Dissertation > Excellent graduate degree dissertation topics show

The Extract Impervious Surface and Its Effect on Hydrological on the Qinhuai River Basin

Author: LiCaiLi
Tutor: DuJinKang
School: Nanjing University
Course: Cartography and Geographic Information Systems
Keywords: Impervious surface Hydrological effects Qinhuai River basin L-THIA
CLC: P237;P333;F301
Type: Master's thesis
Year: 2011
Downloads: 235
Quote: 1
Read: Download Dissertation

Abstract

Qinhuai River basin as the research object, the application of RS and GIS technology to extract the study area impervious surface and land use information. 1986-2009 study area impervious surface change process as the starting point, through statistical methods and hydrological models, quantitative and qualitative changes in the hydrological system to investigate the study area impervious surface response. Future land use scenarios under different impervious surface distribution, to analyze the impact of long-term hydrological factors predict the Qinhuai River basin. For the watershed in the future of urban construction, land use, water resources allocation, flood control and disaster mitigation decision-making. The thesis is as follows: a study of multi-temporal and multi-source remote sensing images to extract impervious surface. Landsat images and CBERS images of two data sources. First images of the CMB PCA transformation, take the first two principal components of the original image synthesis informative band more images, in order to meet the conditions of the linear mixed pixel decomposition model. Followed by the remote sensing image for each pixel are seen as a high anti illumination feature, the low anti illumination feature, the combination of vegetation and bare soil, using linear spectral mixture model to extract the information of impervious surface. The last application time rules to improve the accuracy of long sequences of impervious surface information extraction. The results show that, of the CMB image pre-processing and time rules can get higher accuracy impervious surface. 2, based on the qualitative and quantitative analysis of statistical methods impervious surface change on the hydrological effects of the study area. Applications MK test, the sequential clustering time series methods for qualitative the 1986-2006 runoff depth, rainfall and other hydrological factors trends and mutation of the Qinhuai River basin. Using multiple linear stepwise regression analysis basins impervious surface affect the extent of the change of the start time and hydrological factors. The research results show that the rapid increase in impervious surface causes changes in the hydrological elements of the study area from 2003 significantly. The increase in impervious surface result in annual runoff and flood season runoff depth, flood volume and runoff coefficient have shown a growing trend to decrease evaporation, the smallest relative change of annual runoff, the relative change of the annual evaporation. 3, based on the L-THIA model further quantitative analysis of the effect of changes in impervious surface hydrology of the study area. Land use scenarios, first established in the study area and its purpose is only to consider the change of impervious surface hydrological elements. L-THIA model building suitable for the study area, and provide a strong technical support for the long-term hydrological effects explain and predict impervious surface. On this basis, the combination of different periods of land use scenario simulations impervious to face the long-term effects of hydrological processes. The results show that, under the same rainfall conditions, changes in impervious surface lead to basin-wide average annual runoff depth, runoff coefficient increased average annual decrease in evaporation. Beginning in 2003, the the hydrological factors change significantly strengthened to 11.99mm / 4.66mm / year by 2003, the rate of increase of the average annual runoff depth. The average annual runoff depth impervious rate corresponding linear relationship, that is, with the improvement of the impervious surface ratio, the average annual runoff depth linear growth. 4, in the study area, the hydrological effects of urbanization. CA-Markov model to predict the future in 2012 and 2018 land use based on the study area from 2003 to 2006 land use change trends. L-THIA model application has been constructed to analyze the different impervious surface distribution of average annual runoff depth, evaporation hydrological factors. The results show that, when the average annual runoff depth impervious rate of 23.83% of the study area, the average annual runoff depth 532.44mm, an increase of 38.81% than the measured basin average annual runoff depth; When impervious rate increased to 33.13 percent, to simulate the increased ratio measured 613.54mm, 229.95mm, 59.95%. When watershed impervious rate increased to about 30%, the increase in watershed runoff depth half cause floods in the area of ??water resources and water environment problem is exacerbated by the need to strengthen the management of the urbanization of the area.

Related Dissertations

CLC: > Economic > Agricultural economy > Agricultural economic theory > Land Economics
© 2012 www.DissertationTopic.Net Mobile