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The study of the temporal and spatial evolution of wetland landscapes and its driving factors is an important reference for wetland ecological restoration and protection. This article utilized seven periods of land use data in Henan Province from 1980 to 2015 to extract the spatial distribution characteristics of wetlands and analyze the temporal and spatial changes of wetlands in Henan Province. Transfer matrix, landscape metrics, correlation analysis, and redundancy analysis were applied to calculate and analyze the transformation types and area of wetland resources between all consecutive periods, and then the main driving factors of wetland expansion/contraction were explored. First, the total wetland area in Henan Province increased by 28% from 1980 to 2015, and the increased wetland area was mainly constructed wetlands, including paddy field, reservoir and pond, and canal. Natural wetlands such as marsh, lake, and floodplain decreased by 74%. Marsh area declined the most during 1990–1995, and was mainly transformed into floodplain and “Others” because of agricultural reclamation, low precipitation, and low Yellow River runoff. The floodplain area dropped the most from 2005 to 2010, mainly converted to canals and “Others” because of reclamation, exploitation of groundwater, the construction of the South–to–North Water Transfer Project, and recreational land development. Second, the results of correlation analysis and redundancy analysis indicated that economic factors were positively correlated with the area of some constructed wetlands and negatively correlated with the area of some natural wetlands. Socioeconomic development was the main driving factors for changes in wetland types. The proportion of wetland habitat in Henan Province in 2015 was only 0.3%, which is low compared to the Chinese average of 2.7%. The government should pay more attention to the restoration of natural wetlands in Henan Province.
Heying Li; Jiayao Wang; Jianchen Zhang; Fen Qin; Jiyuan Hu; Zheng Zhou. Analysis of Characteristics and Driving Factors of Wetland Landscape Pattern Change in Henan Province from 1980 to 2015. Land 2021, 10, 564 .
AMA StyleHeying Li, Jiayao Wang, Jianchen Zhang, Fen Qin, Jiyuan Hu, Zheng Zhou. Analysis of Characteristics and Driving Factors of Wetland Landscape Pattern Change in Henan Province from 1980 to 2015. Land. 2021; 10 (6):564.
Chicago/Turabian StyleHeying Li; Jiayao Wang; Jianchen Zhang; Fen Qin; Jiyuan Hu; Zheng Zhou. 2021. "Analysis of Characteristics and Driving Factors of Wetland Landscape Pattern Change in Henan Province from 1980 to 2015." Land 10, no. 6: 564.
Spatially-explicit, fine-scale mapping of poor population distribution at a village level is a necessary prerequisite for developing precise anti-poverty strategies in rural China. To address the data missing of poor population at a village scale, we proposed a modeling methodology from the perspective of spatial poverty, integrating BP and MGWR-SL (Mixed Geographically Weighted Regression model with Spatially Lagged dependent variable) that correspond to population estimation and poverty incidence estimation, respectively, to explore a more accurate and detailed village-level poor population distribution. Furthermore, we justified the accuracy, reliability, and scale effects of the model by using GIS spatial analysis and cross-validation. From the case test, we found that, the proposed model could characterize poor population distribution more accurately than other existing methods, resulting in that the errors of both population spatialization and poverty incidence for each village are less than 5% at a 500 * 500 m grid scale. It can also be inferred that the spatialization of socioeconomic data at a fine scale should take into full account of spatial heterogeneity and spatial autocorrelation for both dependent and independent variables, so as to improve the modeling accuracy. This study may provide a perspective for better understanding the detailed and accurate poverty status of data–scarce village in poverty-stricken rural areas, and serves as a scientific reference regarding decision-making in both promoting “entire-village advancement” anti-poverty harmonious development and constructing the new countryside of China.
Yanhui Wang; Jianchen Zhang. Integrating BP and MGWR-SL Model to Estimate Village-Level Poor Population: An Experimental Study from Qianjiang, China. Social Indicators Research 2017, 138, 639 -663.
AMA StyleYanhui Wang, Jianchen Zhang. Integrating BP and MGWR-SL Model to Estimate Village-Level Poor Population: An Experimental Study from Qianjiang, China. Social Indicators Research. 2017; 138 (2):639-663.
