The Response Of Lakes To Climate Change In The Hunshandake Sand Land

As an important part of the land water cycle,lakes play an important role in the water cycle of natural system in the arid and semi-arid areas especially. Otindag sand land located the eastern asian monsoon area,temperate and desert steppe,which is across the sub-humid Semi-arid and arid climate zone. It's controlled by the Siberia-Mongolia high atmosphere pressure in the winter,cold and dry. Affected by the southeast summer monsoon in summer,it is rainy and warm,and rain heat over the same period. The result of the characteristics of water hot combination,space-time structure and ecological environment has unusual trait. The one hand,as the intensity of the quaternary tectonic movement and climate change,there formed many lakes basin and aeolian sediments,the hole of spring and interior river and other complex features make it become the most sensitive and typical area of response to global change. On the other hand,the arid and semi-arid climate lead to sensitive fragile ecological environment in this area. The animal husbandry modes of production make the production level of the region low relatively.anti disaster ability is weak,and lead to major natural disasters easily. At present,under the background of the global change,ecological and environmental problems produced in the regionis still very prominent,for example,desertification aggravate,surface runoff decreased,lake shrinking and dried up,and seriously hampered local economic development,endangering the ecological security,attracted much attention of scholars,and which affects water resource,grassland landscape and local resident's life and production. So the researches of the Otindag sand land lake changing process and its response to the climate change is contribute to understand the strength of the regional climate change and human activities,provides a scientific basis of current lake ecological environment management measures and lakes changing in the future,has important application value and scientific significance.Otindag sand land located in the monsoon area,the climate and human activitis in region. Lead to ecological environment fragile sensitively. This paper choosing 176 lakes which covers more than 0.01 km2 in 1969 as research objects indicated by topographic map in scale of 1:50000,combining with 17 stages of Landsat MSS/TM/ETM/OLI satellite remote sensing images data in 1973-2013,analysis of total area,numbers and the groups of typical lakes that is more than 10 km2 during 1969 to 2013. In concurrently,lakes are verified through the field,and the typical lakes in the lake water quality monitoring, combined with the typical lakes in the past,and the data of lake water quality changes. This article also collected Otindag sand 7 meteorological site in 7 county over the xilingol league area from 1956 to 2013 convening temperature and precipitation data from month to month. By analyzing the changes of the temperature and precipitation,this paper discusses Otindag sand lake area,group number and the lake water quality changes and climate change response mechanism.1?Otindag sand land lakes group's total area assumes the declining trend, almost decreased by 198.62km2 with a rate of 4.64 km2/a in recent 45 years,and experienced the process of "decline-rising rapidly-decline rapidly-edged up-lower volatility-increase". During 1969 to 2013,there 88 shrinking lakes,85 dried lakes and 2 expanding lakes(building dams). Concretely speaking,the fluctuating downtrend of total area of lakes occurred in 70s to 80s of 20th century,continuously showed an upward trend in early 1990s,the overall downtrend in 1995-2011, lower volatility in 2003-2011, and slightly expanding trend after 2013.2?In the view of spatial distribution pattern, Otindag sand land lakes group is given priority to lake shrinking,dry up in recent 45 years. These lakes are distributed in the desert hinterland of study area. In 1995-2001,the number lakes has dropped strongly,and make lakes serious shrinking,dry up in the desert hinterland of study area.3?In the view of the water quality data analysis in Otindag sand land lakes, PH is more then 8,making the liquid quality tends to alkaline. In concurrently, other quality indexes also showed a higher concentration,the studies showed Dalai lake has reached to an extremely eutrophic rank. All of lake salinity,Tp,TN,ion concentration.turbidity,Chlorophy.BGA PC Con and ODO density have shown high value showing that the smaller lakes area of the lake water turbidity is higher.the lower lakes transparency.4?The annual temperature and precipitation change results:Otindag sand land lakes has a good corresponding relationship between the temperature rising precipitation downward water hot combination became warming and drying. In 1969-2013,the study area meteorological sites presented ascendant trend of annual average temperature,the change rate is 0.0434?/a,while the precipitation showed a downward trend with volatility and its change rate is 5.99 mm/10 a, lead to the decrease of runoff into the lake and increasing evaporation of lake surface,render the lakes severe atrophy,lakes shrinking,drying Serious. On the other hand, the climate change caused the water salinity increasing,lakes water salinity alkalinity,and salinity will likely continue to rise in studies.