Industrial development and land use/cover change and their effects on local environment: a case study of Changshu in eastern coastal China

Estimating the pollutant loss rate based on the concentration process and landscape unit interactions: a case study of the Dianchi Lake Basin, Yunnan Province, China

The landscape analysis model establishes a quantitative relationship between landscape patterns and pollution processes. The spatial heterogeneity within and between landscapes affects the pollutant transmission process and originates from the superposition effect of terrestrial geographical and morphological characteristics. This study aimed to develop a new method to estimate the pollutant loss rate. From the perspective of the flow process of pollutants entering a water body, the interaction between each landscape unit and adjacent unit during pollutant migration was simulated along the pollutant migration flow path. The role of pollutants affected by external forces in the process of migration could be divided into "promoting" and "hindering." Four indices were proposed to simulate the pollutant loads entering the lake. The linear coefficients between the load of the pollutants chemical oxygen demand (COD_Cr), ammoniacal nitrogen (NH₃-N), total nitrogen (TN), and total phosphorus (TP) entering the lake and the pollutant load emission weighted by the upstream and downstream confluence ratio index were 0.930, 0.835, 0.925, and 0.795, respectively, and the non-linear variance explanation coefficients were 87.70%, 87.50%, 87.60%, and 84.70%, respectively. When the surface resistance was integrated into the index as a parameter, the linear and nonlinear correlation coefficients were significantly improved. The linear coefficients were 0.952, 0.897, 0.919, and 0.939, respectively, and the non-linear variance explanations were 99.00%, 97.30%, 95.10%, and 97.30%, respectively. The spatial distribution of landscape surface resistance reflects the spatial movement trend of pollutants from different sources. The indices characterizing the promoting and hindering effects could be integrated to calculate the loss rate of pollutant load entering the lake from landscape units at different locations in the basin space.

Analyzing Macro-Level Ecological Change and Micro-Level Farmer Behavior in Manas River Basin, China

Environmental degradation is closely related to unreasonable land use behaviors by farmers. In this study, participatory rural assessment (PRA) is used to conduct a detailed survey of farmers and plots and to collect relevant natural and social statistics. The accuracy of remote sensing data is verified by comparative analysis, and the change in status of various land use types in each research period is reflected by the change in the dynamic degree and change in range. We examine how farmers’ attitudes and behaviors affect environmental degradation, using a sample of 403 farmers in China’s Manas River Basin. Due to age, education, income and other differences, farmers’ land use behaviors, as well as their attitude toward and feelings about environmental degradation, vary greatly. We found that most farmers considered the environment to be very important to their lives and crop production, but nearly 21% did not know the causes of environmental degradation and nearly 8% did not consider the environmental impacts of their crop production activities. A new model for oasis expansion—land integration—is presented here. This model can increase the area of cultivated land, reduce cultivated land fragmentation, save irrigation water, improve the field microclimate and form a good ecological cycle. Through land transfer, ecological compensation and ecological protection incentives, the government should guide farmers’ land use behaviors toward cooperation with the river basin’s ecological protection and land use planning.

Analysis of Coupling Coordination Variance between Urbanization Quality and Eco-Environment Pressure: A Case Study of the West Taiwan Strait Urban Agglomeration, China

Rapid urbanization has affected the eco-environment in China. A clear understanding of the coupling relationship between urbanization quality and eco-environment pressure is needed for sustainable urban development. This study focused on the relationship between urbanization quality and eco-environment pressure in the West Taiwan Strait Urban Agglomeration (WTSUA) with panel data collected from 2003 to 2017. An index system was established to measure urbanization quality from four urbanization subsystems: demographic urbanization, spatial urbanization, economic urbanization, and social urbanization. An index of eco-environment pressure was developed from resource availability, energy consumption, pollution emissions, and pressure response. The level of urbanization quality and eco-environment pressure was assessed using analytic hierarchy process (AHP) and entropy method (EM). The coupling process was described using a coupling coordination degree model. Results showed the following: (1) Economic urbanization contributed the most to urbanization quality. The contribution of the four subsystems to eco-environment pressure was similar. (2) Eco-environment pressure decreased with improving urbanization quality. The coupling coordination degree between urbanization quality and eco-environment pressure increased. Spatially, the coupling coordination degree of eastern cities was higher than that of western cities. The findings of this paper will help government in planning and implementing sustainable urban development and eco-environment conservation.

