class: inverse, left, nonum, clear background-image: url("figs/rayshader.png") background-size: cover <link rel="stylesheet" type="text/css" href="//fonts.googleapis.com/css?family=Oswald" /> .titlestyle[Current state and changes] <br> .titlestyle[in the] <br> .titlestyle[composition] <br> .titlestyle[and] <br> .titlestyle[configuration] <br> .titlestyle[of landscapes worldwide] .captionstyle[Jakub Nowosad and Tomasz F. Stepinski] .pull-right2[.captionstyle[2020-05-13, the IALE-North America 2020 Annual Meeting]] <!-- idea: background - entropy map with 3d rayshader --> --- # Introduction .lc[ - Quantifying composition and configuration of landscapes is often done on a local scale - The systematic study of landscape compositions and configurations over the entire landmass is lacking **Goals:** - Create a global inventory - Show current state and changes in spatial composition and configuration of landscapes worldwide <!-- - Extracting and quantifying the composition and configuration of landscapes is the starting point for landscape ecology --> <!-- - While this is often done on a local scale using landscape indices selected to quantify a particular feature of landscape pattern, the systematic study of landscape compositions and configurations over the entire landmass is lacking --> <!-- - The goal of this study is to create a global inventory of spatial composition and configuration of landscapes for several time frames and to show how these properties change over time --> ] .rc[ <img src="figs/lc_map2016.png" width="3333" style="display: block; margin: auto;" /> ] -- .rc[ - Land cover data for years 1992-2016 from the CCI-LC project - [Goode homolosine projection](https://en.wikipedia.org/wiki/Goode_homolosine_projection) and nine main categories - Partitioned into 30 x 30 kilometers square blocks - 150,000 mesoscale landscapes - For each of these landscapes, for each year, a large set of variables was extracted, including **marginal entropy** and **relative mutual information** ] --- # IT metrics .pull-left[ - Five information theory metrics based on a co-occurrence matrix exist [(Nowosad and Stepinski, 2019)](https://link.springer.com/article/10.1007/s10980-019-00830-x) <img src="figs/it_metrics_maps1.png" width="2533" style="display: block; margin: auto;" /> <!-- - Different patterns generate different co-occurrence matrices --> <!-- - **Marginal entropy [H(x)]** and **relative mutual information [U]** were used in this study --> <!-- Important note: when entropy is zero, when we set relative mutual information to 1 --> - **Marginal entropy [H(x)]** - diversity (*composition*) of spatial categories - **from monothematic patterns to multithematic patterns** - **Relative mutual information [U]** - clumpiness (*configuration*) of spatial categories **from fragmented patterns to consolidated patterns**) - **H(x) and U** are uncorrelated ] .pull-right[ <img src="figs/it_metrics_maps2.png" width="100%" style="display: block; margin: auto;" /> <img src="figs/it_metrics_maps3.png" width="100%" style="display: block; margin: auto;" /> ] --- # Current state: composition <!-- - Composition of land cover categories, marginal entropy, and relative mutual information calculated using the data for the year 2016 was used to describe a current state in the composition and configuration of landscapes worldwide --> <img src="figs/lc_shares2016.png" width="90%" style="display: block; margin: auto;" /> --- # Current state: composition <div class="figure" style="text-align: center"> <img src="figs/entropy_map2016.png" alt="Spatial distribution of marginal entropy values" width="2400" /> <p class="caption">Spatial distribution of marginal entropy values</p> </div> --- # Current state: configuration <div class="figure" style="text-align: center"> <img src="figs/relmutinf_map2016.png" alt="Spatial distribution of relative mutual information values" width="2400" /> <p class="caption">Spatial distribution of relative mutual information values</p> </div> --- # Global changes: composition <img src="figs/lc_composition_changes.png" width="88%" style="display: block; margin: auto;" /> --- # Global changes: composition .lc[ <img src="figs/entropy_changes2.png" width="1600" style="display: block; margin: auto;" /> ] .rc[ - Global changes in entropy between 1992 and 2016 are spatially autocorrelated - **Increases in entropy:** Amazon region, east China, as well as most of Europe - **Decreases in entropy:** Northern Canada, and north parts of Eurasia, as well as central Asia and west Africa - More areas had an increase in entropy than the decrease <!-- - More than 1/3 of studied landscapes showed an increase of entropy of 0 to 0.1 --> <!-- - Entropy had not change for about 20% of landscapes --> <img src="figs/entropy_changes_map2.png" width="2400" style="display: block; margin: auto;" /> ] --- # Local changes: composition .pull-left[ **Major decreases in entropy:** <img src="figs/lc_change_africa3.png" width="100%" style="display: block; margin: auto;" /> ] .pull-right[ **Major increases in entropy:** <img src="figs/lc_change_amazon3.png" width="100%" style="display: block; margin: auto;" /> ] --- # Global changes: configuration .lc[ <img src="figs/relmutinf_changes2.png" width="1600" style="display: block; margin: auto;" /> ] .rc[ - **Increases in relative mutual information:** northern Argentina - **Decreases in relative mutual information:** Amazon region, east China, as well as most of South Sudan - More areas had an increase in relative mutual information than the decrease <!-- - Global changes in relative mutual information seem to be less spatially autocorrelated than changes in entropy --> <!-- - Overall, more than 1/3 of studied landscapes showed an increase of relative mutual information between 0 and 0.1 --> <!-- - Relative mutual information had not change for about 20% of landscapes --> <img src="figs/relmutinf_changes_map2.png" width="2400" style="display: block; margin: auto;" /> ] --- # Local changes: configuration .pull-left[ **Major decreases in relative mutual information:** <img src="figs/lc_change_china3.png" width="100%" style="display: block; margin: auto;" /> ] .pull-right[ **Major increases in relative mutual information:** <img src="figs/lc_change_argentina3.png" width="120%" style="display: block; margin: auto;" /> ] --- class: left, top, clear <img src="figs/cropped_entropy.png" width="1576" style="margin: -110px 0px -57px 0px" > .lc2[ ## Summary - **Marginal entropy** and **relative mutual information** are universal indicators of landscapes configuration and composition - These metrics are **not dependent on a certain category of land cover** (but this information can be incorporated into analyses) - Globally, there is a trend of increasing entropy **(more landscapes with multithematic patterns)** - There is also a trend of increasing relative mutual information **(more landscapes with consolidated patterns)** ## Next steps - Confirming the results on different scales and levels of details - Relating the state and trends of landscape changes to human and environmental factors ] .rc2[ ## Contact:
jakub_nowosad https://nowosad.github.io ## Resources: - **Slides:** [nowosad.github.io/iale-na_20](https://nowosad.github.io/iale-na_20) - [**iPoster**](https://2020toronto-ialena.ipostersessions.com/default.aspx?s=40-15-E7-38-9A-EE-C6-76-09-30-1D-88-C9-A5-81-B5) - **Software:** R packages [motif](https://nowosad.github.io/motif/) and [landscapemetrics](https://r-spatialecology.github.io/landscapemetrics/index.html) - **Blog post:** [Information theory provides a consistent framework for the analysis of spatial patterns](https://nowosad.github.io/post/ent-bp1/) ]