Watershed.IOR1: Watershed inlet and outlet nodes: case 1
In Watersheds: Spatial Watershed Aggregation and Spatial Drainage Network Analysis

Description Usage Arguments Value Note Author(s) See Also Examples

The function determines the inlet and outlet nodes for zhyd watershed objects. This case 1 is for those watersheds that its river inlet and outlet object is length 1 (length(riverIO)=1).

1	Watershed.IOR1(x, dist)

`x`	An object `"SpatialPointsDataFrame"` as is described in package `sp` over the function will search the inlet and outlet nodes of the watershed.
`dist`	A vector with the distances of each point in `x` to the current zhyd boundary.

A list of length 2:

`inlet`	A `"SpatialPointsDataFrame"` that represents the inlet node of the current `zhyd`.
`outlet`	A `"SpatialPointsDataFrame"` that represents the outlet node of the current `zhyd`.

If there are not inlet or outlet node of the current zhyd, 0 is returned.

J.A. Torres

See Also the functions Watershed.IOR2, Watershed.IOR3, Watershed.IOR4.

library(Watersheds)
data(WatershedsData)

station1 = WatershedsData$station
subbasin1 = WatershedsData$subbasin
zhyd1 = WatershedsData$zhyd
river1 = WatershedsData$river
node1 = WatershedsData$node	

station1 = SpatialPoints(coords=cbind(4232972,3327634), 
	proj4string=slot(subbasin1,"proj4string"))
watershed = new("Watershed",station=station1,subbasin=subbasin1,
	zhyd=zhyd1,river=river1,c1=subbasin1,node=node1)

a = Watershed.Order(watershed)
c1 = a[[1]]
nodeIO = a[[9]]			
c1_river = a[[10]]
		
# determining inlet and outlet watershed nodes
	# determining distances of nodeIO to c1
	boundary = gBoundary(c1)
	dist = gDistance(nodeIO, boundary, byid =TRUE)
	a = Watershed.IOR1(x=nodeIO, dist=dist)
	c1_inlet = a$inlet; c1_inlet
	c1_outlet = a$outlet; c1_outlet
	
plot(c1,col="gray50")			
plot(station1,pch=24, bg="blue",add= TRUE)
plot(c1_river, col="blue", add=TRUE)
plot(c1_outlet,pch=21, bg="red",add= TRUE)
plot.PointAttribute(c1_outlet,"ELEV",700,0.8)
title(main="Watershed outlet, case I")