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She J.,Nanjing University | Guan Z.,Nanjing University | Cai F.,Nanjing University | Pu L.,Nanjing University | And 3 more authors.
Sustainability (Switzerland) | Year: 2017

Reclamation is capable of creating abundant land to alleviate the pressure from land shortages in China. Nevertheless, coastal reclamation can lead to severe environmental degradation and landscape fragmentation. It is quite important to monitor land use and cover change (LUCC) in coastal areas, assess coastal wetland change, and predict land use requirements. The siltation of tidal flats will result in the dynamic growth and continuous expansion of coastal areas. Therefore, the process of land change in coastal areas is different from that under the fixed terrestrial boundary condition. Cellular Automata and Multi-Agent System (CA-MAS) models are commonly used to simulate LUCC, and their advantages have been well proven under the fixed boundary condition. In this paper, we propose CA-MAS combined with a shoreline evolution forecast (CA-MAS-SEF) model to simulate the land change in coastal areas. Meanwhile, the newly increased area, because of the dynamic growth of tidal flats, is considered in the simulation process. The simulation results using the improved method are verified, and compared with observed patterns using spatial overlay. In comparison with simulation results that do not consider the expansion of tidal flats, the Kappa coefficient estimated while considering the dynamic growth of tidal flats is improved from 65.9% to 70.5%, which shows that the method presented here can be applied to simulate the LUCC in growing coastal areas. © 2017 by the authors.

Li J.,Nanjing University | Huang X.,Nanjing University | Huang X.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Yang H.,University of Oslo | And 4 more authors.
Habitat International | Year: 2016

Household CO2 emission is one of the main sources of carbon emissions. Reducing this type of CO2 emissions plays an important role in decreasing global carbon emissions. Based on household CO2 emission survey data in Northwest China, we analysed the current situation of household CO2 emissions and produced a map of per capita household CO2 emissions for each survey location. We also analysed the relationship between per capita household CO2 emissions and explanatory factors using spatial econometric models. The results showed that 87.56% of the per capita household CO2 emissions range from 0.3912 t to 2.5895 t. Carbon intensity and per capita income are the main explanatory factors of household CO2 emission. High per capita CO2 emissions are mainly related to carbon intensity, per capita income, January average temperature and urbanization level. The results also revealed the importance of other variables, such as total household population, age structure and July average temperature. This study contributes to the understanding of the main explanatory factors of household CO2 emission in Northwest China and proposes some emission reduction measures. © 2015 Elsevier Ltd.

Sun X.,Guangxi University | Sun X.,Nanjing University | Li Y.,Xiamen University | Li Y.,The Key Laboratory of the Coastal Zone Exploitation and Protection | And 3 more authors.
Journal of Cleaner Production | Year: 2015

The coastal wetland ecosystems are the critical ecological infrastructure and have a close relation to coastal sustainability. Rapid urbanization lead to a big demand of coastal reclamation in China thereafter caused the loss and degradation of coastal wetlands. In this study, we presented modified model suitable for quantifying ecosystem service values of different coastal system subtypes and assessing their loss due to coastal reclamations with a case of coastal agriculture-dominated city of Eastern China (Lianyungang). We focused on four major agriculture-related ecosystem services as follows: food production, raw material supply, disturbance regulation, and water purification. The results showed that: 32,346 ha of loss in coastal wetlands resulted in US$ 806 million year-1 loss in ecosystem service. The modified ecosystem service valuing models enable achieving categorized management of coastal ecological infrastructures. Furthermore, this study showed how to integrate the ecosystem service estimate into assessment, management, planning, restoration, and compensations of coastal ecological infrastructures. © 2015 Elsevier Ltd.

Li H.,Nanjing University | Li H.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Li H.,University of Illinois at Urbana - Champaign | Hung X.,Nanjing University | And 4 more authors.
Land Use Policy | Year: 2015

The marked impact of the welfare gap on total welfare within collectives has rarely, if at all, been addressed in traditional welfare theories and in Amartya Sen's theory of welfare functioning and capabilities. With this observation as our starting point, we constructed a research framework that combined welfare functioning, the welfare gap, and welfare capability to assess and analyze changes in the welfare of farmers whose land was requisitioned in Zhejiang province. The findings of our study were as follows. (1) The total welfare functioning of farmers whose land was requisitioned increased by 11.8% as a result of improvements in economic and dwelling conditions and community surroundings. However, social security and psychological conditions deteriorated. (2) Although total welfare functioning has improved, gaps are widening in the distribution of welfare functioning among farmers who underwent land requisition. This was evidenced by the increase of the weighted Gini coefficient, which rose from 0.26 to 0.32 after land requisition. (3) As a result of the improvement in welfare capability, a judgmental bias is evident when farmers assess whether they have gained or lost welfare after land requisition. We conclude that welfare studies should focus not only on the quantitative aspects of welfare distribution, but should also pay more attention to its fairness and impartiality. This can prevent social problems posed by an oversized welfare gap. Moreover, after land requisition, the government and community should provide education and training services, and the current one-time compensation model should be replaced by a lifelong compensation model. At the same time, endowment insurance should be extended in rural areas and urban medical insurance should be progressively incorporated into the social security benefits of farmers who have undergone land requisition. © 2014 Elsevier Ltd.

