Monthly Archives: December 2014

Two New Maps that Could Change the World

GIS and Science

Maps have long been used by people to help navigate and understand our world. Early maps guided early humans to basic necessities such as food and water.

Today, the world is changing rapidly, and it’s difficult for traditional maps to keep up with the pace of that change. To help us keep pace with our evolving planet, we need something better. We need new, more comprehensive maps.

Esri has developed two new maps—the most detailed population map in the world and the most detailed ecological land unit map in the world—to help address the challenges we face and make our world a better place.

A New Map of World Population

Esri has compiled a human geography database of demographics and statistics about all countries in the world and has mapped this data using a new, innovative methodology.

Advances in technology are changing the type, quantity, quality, and timeliness of information…

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Space Time Pattern Mining toolbox in ArcGIS 10.3

ESRI just released ArcGIS 10.3.  The newly added Space Time Patter Mining toolbox seems very interesting.

The Space Time Pattern Mining toolbox has two tools: Create Space Time Cube and Emerging Hot Spot Analysis. Create Space Time Cube takes potentially very large point datasets and builds a multidimensional data structure for analysis.Emerging Hot Spot Analysis takes the space time cube data structure as input and identifies hot and cold spot trends. You might use Emerging Hot Spot Analysis to analyze crime data, for example, in order to locate new, intensifying, persistent, or sporadic hot spot patterns.

Space Time Cube Creation

Space-time bins in a three-dimensional cube

Locations in the space-time cube

New peer-reviewed article on wetland classification

My co-authored article on wetland classification just got published online:

Improved Wetland Classification Using Eight-Band High Resolution Satellite Imagery and a Hybrid Approach

Charles R. Lane 1,* , Hongxing Liu 2,3, Bradley C. Autrey 1, Oleg A. Anenkhonov 4, Victor V. Chepinoga 5,6 and Qiusheng Wu 2,3

Abstract: Although remote sensing technology has long been used in wetland inventory and monitoring, the accuracy and detail level of wetland maps derived with moderate resolution imagery and traditional techniques have been limited and often unsatisfactory. We explored and evaluated the utility of a newly launched high-resolution, eight-band satellite system (Worldview-2; WV2) for identifying and classifying freshwater deltaic wetland vegetation and aquatic habitats in the Selenga River Delta of Lake Baikal, Russia, using a hybrid approach and a novel application of Indicator Species Analysis (ISA). We achieved an overall classification accuracy of 86.5% (Kappa coefficient: 0.85) for 22 classes of aquatic and wetland habitats and found that additional metrics, such as the Normalized Difference Vegetation Index and image texture, were valuable for improving the overall classification accuracy and particularly for discriminating among certain habitat classes. Our analysis demonstrated that including WV2’s four spectral bands from parts of the spectrum less commonly used in remote sensing analyses, along with the more traditional bandwidths, contributed to the increase in the overall classification accuracy by ~4% overall, but with considerable increases in our ability to discriminate certain communities. The coastal band improved differentiating open water and aquatic (i.e., vegetated) habitats, and the yellow, red-edge, and near-infrared 2 bands improved discrimination among different vegetated aquatic and terrestrial habitats. The use of ISA provided statistical rigor in developing associations between spectral classes and field-based data. Our analyses demonstrated the utility of a hybrid approach and the benefit of additional bands and metrics in providing the first spatially explicit mapping of a large and heterogeneous wetland system.

Getting started with SRTM elevation data: downloading, processing, clipping and visualizing.

Very detailed instruction for dealing with STRM data. Good stuff!

Scientia Plus Conscientia

As a prelude to a post on topographic correction of Landsat images, we here review the basic steps to get elevation data and preparing them for using as a base for topographic correction.

The Shuttle Radar Topography Mission (SRTM) is a tremendous resource because of its high accuracy and its consistency as a “snapshot” of Earth’s surface, acquired over just 10 days during February 2000. It is also freely available for anyone! SRTM was a specially designed mission of the Endeavour space shuttle, with a specially built sensor antenna, and aimed to map the Earth’s land topography using radar interferometry. As a result, during the 10 days of the mission, the land surface topography between latitudes 60°N and 56°S, or about 80% of Earth’s surface, was mapped with a final cell size of 1 arc-second (about 30 m) and absolute elevation errors under 10 m. More details about the mission…

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Alex Tereshenkov

Programming and managing GIS

REDD+ for the Guiana Shield

Technical Cooperation Project

Dr. Qiusheng Wu @ University of Tennessee

Writing Science

How to write papers that get cited and proposals that get funded

GIS In Ecology

Providing Training, Advice And Consultation On The Use Of GIS In Ecology


On cities, land, ...

Scientia Plus Conscientia

Thoughts on Science and Nature


Learning hydrology with R

Karl Hennermann

GIS at the University of Manchester

GIS and Science

Applications of geospatial technology for scientific research and understanding.

Whitebox Geospatial Analysis Tools

Open-source GIS development and spatial analysis with Whitebox GAT


MATLAB-based software for topographic analysis

Anything Geospatial

Dr. Qiusheng Wu @ University of Tennessee

Dr. Qiusheng Wu @ University of Tennessee

Another GIS Blog

Dr. Qiusheng Wu @ University of Tennessee

ArcPy Café

Get all your ArcGIS Python Recipes here!