Snowmelt runoff is the main composition of water resources in middle and high latitude region.Research on the snowmelt runoff process are important in monitoring and foresting flood and drought disaster as well as managing water resources.In recent years the studies on distributed snowmelt runoff model are based on the application and local improvement of foreign mature models such as the SRM

have more limitations in their applicabilities.A Distributed Snowmelt Runoff Model based on RS and GIS has been designed and explored in this paper.The model consists of three parts

grid snowmelt model

grid snowmelt flow generation model and grid snowmelt flow concentration model.It was based on energy balance and water quantity balance.The grid snowmelt model was based on the energy balance.And the grid flow model was based on the water volume balance as well as the distributed grid runoff model

thus has formed a completely

distributed snowmelt runoff model which could apply to the actual service.Snowmelt and runoff process were all based on grid scale

all of the input/output data were distributed processed

the primary format were TIFF

so the model was provided with distributing character and had strict physical mechanism.An important concept of "Unit Period of Time" was put forward in the paper

and thereby developed a "Degree and Cent Snowmelt Runoff Model"from the traditional "Degree-Day Method" which has widespread application nowadays

for it was not fit for the practical applications because of its glancing time-resolution

in the snowmelt period

the processes were usually very unabiding

so the time-step in day is not appropriate

but with the "Degree and Cent Snowmelt Runoff Model"

the computing time-stride of the snowmelt flood precaution decision support system could adjust itself

and to make use in the real-time computation and the forecast.It also brought forward another important concept of "Freezing and Melting Coefficient"

which was aimed to explain the snow freezing and melting repetitive physical mechanism and this concept is significant to exactly hold the snowmelt process

because the water melting of snow/ice usually refreeze in the afternoon.Besides

a Distributed Snowmelt Runoff Stimulating System by GIS has been developed

which is the platform and support of the running of the Distributed Snowmelt Runoff Model

has all of the basic functions of GIS

such as spatial analysis

hydrological analysis

dynamic simulation

and so on.Both the model and the system are the kernel modules of Snowmelt Flood Prewarning Decision Support System.At last

based on a great deal of remote sensing data

obtained distributed input data for the model

for example

distilled snow cover information with Unmixing Pixel Method

and land surface temperature（LST） with Split-window Arithmetic designed by Zhihao Qin

Kebiao Mao and so on

with our proper correction.Basic geo information data like DEM and its relevant data such as shope and asect

field simultaneous observation data mainly including weather data and hydrology data

were disposed with uniform spatial resolution（30m×30m in this paper） and the same data format（TIFF）

stimulated the runoff process in representative snow melt period in 2006 of the typical study area

Juntanghu river basin

a close watershed

which located in the middle of the northern Tianshan Mountain

Xinjiang

China

the area of it is 833.57km2

with the Distributed Snowmelt Runoff Stimulating System

the time-step was 15 minutes.An average relative error of this model with the synchronous true measuring data was under 0.18

indicating that the model was able to meet the need of snowmelt flood alarming and foresting.