Google Earth Engine ——資料全解析專輯(US NED Topographic Diversity地貌多樣性拓撲資料集)

Topographic diversity (D) is a surrogate variable that represents the variety of temperature and moisture conditions available to species as local habitats. It expresses the logic that a higher variety of topo-climate niches should support higher diversity (especially plant) and support species persistence given climatic change.

To calculate D, the multi-scale Topographic Position Index (mTPI), being a dominant control of soil moisture (T), was used for measuring hillslope position. The mTPI was combined with the square-root transform for mTPI>0 (T’) and with the standard deviation of the Continuous Heat-Insolation Load Index (CHILI), calculated at multiple scales (C’) as: D = 1 – ((1-T’) * (1-C’). It is based on the USGS's 10m NED DEM (available in EE as USGS/NED).

The Conservation Science Partners (CSP) Ecologically Relevant Geomorphology (ERGo) Datasets, Landforms and Physiography contain detailed, multi-scale data on landforms and physiographic (aka land facet) patterns. Although there are many potential uses of these data, the original purpose for these data was to develop an ecologically relevant classification and map of landforms and physiographic classes that are suitable for climate adaptation planning. Because there is large uncertainty associated with future climate conditions and even more uncertainty around ecological responses, providing information about what is unlikely to change offers a strong foundation for managers to build robust climate adaptation plans. The quantification of these features of the landscape is sensitive to the resolution, so we provide the highest resolution possible given the extent and characteristics of a given index.

地形多樣性（D）是一個替代變量，代表了物種作為當地栖息地可用的各種溫度和濕度條件。它所表達的邏輯是，較多的地形氣候龛位應支援較高的多樣性（尤其是植物），并在氣候變化的情況下支援物種的持續存在。

為了計算D，多尺度地形位置指數（mTPI），作為土壤水分（T）的主要控制因素，被用來測量山坡位置。mTPI與mTPI>0時的方根變換（T'）和連續熱阻負荷指數（CHILI）的标準差相結合，在多尺度下計算（C'）。D=1-（（1-T'）*（1-C'）。它基于美國地質調查局的10米NED DEM（在EE中可作為USGS/NED）。

保護科學夥伴（CSP）生态相關地貌（ERGo）資料集、地貌和地形學包含詳細的、多尺度的地貌和地形學（又稱土地面）模式資料。盡管這些資料有許多潛在的用途，但這些資料的最初目的是開發适合氣候适應規劃的生态相關的地貌和自然地理類别的分類和地圖。因為未來的氣候條件有很大的不确定性，圍繞生态反應的不确定性甚至更大，提供有關不太可能改變的資訊為管理者建立強大的氣候适應計劃提供了一個堅實的基礎。景觀的這些特征的量化對分辨率很敏感，是以我們在給定指數的範圍和特征的情況下，提供盡可能高的分辨率。

Dataset Availability

2006-01-24T00:00:00 - 2011-05-13T00:00:00

Dataset Provider

Conservation Science Partners

Collection Snippet

ee.Image("CSP/ERGo/1_0/US/topoDiversity")

Resolution

90 meters

Bands Table

Name	Description	Min*	Max*
constant	NED-derived topographic diversity	1

* = Values are estimated

代碼：

var dataset = ee.Image('CSP/ERGo/1_0/US/topoDiversity');
var usTopographicDiversity = dataset.select('constant');
var usTopographicDiversityVis = {
  min: 0.0,
  max: 1.0,
};
Map.setCenter(-111.313, 39.724, 6);
Map.addLayer(
    usTopographicDiversity, usTopographicDiversityVis,
    'US Topographic Diversity');