AN ARCOBJECT BASED ANALYSIS OF THE SPATIAL DISTRIBUTE MODEL OF MONTHLY RUNOFF IN CHANGDU SUB-BASIN AT THE LANCANG RIVER BASIN

L. Gang¹, Z. Rong², L. Ji-ping², Z. Qing-pu²

1 - Chinese Academy of Surveying and Mapping, Beijing, China; Institute of Surveying and Mapping of University of Information Enginerring, Zhengzhou, China

2 - Institute of Surveying and Mapping of University of Information Enginerring, Zhengzhou, China

liugang@casm.ac.cn

The Lancang River Basin is narrow and its hydrological and meteorological information are flexible. The Rainfall, evaporation, glacial melt water and groundwater affect the runoff whose replenishment forms changing notable with the season in different areas at the basin. The paper analyzed characters of different kind of distributed model and conceptual model. A model of relation between monthly runoff and rainfall, temperate and soil type has been built in Changdu County based on VB and ArcObject. The way of discretization of distributed hydrological model was used in the model, and principles of conceptual model are taken into account. The sub-basin of Changdu which is taken as the research area is extracted by ArcGIS and divided into regular cells, and all kinds of hydrological and meteorological information and land use classes and slope extracted from 1:250000 digital elevation model are distributed in each cell. The model does not think of the rainfall-runoff hydro-physical process but use the conceptual model to simulate the whole contributes to the runoff of the area. The affection of evapotranspiration loss and underground water is taken into account at the same time. The parameters of the model are set according to the hydrological data of 1991~1994, and emendated by the data of 1995~1998.The spatial distribute characteristics of the monthly runoff in the area are simulated and analyzed with a few parameters.