The dry-hot valley is a special landscape in the mountainous area of south-west China.It is found that the typical dry-hot valleys were mainly occupied by slope non-irrigated field

grass land

bare and semi-bare land below 1650m

topographic shadows and seasonal leave unused land with the value of slope less than 0.5° when the altitude is below 1350m.So it is not enough to identify the dry-hot areas just by elevation of 1100—1350m（the traditional method）.Because it is influenced not only by the topographic characteristics related to elevation

aspect and slope

but also by human activities.In this paper

land use/cover mapping method

brightness temperature threshold method and dry-hot index method were used to identify the typical dry-hot valleys in Yuanmou

Yunnan province

China.Landsat ETM+ data acquired on 23rd November

1999 were selected for the mapping of typical dry-hot valleys.For the land use/cover mapping method

more works were involved including mapping different land use/cover types and identifying topographic shadows.And then the brightness temperature threshold method was proposed and employed

for which the determination of brightness temperature threshold was difficult and the identification of topographic shadows was also involved to eliminate the influence of topographic shadows on brightness temperature.To solue this problem

a multi-spectral operation method was proposed.It is not enough for brightness temperature threshold method to represent the characteristics of dry-hot landscapes

so a dry-hot index method（RTVI

ratio of temperature and NDVI）was proposed.In the mapping of typical dry-hot valleys by RTVI

bare land between 1350m and 1650m was eliminated from the typical dry-hot valleys

which should be included by dry-hot landscapes.So normalized difference bareness index（NDBaI） was used to rectify the mapping results.The identification results were compared with landscape ecological method.The agreements between the results of land use/cover mapping and RTVI suggested that the proposed dry-hot index method in this paper was feasible and easily performed.And then the dry-hot landscape characteristics were analyzed in different vertical zones.The analysis of dry-hot landscape in different vertical zones show that the dry-hot landscape obviously exceeds the upper limit of traditional elevation（i.e.

1350m）

and the values of NP and PD in the elevation of 1350—1650m（6732 and 0.5117） were much greater than those below the elevation of 1350m（1873 and 0.1424）

and the value of LPI in the elevation of 1350—1650m（0.3757） was much smaller than that below the elevation of 1350m（2.57）.Those values indicated that the exceeded patches were fragmentized.The mapping results showed that the exceeded patches were mosaic distributed with water and vegetation patches

which suggested that the recovery of original landscape in the elevation of 1350—1650m was easier than the area in the elevation of 1100—1350m.