Computer-based estimation system for land productivity

International Science and Education Researcher Association (ISER); Gireida Education Co. Ltd; Wuhan University of Science and Technology; VIP Information Conference Center<span class="MedBlackText">Land productivity generally refers to the overall productivity related to various combinations of the natural characteristics of the land and socioeconomic factors. Structural change and pattern succession in land systems undoubtedly leads to changes in the suitability and quality of different kinds of land types and directly influences agricultural productivity. In this paper we describe the processes, parameters needed and methods of data preparation, which will improve the ability of readers to use this model and provide a foundation for its wide application.</span

Estimation of land production and its response to cultivated land conversion in North China Plain

Major State Basic Research Development Program of China 2010CB950904;National Natural Science Foundation of China 70503025 40801231;Chinese Academy of Sciences KZCX2-YW-305-2Food safety and its related influencing factors in China are the hot research topics currently, and cultivated land conversion is one of the significant factors influencing food safety in China. Taking the North China Plain as the study area, this paper examines the changes of cultivated land area using satellite images, estimates land productivity from 1985 to 2005 using the model of Estimation System for Land Productivity (ESLP), and analyzes the impact of cultivated land conversion on the land production. Compared with the grain yield data from statistical yearbooks, the results indicate that ESLP model is an effective tool for estimating land productivity. Land productivity in the North China Plain showed a slight decreasing trend from 1985 to 2005, spatially, increased from the north to the south gradually, and the net changes varied in different areas. Cultivated land area recorded a marginal decrease of 8.0 x 10(5) ha, mainly converted to other land uses. Cultivated land conversion had more significant negative impacts on land production than land productivity did. Land production decreased by about 6.48 x 10(6) t caused by cultivated land conversion between 1985 and 2005, accounting for 91.9% of the total land production reduction. Although the land productivity increased in Anhui and Jiangsu provinces, it can not offset the overall adverse effects caused by cultivated land conversion. Therefore, there are significant meanings to control the cultivated land conversion and improve the land productivity for ensuring the land production in the North China Plain

Unintended effects of urbanization in China: Land use spillovers and soil carbon loss

This paper uses a national-level geographic information system database on land use, weather conditions, land quality, soil organic carbon (SOC), topographic features, and economic variables to analyze the major drivers of land use change and the resulting impact on soil carbon storage in China. The framework developed in this study includes two main components. One is a spatial panel multinomial logit land use model that takes into account the spatial and temporal dependence of land use choices explicitly. The other is a statistical causal evaluation model that estimates the effect of land use change on SOC density. Results indicate that local economic growth, as measured by county-level gross domestic product, was a major cause of urban development and grassland conversions. Rapid expansion of road networks, promoted by massive public investment, increased the conversion of forests, grassland, and unused land to crop production and urban development. Urbanization had significant secondary ripple effects in terms of both indirect land use change and soil carbon loss. Some of the soil carbon loss may be irreversible, at least in the short run.Land use, propensity score-matching, road density, soil organic carbon, spatial panel,

Dynamics of land use and land cover changes in China

A key contribution of environmental economics to policy making has been to provide empirical indicators of sustainable economic development. An economy is (weakly) sustainable if it saves more than the combined depreciation of its stocks of natural capital and produced capital. Thus, these indicators allow trade-offs where, for example, natural capital might be depreciated in order to build up other forms of capital, such as in the built environment or in the form of human capital. As an application of this general idea, this thesis focuses on the trade-offs between ecosystem services, provided by natural capital, and certain land use and land cover changes (LUCC) in China. With better understanding of these trade-offs, this thesis contributes to optimum management for sustaining ecosystem services and supporting socio-economic development. The three case study areas are Hebei, Qinghai and Shandong provinces. I study trade-offs between landscape diversity and crop production, between grassland quality and livestock production, and between net primary productivity (NPP, a measure of the energy that enters ecosystems) and urbanization. After reviewing trade-off analyses of ecosystem services for sustainable land-use management (Chapter 2), the case studies are presented, with two chapters on Hebei, one on Qinghai, and three on Shandong. These chapters have econometric models for monitoring and assessing LUCC-induced ecosystem service changes, to enable quantitative analysis of the mechanisms available for policy-oriented optimum land-use management. The case study areas each have different policy interventions that are designed to preserve or restore natural capital. For example, Hebei has ecological restoration programs, such as the Green for Grain program, that are implemented in an attempt to conserve landscape diversity. Qinghai province has policies of enhancing ecological restoration for grassland conservation, in order to improve livestock production. Shandong province has enforced a prime cropland preservation policy in order to ensure high cropland productivity. Collectively, the case studies add to the literature on the use of sustainable land-use management strategies, while helping to illustrate some of the trade-offs that are central to environmental economics. The results highlight issues created by conversion of cultivated land to urban use, in both Hebei and Shandong. In Qinghai province, grassland degradation, livestock production and farmers’ income interact and affect LUCC and changes in ecosystem services. Restorative interventions, such as nature reserves, seem to have a positive effect on NPP, as a measure of ecosystem productivity. On the other hand, in Shandong province there is relatively low land productivity, as measured by the NPP, in regions covered by built-up area. While this thesis does not calculate a value for the produced capital and human capital in built-up areas, the reduction in the value of natural capital as a result of urbanization highlights the potential trade-offs and the need for careful measurement to help whether China is on a sustainable development path. In summary, the research in this thesis examines various land-use practices and management regimes for conserving ecosystem services, and contributes to the literature on how management of land use change and land cover change can influence ecosystem services in rapidly urbanizing China