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#1
BZero

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Is there anyway to get this statewide map to not show water so extensively on the east side. There is not that much water in kansas, but it gives that impression. When you zoom in to a county you see that it is not that extensive. It is kind of like a pyramid issue, but this is vector not raster.

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#2
rudy

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Very odd - the number of water bodies seem to differ significantly from county to county. This seems like county data pieced together to make a state wide layer - but the standards for water body inclusion seem to differ from county to county.

#3
BZero

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They were merged together, but that is just how kansas looks in a jpeg file. Its from the census. See the topic below this.

It looks the exact same way in the USGS 2006 national atlas water file.

Edited by BZero, 06 November 2009 - 01:11 PM.


#4
eli

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You could do a query to exclude polygons that are less than a certain area number.

#5
jbl

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Is there anyway to get this statewide map to not show water so extensively on the east side. There is not that much water in kansas, but it gives that impression. When you zoom in to a county you see that it is not that extensive. It is kind of like a pyramid issue, but this is vector not raster.


I assume that your data is from the US Census Tiger files, though I don't know what year or version.
In the most current version the edges shapefile contains the hydrology polylines (the polygons are in the areawater shapefile). The MTFCC class 'H' has a siginificant flag, 'PERSIST', options null, I (intermittant) and P (persistent). The null and intermittant would be the features that are normally dry and probably not of interest.

In ArcMap you could select by attribute using something like
"MTFCC" LIKE 'H%' AND "PERSIST" = 'P'

and get only the persistent, normally flowing rivers and streams.
The tiger files are extensive but not intuitive as the documentation is written by bureaucrats. If you have plenty of time to get familiar with them, they are worth the price.

I just experimented on the Johnson County and tried this (some of the normally dry features did have names so I kept them)
"MTFCC" LIKE 'H%' AND "PERSIST" NOT LIKE 'P' AND "FULLNAME" = ' '
This returns un-named normally dry features
jbl

Edited by jbl, 15 November 2009 - 12:42 PM.


#6
BZero

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Is there anyway to get this statewide map to not show water so extensively on the east side. There is not that much water in kansas, but it gives that impression. When you zoom in to a county you see that it is not that extensive. It is kind of like a pyramid issue, but this is vector not raster.


I assume that your data is from the US Census Tiger files, though I don't know what year or version.
In the most current version the edges shapefile contains the hydrology polylines (the polygons are in the areawater shapefile). The MTFCC class 'H' has a siginificant flag, 'PERSIST', options null, I (intermittant) and P (persistent). The null and intermittant would be the features that are normally dry and probably not of interest.

In ArcMap you could select by attribute using something like
"MTFCC" LIKE 'H%' AND "PERSIST" = 'P'

and get only the persistent, normally flowing rivers and streams.
The tiger files are extensive but not intuitive as the documentation is written by bureaucrats. If you have plenty of time to get familiar with them, they are worth the price.

I just experimented on the Johnson County and tried this (some of the normally dry features did have names so I kept them)
"MTFCC" LIKE 'H%' AND "PERSIST" NOT LIKE 'P' AND "FULLNAME" = ' '
This returns un-named normally dry features
jbl


I was unaware of this. Thank you. I dont know if I will use it since I already downloaded all of the area polygons and not the edges, but this is good to know.

The only thing I don't understand is the NOT LIKE for P and FULLNAME. I would assume it would be LIKE and not NOT LIKE for P. Wouldnt you want to select persistent water featurees, hence LIKE P and Fullname = %

EDIT: oh nvm you meant to do that for dry features.

Edited by BZero, 15 November 2009 - 03:32 PM.





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