Sustainable development Environmental aspects 10 Economic conditions 9 City planning 7 Economic development 7 Environmental protection 6 Rural development 6 更多 ... Urban ecology (Sociology) 6 Law and legislation 5 Economic aspects 4 Environmental law 3 Environmental policy 3 International cooperation 3 Regional planning 3 Technological innovations 3 Agricultural ecology 2 Climatic changes 2 Conservation of natural resources 2 Economic policy 2 Energy policy 2 Environmental education 2 Environmental management 2 Environmentalism 2 Government policy 2 Human rights 2 International economic relations 2 Rural conditions 2 Social aspects 2 Social conditions 2 Urbanization 2 少 ...