir and used with a sediment retention function to predict the proportion of incident sediment flux trapped within each impoundment. More than 40% of global river discharge is intercepted locally by the LRs analyzed and a significant proportion (≈ 70%) of this discharge maintains a sediment trapping efficiency in excess of 50%. Half of all discharge entering LRs shows a local trapping efficiency of 80% or more. Several large basins such as the Colorado and Nile show nearly complete trapping due to large reservoir construction and flow diversion. From the standpoint of sediment retention rates, the most heavily regulated drainage basins reside in Europe. North America, Africa, Australia/Oceania are also strongly affected by LRs. Globally, greater than 50% of basin-scale sediment flux in regulated basins is potentially trapped in artificial impoundments, with a discharge-weighted sediment trapping due to LRs of 30%, and an additional contribution of 23% from SRs. If we consider both regulated and unregulated basins, the interception of global sediment flux by all registered reservoirs (n ≈ 45,000) is conservatively placed at 4 to 5 Gt yr-1 or 25-30% of the total. There is an additional but unknown impact due to still smaller unregistered impoundments (n ≈ 800,000). From a global change perspective, the long-term impact of such hydraulic engineering works on the world's coastal zone appears to be significant but has yet to be fully elucidated.
The potential impact of neo-Castorization on sediment transport by the global network of rivers. ... more The potential impact of neo-Castorization on sediment transport by the global network of rivers. CJ Voeroesmarty, M Meybeck, B Fekete, K Sharma IAHS Publication 245, 261-273, 1997. In this paper, we assess the potential ...
A great debate exists concerning theinfluence of land-use and climatic changes onhydrology in the... more A great debate exists concerning theinfluence of land-use and climatic changes onhydrology in the Himalayan region and its adjacentplains. As a representative basin of the Himalayas, westudied basinwide land-use, climatic and hydrologictrends over the Kosi Basin (54,000 km2) in themountainous area of the central Himalayan region. Theassessment of anthropogenic inputs showed that thepopulation of the basin grew at a compound rate ofabout one percent per annum during the past fourdecades. The comparison of land-use data between thesurveys made during the 1960s and 1978–1979 did notreveal noticeable trends in land-use change. Theanalysis of meteorological and hydrological timeseries from 1947 to 1993 showed some increasingtendency of temperature and precipitation. Thestatistical tests of hydrologic trends indicated anoverall decrease in discharge on the Kosi River andits major tributaries. The decreasing trends ofstreamflow were more significant during the low-flowmonths. The statistical analysis of homogeneityshowed that the climatic as well as the hydrologictrends were more localized in nature lacking adistinct basinwide significance.
Land-use and climatic changes are ofmajor concerns in the Himalayan region because oftheir potent... more Land-use and climatic changes are ofmajor concerns in the Himalayan region because oftheir potential impacts on a predominantlyagriculture-based economy and a regional hydrologydominated by the monsoons. Such concerns are notlimited to any particular basin but exist throughoutthe region including the downstream plains. As arepresentative basin of the Himalayas, the Kosi Basin(54,000 km2) located in the mountainous area ofthe central Himalayan region was selected as a studyarea. We used water balance and distributeddeterministic modeling approaches to analyze thehydrologic sensitivity of the basin to projectedland-use, and potential climate change scenarios.Runoff increase was higher than precipitation increasein all the potential precipitation change scenariosapplying contemporary temperature. The scenario ofcontemporary precipitation and a rise in temperatureof 4 °C caused a decrease in runoff bytwo to eight percent depending upon the areasconsidered and models used. In the absence of climaticchange, the results from a distributed water balancemodel applied in the humid south of the basinindicated a reduction in runoff by 1.3% in thescenario of maximum increase in forest areas below4,000 m.
