Taking two SPOT-5 orthophoto images of Beijing-Hangzhou Grand Canal in 2003 as the data source,this paper uses the least square multiple regression to build the model between water quality data and land-use proportion in high flow period and low water period.The result shows that the spatial change of the buffer distance which is the center of the monitoring sections presents obvious responsive relationship with water quality monitoring indexes.In high flow period,the maximum response ranges of DO,CODMn,BOD5,TN and TP are 100 m,100 m,300 m,200 m and 100 m,respectively.But in low water period,the maximum response ranges are 500 m,200 m,300 m,400 m and 200 m.The canal water pollution is influenced by neritic land-use structure.Agricultural effluent,commercial and industrial wastewater,bare land effluent,which are composed by living rubbish and construction refuse,are the important reasons to cause the Beijing-Hangzhou Grand Canal water quality deterioration.

Taking Taihu Lake as the study area,this paper built linear model based on the satellite data of band 4 of HJ-1,to inverse the concentration of suspended solids and studied the spatial distribution of suspended solids in different months.By extracting each sample's concentration by sampling equidistantly,the spatial variation can be known by geostatistics.The result shows that the concentration of suspended solids was very high during 2009,and the main grades were 30-50 mg/L and 50-70 mg/L.The distribution of high value zone spread from the northwest or southwest to the center of Taihu Lake.At last,a large area of high value zone was formed in the lake center finally.By the geostatistics theory,we can find that the spatial variation of suspended solids in Taihu Lake existed objective.Not only has it nugget effect,but also it has a strong spatial correlation.The ranges of variation in 2009 were greater than 20 km,except June in which that was 9.2 km.

Taking the six sections' water quality monitoring data of Beijing-Hangzhou Grand Canal in Wuxi and SPOT-5 orthophoto images in July 2003 as the data source,this paper analyses the response relationship between land-use area proportion and the transit water quality.The result shows that the spatial change of the buffer distance which takes the monitoring section as center responds to the five water quality monitoring indexes.The canal water quality pollution is mainly affected by land use structure which is close to the river.So the agricultural effluent,commercial and industrial wastewater and effluent from large area of bare land which is made by living rubbish and construction refuse is an important reason to make the Beijing-Hangzhou Grand Canal water quality worse.

Taking the Landsat TM / ETM + images of Wuxi City in 2001and 2008 as the data source,this paper uses the DBI-SAVI index to extract the information of town in Wuxi City,and achieves the urban expansion map of Wuxi City from 2001 to 2008.At the same time it uses thermal infrared band to invert the urban surface temperature,and respectively achieves the surface temperature map of Wuxi City in 2001 and 2008.At last,combining with urban thermal field variance index and the data of socio-economic and humanities,the relationship between urban expansion and heat island response is analyzed.The results show that urbanization of Wuxi City presents a growing trend from 2001 to 2008,with an uneven development of spatial expansion which mainly includes centralized development and ribbon-shaped development.The mostly direction is along the centerline of Changzhou-Wuxi-Suzhou Cities and encircles the Taihu Lake.The expansion speed in south-east is the fastest.In the process of urban expansion,surface temperature of Wuxi City has increased,area of urban heat island has been growing,and from ribbon-shaped to dumbbell-shaped distribution,urban expansion and heat island distribution have shown consistency in space,so urban heat island is a direct reflection of the urban expansion.

Taking the Landsat TM/ETM+images of Wuxi City in 1991,1996,2001 and 2005 as the data source,this paper used the improved band combination threshold extraction to extract the spatial information of urban built-up in Wuxi City.Then the result was corrected referring to the land use classification map in drainage area of Lake Taihu.By overlaying of four classified images,the law of spatial distribution of urban expansion in Wuxi City from 1991 to 2005 were researched.Result indicates that the overall expansion of Wuxi has increased continually since 1991.In particularly,after 2000,urban expansion had a rapid development.At the same time,Wuxi showed an uneven development of spatial expansion.The spatial expansion mainly included two typical expansion modes which were centralized flaky development and axial expansion.The mostly direction of urban expansion in Wuxi was along the centerline of Changzhou-Wuxi-Suzhou and encircle the Lake Taihu.Meanwhile,the speed of expansion in south-east and east was the fastest.Combining with the data of socio-economic and humanities,the impact of urban expansion by population and economic development was analyzed too.The results show that population growth and economic developments are two important factors which impact on the urban expansion of Wuxi City.