This article contributes to research on how climate change will impact crops in China by moving from ex-post empirical analysis to forecasting. We construct a multiple regression model, using agricultural observations and meteorological simulations by GCMs, to simulate the possible planting boundaries and suitable planting regions of spring wheat under RCP4.5 scenario for the base period 2040s and 2070s. We find that the south boundary of possible planting region for spring wheat spreads along the belt: south Shandong—north Jiangsu—north Anhui—central Henan—north Hubei—southeast Sichuan—north Yunnan provinces, and will likely move northward under RCP4.5 scenario in 2040s and 2070s, resulting in the decrease of possible planting area in China. Moreover, the sowing and harvest date of spring wheat in the base period shows a gradually delayed phenomenon from the belt: south Xinjiang — Gansu, to the Tibet Plateau. As a result, the growth period of spring wheat in China will shorten because of the impacts of climate change. These results imply that a variety of adaptations measures should be set up in response to changing climatic conditions, including developing the planting base for spring wheat, restricting the planting area of spring wheat in sub-suitable areas at risk while expanding the planting area of optimal crops.

This paper analyzed the development of different types of natural gas flow zones in China, and then divided all provinces into four flow types: non-flow zones, output centers, input centers and exchanging centers. Next, we analyzed the concentration and diffusion characteristics, current spatial pattern and evolution of source and terminal regions of natural gas resource flows. The numbers of non-flow zones, output centers, input centers and exchanging centers all stabilized during the Eleventh Five-Year Plan period. The number of output centers is small but the quantity of flow is large. The number of input centers is large and they are widely distributed. Generally speaking, it presents a significant characteristic of centralized output and dispersed input in geographic space. The current situation for China's natural gas output source has random distribution characteristics, but the terminal regions of natural gas flow have strong positive spatial correlation, presenting a significant spatial agglomeration pattern. Shandong, Jiangsu, Zhejiang and Shanghai have a high-high agglomeration mode, but Yunnan, Sichuan, Tibet, Qinghai and Gansu have a low-low agglomeration mode. Spatial pattern changes in China's natural gas output zones had three different stages: relatively stable from 2001–2003; moved northwestward, expanded in space, and widely dispersed during 2004–2006; and transferred to the east, spatially contracted and significantly concentrated during 2007–2011. Spatial pattern changes in China's natural gas input zones have two stages: expanded in east-west direction while contracted in north-south direction during 2001–2005; and relatively stable in spatial structure with intensification from 2006–2011.

The study of waters ecosystem and their population carrying capacity demonstrates the role of these ecosystems in economic and social development and provides a theoretical basis for the management and allocation of aquatic ecosystems. In this study, the concept of waters ecosystem population carrying capacity was defined and developmental trends in the population carrying capacity of waters ecosystem in China were evaluated. Results show that waters ecosystem population carrying capacity in China increased from 0.176×10⁹ person year^-1 in 2000 to 0.255 ×10⁹ person year^-1 in 2010; the population carrying capacity of the standard sea remained at 0.2–0.3 person ha^-1; and the standard inland waters population carrying capacity increased from 1.8 to 3.2 person ha^-1. This analysis indicates notable regional difference in waters population carrying capacity. In southeastern coastal China and Yangtze River drainage areas where inland waters are widely distributed and aquaculture is developed, the population carrying capacity is higher; however, in northwest China where water resource are deficient and the distribution is relatively small, the waters population carrying capacity is low. The waters ecosystem population carrying capacity of China in 2030 was predicted and results indicate strong potential for increasing waters population carrying capacity.

Changes in grain production are decomposed and compared among nine major Chinese river basins for the sake of optimal water allocation. The results show that water-deficient northern China, especially the Songliao River Basin and Huai River Basin, contributed the greatest share of the total grain increment from 1995 to 2010. The Songliao River Basin achieved increased grain output largely by expanding multiple cropping, while the Huai River Basin achieved it mainly by improving the yield per unit area. With increased reliance on expanding irrigation and multi-cropping, most northern basins have high levels of agricultural water consumption, despite the rising share of corn, a lower water intensive crop. In contrast, over the same period the warm and humid south, traditionally a major rice-growing area, mostly experienced a sharp decline in rice cropping area and the Southeast Rivers Basin even reduced multiple cropping indexes, contributing to decreased agricultural water consumption. Implications of our findings and the need for tackling the imbalance of agricultural water use in grain production are discussed.