Although the Manning equation is widely accepted as the empirical flow law for rough turbulent op... more Although the Manning equation is widely accepted as the empirical flow law for rough turbulent open-channel flow, using the equation in practical situations such as slope-area computations is fraught with uncertainty because of the difficulty in specifying the value of the reach resistance, Manning's n. Riggs (1976, J. Res. US Geol. Surv., 4: 285–291) found that n was correlated with water-surface slope, and proposed a multiple-regression equation that obviates the need for estimating n in slope-area estimates of discharge. Because his relation was developed from a relatively small sample (N = 62), had potential flaws owing to multicollinearity, and was not thoroughly validated, we used an expanded data base (N = 520) and objective methods to develop a new relation for the same purpose: Q = 1.564A1.173R0.400S−0.0543logS where Q is discharge (m3 s−1), A is cross-sectional area (m2), R is hydraulic radius (m), and S is water-surface slope. We validated Rigg's model and our model using 100 measurements not included in model development and found that both give similar results. Riggs's model is somewhat better in terms of actual (m3 s−1) error, but ours is better in terms of relative (log Q) error. We conclude that either Riggs's or our model can be used in place of Manning's equation in slope-area computations, but that our model is preferable because it has less bias, minimizes multicollinearity, and performs better when applied to discharge changes in individual reaches. We also found that our model performs better than those of Jarrett (1984, J. Hydraul. Eng., 110: 1519–1539) or Riggs in the range of applicability of Jarrett's equation (0.15 m ≤ R ≤ 2.13 m; 0.002 ≤ S ≤ 0.052). Both Riggs's and our models significantly overestimate Q in flows satisfying both the following conditions: Q < 3 m3s−1 and Froude number less than 0.2. For other in-bank flows in relatively straight reaches, our model can be recommended for use in slope-area computations and other applications of the Chézy or Manning equations over a wide range of channel sizes (0.41 m2 ≤ A ≤ 8520 m2) and slopes (0.00001 ≤ S ≤ 0.0418), thus obviating the difficulty of a priori determination of the resistance factor.
By reading, you can know the knowledge and things more, not only about what you get from people t... more By reading, you can know the knowledge and things more, not only about what you get from people to people. Book will be more trusted. As this climate change trends and instances of socio economic effects in nepal, it will really give you the good idea to be successful. It is not only for you to be success in certain life you can be successful in everything. The success can be started by knowing the basic knowledge and do actions.
(1997) Vörösmarty et al. Ambio. Read by researchers in: 100% Environmental Sciences. In this stud... more (1997) Vörösmarty et al. Ambio. Read by researchers in: 100% Environmental Sciences. In this study we analyze the scope and potential impact of reservoir construction on the world&amp;amp;amp;amp;amp;amp;#x27;s river systems. Water storage behind the global population of large dams represents a 700% increase ...
The participation of the general public in the research design, data collection and interpretatio... more The participation of the general public in the research design, data collection and interpretation process together with scientists is often referred to as citizen science. While citizen science itself has existed since the start of scientific practice, developments in sensing technology, data processing and visualization, and communication of ideas and results, are creating a wide range of new opportunities for public participation in scientific research. This paper reviews the state of citizen science in a hydrological context and explores the potential of citizen science to complement more traditional ways of scientific data collection and knowledge generation for hydrological sciences and water resources management. Although hydrological data collection often involves advanced technology, the advent of robust, cheap, and low-maintenance sensing equipment provides unprecedented opportunities for data collection in a citizen science context. These data have a significant potential...
Twenty microsatellite primer pairs, previously developed in peach, were used to characterize and ... more Twenty microsatellite primer pairs, previously developed in peach, were used to characterize and to explore genetic relationships among 44 clones, representing three groups of rootstocks defined as: (1) Peach-based rootstocks (Prunus dulcis × P. persica, P. persica × P. ...
Hydro Nepal: Journal of Water, Energy and Environment, 2012
On average, South Asian river basins drain about 2,672 km3 of water to the oceans every year, whi... more On average, South Asian river basins drain about 2,672 km3 of water to the oceans every year, which is almost 6% of the global runoff. These rivers also contribute 15% to 20% of the global oceanward sediment flux. Retreating glaciers and decreasing flows during low flow seasons have already shown the signatures of global warming in the region. Temperature trends in the South Asian region range from -2.9°C per decade to +4.0°C per decade. Similarly, precipitation changes fall in the range of -8% to +18% during the period of available records. One of the major concerns regarding climatic change in the region is the tendency of decreasing low flows in several major river basins. Such alterations in river discharge may cause adverse impacts on available water supplies during critical periods. Besides, the region is subjected to high vulnerabilities of water resources because of population pressure, poverty and agriculture-based economy, strong temporal and spatial variation of precipita...
