Research On Water Ecosystem Services Value Of Taiyuan Urban District Based On RS

All kinds of ecological services which ecological resources provide are basic guarantees for the development of the social economy and human survival. The gap between supply and demand of the ecological resources in urban area is increasing. Water resource is a key factor to sustain the healthy development of the regional ecological environment. So the research on water ecosystem services of urban district has great theoretical and practical significance in many aspects, such as exploring the change law of urban water ecosystem, setting up the reasonable management and evaluation mechanism of water ecosystem.Taiyuan, the capital of Shanxi Province, is the research area in this paper. Firstly, the images of Landsat TM and Landsat OLI from 2000 to 2013 are used to show the land use classification and the temporal and spatial variation of the landscape. Secondly, the three grades buffer zones surrounding water coastline are set with the buffer analysis method based on ArcGIS, and the space-time characteristic of LUCC in water coastline buffer regions is analyzed. Thirdly, the SEBS model based on the MODIS data is used to retrieve the daily evaporation in 2000 and 2013. With that the annual evaporation is extended to estimate and the spatial overlay analysis is operated. At last, the calculation results of ecosystem services value model and its modified model which is established with the method of analytic hierarchy process are verified relatively. The result shows that the modified model is more suitable to the change law of the study area. The research results can provide certain basis for the management and protection of urban water ecosystem, the construction of green development in Shanxi Province and the construction of Sponge City in Taiyuan.The main research results in this paper are as follows:(1) The change rules of the land use in Taiyuan urban district are as follows. The distinctive features of land use in Taiyuan urban district are that there is a large increase in the area of construction land and water body, the change rates of which are 60.26% and 25.87% respectively, and the spatial arrangement of water body has been optimized. Green land and cultivated land both have decreased with different degree, and their change rates are-1.73% and-21.09% respectively. Unused land has decreased by nearly 50%. The landscape fragmentation of water body has been increased by 5.1 because of Human activities, as the result the water landscape is beautified and the water ecology is restored. The change rate of the land use degree from 2000 to 2013 in Taiyuan urban area is larger than zero, which shows the land use of the city is in the developing period.(2) LUCC change characteristics of Jinyang Lake and the Fenhe River are as follows. The LUCC characteristics in Jinyang Lake and its 0-600 m buffer zone of the shore in 13 years are that the area of construction land has increased largely, cultivated land and green land have decreased, and the water area and unused land have decreased slightly. In 0-200 m, 200-400 m and 400-600 m buffer zones, the proportion of green land has decreased by 19.6%, 4.5%, 14.6% respectively. The proportion of cultivated land has decreased by 16.4%, 43.5%, 1.4% respectively. But the proportion of construction land has increased by 39.7%、49.1%, 16.9% respectively. The LUCC characteristics of the Fenhe River and its 0-1000 m buffer zones are that the area of water body, green land of 0-500 m and construction land of 500-1000 m all have increased, while construction land has decreased of 0-500 m. The water area of the Fenhe River Park has increased by 402.35 hm2. The proportion of green land has increased by 16.0% and 10.3% and the proportion of construction land has decreased by 20.4%, 15.7% in the first two buffer zones of shore which are closer to the water body. In the outermost 500-1000 m zone of the shore, the proportion of green land has decreased by 9.7%, but the proportion of construction land has increased by 7%.(3) The change rules of evaporation in urban district are as follows. The annual evaporation of Taiyuan urban district has increased from 653.498 mm in 2000 to 802.602 mm in 2013. The annual evaporation of the Fenhe River and its buffer zones has increased from 721.15 mm to 980.21 mm, the main reason of which is the large increase of water area. However the annual evaporation of Jinyang Lake and its buffer zones has reduced from 1102.12 mm to 1001.20 mm, and the main reason is the large increase of construction land area and the decrease of water area and green land around water body. The evaporation of Jinyang Lake, the shape of which is planar, the proportion of water body in which and its buffer region is greater, always greater than that of the Fenhe River.(4) The change rules of the total value of ecosystem service are as follows. The total value of ecosystem service of Taiyuan urban district in 13 years has reduced by 849.766 million yuan, and its annual change rate is-2.007%. The total value of ecosystem service of Jinyang Lake and its 0-600 m buffer zone has decreased by 19.351 million yuan, and the change rate is-20.466%. The total value of ecosystem service of the Fenhe River and its 0-1000 m buffer zone has decreased by 28.34 million yuan, and the change rate is-13.706%. It is shown that the estimation results have certain reference value, but they can not reflect the actual change law of ecosystem in the study area with sensitivity analysis.(5) The correction and the results of the calculation model of water ecosystem services value are as follows. The calculation model of water ecosystem services value is modified based on the structure and functions of urban water ecosystem. And then the model of ecosystem services value is esteblished with the method of analytic hierarchy process. The value of water ecosystem services in Taiyuan urban district from 2000 to 2013 has increased by 659.2673 million yuan, and the change rate is 21.11%. The total value of water ecosystem service in Jinyang Lake and its buffer zone has decreased by 24.0090 million yuan, and the change rate is-24.75%. The total value of water ecosystem service in the Fenhe River and its buffer zone has increased by 25.9532 million yuan, and the change rate is 23.29%. It is shown that the larger the area of water body is, the higher water ecosystem service value is. The results accord with the practice of Taiyuan urban construction and reflect the construction concept of green and livable city.Main innovative points are as follows in this paper:(1) Three grades buffer regions of the stripe river and the planar lake are set, so the general research scope of water body is expanded to the surrounding land area of water. This provides thoughts and methods for the research on water ecosystem services in the transitional zone.(2) The modified model of water ecosystem service value is established and then water ecosystem services value of Taiyuan urban district and its water system is studied.