Studies On The Technology Models And Effects For Ecological Reconstruction In The Coast Area With Heavy Soil Salinity

Tianjin Economic Development Area (TEDA) is established at the abandoned saltpan in Tanggu, Tianjin, China. It is located in desolated heavy saline coast area with no vegetation in Bohai Bay . Before the TEDA established, the ecological environment in this area was very poor. With the establishment of TEDA, the area has become one of the most important areas for the fast economic growth in the north China. It is also required that the environment improvement should keep pace with the economic development Therefore ,it is very essential to research ecological reconstruction technology, assembly model and effects in this area .From this point ,the author tries to discuss the effective model about ecological reconstruction by theory and technology in this area.This is a very hard and big task for the ecology recovery and reconstruction at abandon area with heavy saline land in the coast .It should be a new research by combining the ecology environment and landscape work at the same construction project. There are many difficulties in both theory and technological problems that require to be overcome for this work. This paper is to develop an ecological reconstruction model after many years of research and practice in heavy saline coastland. It has not only enriched the theory and practical technology for ecological reconstruction and landscape in the saline coast area, but also has a roll in the guidance for the environment reconstruction in the saline land in the coast area.1. Based on the theory of ecological reconstruction in the heavy saline coast area, a principle should be made for the ecology project. In the project the ecological technology for the reconstruction would be applied. After analyzing the ecological condition in the coast area of TEDA, the main factors restricting the reconstruction are discussed with the theory.2. Through the analysis of the natural ecological systems and social conditions, the soil salinity, water shortage, and organic fertility scarcity are the main limitations for the reconstruction. The relevant studies on the technology in salt leaching, water and salt reaction, compound soils, soil salinity and sodicity control, waste waterreusing, water saving irrigation, waste organic materials and cultured soil fertilization are conducted for those factors. In the technology the permitted depth, and tolerable salt accumulation theory are new in the engineering technology by using shallow drainage pipelines, combine the salt drainage system with urban sewage drainage system. In the compound soil research, six new formulations with different waste materials were tested at three basements. This is a great progress in reusing the waste materials and makes a balance in the industrial development and environment ecological protection. In the water saving irrigation the rainwater and living sewage water have been used for the economic model. Biological method in reconstruction is the most important technology in the future.3. The models of ecological reconstruction are discussed based on the technological level, economic and social development levels in TEDA. Four models are compared through the landscapes by using the four models respectively.4. The great economic and social benefits produced by the reconstruction were analyzed after years of tracing and analyzing the soil salt changes.