Land-use and climatic changes are of major concern in the Himalayan region because of their poten... more Land-use and climatic changes are of major concern in the Himalayan region because of their potential impacts on a predominantly agriculture-based economy and a regional hydrology dominated by strong seasonality. Such concerns are not limited to any particular basin but exist throughout the region including the downstream plain areas. As a representative basin of the Himalayas, we studied the Kosi basin (54,000 km2) located in the mountainous area of the central Himalayan region. We analyzed climatic and hydrologic information to assess the impacts of existing and potential future land-use and climatic changes over the basin. The assessment of anthropogenic inputs showed that the population grew at a compound growth rate of about one percent per annum over the basin during the last four decades. The comparison of land-use data based on the surveys made in the 1960s, and the surveys of 1978-79 did not reveal noticeable trends in land-use change. Analysis of meteorological and hydrological trends using parametric and nonparametric statistics for monthly data from 1947 to 1993 showed some increasing tendency for temperature and precipitation. Statistical tests of hydrological trends indicated an overall decrease of discharge along mainstem Kosi River and its major tributaries. The decreasing trends of streamflow were more significant during low-flow months. Statistical analysis of homogeneity showed that the climatological as well as the hydrological trends were more localized in nature lacking distinct basinwide significance. Statistical analysis of annual sediment time series, available for a single station on the Kosi River did not reveal a significant trend. We used water balance, statistical correlation, and distributed deterministic modeling approaches to analyze the hydrological sensitivity of the basin to possible land-use and climatic changes. The results indicated a stronger influence of basin characteristics compared to climatic characteristics on flow regime. Among the climatic variables, hydrologic response was much more sensitive to changes in precipitation, and the response was more significant in the drier areas of the basin. Rapid retreat of glaciers due to potential global warming was shown to be as important as projected deforestation scenarios in regulating sediment flux over the basin.
A framework for estimating global-scale impacts from reservoir construction on riverine sediment ... more A framework for estimating global-scale impacts from reservoir construction on riverine sediment transport to the ocean is presented. Framework results depict a large, global-scale, and growing impact from anthropogenic impoundment. This study analyzes data on 633 of the world’s largest reservoirs (LRs) (>= 0.5 km^3 maximum storage) and uses statistical inference to assess the impact of the remaining >44,000 smaller reservoirs (SRs). Information on the LRs was linked to a digitized river network at 30' (latitude x longitude) resolution. A residence time change BoxBox_R) for otherwise free-flowing river water is determined locally at each reservoir and used with a sediment retention function to predict the proportion of incident sediment flux trapped within each impoundment. More than 40% of global river discharge is intercepted locally by the LRs analyzed and a significant proportion (≈ 70%) of this discharge maintains a sediment trapping efficiency in excess of 50%. Half of all discharge entering LRs shows a local trapping efficiency of 80% or more. Several large basins such as the Colorado and Nile show nearly complete trapping due to large reservoir construction and flow diversion. From the standpoint of sediment retention rates, the most heavily regulated drainage basins reside in Europe. North America, Africa, Australia/Oceania are also strongly affected by LRs. Globally, greater than 50% of basin-scale sediment flux in regulated basins is potentially trapped in artificial impoundments, with a discharge-weighted sediment trapping due to LRs of 30%, and an additional contribution of 23% from SRs. If we consider both regulated and unregulated basins, the interception of global sediment flux by all registered reservoirs (n ≈ 45,000) is conservatively placed at 4 to 5 Gt yr-1 or 25-30% of the total. There is an additional but unknown impact due to still smaller unregistered impoundments (n ≈ 800,000). From a global change perspective, the long-term impact of such hydraulic engineering works on the world's coastal zone appears to be significant but has yet to be fully elucidated.
The potential impact of neo-Castorization on sediment transport by the global network of rivers. ... more The potential impact of neo-Castorization on sediment transport by the global network of rivers. CJ Voeroesmarty, M Meybeck, B Fekete, K Sharma IAHS Publication 245, 261-273, 1997. In this paper, we assess the potential ...
