Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variabilit...Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variability silt charge waters in the river Sluch in time and on length of the river are considered.It is revealed that in time average and maximal silt charge waters decrease.While on length of the river change silt charge waters is shown not precisely,similar on some increase silt charge waters to a mouth of the river.The researches led by the factorial analysis and graphic-analytical method on the basis of long-term materials of measurement of charges of water have shown that,on a part of posts average depth of water in the river grows,and on others-cyclically changes with the general tendency to reduction.Average speed in them,accordingly,falls and grows.Stratification of interrelations of a silt charge with other factors on years is observed.The reasons of reduction of a silt charge are:1)agrarian and forest meliorative actions on a catchments of the river,hydraulic engineering construction;2)grassy bed of the river;3)change of a climate that promotes growth of temperature of a surface of soils and grassy bed of the river.In developed natural-climatic conditions expediently application on reservoirs of the antierosion organization of territory of the land tenure including agrarian-forests-meliorative actions that will allow to adjust outflow of a moisture from reservoirs to lower warming up of a surface of the soils,to provide against a high water protection and it will favorably be reflected in manufacture of agricultural production.展开更多
Rainfall-runoff relationship in arid regions is unique and challenging to study.Studies for bridging the hydro-meteorological knowledge gap for planning,designing and managing water resources is therefore vitally impo...Rainfall-runoff relationship in arid regions is unique and challenging to study.Studies for bridging the hydro-meteorological knowledge gap for planning,designing and managing water resources is therefore vitally important.The objective of this study is to develop a method for estimating unit hydrograph at reasonably finer time resolutions(10-min and 1-h)which can be easily adaptable by practitioners at subcatchment levels,especially when the focus area is ungauged.Observed wadi-flow at 5-min interval and tipping bucket rainfall measurements at 1-min interval were obtained to cover 10 major watersheds in Oman.The deconvolution method was applied to derive the unit hydrographs(UHs)from wadi-flow and excess rainfall.Key catchment characteristics such as the watershed area,length of the main wadi and the length to the centroid of the catchment area were derived from digital elevation model(DEM)data.The whole study area was then divided into 515 sub-catchments with various shapes and sizes.A strong relationship was found between the wadi length and the length to the centroid of the catchment area(R2>0.89).This relationship was then adopted to simplify the classical Snyder method to determine UHs.Moreover,several parameters of the Snyder method were calibrated to the arid environment by matching the peak-flow,lag-time and three time-widths(75%,50%and 30%of the peak-flow)of 10-min and 1-h UHs with physical characteristics of the watersheds.All developed relationships were validated with independent rainfall and wadi-flow events.Results indicate that the calibrated parameters in these arid watersheds are quite distinct from those suggested for other regions of the world.A marked difference was found between the 10-min UHs estimated by the S-hydrograph method and the deconvolution method.Therefore,it is concluded that a method depends on natural hydro-meteorological conditions would be more practical in arid region.The proposed methodology can be used for water resources management in arid regions having similar climate and geographical settings.展开更多
文摘Change silt charge of water in the rivers can negatively be reflected in throughput the rivers beds,stability of coast,change of river structures,disappearance of boggy places,etc.In work questions of variability silt charge waters in the river Sluch in time and on length of the river are considered.It is revealed that in time average and maximal silt charge waters decrease.While on length of the river change silt charge waters is shown not precisely,similar on some increase silt charge waters to a mouth of the river.The researches led by the factorial analysis and graphic-analytical method on the basis of long-term materials of measurement of charges of water have shown that,on a part of posts average depth of water in the river grows,and on others-cyclically changes with the general tendency to reduction.Average speed in them,accordingly,falls and grows.Stratification of interrelations of a silt charge with other factors on years is observed.The reasons of reduction of a silt charge are:1)agrarian and forest meliorative actions on a catchments of the river,hydraulic engineering construction;2)grassy bed of the river;3)change of a climate that promotes growth of temperature of a surface of soils and grassy bed of the river.In developed natural-climatic conditions expediently application on reservoirs of the antierosion organization of territory of the land tenure including agrarian-forests-meliorative actions that will allow to adjust outflow of a moisture from reservoirs to lower warming up of a surface of the soils,to provide against a high water protection and it will favorably be reflected in manufacture of agricultural production.
文摘Rainfall-runoff relationship in arid regions is unique and challenging to study.Studies for bridging the hydro-meteorological knowledge gap for planning,designing and managing water resources is therefore vitally important.The objective of this study is to develop a method for estimating unit hydrograph at reasonably finer time resolutions(10-min and 1-h)which can be easily adaptable by practitioners at subcatchment levels,especially when the focus area is ungauged.Observed wadi-flow at 5-min interval and tipping bucket rainfall measurements at 1-min interval were obtained to cover 10 major watersheds in Oman.The deconvolution method was applied to derive the unit hydrographs(UHs)from wadi-flow and excess rainfall.Key catchment characteristics such as the watershed area,length of the main wadi and the length to the centroid of the catchment area were derived from digital elevation model(DEM)data.The whole study area was then divided into 515 sub-catchments with various shapes and sizes.A strong relationship was found between the wadi length and the length to the centroid of the catchment area(R2>0.89).This relationship was then adopted to simplify the classical Snyder method to determine UHs.Moreover,several parameters of the Snyder method were calibrated to the arid environment by matching the peak-flow,lag-time and three time-widths(75%,50%and 30%of the peak-flow)of 10-min and 1-h UHs with physical characteristics of the watersheds.All developed relationships were validated with independent rainfall and wadi-flow events.Results indicate that the calibrated parameters in these arid watersheds are quite distinct from those suggested for other regions of the world.A marked difference was found between the 10-min UHs estimated by the S-hydrograph method and the deconvolution method.Therefore,it is concluded that a method depends on natural hydro-meteorological conditions would be more practical in arid region.The proposed methodology can be used for water resources management in arid regions having similar climate and geographical settings.
