Research On Vegetation Coverage Rate In Danjian Gkou Reservior

Changing for land utilization not only the determining factors to change of land coverage, but also a priority problem for human sustaining development since core plan of Land Utilization/Coverage change (LUCC) has established in1992. Land utilization as the most important factor to Land utilization coverage rate and regional change of vegetation coverage has already played important role in field for researching on global change. Different kinds of resources problem and environmental effect caused by LUCC has already aroused people attention.This paper was to select Danjiangkou reservoir as researching location and with the aid of method for analyzing and processing data which origin from40years ago on basis of researching on regional characteristics of Danjiangkou reservoir. The method for analyzing land utilization type and vegetation coverage were divided into specific analysis research method、GIS、quadrat method and GIS explanation, and the drawing conclusion were followed.(1) According to results obtained from vegetation form in the reservior were indicated that the total area for reservoir vegetation was191162.65hm2, the reservoir vegetation rate was77.95%, the area of broad-leaved forestry was accounted for18.87%of total reservoir vegetation area, coniferous forestry area was accounted for6.71%of total reservoir vegetation area, brush fallow area was accounted for23.28%of total reservoir vegetation area, scrub-grassland vegetation area was accounted for1.67%of total reservoir vegetation area, crop as main vegetation form which its area was accounted for49.47%of total reservoir vegetation area, respectively.(2) By selecting satellite image in1973、1983、1993、2003and2013to explain land utilization type, it demonstrated that land utilization type has changed dramatically. In general, cultivated land has deceased and forestry area has increased. Cultivated land as main land utilization was shifted to land utilization for forestry, and simultaneously land utilization for reservoir construction was established an increasing trend which its stem from requirement for development of regional economy.(3) By applying GIS technology and decoding the data since40years ago to evaluate the trends of vegetation coverage change, the results indicated that reservoir vegetation coverage rate was established a decreasing trend. The vegetation coverage rate from1973to2013was ranged from65.19%to67.18%, specifically,67.29%for1983,66.99%for1993and66.57%for2003,respectively. Compared by construction of hydro-junction in Danjiangkou reservoir in1973and completion of South-to-North Water Transfer Scheme (SNWT) in2013,the vegetation coverage area was reduced up to1.99%. Compared by beginning of South-to-North Water Transfer Scheme during first-stage project in2003, the vegetation coverage area was deceased approximately3400hm2, and corresponding vegetation coverage rate was reduced1.39%. The vegetation coverage area and corresponding coverage rate were reduced1482.89hm20.60%during1973-2000respectively.(4) According to characteristics of region, we analyzed driving factor which influencing the vegetation coverage change in Danjiangkou reservoir and demonstrated influencing of other factors like SNWT、social and economic aspect and human activities on vegetation coverage change, simultaneously, we still highlighted to pay a attention ecological environment protection and enhanced vegetation remediation, which were created necessary condition for regional sustainable development.