The Building Of City Water System Database In Liangjiang New Area Of Chongqing Based On The Technology Of GIS

In June 2010 the State Council set up Chongqing Liangjiang New Area. The population is about 4 million, and the watershed area is about 1143.6 square kilometers. Through the rapid development of Liangjiang New Area, and large patch of the city had been developed, causing large increase of the impermeable hardening ground in city region. The natural state of Liangjiang New Area water system was permanently changed. Underlying surface characteristics and a substantial reduction in infiltration of rain water, the ability of groundwater recharging lake became insufficient. There are plenty of natural ponds been buried, while the rain flood occurs frequently; most rivers in Liangjiang New Area are located in the urban built-up area. Through the changing of river configuration and river net structure, as well as the river channel type reservoirs which were built along development projects, it leads to the deterioration of the river water quality and the drying-up of the river. Part of the rivers' ecosystem degradation is serious, which lost their water environment function. So it becomes the main driving force of building Liangjiang New Area city water system database and the digital management of city water system.On database design, the paper aimed at Liangjiang New Area city water system database construction, using geographic information system(GIS) as development platform to abstract the spatial geographic information of Liangjiang New Area. Then use Geodatabase to construct the spatial data model. Use database management system which supported by Geodatabase to store and manage the attribute data which describes the feature of spatial data. The paper uses the Access database, with two-dimensional table as the carrier, using the classification of the data to design table name and field name and then storing the attribute data.The construction of water system database serves the Liangjiang New Area water system building technical scheme. In order to study the composite effect of basin natural water system and urban social water system, the Liangjiang New Area city water system database is divided into basic geographic information database, natural water system database and the social system database:(1)basic geographic information database: use the data of Liangjiang New Area base information data and hydrology and water quality monitoring data which have been abstracted to build the Liangjiang New Area watershed space model, Liangjiang New Area digital elevation model database, soil type database, land use database, land cover types database, hydrology monitoring database and water quality monitoring database.(2)natural water system database: through data investigation, abstract the rivers which located in 20 major watershed of Liangjiang New Area to build the river spatial database and lake spatial database; Through the river and lake water quality's data statistics and classification, the river grid attribute database, river water quality attribute database, lake type attribute database and lake water quality attribute database can be built.(3)social water system database: through data investigation, until April 2015,there are 22 water supply plants and 10 sewage treatment plants in Liangjiang New Area. Vectoring the quantization space position of the water treatment, water supply factory attribute database, spatial database, water supply plant effluent plant spatial database and attribute database can be built.The building of Liangjiang New Area urban water system database, can provides spatial data base for the study of natural water system and social system of composite effect, as well as the simulation under different development situation of water environment effects.