Quantitative Determination of Boundary Fluctuation in Arid Valley of the Upper Min River and Its Evolution Feature
Summary:With rapid population growth and socio-economic development in mountainous regions of western Chi-na,arid valleys are acting as an important part in support of mountain ecosystems and suffering serious engineered interference and over-exploitation.With the help of RS and GIS technology,this research took arid valleys in the upper reaches of Min River as a case study.It applied the Markov prediction method and the model of dynamic change of land use space analysis calculation to perform a quantitatively investigation on the boundary fluctuation of arid valleys in the upper reaches of Min River and its evolutionary features.Results confirmed that:The area of ar-id valleys in the upper reaches of Min River and its upper border had been growing for years,On an annual average, the upper boundary kept uplifting about 5 m per year in the vertical direction,and the growth trend in the arid valley areas would be getting stronger in the long run;During 1970 to 2010,the expansion rate of arid valley(TRL70-2010) presented a rising trend,with TRL70=1.44%, TRL80=0.95%, TRL90=2.32%, TRL2000=2.45%, TRL2010=3.59%.separately;And arid valleys had been highly developing from 1990 to 2000 with a unprecedented maxi-mum rate(IRL90-2000),which was regarded as high-speed expansion period,whereas for the period of 1970 to 1980,its rate IRL70-80dropped to the minimum;As for the period of 1990 to 2000,arid valley had the highest"sen-sitivity",with a annual rate of change(CCL90-2000)13.01%,followed by CCL2000-2010=6.51%,and in the remai-ning period,a average annual rate of change was about 4%.This research achievement can provide important scien-tific basis for rational site planning for settlements,disaster risk management,proper population distribution and re-adjustment in some areas of western China with a high susceptibility in geohazards.
arid valleyboundary fluctuationevolution patternrisk managementthe upper reaches of Min River
NETL
NSTL
万方数据
维普
