Indicate whether each statement below is TRUE or FALSE [1 One advantage of using
ID: 1714250 • Letter: I
Question
Indicate whether each statement below is TRUE or FALSE [1 One advantage of using the D-8 method to calculate flow direction and flow accumulation over an area is that you can easily identify streams and watersheds. Also, by using the flow accumulation raster, you can calculate the drainage area anywhere inside the raster extent by multiplying the flow accumulation value to the pixel cell area. 1 Curve numbers are higher for soils that are more pervious. [] When delineating a watershed, it's imperative that the watershed boundary do not cross any streams beside the outlet point [] A reliable source of precipitation data is the USGS National Elevation Dataset web service. [1 Two common methods to develop a unit hydrograph for ungagged basins are the Snyder and the SCS ] Base flow in a stream results mainly from contributions of the groundwater flow into the stream. [] The 100-year, 1 hour duration storm has a rainfall depth greater than the 50-year, 1 hour duration storm. [1 Considering that for a given river reach the Muskingum routing coefficients CO and CI were determined to be 0.3 and 0.4; it is reasonable to assume that C2 would be 1.3. [ ] non-stationarity of hydrological variables does not impact design methods based on the methods of moments for frequency analyses. [1 The Bulletin 17 B was designed to provide Guidelines for Determining Flood Flow Frequency.] Two common vertical datum's used in the US are the NGVD29 (National Geodetic Vertical Datum of 1929) and NAVD88 (North American Vertical Datum of 1988) [ ] A reliable source of precipitation data is the USGS National Elevation Dataset web service. [1 One advantage of using the D-8 method to calculate flow direction and flow accumulation over an area is that you can casily identify streams and watersheds. Also, by using the flow accumulation raster, you can calculate the drainage area anywhere inside the raster extent by multiplying the flow accumulation value to the pixel cell area. [ 1 Curve numbers are higher for soils that are more pervious. [1 When delineating a watershed, it's imperative that the watershed boundary do not cross any streams beside the outlet point. 1 Two common methods to develop a unit hydrograph for ungagged basins are the Snyder and the SCS Base flow in a stream results mainly from contributions of theExplanation / Answer
1) True.
2) False . curve numbers for imervious soil like clay is more. Example Impervious areas like roofs, drive ways, curve number is 98
3) True
4) False. USGS water resourses gives the precipation data
5) true
6) True . Groundwater seepage into a stream channel is called baseflow. It may happen during dry weather. Base flow is also called dry weather flow.
8) False. The sum of these coefficients should be one.
9) False. It is sensitive to non stationarity of hydrological variables.
10) True. Bulletin 17 B gives guidelines for determining flood flow frequency. NGS develops and maintains the current national geodetic vertical datum, NAVD 88. NGS provides the relationships between past and current geodetic vertical datums, e.g., NGVD 29 and NAVD 88.