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The CCD multi-band data of HJ-1A has great potential in inland water quality monitoring, but the precision of atmospheric correction is a premise and necessary procedure for its application. In this paper, a method based on dark pixel for water-leaving radiance retrieving is proposed. Beside the Rayleigh scattering, the aerosol scattering is important to atmospheric correction, the water quality of inland lakes always are case II water and the value of water leaving radiance is not zero. So the synchronous MODIS shortwave infrared data was used to obtain the aerosol parameters, and in virtue of the characteristic that aerosol scattering is relative stabilized in 560 nm, the water-leaving radiance for each visible and near infrared band were retrieved and normalized, accordingly the remotely sensed reflectance of water was computed. The results show that the atmospheric correction method based on the imagery itself is more effective for the retrieval of water parameters for HJ-1A CCD data.

Interspecies competition is the main factor determining the trophic niche width of sympatric species on both ecological and evolutionary levels. In August 2004, a microscopic analysis of feces was made to analyze the diet compositions of Pantholops hodgsoni, Procapra picticaudata and Equus kiang under free-living circumstances between Chuma River and Wudaoliang in the Kekexili National Nature Reserve. The trophic niche widths and overlaps of these herbivorous ungulates were calculated based on the diet compositions, and the results showed that these three ungulates had similar foods, but the proportions of their diet compositions were different. Gramineous plants were the main food sources for P. hodgsoni, P. picticaudata and E. kiang, accounting for 58.7%, 44.57% and 92.28% of the diet, respectively. The trophic niche widths of P. hodgsoni, P. picticaudata and E. kianthese were 0.878, 0.735 and 0.695, and the niche overlaps of P. hodgsoni and E. kiang, P. hodgsoni and P. picticaudata, and E. kiang and P. picticaudata were 0.869, 0.985 and 0.785, respectively, which suggested that there was a potential intense competition among them, especially for P. hodgsoni and P. picticaudata. The relations between competition and coexistence among P. hodgsoni, P. picticaudata and E. kiang were discussed from the viewpoints of their ecological characteristics and trophic ecology.