Incorporating ecological constraints into urban growth boundaries: A case study of ecologically fragile areas in the Upper Yellow River

Abstract

Urban growth boundaries (UGBs) are seen as an effective tool to control urban sprawl and promote sustainable urban development. Existing methodologies related to urban boundary delineation focus mainly on increasing land intensification and compact urban development. However, it is not sufficient to focus on optimal urban development, especially in China. The delineation of UGBs should not only take into account the heterogeneity of regional natural resources but also further reconcile urban–ecological conflict. Therefore, this paper proposes a new framework for delineating UGBs in an ecologically sustainable manner. This study first uses the remote sensing ecological index (RSEI) and ecological sensitivity as a basis for ecological constraints (EC). Both the background state of the regional ecology and ecological stress from human activities are considered to be constraints on urban sprawl. These ecological constraints are then combined with a CA-Markov model to simulate future urban development. The framework is applied to the Linxia Hui Autonomous Prefecture, an ecologically fragile region in China, where UGB delineation can be used not only to reconcile ecological and land-use planning conflict but also to ensure sustainable resource development in individual zoning districts. The results suggest that a plan that only considers urban development may have a negative impact on the conservation of natural resources and ecological sustainability. The delineation of UGBs based on the proposed EC-CA-Markov model will thus help guide sustainable urban development. The conceptual and methodological advances in this study are applicable to other ecologically fragile cities and can help in the delineation of UGBs.

Keywords

• Ecologically fragile area
• EC-CA-Markov model
• Urban growth boundary
• Upper Yellow River
• Linxia Hui Autonomous Prefecture