Urban–Rural Construction Land Replacement for More Sustainable Land Use and Regional Development in China: Policies and Practices

With the rapid development of urbanization and industrialization, land exploitation in China has caused a decrease of cultivated land, posing a threat to national food security. To achieve the goals of both economic development and cultivated land protection, China launched an urban–rural land replacement measure supported by a new land use policy of “increasing vs. decreasing balance” of construction land between urban and rural areas in 2008. Setting China’s urban and rural land use policies in a historical context and urban–rural sustainable development, this paper discusses four practices in Jiangsu Province, Tianjin Municipality, Shandong Province, and Chongqing Municipality. These practices achieved success in impelling agricultural modernization development, improving rural infrastructure and living circumstances, releasing the potential of rural land resources, and increasing cultivated land and urban construction land in the past decade. However, in some practices, problems, and even some conflicts, exist in the protection of farmers’ rights and interests. These challenges are discussed in the context of implementation. In order to better implement urban–rural construction land replacement and achieve better results, the authors argue that farmers’ rights and interests must always be put first and their wishes should be respected more, a consolidated urban–rural land market and a better land market mechanism should be founded, the supply of public goods and services for villagers should be further improved, and supervision and evaluation mechanisms should be further strengthened.

Spatio-temporal dynamics of water quality and their linkages with the watershed landscape in highly disturbed headwater watersheds in China

The water quality of headwater streams is a worldwide concern because of their critical roles in supplying clean water for drinking and other consumptive uses. Here, we evaluate temporal trends and spatial dynamics of the permanganate index (COD), ammonia-nitrogen (AN), and total phosphorus (TP) for 31 sites in headwater watersheds of the Huai River Basin, China. The seasonal Mann-Kendall test and correlation and variance analyses were applied to long-term time series (2003-2010) of water quality data in order to investigate the patterns of water quality trends, as well as their linkages with the watershed landscape. The results indicated that (1) more than 1/3 of headwater monitoring sites have exhibited either significantly increasing or decreasing trends in COD, AN and TP, while only TP increased for most them; (2) obvious increasing concentration gradients were observed for all water quality parameters along the upstream to the downstream continuum. Such spatial patterns can be highly explained by land cover and landscape configuration metrics. The percent of urban land and urban-related landscape metrics (such as the Landscape Division Index) were the primary explanatory variables for AN, while the aggregation metrics of cropland and urban land cover were the main predictors of COD and TP; (3) historical dynamics of COD, AN, and TP were influenced by land cover transitions. The trends of COD and TP may be attributable to the change in the wetland landscape, while the trends of AN were likely related to changes in forestland area as well as environmental management. Overall, our study determined the spatial and temporal dynamics of water quality parameters in the headwater watersheds and interpreted the possible reasons behind their spatio-temporal dynamics, which can have important implications for sustainable landscape planning as well as headwater watershed management.

Study on the response of ecological capacity to land-use/cover change in Wuhan city: a remote sensing and GIS based approach

This research examined the spatiotemporal patterns of land-use/cover and the dynamics of ecological capacity in response to land-use/cover change in Wuhan city, central China. The data were derived from five years' remote-sensed images, that is, 1990, 1995, 2000, 2005, and 2010. This paper used an integrated approach of remote sensing and GIS techniques, ecological capacity and the bilateral dynamic degree models. The results are as follows. (1) From 1990 to 2010, remarkable changes in land-use/cover have occurred within the studied area, and the most prominent characteristics of the changes were continuous decline of arable land and rapid increase of built-up land. (2) The total ecological capacity dropped from 450.55 × 10(4) ghm(2) in 1990 to 447.35 × 10(4) ghm(2) in 2010. The eastern, western, and southern parts had higher ecological capacity whereas the northwestern hilly areas and the central district had lower ecological capacity. (3) Due to the conversion from arable land to built-up land, the ecological capacity losses during 1990-1995, 1995-2000, 2000-2005, and 2005-2010 were 155.52 × 10(2) ghm(2), 114.12 × 10(2) ghm(2), 455.48 × 10(2) ghm(2), and 325.26 × 10(2) ghm(2), respectively. The study would contribute to better understanding of the effects of land-use dynamics and the evolution of ecological capacity, which can provide scientific basis for land management and environment protection.