Abstract: Assessment of urban landscape ecological risk could be the quantitative basis of the urban landscape management and the comprehensive risk prevention. In view of the ambiguous relationships of urban landscape ecological risks on various scales, we calculated the correlation of six representative landscape ecological risks on the scales of pixels, watersheds, and subdistricts in Shenzhen City by using the Revised Universal Soil Loss Equation (RUSLE) and the habitat quality evaluation model. The results showed that the higher average value and variation coefficient of the landscape ecological risks in Shenzhen City were found in the western, northern and southeast parts. The soil erosion risk presented a significant negative correlation (P<0.05) with the other risks, while a significant positive correlation (P<0.05) was found among the four risks of urban heat island, habitat damage, surface hardening and crowd gathering. Moreover, the correlation between the landscape diversity and risk increased with the enlargement of the statistical scale. Urban landscape ecological risk was positively correlated to landscape connectivity, which is quite different from the previous studies and reflects the particularity of urban landscape pattern. Therefore, changes in the relationship among urban landscape ecological risks at various scales confirm the needs of multi-scale comprehensive risk prevention of city management.

Key words: grain yield, N uptake efficiency., protein content, extremely-late sowing, winter wheat