Land cover classification and change detection on the Kenai Penisula, 1973 - 2017
Manuscript describing describe a method for classifying land cover and quantifying land cover change over time, using Landsat legacy imagery for three historical periods on the western Kenai Peninsula; 1973–2002, 2002–2017, and 1973–2017.Abstract
Across Alaska’s Kenai Peninsula, disturbance events have removed large areas of forest over the last half century. Simultaneously, succession and landscape evolution have facilitated forest regrowth and expansion. Detecting forest loss within known disturbance events is often straightforward given that reduction of tree cover is a readily detectible and measurable land cover change. Land cover change is more difficult to quantify when disturbance events are unknown, remote, or environmental response is very slow in relation to human observation. While disturbance events and related land cover change are relatively instant, assessing patterns of post-disturbance succession requires long term monitoring. Here, we describe a method for classifying land cover and quantifying land cover change over time, using Landsat legacy imagery for three historical periods on the western Kenai Peninsula; 1973–2002, 2002–2017, and 1973–2017. Scenes from numerous Landsat sensors, including summer and winter seasons, were acquired between 1973 and 2017 and used to classify vegetation cover using a random forest classifier. Land cover type was summarized by era and combined to produce a data set capturing spatially explicit land cover change at a moderate 30-meter resolution. Our results document large scale forest loss across the study area that can be attributed to known disturbance events including beetle kill and wildfire. Despite numerous and extensive disturbances resulting in forest loss, we estimate that the study area has experienced net forest gain over the duration of our study period. Transitions between forest and graminoid non-forest is the most common land cover change – representing recruitment of a graminoid dominated understory following forest loss and the return of forest canopy given sufficient time post-disturbance.
Products
| Title | Type |
|---|---|
| Land Cover Estimates for the Kenai Peninsula Lowlands; 1973, 2002, and 2017 | Data |
| Ecosystems on the Edge: Landscape and Fire Ecology of Forests, Deserts, and Tundra | Project Website |
Contacts
Loehman, Rachael A., 907-786-7089Status: onGoing
Start Year: 2018
End Year: 2020
Project Sites
Location
Kenai PeninsulaUSGS Mission Area and Program
Land Resources → Land Change ScienceKeywords
Biosphere > Vegetation > Afforestation/ReforestationBiosphere > Vegetation > Vegetation Cover
Land Surface > Land Use/Land Cover > Land Cover