Chicago/Turabian StyleYanhui Wang; Jianchen Zhang. 2017. "Integrating BP and MGWR-SL Model to Estimate Village-Level Poor Population: An Experimental Study from Qianjiang, China." Social Indicators Research 138, no. 2: 639-663.
Road selection is a critical component of road network generalization that directly affects its accuracy. However, most conventional selection methods are based solely on either a linear or an areal representation mode, often resulting in low selection accuracy and biased structural selection. In this paper we propose an improved hybrid method combining the linear and areal representation modes to increase the accuracy of road selection. The proposed method offers two primary advantages. First, it improves the stroke generation algorithm in a linear representation mode by using an ordinary least square (OLS) model to consider overall information for the roads to be connected. Second, by taking advantage of the areal representation mode, the proposed method partitions road networks and calculates road density based on weighted Voronoi diagrams. Roads were selected using stroke importance and a density threshold. Finally, experiments were conducted comparing the proposed technique with conventional single representation methods. Results demonstrate the increased stroke generation accuracy and improved road selection achieved by this method.
Jianchen Zhang; Yanhui Wang; Wenji Zhao. An Improved Hybrid Method for Enhanced Road Feature Selection in Map Generalization. ISPRS International Journal of Geo-Information 2017, 6, 196 .
AMA StyleJianchen Zhang, Yanhui Wang, Wenji Zhao. An Improved Hybrid Method for Enhanced Road Feature Selection in Map Generalization. ISPRS International Journal of Geo-Information. 2017; 6 (7):196.
Chicago/Turabian StyleJianchen Zhang; Yanhui Wang; Wenji Zhao. 2017. "An Improved Hybrid Method for Enhanced Road Feature Selection in Map Generalization." ISPRS International Journal of Geo-Information 6, no. 7: 196.
Matching multi-scale road networks in the same area is the first step in merging two road networks or updating one based upon the other. The quality of the merge or update depends greatly on the matching accuracy of the two road networks. We propose an improved probabilistic relaxation method, considering both local and global optimizations for matching multi-scale of road networks. The aim is to achieve local optimization, as well as to address the identification of the M:N matching pattern by means of inserting virtual nodes to achieve global optimization effects. Then, by adding two attribute-related evaluation indicators, we developed four evaluation indicators to evaluate the matching accuracy, considering both geographic and attribute information. This paper also provides instructions on how to identify the proper buffer threshold during matching procedures. Extensive experiments were conducted to compare the proposed method with the traditional approach. The results indicate that: (1) the overall matching accuracy of each evaluation indicator exceeds 90%; (2) the overall matching accuracy increases by 6–12% after an M:N matching pattern is added, and by 4–6% following the addition of topology indicators; and (3) the proper buffer threshold is about twice the average value of the closest distance from all nodes.
Jianchen Zhang; Yanhui Wang; Wenji Zhao. An improved probabilistic relaxation method for matching multi-scale road networks. International Journal of Digital Earth 2017, 11, 635 -655.
AMA StyleJianchen Zhang, Yanhui Wang, Wenji Zhao. An improved probabilistic relaxation method for matching multi-scale road networks. International Journal of Digital Earth. 2017; 11 (6):635-655.
Chicago/Turabian StyleJianchen Zhang; Yanhui Wang; Wenji Zhao. 2017. "An improved probabilistic relaxation method for matching multi-scale road networks." International Journal of Digital Earth 11, no. 6: 635-655.
The paper presents the dynamic change of wetland landscape pattern from 2002 to 2009 using RS and GIS technology along the lower Yellow River. Results show that: (1) the total area of wetland reduces obviously. (2) Disturbed by human activity, landscape diversity index ascends. (3) The total area of the rice wetland and mud flat decreases while the other area increases.
Jianchen Zhang; Yanhui Wang. Change Analysis on Wetland Landscape Pattern along the Lower Yellow River. 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering 2012, 1 -4.
AMA StyleJianchen Zhang, Yanhui Wang. Change Analysis on Wetland Landscape Pattern along the Lower Yellow River. 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering. 2012; ():1-4.
Chicago/Turabian StyleJianchen Zhang; Yanhui Wang. 2012. "Change Analysis on Wetland Landscape Pattern along the Lower Yellow River." 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering , no. : 1-4.