Yu R.,Nanjing University | Yu R.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Wang J.,Anhui Agricultural University
Environmental Monitoring and Assessment | Year: 2015

Environmental sustainability has become the focus of agricultural sustainability. This study is aimed at evaluating the environmental sustainability of farmers’ land use decisions on saline-alkaline soil in China. Based on empirical and theoretical approaches, the decisions mainly include planting, crop distribution, irrigation, drainage, and fertilization. By surveying 22 administrative villages in typical ecologically fragile saline-alkaline areas of five regions (Shandong, Jiangsu, Jilin, Ningxia, and Xinjiang), the paper builds the evaluation criteria at village level, and obtains a comprehensive index. From the results, irrigation concerns are absent from decision-making. For other decisions, farmers in most villages can appropriately deal with planting, drainage, and fertilization according to the regional natural and social geography conditions. But the comprehensive index of crop distribution in the coastal areas is much stronger than in the northeast and northwest. It is found that the similarities of unsustainability lie in the planting of water-consuming crops, the arbitrary distribution of crops, lack of drainage planning, obsolete water conservancy facilities, excessive use of chemical fertilizers, etc. According to the research, on the one hand, it can guide farmers to rationally make use of saline-alkaline land; on the other hand, it can also provide the basis for government to make differentiated policies in different areas and enhance pertinence in the course of technological extension and application. © 2015, Springer International Publishing Switzerland.

Li J.,Nanjing University | Pu L.,Nanjing University | Pu L.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Zhu M.,Nanjing University | And 5 more authors.
Geoderma | Year: 2014

Reclamation in coastal zones is effective for relieving population pressure and ensuring food safety. Since the 1950s, the development of coastal zones has entered a peak period. At present, the reclamation of coastal zones mainly occurs in developing countries. The coastal reclaimed lands are mainly used for agricultural production, urban and industrial development, and port construction. The scale and scope of reclamation in coastal lands are larger than in interior lands, and pose substantial environmental risks. This review summarizes the trends in soil physicochemical property evolution following reclamation in salt marshes from around the world. The following important conclusions were obtained: physicochemical properties of coastal saline soils (CSSs) significantly improved over the long term following reclamation in Eastern Asia. Long term fertilization and cultivation resulted in modified soil structure [an increase in the proportion of macroaggregates (>250μm) and silt (0.002-0.05mm)], enhancing the capacity for preserving fertility and C sequestration. Reclamation significantly increased soil organic matter (SOM), phosphorus (P), and nitrogen (N) concentrations, and soil properties approached a relatively stable level nearly 30years after reclamation, especially in Eastern Asia. However, in Europe and North America, SOM in coastal reclaimed soils (CRSs) decreased rapidly after reclamation, and soil acidification was also a severe problem during reclamation. Coastal reclamation could significantly increase soil GHG (CO2, CH4, and N2O) emissions, further affecting global C cycle. Microbial biomass and activity as well as activities of related enzymes increased gradually in CRS in Eastern Asia, in particular the activities of urease and phosphatase involved in nutrient cycling. In general, physicochemical properties of CRS in Eastern Asia tend to modify, but deteriorate in Europe and North America. Nevertheless, offshore eutrophication, soil heavy metal and organic pollutant concentrations, and salt marsh ecosystem degradation were the most serious environmental risks posed by coastal reclamation. Some strategies to alleviate these risks are put forward. In this review, we also identified priority areas of future research on CRS. © 2014 Elsevier B.V.

Li M.,Huaihai Institute of Technology | Li M.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Lin L.,Jackson State University | Zhang Z.,Huaihai Institute of Technology | Li C.,Inner Mongolia University of Technology
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2016

Microbial induced calcium carbonate precipitation (MICP) can produce CaCO3 cementation, which may result in the improvement of strength and the reduction of permeability by filling soil pores and bonding soil particles. The improved performance of MICP implies its broad applications including microbial grouting, earth dam reinforcement, wind protection and sand fixation, seepage protection for dam and dam bottom, remediation for contaminated soil or groundwater. The studies on soil improvement by MICP were summarized, analyzed and outlooked. It is seen that with MICP, the unconfined compressive strength of sand can be improved to 20 MPa, its permeability may be reduced to 1% of that of untreated sand, and its shear wave velocity may be increased to 4 times of that of untreated sand, which makes it applicable to geotechnical engineering. It is also believed that in the next research stage, emphasis shall be put on the systematic studies on the uniformity of treatment effect, the applicable scope of ground soil, and the comprehensive performance (such as durability, dynamic performance, corrosion resistance, etc.) of treated soil. To a small extent, MICP has been applied to the stabilization of gravel soil and leakage prevention of basement. It is found that construction technologies are the bottleneck of MICP in practical egnineering application. Construction technologies of MICP in geotechnical engineering are designed, including ground reinforcement, improvement of liquefied ground, remediation of contaminated soil (or groundwater), leakage prevention of dam and sand pile reinforcement, so that MICP technologies an be broadly applied to engineering practice. © 2016, Editorial Office of China Civil Engineering Journal. All right reserved.