Northeast Asia is an area with relative concentrations of resources, a complex ecological environment pattern, and a marked human—land contrast relationship. This area has significance for analyzing land cover patterns and variations for regional sustainable development among the trans-boundary areas of China, Russia, and Mongolia. In this paper, the transect analysis research tool and transfer matrix method are used to capture the regional land cover change characteristics by using Moderate Resolution Imaging Spectroradiometer(MODIS) datasets recorded from 2001 to 2012. The spatial distribution results show that forests have increased dramatically, cropland increased marginally, and grassland and shrubs decreased totally. The inter-annual variation, results show a steady and slowly increasing trend for grassland and shrubs, dramatic fluctuation features with an increasing trend for forest land, and zigzag wave changing characteristic for cropland. The total land use dynamic degree (TLUDD)was steady, with an overall slightly increasing trend.

Habitat management is essential for the conservation of wildlife, especially cranes. Here, we collected occurrence data at wintering grounds for four cranes (Leucogeranus leucogeranus, Grus monacha, Antigone vipio and G. grus) and analyzed associated environmental variables to model and project overall potential wintering habitat using Maxent. ENMTools was used to calculate the degree of niche overlap among cranes. Results showed that lakes in the middle and lower reaches of the Yangtze River are main habitats for the four focal species. Inland water and coastal wetlands in Jiangsu are also potential wintering areas. G. grus spreads over central and eastern China. The four cranes show tight niche overlap in the middle and lower reaches of the Yangtze River. Poyang Lake is one of the most important habitat sites for all four cranes, according to modeling and niche overlap results. Poyang Lake is cut into a dozen nature reserves, but a bigger nature reserve or system would be more effective for cranes. The conservation of these four crane species will be improved on the basis of this study.

As a prerequisite for groundwater protection and contamination control, evaluation of groundwater contamination risk was the extension of groundwater vulnerability assessment. Based on disaster theory and using shallow groundwater of the lower reaches of Liaohe River Plain as the study area, we built an evaluation index system and a contamination index model for groundwater contamination risks from the perspectives of intrinsic vulnerability, external stresses, and functional value. We used data acquisition technology (remote sensing) and spatial analysis technology (GIS) to calculate the value of groundwater contamination risks. The spatial distribution of hotspots was obtained by calculating G index. Results show that groundwater contamination is above a mid-level risk in most of the study area. Areas with extreme high risk account for 37.86%, areas with high risk 32.47%, areas with moderate risk 12.07%, areas with light risk 3.17%, and areas with slight risk 14.43%. Hotspots areas are mainly located in central Shenyang City, northwest of Xinmin City, Beizhen City and Liaozhong County. Coldspots are mainly in Panjin City, Yingkou City, Dashiqiao City, Dawa County and Panshan County. The results reflect the spatial distribution and mechanism of groundwater contamination risk in the study area and provide relative references for land use planning and groundwater resource protection in the lower reaches of the Liaohe River Plain.

Farmland resources in mountainous areas are important for regional food security and ecological security. Studies concerning changes in farmland use in mountainous areas are of considerable significance in China. Here, we analyzed marginalization characteristics of farmland in Renhuai city from 2005 to 2011 and driving factors using land information systems, surveys of farmer households and statistical data. Our results indicate that from 2005 to 2011, 3095.76 hm² of farmland was converted to forest land and natural reserve, accounting for 5.45% of the total farmland area. This suggests significant marginalization of farmland. Marginalization of farmland in mountainous areas was affected by topography, labor forces and effectiveness of land management. Farmland with a greater slope gradient was more likely to be abandoned; among marginalized land in Renhuai, a slope greater than 15° accounted for 62.26%. A high non-agricultural employment rate of rural labor force and annual income per capita of farmer households in mountainous areas were consistent with high speed farmland marginalization. Low land management benefits were the key reason for farmland marginalization. Although farmland marginalization was advantageous for eco-environment protection and sustainable development in mountainous areas, it resulted in inefficient land resource utilization. A win-win model for the exploitation and utilization of sloping farmland should be explored for production development and environmental protection.

Land use changes in mountainous regions were greatly enhanced as the rapid development of economy due to the expanded population in developing countries. Acting geographically as the basic unit of mountainous regions, valleys are the primary sites of economic activities. Therefore optimization of land use policy in valleys is of critical important to the sustainable development in mountainous regions. On the basis of land use data in 1995 and 2012, this study explored the changes of land use according to the assessment of varied topographic factors (i.e., altitude and slope) in typical valleys of the Beijing mountainous regions, China. Our results showed that the valley is an efficiently geographical unit to evaluate land use changes in mountainous regions. We also found that major land use changes in mountainous regions of Beijing from 1995 to 2012 were the dramatic losses of grassland to the cultivated and construction lands, while most of these changes took place at the altitude of 0–400m and the slope of 6–15°. Considering the ever increasing economic development in Beijing mountainous regions, the increases of the construction and cultivated lands are inevitable, however, the great changes at a steeper slope imply the need to tailor land use structure coming into line with topographic factors, and suggesting ecological barriers and water conservation must be exercised in the developments of these areas.