GIBSI - An integrated modelling system prototype for river basin management

This paper introduces GIBSI, an integrated modelling system prototype desig ned to assist decision makers in their assessment of various river basin ma nagement scenarios in terms of standard water physical and chemical paramet ers and standards for various uses of the water. GIBSI runs on a personal c omputer and provides a user-friendly framework to examine the impacts of ag ricultural, industrial, and municipal management scenarios on water quality and yield. A database (including spatial and attribute data) and physicall y-based hydrological, soil erosion, agricultural-chemical transport and wat er quality models comprise the basic components of the system. A geographic al information system and a relational database management system are also included for data management and system maintenance. This paper illustrates potential uses of GIBSI by presenting two sample applications applied to a 6680 km(2) complex river basin (63.2% forest, 17.2% agricultural land, 15. 3% bush, 3.1% urban development and 1.2% surface water; population: 180 000 ) located in Quebec, Canada: (i) a timber harvest scenario and (ii) a munic ipal clean water program scenario. Simulation results of the timber harvest scenario showed how clear-cut activities could lead to earlier and larger spring runoff than in the investigated reference state. Results of the muni cipal clean water scenario revealed that substantial reduction in coliform counts and total phosphorus could be made by constructing and operating was tewater treatment plants. These applications provide a framework of how GIB SI can be used as a decision support system and ultimately as a means of in corporating sound science into political decisions involving river basin ma nagement.