A great debate exists concerning theinfluence of land-use and climatic changes onhydrology in the... more A great debate exists concerning theinfluence of land-use and climatic changes onhydrology in the Himalayan region and its adjacentplains. As a representative basin of the Himalayas, westudied basinwide land-use, climatic and hydrologictrends over the Kosi Basin (54,000 km2) in themountainous area of the central Himalayan region. Theassessment of anthropogenic inputs showed that thepopulation of the basin grew at a compound rate ofabout one percent per annum during the past fourdecades. The comparison of land-use data between thesurveys made during the 1960s and 1978–1979 did notreveal noticeable trends in land-use change. Theanalysis of meteorological and hydrological timeseries from 1947 to 1993 showed some increasingtendency of temperature and precipitation. Thestatistical tests of hydrologic trends indicated anoverall decrease in discharge on the Kosi River andits major tributaries. The decreasing trends ofstreamflow were more significant during the low-flowmonths. The statistical analysis of homogeneityshowed that the climatic as well as the hydrologictrends were more localized in nature lacking adistinct basinwide significance.
Land-use and climatic changes are ofmajor concerns in the Himalayan region because oftheir potent... more Land-use and climatic changes are ofmajor concerns in the Himalayan region because oftheir potential impacts on a predominantlyagriculture-based economy and a regional hydrologydominated by the monsoons. Such concerns are notlimited to any particular basin but exist throughoutthe region including the downstream plains. As arepresentative basin of the Himalayas, the Kosi Basin(54,000 km2) located in the mountainous area ofthe central Himalayan region was selected as a studyarea. We used water balance and distributeddeterministic modeling approaches to analyze thehydrologic sensitivity of the basin to projectedland-use, and potential climate change scenarios.Runoff increase was higher than precipitation increasein all the potential precipitation change scenariosapplying contemporary temperature. The scenario ofcontemporary precipitation and a rise in temperatureof 4 °C caused a decrease in runoff bytwo to eight percent depending upon the areasconsidered and models used. In the absence of climaticchange, the results from a distributed water balancemodel applied in the humid south of the basinindicated a reduction in runoff by 1.3% in thescenario of maximum increase in forest areas below4,000 m.
Although the Manning equation is widely accepted as the empirical flow law for rough turbulent op... more Although the Manning equation is widely accepted as the empirical flow law for rough turbulent open-channel flow, using the equation in practical situations such as slope-area computations is fraught with uncertainty because of the difficulty in specifying the value of the reach resistance, Manning's n. Riggs (1976, J. Res. US Geol. Surv., 4: 285–291) found that n was correlated with water-surface slope, and proposed a multiple-regression equation that obviates the need for estimating n in slope-area estimates of discharge. Because his relation was developed from a relatively small sample (N = 62), had potential flaws owing to multicollinearity, and was not thoroughly validated, we used an expanded data base (N = 520) and objective methods to develop a new relation for the same purpose: Q = 1.564A1.173R0.400S−0.0543logS where Q is discharge (m3 s−1), A is cross-sectional area (m2), R is hydraulic radius (m), and S is water-surface slope. We validated Rigg's model and our model using 100 measurements not included in model development and found that both give similar results. Riggs's model is somewhat better in terms of actual (m3 s−1) error, but ours is better in terms of relative (log Q) error. We conclude that either Riggs's or our model can be used in place of Manning's equation in slope-area computations, but that our model is preferable because it has less bias, minimizes multicollinearity, and performs better when applied to discharge changes in individual reaches. We also found that our model performs better than those of Jarrett (1984, J. Hydraul. Eng., 110: 1519–1539) or Riggs in the range of applicability of Jarrett's equation (0.15 m ≤ R ≤ 2.13 m; 0.002 ≤ S ≤ 0.052). Both Riggs's and our models significantly overestimate Q in flows satisfying both the following conditions: Q < 3 m3s−1 and Froude number less than 0.2. For other in-bank flows in relatively straight reaches, our model can be recommended for use in slope-area computations and other applications of the Chézy or Manning equations over a wide range of channel sizes (0.41 m2 ≤ A ≤ 8520 m2) and slopes (0.00001 ≤ S ≤ 0.0418), thus obviating the difficulty of a priori determination of the resistance factor.
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