Editing Delaware (section)

==Geography==
{{Main|Twelve-Mile Circle|Wedge (border)|Mason–Dixon Line|Transpeninsular Line}}
{{See also|#Counties|l1="Counties" section below}}
[[File:Twelve-mile-circle.gif|thumb|The [[Twelve-Mile Circle]]]]
[[File:National-atlas-delaware.png|thumb|Map of Delaware]]
[[File:Woodbrook test.jpg|thumb|Sunset in [[Woodbrook, Delaware]]]]
[[File:Blackbird pond.jpg|thumb|The Blackbird Pond on the [[Blackbird State Forest]] Meadows Tract in [[New Castle County, Delaware]]]]
[[File:MiddleRunArea Field LenapeTrail.jpg|thumb|A field north of Fox Den Road along the Lenape Trail in [[Middle Run Valley Natural Area]]]]
Delaware is {{convert|96|mi|km}} long and ranges from {{convert|9|to|35|mi|km}} across, with a land area of {{convert|1982|sqmi|km2}}<ref>{{Cite web|last=Delaware|first=The State of|title=State of Delaware|url=https://de.gov/topics/facts/geo.shtml|url-status=dead|archive-url=https://web.archive.org/web/20210818174548/https://de.gov/topics/facts/geo.shtml|archive-date=August 18, 2021|access-date=August 18, 2021|website=delaware.gov|language=en}}</ref> and a total area of {{convert|2489|sqmi|km2}},<ref name="ReferenceA">britannica.com/facts/Delaware-state</ref> making it the second-smallest state by either metric in the United States after [[Rhode Island]]. Delaware is bounded to the north by [[Pennsylvania]]; to the east by the [[Delaware River]], [[Delaware Bay]], [[New Jersey]], and the Atlantic Ocean; and to the west and south by [[Maryland]]. Small portions of Delaware are also situated on the eastern side of the Delaware River sharing land boundaries with New Jersey. The state of Delaware, together with the [[Eastern Shore of Maryland|Eastern Shore counties of Maryland]] and [[Eastern Shore of Virginia|two counties of Virginia]], form the [[Delmarva Peninsula]], which stretches down the Mid-Atlantic Coast.

The definition of the northern boundary of the state is unusual. Most of the boundary between Delaware and Pennsylvania was originally defined by an arc extending {{convert|12|mi|km|sigfig=3}} from the [[cupola]] of the courthouse in the city of [[New Castle, Delaware|New Castle]].<ref>{{Cite web |title=The story of how Delaware got its shape |url=https://www.delawareonline.com/story/life/2018/07/05/delaware-defined-story-how-first-state-got-its-shape/744188002/ |access-date=2023-05-24 |website=The News Journal |language=en-US}}</ref> This boundary is often referred to as the [[Twelve-Mile Circle]].{{efn|Because of surveying errors, the actual line is several compound arcs with centers at different points in New Castle.}} Although the Twelve-Mile Circle is often claimed to be the only territorial boundary in the U.S. that is a true [[Arc (geometry)|arc]], the Mexican boundary with Texas includes several arcs,<ref>{{cite web |url=http://faolex.fao.org/docs/pdf/bi-51757.pdf |title=Treaty to resolve pending boundary differences and maintain the Rio Grande and Colorado River as the international boundary |access-date=February 1, 2019 |archive-url=https://web.archive.org/web/20160410052222/http://faolex.fao.org/docs/pdf/bi-51757.pdf |archive-date=April 10, 2016 |url-status=live}}</ref> and many cities in the South (such as [[Plains, Georgia]])<ref>Frank Jacobs, [http://bigthink.com/strange-maps/655-enigma-georgia-mystery-of-the-souths-circular-towns "Enigma, Georgia: Mystery of the South's Circular Towns"] {{webarchive |url=https://web.archive.org/web/20140523230226/http://bigthink.com/strange-maps/655-enigma-georgia-mystery-of-the-souths-circular-towns |date=May 23, 2014}}, Strange Maps, April 30, 2014.</ref> also have circular boundaries.

This border extends all the way east to the low-tide mark on the New Jersey shore, then continues south along the shoreline until it again reaches the {{convert|12|mi|adj=on}} arc in the south; then the boundary continues in a more conventional way in the middle of the main channel ([[thalweg]]) of the Delaware River.

On the west, Delaware and Maryland are mostly separated by a line running from the midpoint of the [[Transpeninsular Line]], going slightly west of due north up to its tangent point on the [[Twelve-Mile Circle]]. The border follows the Circle for a short distance and then continues in a straight line due north until reaching the southern border of Pennsylvania.<ref>{{Cite web |last=Schenck |first=William |date=2007 |title=Delaware's State Boundaries |url=https://www.dgs.udel.edu/sites/default/files/publications/info6.pdf |access-date=2024-09-13 |website=Delaware Geological Survey}}</ref> [[The Wedge (border)|The Wedge]] of land between the northwest part of the arc and the Maryland border was claimed by both Delaware and Pennsylvania until 1921, when Delaware's claim was confirmed.

