Spatio-temporal Change Characteristics And Analysis Of Surface Water Resources In The Tarim River Basin

The Tarim River Basin is the sensitive region of global/regional change.The basin water resources,as the carrier and characterization of the regional environment(climate),it plays an important role in the social economic development and the ecological environment evolution.Affected by global warming,increased demand for water resources and the disorderly development and inefficient utilization of water resources,there are many environmental problems such as shortage of water resources,degeneration of desert riparian forest,and desertification.So,in order to reveal the temporal and spatial variation characteristics of surface water bodies and its influence factors,based on the basic land use data,and the surface water classification data extracted by the remote sensing data of Landsat TM/ETM+/OLI of the Tarim River Basin study area from 1990-2015,the area dynamic change,temporal and spatial transfer rule and landscape pattern change characteristics of surface water bodies in Tarim River Basin were studied combined with the correlation model and method,and the influence factors of surface water bodies were also analyzed from the three aspects of geographical environment,climate change and human activities.The temporal and spatial variation of surface water bodies in Tarim River Basin was studied,the results are as follows:(1)Over the past 25 years,the land use/cover change of study area have a law that the natural landscape dominated by natural vegetation decreased and the man-made landscape that mainly for human use increased,this has also led to an increase in regional land use.(2)Over the past 25 years,the total surface water bodies area have a change rend of increased first and then decreased,and the area of the surface water bodies of glacier and non glacier have a change law that one of increased first and then decreased,and second of first increased then decreased and last increased respectively.The total area of surface water bodies,glacier and non-glacial surface water bodies area in 2015 was reduced by 2585 km2,2508 km2 and 77 km2 respectively science 1990.In addition,the beach area decreased,and the area of other water sub-classes increased.In addition,in the six sub basins,the total surface water bodies area and non glacial surface water bodies area were all mainly reduced,and the glacier area increase or decrease fairly,and they all maily decrease in the Karakoram mountain region and increase in the Tianshan region.Later,the change trend of sub-classes of non glacial surface water bodies area show: canal area increased,beach area reduced,most of the lake area decreased,while the majority of the reservoir area increased.(3)Over the past 25 years,the proportion of unchanged surface water bodies area is 73.25%,the transfer-out proportion is 16.32%,and the transfer-in proportion is 10.43%.Generally,surface water bodies transferred with grassland and unused land.The transfer characteristics of sub-class water were also analyzed,and there were obviously transfer with glacier and grassland/unused land,canal with beach,lake with farmland/grassland/unused land/beach,reservoir with farmland/grassland/beach,and beach with farmland/grassland/canal/reservoir.(4)Over the past 25 years,the landscape pattern of the study area presents a complex simple complex process,the overall landscape pattern has the tendency of fragmentation,separation,shape complication and landscape elements equalization.In addition,the landscape pattern of surface water bodies,glacier and non glacier surface water bodies are complicated.Among them,the surface water bodies landscape tends to fracture,separation,and shape regularization,the glacier landscape tends to aggregation,separation and shape complication,and non glacier surface water bodies landscape tends to fracture,continuation,and shape regularization.The change trend of landscape pattern of non glacier surface water bodies in each sub basin is weak,and it is consistent with the trend of the whole study area.However,the change trend of glacier landscape pattern in different sub basins is not consistent,it tends to fracture,continuation,and shape complication.In addition,the analyze of the influencing factors of surface water in Tarim River Basin show that:(1)In the past 25 years,the proportion of non glacial surface water bodies in the higher altitude and bigger slope areas increased,and glaciers tend to shrink to high altitudes;surface water bodies in the study area are affected by the two geographical factors of elevation and slope more.(2)In the past 25 years,both the annual precipitation and the annual average temperature have a trend of increasing,this will inevitably increase the regional precipitation and glacier melting,and then increase the regional surface water supply,this is match with the increase change of actual canal,lake and reservoir water area.(3)In the past 25 years,the correlation coefficient between county population/GDP/farmland area and non glacial surface water bodies area have the change trend of increased first and then decreased,increased first and then decreased,and significant increased,respectively.This shows that the human activities have strong dependence on regional water resources in the early period of the study,while the dependence of the later period is a little lower than the previous period.However,there is still a strong use and give relationship between them,human activities is the main reason for the decrease of beach area and the change of landscape pattern of non glacier surface water bodies.