Monitoring and Modeling Urbanization in China: A Mixed Methods and Multi-Scale Approach

This project aims to improve our understanding of China’s extraordinary social, economic and environmental transformation and its impact on urbanization across the country. Given the size and scale of China’s urban development - urban populations have more than doubled during the last 30 years, and more than 70% of economic activity in now located in cities - urban environments are playing an increasingly important role in daily quality-of-life issues, ecological processes, climate, flows of materials, and land transformations. In order to confront the environmental consequences of urbanization at local to global scales, we need to monitor urban expansion and provide projections of its influence into the future. Our multidisciplinary research program has three main components: Objective #1: Characterizing the rates and patterns of urban expansion. We are utilizing Landsat data as input to data mining algorithms to derive spatially explicit datasets of the rates and amounts of land cover change in 15 cities located across China. We focus on five critical periods spanning 1980 to 2009 to monitor urban growth both before and after economic reforms took effect. We will combine these estimates with spatial metrics to quantify the form of urban growth, so that we might understand the forces leading to landscape fragmentation and suggest better policies for managing the resulting patterns. Objective #2: Documenting the driving forces of urban expansion. Using two econometric modeling techniques, one spatial and one aspatial, we will integrate our satellite-based measures of urban expansion with detailed socioeconomic data and policy variables to quantify the factors responsible for variations in the rates, amounts and patterns of urban expansion across China. Determining the relative impact of drivers such as rural-urban migration, rising incomes, infrastructure investment, and local land management and policy on urbanization is a critical first step to developing accurate simulations of future land conversion and urban sprawl. Objective #3: Building scenarios of future urbanization. By exploiting the results of the aspatial and spatial econometric models, we will develop simulations that explore how urban areas will respond to scenarios such as business-as-usual, increased economic growth and policy-based stimulus. We will project levels of urbanization at the county level for each of our 15 sample cities from 2010 to 2040 (five-year intervals). The primary outcome of this project is a series of reconstructions of past land cover change and projections of future urban expansion in China under different political and economic scenarios. These forecasts can help improve our understanding of the dynamics of land use transformations, the relative importance of the drivers that foster/impede land conversion, and the complex interactions between urban change and sustainable systems. In addition, this project includes a substantial methodological component that advances multi-scale predictive modeling and change detection techniques for remotely sensed data. This research represents the first comprehensive study of Chinese metropolitan development based on empirical results from satellite imagery, socioeconomic data and field surveys. By combining urban simulations with NASA’s unique remote sensing capabilities, our research falls under the Projections component NASA’s Land Cover-Land Use Change Program (LCLUC). This study is uniquely suited to answer key LCLUC questions, including What are the causes and consequences of LCLUC? and What are the projected changes of land use and their potential impacts? This research also contributes significantly to three international projects whose goals are closely aligned with the NASA LCLUC program: the IGBP/IHDP Global Land Project, the IHDP Urbanization and Global Environmental Change Project, and the Monsoon Asia Integrated Regional Study (MAIRS).