Zhang R.,Kyoto University | Zhang R.,Nanjing University | Pu L.,Nanjing University | Pu L.,The Key Laboratory of the Coastal Zone Exploitation and Protection | And 3 more authors.
Environmental Monitoring and Assessment | Year: 2016

As coastal development becomes a national strategy in Eastern China, land use and landscape patterns have been affected by reclamation projects. In this study, taking Rudong County, China as a typical area, we analyzed land use change and its landscape ecological security responses in the tidal flat reclamation zone. The results show that land use change in the tidal flat reclamation zone is characterized by the replacement of natural tidal flat with agricultural and construction land, which has also led to a big change in landscape patterns. We built a landscape ecological security evaluation system, which consists of landscape interference degree and landscape fragile degree, and then calculated the landscape ecological security change in the tidal flat reclamation zone from 1990 to 2008 to depict the life cycle in tidal flat reclamation. Landscape ecological security exhibited a W-shaped periodicity, including the juvenile stage, growth stage, and maturation stage. Life-cycle analysis demonstrates that 37 years is required for the land use system to transform from a natural ecosystem to an artificial ecosystem in the tidal flat reclamation zone. © 2015, Springer International Publishing Switzerland.

Zhang M.,Nanjing University | Pu L.J.,Nanjing University | Pu L.J.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Wang X.H.,Nanjing University | And 2 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2016

The coastal regions of the Jiangsu Province have abundant tidal flat resources. Tidal flat reclamation has supported vast land backup resources and provided land primarily for farming. Soil analyses were carried out to investigate physicochemical properties of the farmland soil and changes in wheat productions at reclaimed areas in Dongtai County over the 60-year period. The results demonstrated the following: (1) In general, during 58 years of cultivation, soil underwent desalination, dealkalization, and nutrients accumulation, soil electronic conductivity (EC1:5) and pH1:2.5 decreased from 5.29 dS/m and 8.76 before cultivation to 0.11 dS/m and 7.93 after that, respectively, and soil organic matter and total nitrogen increased from 2.64 g/ kg and 0.15 g/ kg to 13.72 g/ kg and 1.12 g/ kg, respectively; (2) Alkali-hydrolysable nitrogen (AH-N), available phosphorus (AP), and available potassium (AK) were strongly affected by fertilization and crop growth; AH-N and AP dropped after initial increase, whereas AK levels continuously decreased; (3) Soil carbon/nitrogen ratio and cation exchange capacity fluctuated sharply between 15 and 53 years of cultivation, reflecting the vulnerability of soil at this region. Studied physicochemical properties revealed that the soil at a depth of more than 20 cm was affected after 53 years of cultivation with the exception of AK; (4) With the improvement of soil environment, there were three stages in wheat production increase: high-speed increase (0-15 years), fluctuation in the production (15-53 years), and stable high production (over 53 years); wheat can reach stable production of this cultivar (Yangmai-16) after 53 years. Although heightened agricultural development greatly enhanced soil quality and wheat production, it also caused dramatic changes and fluctuations in soil environment triggering ecosystem problems; hence, the correlation between chemical fertilization and wheat production should be carefully assessed. © 2016, Ecological Society of China. All rights reserved.

Wang X.,Nanjing University | Pu L.,Nanjing University | Pu L.,The Key Laboratory of the Coastal Zone Exploitation and Protection | Zhang M.,Nanjing University | And 2 more authors.
Environmental Earth Sciences | Year: 2015

The spatial and temporal variation of soil organic carbon (SOC) and soil total nitrogen (STN) in a coastal reclamation area in eastern China were studied based on the ordinary kriging method. The 0–20 cm soil organic carbon pool (SOCP) and soil total nitrogen pool (STNP) ranged from 4.38 to 15.92 Mg/ha and from 0.24 to 2.37 Mg/ha, respectively, during the observed period. The results show there was a low level of spatial variation in both SOC and STN, which is to some extent the result of the same farmland management practiced in this region. The seasonal variation of SOC was attributed to plant growth and crop residue returning back to soil, while the spatial variation was mainly resulted from the fertilization practice. The average 0–20 cm SOCP and STNP were 10.38 ± 2.50 and 1.27 ± 0.38 Mg/ha, respectively, in the study region, both of which were much lower than in other ecosystems. Further analysis indicated that SOC was positively correlated with STN. This work revealed that the reclamation area from the tidal flat should be a potential sink for SOC and STN. © 2015, Springer-Verlag Berlin Heidelberg.

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