Urban Monitoring and NADP/NTN

Mark Nilles, USGS
USGS Circular 964, Design of the National Trends Network


Done by Robertson and Wilson, U.S. Military Academy, 1985
Product of the Deposition Monitoring Task Group of NAPAP
Network was largely in place when this document was published.
Documented the design effort at Bear Mountain, NY of early 1982.


Design element 1

Assurance that all areas of the country are represented in the network on the basis of ecological properties (96 sites)


Design element 2

Placement of additional sites in the east to better define areas of high deposition gradients (27 sites)


Design Element 3

Placement of sites to assure that potentially sensitive regions are represented (15 sites)


Design element 4

Placement of sites to allow for other considerations, such as urban area effects (5 sites), intercomparison with Canada, (3 sites) and apparent disparities in regional coverage (5 sites)


Rational for design element 4, Urban influenced sites

Criticism that the authors were developing a "positive network"
Sites located such that nationwide estimates of deposition would underestimate actual deposition


Consequence of Design element 4

5 Sites were added to the network that did not meet the NADP/NTN siting criteria because of their proximity to large urban complexes of:
Los Angeles
Philadelphia
New York
Chicago
Boston


Original "urban sites"

CA42 (still operating) Los Angeles
IL19 (still operating) Chicago
MA13 (still operating) Boston
NJ29 (now NJ99) Philadelphia
NY51 (now NY99) New York