Production of the Japan 30-m Land Cover Map of 2013–2015 Using a Random Forests-Based Feature Optimization Approach

Keitarou Hara,Kotaro Iizuka,Ram Sharma,Ryutaro Tateishi

doi:10.3390/rs8050429

Abstract

Achieving more timely, accurate and transparent information on the distribution and dynamics of the world’s land cover is essential to understanding the fundamental characteristics, processes and threats associated with human-nature-climate interactions. Higher resolution (~30–50 m) land cover mapping is expected to advance the understanding of the multi-dimensional interactions of the human-nature-climate system with the potentiality of representing most of the biophysical processes and characteristics of the land surface. However, mapping at 30-m resolution is complicated with existing manual techniques, due to the laborious procedures involved with the analysis and interpretation of huge volumes of satellite data. To cope with this problem, an automated technique was explored for the production of a high resolution land cover map at a national scale. The automated technique consists of the construction of a reference library by the optimum combination of the spectral, textural and topographic features and predicting the results using the optimum random forests model. The feature-rich reference library-driven automated technique was used to produce the Japan 30-m resolution land cover (JpLC-30) map of 2013–2015. The JpLC-30 map consists of seven major land cover types: water bodies, deciduous forests, evergreen forests, croplands, bare lands, built-up areas and herbaceous. The resultant JpLC-30 map was compared to the existing 50-m resolution JAXA High Resolution Land-Use and Land-Cover (JHR LULC) map with reference to Google Earth™ images. The JpLC-30 map provides more accurate and up-to-date land cover information than the JHR LULC map. This research recommends an effective utilization of the spectral, textural and topographic information to increase the accuracy of automated land cover mapping.

Highlights

Land cover and land use change is a paramount global environmental issue
Higher resolution (~30–50 m) land cover mapping is expected to advance the understanding of the multi-dimensional interactions of the human-nature-climate system with the potentiality of representing most of the biophysical processes and characteristics of the surface of the Earth required for environmental conservation and management, hydro-climatic characterization and modeling and ensuring crop insurance and food security
Land cover conversion, cultivation of favorable species and the transfer of organisms between locations are the primary interfaces between human society and the Earth system [5]

Summary

Introduction

Land cover and land use change is a paramount global environmental issue. Achieving more timely, accurate and transparent information on the distribution and dynamics of the world’s land cover is essential to understand the fundamental characteristics, processes and threats associated with human-nature-climate interactions, including, among others, biogeochemical and hydrological cycles, biodiversity and genetic variations, land degradation and environmental pollution, climateRemote Sens. 2016, 8, 429; doi:10.3390/rs8050429 www.mdpi.com/journal/remotesensingRemote Sens. 2016, 8, 429 change and poverty, globalization and sustainability and environmental scarcity and societal conflicts.Higher resolution (~30–50 m) land cover mapping is expected to advance the understanding of the multi-dimensional interactions of the human-nature-climate system with the potentiality of representing most of the biophysical processes and characteristics of the surface of the Earth required for environmental conservation and management, hydro-climatic characterization and modeling and ensuring crop insurance and food security.Dramatic alteration of the Earth’s land surface by human activities has caused significant impact on the atmospheric carbon budget, chemical fluxes, fresh water and biodiversity; resulting in a human-dominated planet [1,2]. Local changes in land use driven by increased human requirements of food, fiber, water and shelter have accelerated energy, water and fertilizer consumption; undermining the capacity of ecosystems to sustain food production and biodiversity and to regulate climate and air quality; challenging the capacity of the biosphere to provide goods and services in the long term [3]. Land cover conversion, cultivation of favorable species and the transfer of organisms between locations are the primary interfaces between human society and the Earth system [5]. Both natural and anthropogenic land use change can substantially impact global air quality with significant radiative effects on global and local climate [6] and even pollinators necessary for maintaining plant communities [7]

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