Research On The Impact Of Urbanization Development In Jinzhong Basin On Regional Ecological Environment

The urbanization (i.e.townization) development, especially the regionalurbanization development, has made the obvious impacts on the regionalecological environment, which has caused the change of the regionallandscape structure, ecosystem function and environmental quality. Theacademic circles and the government pay more the attention on it. Therefore,those problems are studied not only has the theoretical meaning for urbanecological researches, but a vital important practical meaning for urbanecology and management.The dynamics of urbanization development in Jinzhong Basin in recent 30years and its impacts on key ecological factors such as regional climate,underground water, surface water and plant diversity were studied by usingregression analysis, t-test, ANOVA, Gleason index etc., based on theinvestigated vegetation data from the field and the datasets, includinghydrologic records, weather dataset, and environmental monitoring datasetprovided by the related organizations in Shanxi.The result of on the urbanization development of Jinzhong Basin showed thatthe urbanization rate reached at 60.33% in 2003 during several thousandsyears period, this suggested that the urbanization in the basin is one of thefaster development regions in China.The variation of annual mean temperature in Jinzhong Basin is studied by useof 33-year observational data of 10 meteorological stations in Jinzhong Basin,the results indicate that local air temperature is keeping a continuous rise. Inrecent 5 years (1999～2003), annual mean temperature rises by 1.37℃higherthan that in the first 5 years of 1970s (1971～1975), annual mean riseamplitude is 0.0415℃, which is 8.83 times as high as annual meantemperature rise amplitude (0.0047□) in the Northern Hemisphere in recent 100 years, which is 1.88 times as high as annual mean temperature riseamplitude (0.022□) in china in recent 50 years, and the amplitude is larger.The analysis on the correlation between annual mean temperature and theurbanization rate in the basin indicates that: positive correlation existsbetween the urbanization rate and annual mean temperature, correlationbetween them is significant at 0.01 level (r=0.45, p＜0.01). This shows that theurbanization development in the basin makes an obvious impact on local airtemperature and is a main cause for larger local temperature rise amplitude.The study on the annual precipitation change in Jinzhong Basin in recent 33years (1971～2003) shows that the higher precipitation period is in 1970s, and1990s is an obvious decreasing period for the precipitation. The change trendof annual precipitation in Jinzhong Basin in recent 33 years shows a slowlydecreasing trend, annual average reduction amplitude of 2.28 mm/a, which is4.23 times as much as the global precipitation of 0.54 mm/a in recent 50years.The study on underground water level variation in the basin has been made byuse of 21-year (1983～2003) fixed observation data on the underground waterburied depth change in Jinzhong Basin. The results show that the undergroundwater level reveals a continuously-decreasing trend in recent 21 years. Thecorrelation analysis between the buried depth of underground water andurbanization rate indicates that correlation relation between them is the mostobvious positive correlation(r=0.80, p＜0.01). This shows that the urbanizationdevelopment in the basin has made an obvious descending impact on localunderground water level.The study on underground water quality of Jinzhong Basin in recent 18 yearsis performed by utilizing the monitoring data from the environmentalmonitoring stations at province, city (prefecture) and county level. The resultshows that the concentration of various pollutants in underground water increases correspondingly along with the increase of the urbanization rate.The study on the variation of the surface water quality has been made through18-year (1986～2003) monitoring data from 10 monitoring sections in JinzhongBasin. The results indicate that the content of 13 key pollutants in the surfacewater reduces slightly in the specific year, but as a whole it showscontinuously-increasing trend.The study on the impacts of the urbanization development upon the plantdiversity has been made through the sampleⅠ,Ⅱ,Ⅲ, andⅣcomposed of 54villages, 38 towns, 8 counties and 4 cities respectively. The results show that,as viewed from the wild plants, the species richness of the wild plants in thecities (sampleⅣ) is the lowest, the species richness of the wild plants in thevillages (sampleⅠ) is the highest; as viewed from the artificially-cultivatedplants, the species richness of the artificially-cultivated plants in the cities(sampleⅣ) is the highest, that in the villages (sampleⅠ) is the lowest; asviewed from the general plant species, the species richness of them in thecities (sampleⅣ) is the highest, while that in the towns (sampleⅡ) is thelowest because the man-made interference is large, which results in theobvious reduction of the wild plants, moreover, effective species introductionwork fails to be developed as a result of the poor financial capacity. Thedrawn conclusion is that from villages to cities, with the expansion of thetown scale, the species richness of wild plants shows a descending trend,while those of the artificially-cultivated plant and general plant species showthe increasing trend.The study on the ecological impact of the reconstruction project for TaiyuanSection of Fenhe River indicates that the river course reconstruction duringthe urbanization development will make an obvious impact on the wildvascular plants of the river ecological system, and the conclusion is that thespecies richness of the wild vascular plants in the river ecological system reduces obviously.