Xuhong Yang

Spatial Pattern of Land Use Change and Its Driving Force in Jiangsu Province

Scientific interpretation of the mechanism of land use change is important for government planning and management activities. This study analyzes the land use change in Jiangsu Province using three land use maps of 2000, 2005 and 2008. The study results show that there was a significant change in land use. The change was mainly characterized by a continuous built-up land expansion primarily at the expense of cropland loss, and the trend became increasingly rapid. There was an obvious regional difference, as most of the cropland loss or built-up land expansion took place in southern Jiangsu, where the rate of built-up land expansion was faster than in central and northern Jiangsu. Meanwhile, the spatial pattern changed remarkably; in general, the number of patches (NumP) showed a declining trend, and the mean patch size (MPS) and patch size standard deviation (PSSD) displayed increase trends. Furthermore, the relative importance of selected driven factors was identified by principal component analysis (PCA) and general linear model (GLM). The results showed that not only the relative importance of a specific driving factor may vary, but the driven factors may as well. The most important driven factor changed from urban population (UP), secondary gross domestic product (SGDP) and gross domestic product (GDP) during 2000–2005 to resident population (RP), population density (POD) and UP during 2005–2008, and the deviance explained (DE) decreased from 91.60% to 81.04%. Policies also had significant impacts on land use change, which can be divided into direct and indirect impacts. Development policies usually had indirect impacts, particularly economic development policies, which promote the economic development to cause land use change, while land management policies had direct impacts. We suggest that the government should think comprehensively and cautiously when proposing a new development strategy or plan.

Spatial-temporal pattern changes of main agriculture natural disasters in China during 1990–2011

China is a disaster prone country, and a comprehensive understanding of change of disasters is very important for China’s agricultural development. In this study, statistical techniques and geographic information system tools are employed to quantify the main agriculture disasters changes and effects on grain production in China during the period of 1990–2011. The results show that China’s grain production was severely affected by disasters including drought, flood, hail, frost and typhoon. The annual area covered by these disasters reached up to 48.7×106 ha during the study period, which accounted for 44.8% of the total sown area, and about 55.1% of the per unit area grain yield change was caused by disasters. In addition, all of the disasters showed high variability, different changing trends, and spatial distribution. Drought, flood, and hail showed significantly decreasing trends, while frost and typhoon showed increasing trends. Drought and flood showed gradual changes and were distributed across the country, and disasters became more diversified from north to south. Drought was the dominated disaster type in northern China, while flood was the most important disaster type in the southern part. Hail was mainly observed in central and northern China, and frost was mainly distributed in southern China. Typhoon was greatly limited to the southeast coast. Furthermore, the resilience of grain production of each province was quite different, especially in several major grain producing areas, such as Shandong, Liaoning, Jilin and Jiangsu, where grain production was seriously affected by disasters. One reason for the difference of resilience of grain production was that grain production was marginalized in developed provinces when the economy underwent rapid development. For China’s agricultural development and grain security, we suggest that governments should place more emphasis on grain production, and invest more money in disaster prevention and mitigation, especially in the major grain producing provinces.

Farmland dataset reconstruction and farmland change analysis in China during 1661–1985

This research reconstructs China’s provincial farmland dataset in the last 300 years (1661–1985) by applying factor correction, citing replacement, linear interpolation, cohesion and contrast, man-land relationship test, farming trend test, provincial administrative area adjustment, etc. on available farmland data based on China’s current provincial administrative boundary. Based on this dataset, a quantitative analysis has been applied to study the farmland amount and its change characteristics at both national and provincial level. Three conclusions are derived: (1) Along with the rapid population growth, national farmland amount has increased by about 320% in the last 300 years from 424,480 km2 in the early Qing Dynasty to 1,368,600 km2 in 1985. Comparing with global and national farmland datasets, in terms of the overall trend of national farmland growth, very low deviation exists but significant variances do appear for some provinces. (2) At the beginning of the Qing Dynasty, Chinas farming activities mainly existed in the Yangtze River Plain, the North China Plain, the Guanzhong Basin and the Yinchuan Plain. Thereafter, reclamation activities expanded to outer agricultural areas. Regarding of the growth rate, national farmland increase can be divided into five phases. National policy, disasters, wars, and economic development, are the main factors affecting farmland changes. (3) Significant regional variances exist in farmland changes. In the space shaped by the average farmland amount and the average annual change rate of farmland, the nation can be divided into six areas.

