Master thesis Land subsidence and water management in Shanghai Quanlong Wei May 2006 Land and water resource management 5/24/2006 ii Land and water resource management Master’s thesis Land subsidence and water management in Shanghai Copyright by Quanlong Wei Delft, the Netherlands May 2006 Committee members: prof.dr.ir. N.C. van de Giesen TU Delft Water Resources Management dr. ir. F.H.M. van de Ven TU Delft Water Resources Management dr.ir.Robert Verhaeghe TU Delft Transport &Planning Ir. David Biron Witteveen + Bos 5/24/2006 iii Land and water resource management 5/24/2006 iv Land and water resource management Abstract Land subsidence is the lowering of the land surface elevation due to the compaction of soil. It is a geological event that is accelerated by man through a long term exploration of the ground sources, and they represent a disruption of a natural equilibrium. Land subsidence combined with a global sea level rise creates a serious environmental problem in the coastal region. Land subsidence is an international hot issue now because it happens in lots of big cities. This thesis is about the land subsidence happening in Shanghai. It is a serious geology problem now. It results in permanent loss of ground elevation, lowers the standard of flood preventing establishments and increases the risk of natural disasters of typhoon, rainstorm, flood and astronomical spring tides. In summer, under the complex effect of land subsidence, river flood of Yangtze, local rainstorm, typhoon surge and annually high tide, the disaster of flood and waterlog can be very severe. Spatially, urban land subsidence occurs in active regions of economy and engineering and is consistent with distribution of heat island and rain-island. Therefore land subsidence is an important factor which can affect the city development in Shanghai. It is very necessary to do some research on this subject because it not only leads to the loss of economic but also even people’ lives. In this thesis land subsidence is explained in details. The theory of land subsidence is discussed. The history data of land subsidence is used as a reference. The present measures are evaluated. The tendency of land subsidence is predicted and some suggestions are given on how to solve this problem in the future. The main reason of land subsidence in Shanghai is the groundwater over extraction and it can also leads to some problems related to water. Because my major is Land and Water Resource Management it is suitable for me to do some research using the knowledge got from two years master study in TU Delft. I hope thesis can make people know more about land subsidence and some recommendations I give are useful for land subsidence prevention. 5/24/2006 v Land and water resource management 5/24/2006 vi Land and water resource management Biographical sketch Quanlong Wei was born in Shandong Province of China on August 8 th 1978. He grew up in this big country characterized by one of the human being’s cradles. His hometown is a poor rural area. Not enough water for irrigation in his home town made him suffered a lot during the child period. He decides to change the actuality by his effort. So he studied hydraulic engineering at Wuhan University in China. In 2001 he got his B.S. degree. From 2001 to 2004 he worked in Jinan Water board in Shandong Province. He thinks what he learned is not enough. So he decides to finish master degree. The Netherlands is the best choice for him because of its long famous water management history. He selects the suitable university TU Delft as the next station. He has finished all the courses study now and after completion of his thesis he will receive his M.S. degree from TU Delft. 5/24/2006 vii Land and water resource management 5/24/2006 viii Land and water resource management Acknowledgments First, I would like to express my sincere thanks to Van de Ven, From the beginning to the end he gave me lots of help and encouragement. He is good at urban water management and he gives me lots of good ideas how to write this thesis. Nick van de Giesen gives me the general supervise and some good supports. Robert Verhaeghe and David Biron give me some good advices and comments about my thesis during the committee meeting. They are very friendly and patient for me. Jaap de Koning and Mw. Betty Rothfusz give me lots of helps during my study life in TU Delft. I would like to express my sincere thanks to my friends Wangjun and Dong Bibo who is working in Shanghai Water Board for giving me some valuable data and technical support about urban water management and land subsidence. I am very grateful to Prof Gao Dazhao for the helpful discussions about my thesis. Thanks for all the students who are studying in the same office with me for the time spent together. Thanks for all the staffs of TU Delft who give me a good environment for studying. Finally, I wish to thank everyone who contributed to this research project. Without their supports I can not do my thesis so well. 5/24/2006 ix Land and water resource management 5/24/2006 x Land and water resource management Contents 1 Introduction ............................................................................................................................ 1 2 Land subsidence in Shanghai ........................................................................................... 3 2.1 The city of Shanghai ......................................................................................... 3 2.2 The geology and hydrology .............................................................................. 3 2.2.1 Geology of Shanghai ................................................................................... 3 2.2.2 Hydrology of Shanghai ................................................................................ 5 2.3 The necessity research on land subsidence .................................................... 6 2.4 The harm of land subsidence ......................................................................... 10 2.4.1 Flood defense affected by land subsidence .............................................. 10 2.4.2 Waterlog and land subsidence .................................................................. 12 2.4.3 Tidal disasters and land subsidence ......................................................... 14 2.4.4 Land subsidence effects on municipal safety............................................ 15 3 The analysis on land subsidence ................................................................................... 16 3.1 Reasons of land subsidence........................................................................... 16 3.1.1 Factors affecting land subsidence ............................................................. 16 3.1.2 Heat-island and land subsidence .............................................................. 18 3.2 The groundwater and the land subsidence .................................................... 19 3.2.1 The theory of land subsidence caused by groundwater use..................... 19 3.2.2 The time series analysis ............................................................................ 22 3.3 High buildings and land subsidence............................................................... 24 3.3.1 The building scope and the land subsidence ............................................ 28 3.3.2 Building space ratio and the land subsidence ........................................... 29 3.3.3 The local subsidence and building site preparation .................................. 30 3.4 The current characters of land subsidence in Shanghai ................................ 32 3.4.1 Recent land subsidence character ............................................................ 32 3.4.2 The analysis of each confined aquifer....................................................... 33 4 The prediction of land subsidence in Shanghai .............................................................. 38 4.1 The analysis of groundwater requirement ............................................................ 38 4.2 The deform analysis of the soil ............................................................................. 39 4.3 The city construction ............................................................................................. 39 5 The current methods evaluation and suggestions for the future ............................. 41 5.1 The current methods and measures............................................................... 41 5.2 The current questions ..................................................................................... 46 5.2.1 The whole area study ................................................................................ 46 5.2.2 Aquifer lays research................................................................................. 47 5.2.3 Groundwater equilibration ......................................................................... 48 5.2.4 Government management and organization ............................................. 49 5.3 Suggestions on next step ............................................................................... 52 5.3.1 Ground water utilization study ................................................................... 52 5.3.2 Integrated management for the Yangtze Delta.......................................... 53 5/24/2006 xi Land and water resource management 5.3.3 Water use in an efficient and suitable way ................................................ 54 5.3.4 Sustainable development .........................................................................