Average watershed slope is between 0.5 and 64%. The watershed slope, or average watershed land slope, is used in the lag equation to estimate the watershed Tc. km area. Active 3 years, 1 month ago. �ظ:|�U�!�`�z��c�,�e���#CUӾ�Ҡ�vƍ mGԂ�L��p�nC�-���� 16 0 obj average watershed slope (w s) = 0 = 0. Slope can be given in two different ways, a percent gradient or an angle of the slope. Define Watershed Create a new Shapefile to define your watershed. 300 : dom_i.query(this).css("width").trim(); count = count+1; Table 3-1 contains CN values for different land EFH2 User's Manual (link to pdf version from NRCS eDirectives website), NRCS Home | USDA.gov | Site Map | Civil Rights | FOIA | Plain Writing | Accessibility Statement, Policy and Links| Non-Discrimination Statement | Information Quality | USA.gov | WhiteHouse.gov Gradient, grade, incline and pitch are used interchangably with slope. : dom_i.query(this).attr("title").trim(); Watershed slope is not to be confused with the slope of the flow path. May be applied when: IMPORTANT Installation Settings (Instructions for incorporating updated rainfall and rainfall distibutions into EFH-2) Average watershed slope is between 0.5 and 64%. dom.query(this).attr("alt") : dom.query(this).attr("title").trim(); 903 (See NEH 650.02 and NEH 630.15, Time of Concentration, for more information on the lag method.) use the SCS dimensionless unit hydrograph. At low flows, water moves faster over riffles, which provides oxygen to the stream. Required information includes watershed characteristics (drainage area, runoff curve number, watershed length, watershed slope) and rainfall amount and rainfall distribution. This file requires Microsoft Word.) imgMarginRight = imgMarginRight.replace("px",""); This means that the average downhill slope of 24th St as water drains along it towards Waller Creek is a little more than 3%. stream Calculating average slope of a watershed upstream of many points in ArcGIS (upstream basin slope) Ask Question Asked 3 years, 1 month ago. 17 0 obj Set the File name and Projection. 10 : dom_i.query(this).css("margin-right").trim(); A less-steep, flatter roof will cause the water to move more slowly, raising the potential for …   EFH2 User's Manual (4.6 mb. potential watershed storage (S) = 0 = 0. inch . Slope is the measure of steepness or the degree of inclination of a feature relative to the horizontal plane. } Other Units: Change Equation Select to solve for a different unknown The range of values in the output depends on the type of measurement units. n Watershed boundaries and lakes: Michigan Geographic Data Library n Great Lakes: Institute for Fisheries Research Great Lakes GIS n Rivers, political borders and cities: Michigan Geographic Data Library and GIS-based ... average,!rain!falls!nearly!oneday!out!of!every!three Watershed Subbasin Maps This web page provides access to five pre-built map series for each of Montana’s subbasins (8-digit HUC level). The authors investigate the effect of digital elevation model (DEM) grid size and source on the average watershed slope. �t�]5���b,�\&���)&Ѡ���of'�TK. Active 3 years, 1 month ago. The quantity of water thus stored by the banks temporarily is known as bank storage. Begin by Opening a MapBook Project in ArcMap. The direction the plane faces is the aspect for the processing cell. Curve numbers (CN) are used to represent watershed characteristics that … dom.query('img').each(function(){ dom_i.query(this).css("margin","0"); %�쏢 Riffles are found entering and exiting meanders and control the streambed elevation. Watershed length is between 200 and 26,000 feet. Lag is a function of the flow length of the watershed, average land slope of the watershed, and the potential maximum retention of rainfall on the watershed. The water depth is relatively shallow and the slope is steeper than the average slope of the channel. Hydrology Water Quantity and … }else{ Use Slope to calculate the slope of the entire farm. } dom.query(this).attr("title",title); Curve numbers (CN) are used to represent watershed characteristics that … The lower the slope value, the flatter the terrain; the higher the slope value, the steeper the terrain. 2. Lloyd-Davies method if you are English, is probably the oldest Abstract. b) The average altitude of a watershed - can be deduced directly from the hypsographical curve or from reading the topographical map. Land-surface slope, land cover, and land use have similar influences on watershed characteristics as those identified for the unsaturated zone. The average annual precipitation represents the amount of water available for transport in a watershed. } Lloyd-Davies method if you are English, is probably the oldest } Watersheds can be as small as a footprint or large enough to encompass all the land that drains water into rivers that drain into Chesapeake Bay, where it enters the Atlantic Ocean. Slope can be given in two different ways, a percent gradient or an angle of the slope. F�Y�5?Q�Ān�!�����S��X�R+�ݶ��6��LU�ѹ�D��� Calculate a curve number, CN, for the drainage area. Lag is the delay between the time runoff from a rainfall event over a watershed begins until runoff reaches its maximum peak. This program has restricted applications. //