Spatial identification and dynamic analysis of land use functions reveals distinct zones of multiple functions in eastern China

Land use function (LUF) is a valuable concept that allows for more integrated assessments of land system change. Identifying the changes and relationships of multiple LUFs is pertinent to land use planning and management. Selection and quantification of LUF indicators are critical for LUFs assessment. However, past studies have mostly assessed LUFs using socioeconomic data, which are not suitable for spatial variable quantification. In this study, we proposed a new LUFs classification system based on spatial planning goals, and we applied the system to assess 12 LUFs across 63 counties in Jiangsu Province of eastern China based on multi-source data using geospatial modeling tools combined with statistical analysis of socioeconomic data. We also analyzed the change in LUFs between 2000 and 2015, as well as the interactions among multiple functions. Finally, we identified distinct function zones based on the LUFs assessment in 2000 and 2015 using k-means clustering. The result showed that 12 LUFs displayed significant changes and interactions between 2000 and 2015, which can be explained by differing topography and social-ecological characteristics among counties. Additionally, we found four distinct LUF zones that are spatially agglomerated in similar landscapes and characterize specific LUF relationships in each cluster. In the future, local LUFs and their changes over time should be taken into consideration for land use planning and management, which provide a reference for policy-makers to make decisions that better match local development realities.

Evaluating and predicting the effectiveness of farmland consolidation on improving agricultural productivity in China

Food security has always been a focus issue in China. Farmland consolidation (FC) was regarded as a critical way to increase the quantity and improve the quality of farmland to ensure food security by Chinese government. FC projects have been nationwide launched, however few studies focused on evaluating the effectiveness of FC at a national scale. As such, an efficient way to evaluate the effectiveness of FC on improving agricultural productivity in China will be needed and it is critical for future national land consolidation planning. In this study, we selected 7505 FC projects completed between 2006 and 2013 with good quality Normalized Difference Vegetation Index (NDVI) as samples to evaluate the effectiveness of FC. We used time-series Moderate Resolution Imaging Spectroradiometer NDVI from 2001 to 2013, to extract four indicators to characterize agricultural productivity change of 4442 FC projects completed between 2006 and 2010, i.e., productivity level (PL), productivity variation (PV), productivity potential (PP), and multi-cropping index (MI). On this basis, we further predicted the same four characteristics for 3063 FC projects completed between 2011 and 2013, respectively, using Support Vector Machines (SVM). We found FC showed an overall effective status on improving agricultural productivity between 2006 and 2013 in China, especially on upgrading PL and improving PP. The positive effect was more prominent in the southeast and eastern China. It is noteworthy that 27.30% of all the 7505 projects were still ineffective on upgrading PL, the elementary improvement of agricultural productivity. Finally, we proposed that location-specific factors should be taken into consideration for launching FC projects and diverse financial sources are also needed for supporting FC. The results provide a reference for government to arrange FC projects reasonably and to formulate land consolidation planning in a proper way that better improve the effectiveness of FC.

Study Area and Data Source

This chapter details the geographical features of China such as topography, climate, soil, river, vegetation and land use/land cover. Specifically, it describes in detail the proceedings of land reclamation, the changes of administrative boundaries in China from Qing Dynasty (1644–1911) to Republic of China (1912–1949) and finally to People’s Republic of China (1949-Now), the climate changes and natural disasters. Based on these solid rich historical data, the spatial-temporal dimension of this research has been determined.

Conclusions and Research Prospects

This chapter concludes that the amount of national farmland had increased about 320% in past the 300 years in China along with rapid population growth. It also discusses the research prospects in the field of reconstructing historical land cover such as strengthening data synthesis, improving the comprehensiveness with multiple land use types, coordinating reconstruction methodologies and synthesizing multiple verification methods.

Overview of the Chinese History During the Past 300 Years

This chapter briefs the China history from Qing Dynasty (1644–1911) to Republic of China (1912–1949) to People’s Republic of China (1949–Now) after reviewing the development and relationship between China and the world. The development of economy and society during the past 300 years in China is further analyzed from the aspects of agriculture, handicraft industry and modern industry. It ends with summaries over the evolution of historical land, population and economic policies.

Farmland Dataset Reconstruction in the Past 300 Years in China

Since the quantity forms the backbone of farmland reconstruction, this chapter focuses on China’s historical records from 1661 to 1985 and related archives to facilitate reconstructing China’s provincial farmland data with the modern provincial administrative settings. China’s farmland growth process and regional changes are also analyzed. The research shows that ever since the population boom in the Qing Dynasty, China’s farmland expanded more than three times i.e. from 42.4 × 106 ha in the early Qing Dynasty to 136.9 × 106 ha in 1985. In terms of the growth rate, the process of China’s farmland expansion can be identified into five phrases. Significant differences in farmland change existed across provinces.

The Spatial-Temporal Pattern of Population Changes in China in the Past 300 Years

Setting 300 years as the time scale and the province as the spatial unit, respectively, using adjusted population data of 286 time phases, this chapter establishes the national population distribution for eight years, i.e., 1724, 1767, 1812, 1855, 1898, 1936 and 1982 as time sections. Generally, population of China in the past 300 years presented an uprising tendency and can be classified into five stages according to the feature of its growth. The distribution of population gradually tended toward equilibrium: the population gravity center changed within a narrow range and generally presented a moving tendency toward south-west, south-east, north-east and north-west.