Mapping essential urban land use categories(EULUC)using geospatial big data:Progress,challenges,and opportunities

Urban land use information that reflects socio-economic functions and human activities is critically essential for urban planning,land-scape design,environmental management,health promotion,and biodiversity conservation.Land-use maps outlining the distribution,pattern,and composition of essential urban land use categories(EULUC)have facilitated a wide spectrum of applications and further triggered new opportunities in urban studies.New and improved Earth observations,algorithms,and advanced products for extracting thematic urban information,in association with emer-ging social sensing big data and auxiliary crowdsourcing datasets,all together offer great potentials to mapping fine-resolution EULUC from regional to global scales.Here we review the advances of EULUC mapping research and practices in terms of their data,methods,and applications.Based on the historical retrospect,we summarize the challenges and limitations of current EULUC studies regarding sample collection,mixed land use problem,data and model generalization,and large-scale mapping efforts.Finally,we propose and discuss future opportunities,including cross-scale mapping,optimal integration of multi-source features,global sam-ple libraries from crowdsourcing approaches,advanced machine learning and ensembled classification strategy,open portals for data visualization and sharing,multi-temporal mapping of EULUC change,and implications in urban environmental studies,to facil-itate multi-scale fine-resolution EULUC mapping research.

Atmospheric and ecosystem big data providing key contributions in reaching United Nations’Sustainable Development Goals

Big open data comprising comprehensive,long-term atmospheric and ecosystem in-situ observations will give us tools to meet global grand challenges and to contribute towards sustainable develop-ment.United Nations’Sustainable Development Goals(UN SDGs)provide framework for the process.We present synthesis on how Station for Measuring Earth Surface-Atmosphere Relations(SMEAR)observation network can contribute to UN SDGs.We describe SMEAR II flagship station in Hyytiälä,Finland.With more than 1200 variables measured in an integrated manner,we can under-stand interactions and feedbacks between biosphere and atmo-sphere.This contributes towards understanding impacts of climate change to natural ecosystems and feedbacks from ecosys-tems to climate.The benefits of SMEAR concept are highlighted through outreach project in Eastern Lapland utilizing SMEAR I observations from Värriöresearch station.In contrast to boreal environment,SMEAR concept was also deployed in Beijing.We underline the benefits of comprehensive observations to gain novel insights into complex interactions between densely popu-lated urban environment and atmosphere.Such observations enable work towards solving air quality problems and improve the quality of life inside megacities.The network of comprehensive stations with various measurements will enable science-based deci-sion making and support sustainable development by providing long-term view on spatio-temporal trends on atmospheric compo-sition and ecosystem parameters.