===Topography===
Delaware is on a level plain, with the lowest mean elevation of any state in the nation.<ref name="census">{{cite web|url=https://www.census.gov/prod/2004pubs/04statab/geo.pdf|page=216|title=Extreme and Mean Elevations by State and Other Area|website=Statistical Abstract of the United States: 2004–2005|publisher=United States Census Bureau|access-date=March 16, 2011|archive-url=https://web.archive.org/web/20110310194411/http://www.census.gov/prod/2004pubs/04statab/geo.pdf|archive-date=March 10, 2011|url-status=live}}</ref> Its highest elevation, located at [[Ebright Azimuth]], near [[Concord High School (Wilmington, Delaware)|Concord High School]], is less than {{convert|450|ft}} above sea level.<ref name="census" /> The northernmost part of the state is part of the [[Piedmont (United States)|Piedmont Plateau]] with hills and rolling surfaces.

The [[Atlantic Seaboard fall line]] approximately follows the [[Delaware Route 2|Robert Kirkwood Highway]] between [[Newark, Delaware|Newark]] and [[Wilmington, Delaware|Wilmington]]; south of this road is the [[Atlantic Coastal Plain]] with flat, sandy, and, in some parts, swampy ground.<ref>{{cite web|url=http://www.dgs.udel.edu/delaware-geology/summary-geologic-history-delaware|title=A Summary of the Geologic History of Delaware|publisher=The Delaware Geological Survey|access-date=March 19, 2013|archive-url=https://web.archive.org/web/20130312150937/http://www.dgs.udel.edu/delaware-geology/summary-geologic-history-delaware|archive-date=March 12, 2013|url-status=live}}</ref> A ridge about {{convert|75|to|80|ft}} high extends along the western boundary of the state and separates the [[drainage basin|watersheds]] that feed Delaware River and Bay to the east and the [[Chesapeake Bay]] to the west.

===Climate===
{{further|Climate change in Delaware}}
[[File:Köppen Climate Types Delaware.png|thumb|The Köppen climate classification for Delaware]]
Since almost all of Delaware is a part of the [[Atlantic coastal plain]], the effects of the ocean moderate its climate. The state lies in the [[humid subtropical climate]] (Köppen ''Cfa'') zone. Despite its small size (roughly {{convert|100|mi|km}} from its northernmost to southernmost points), there is significant variation in mean temperature and amount of snowfall between Sussex County and New Castle County. Moderated by the Atlantic Ocean and [[Delaware Bay]], the southern portion of the state has a milder climate and a longer growing season than the northern portion of the state.

Summers are long, hot, and humid in Delaware, often with intense (but brief) late day thundershowers. Delaware averages 2,300 hrs of sunshine annually (higher than the USA average). Winters are modestly cool to cold in northern Delaware, and cool to mild in southern Delaware. The normal seasonal snowfall ranges from about 20.0 inches in Wilmington to only 10.0 inches in Lewes. In many winters no snow will fall in coastal Delaware. Northern Delaware falls into USDA Garden Zone 7a, while southern and coastal areas fall into USDA zone 7b and 8a. The milder climate in southern Delaware allows for [[subtropical]] [[flora]] such as the [[windmill palm]], [[needle palm]], and [[dwarf palmetto]].

Delaware's all-time record high of {{convert|110|F|C}} was recorded at [[Millsboro, Delaware|Millsboro]] on July 21, 1930. The all-time record low of {{convert|-17|F|C}} was also recorded at Millsboro, on January 17, 1893. The [[hardiness zone]]s are 7B and 8A at the [[Delaware Beaches]].

===Environment===
The transitional climate of Delaware supports a wide variety of vegetation. In the northern third of the state are found [[Northeastern coastal forests]] and mixed [[Quercus|oak]] forests typical of the northeastern United States.<ref name="ecoregions">{{cite journal|author=Olson |title=Terrestrial Ecoregions of the World: A New Map of Life on Earth |journal=[[BioScience]] |year=2001 |volume=51 |issue=11 |pages=933–938 |doi=10.1641/0006-3568(2001)051[0933:TEOTWA]2.0.CO;2 |author2=D. M |author3=E. Dinerstein |display-authors=3 |issn=0006-3568 |last4=Burgess |first4=Neil D. |last5=Powell |first5=George V. N. |last6=Underwood |first6=Emma C. |last7=d'Amico |first7=Jennifer A. |last8=Itoua |first8=Illanga |last9=Strand |first9=Holly E. |doi-access=free }}</ref> In the southern two-thirds of the state are found [[Middle Atlantic coastal forests]].<ref name="ecoregions" /> [[Trap Pond State Park]], along with areas in other parts of Sussex County, for example, support the northernmost stands of [[Taxodium distichum|bald cypress]] trees in North America.

===Environmental management===

Delaware provides [[Government subsidy|government subsidy support]] for the [[Environmental remediation|clean-up]] of property "lightly contaminated" by [[hazardous waste]], the proceeds for which come from a tax on wholesale petroleum sales.<ref>{{cite news |title=Cleaning up contamination |first=Jeff |last=Montgomery |newspaper=[[The News Journal]] |date=May 14, 2011 |access-date=May 14, 2011 |url=http://www.delawareonline.com/article/20110514/NEWS02/105140360/-1/NLETTER01/Cleaning-up-contamination |location=New Castle, Delaware |at=DelawareOnline |archive-url=https://archive.today/20240525083145/https://www.webcitation.org/5ygBz8xTN?url=http://www.delawareonline.com/article/20110514/NEWS02/105140360/-1/NLETTER01/Cleaning-up-contamination |archive-date=May 25, 2024 |url-status=live }} ''The first online page is archived; the page containing information related here is not in the archived version.''</ref>