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基于CA的城市空间动态模型研究 总被引:34,自引:0,他引:34
综述了当前基于CA(Cellular Automata)的城市空间动态模型研究的基本进展,介绍了我国发展的基于CA 的大都市区城市扩展模型(City Expanding Modelin Metropolianarea,CEM)以及利用该模型对北京地区城市发展过程的初步模拟结果。认为离散化的"自下而上"的微观个体模型代表了当前城市空间动态模型的最新发展方向,建立基于CA的城市动态模型,开展中国大都市区城市发展演变过程的模拟研究在当前具有重要的理论和实践意义。 相似文献
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中国东北漫岗黑土区切沟侵蚀发育特征 总被引:4,自引:0,他引:4
In this study, short-term gully retreat was monitored from the active gullies selected in representative black soil area,
using differential global positioning system (GPS). With the support of geographic information system (GIS), multi-temporal
digital elevation models (DEM) were constructed from the data collected by GPS and used for further analysis. Based on the
analysis of multi-temporal DEM, we discussed the erosion-deposition characteristics within gully and a developing model for
black soil gully area of Northeast China was proposed. The results are: (1) The analysis of the monitored gully data in 2004
indicated that the retreat of gully head reached more than 10 m, gully area extended 170–400 m2, net gully eroded volume 220–320 m3, and gully erosion modulus 2200–4800 t·km−2·a−1. (2) Compared with the mature gully the initial gully grows rapidly, and its erosion parameters are relatively large. The
erosion parameters have not only to do with flow energy, but also with the growth phase. (3) There are significant seasonal
differences in gully erosion parameters. The extension of gully area and width dominates in winter and spring without marked
net erosion while changes mainly occur in gully head and net erosion in rainy season. (4) It is remarkable for freeze-thaw
erosion in the black soil area of NE China. The gully wall of SG2 extended 0.45 m under freeze-thaw effect in 2004, and the
distance of gully head retreated maximally 6.4 m. (5) Due to freeze-thaw action and snowmelt, gully is primarily in the interior
adjustment process in winter and early spring. There are much more depositions compared with that during rainy season, which
can almost happen throughout the gully, while erosion mostly occurs near head, esp. for gullies having a relatively long history
of development. On the other hand, the process of energy exchange with exterior dominates in rainy season. It is considered
that this cyclic process is an important mechanism for gully growth in high latitude or/and high attitude regions.
Foundation: Key Project for National Natural Science Foundation of China, No.40235056; The Ph.D. Programs Foundation of Ministry of Education
of China, No.20030027015; China Postdoctoral Science Foundation, No.20070410482; Doctoral Foundation of University of Jinan,
No.B0620; National Natural Science Foundation of China, No.40672158; Key Subject Foundation Supported by Shandong Province
Author: Hu Gang (1976–), Ph.D and Associate Professor, specialized in soil erosion, environmental evolution and regional planning. 相似文献
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