Spatial-temporal variations of ecological vulnerability in the Tarim River Basin,Northwest China

As the largest inland river basin of China,the Tarim River Basin(TRB),known for its various natural resources and fragile environment,has an increased risk of ecological crisis due to the intensive exploitation and utilization of water and land resources.Since the Ecological Water Diversion Project(EWDP),which was implemented in 2001 to save endangered desert vegetation,there has been growing evidence of ecological improvement in local regions,but few studies have performed a comprehensive ecological vulnerability assessment of the whole TRB.This study established an evaluation framework integrating the analytic hierarchy process(AHP)and entropy method to estimate the ecological vulnerability of the TRB covering climatic,ecological,and socioeconomic indicators during 2000-2017.Based on the geographical detector model,the importance of ten driving factors on the spatial-temporal variations of ecological vulnerability was explored.The results showed that the ecosystem of the TRB was fragile,with more than half of the area(57.27%)dominated by very heavy and heavy grades of ecological vulnerability,and 28.40%of the area had potential and light grades of ecological vulnerability.The light grade of ecological vulnerability was distributed in the northern regions(Aksu River and Weigan River catchments)and western regions(Kashgar River and Yarkant River catchments),while the heavy grade was located in the southern regions(Kunlun Mountains and Qarqan River catchments)and the Mainstream catchment.The ecosystems in the western and northern regions were less vulnerable than those in the southern and eastern regions.From 2000 to 2017,the overall improvement in ecological vulnerability in the whole TRB showed that the areas with great ecological improvement increased by 46.11%,while the areas with ecological degradation decreased by 9.64%.The vegetation cover and potential evapotranspiration(PET)were the obvious driving factors,explaining 57.56% and 21.55%of the changes in ecological vulnerability across the TRB,respectively.In terms of ecological vulnerability grade changes,obvious spatial differences were observed in the upper,middle,and lower reaches of the TRB due to the different vegetation and hydrothermal conditions.The alpine source region of the TRB showed obvious ecological improvement due to increased precipitation and temperature,but the alpine meadow of the Kaidu River catchment in the Middle Tianshan Mountains experienced degradation associated with overgrazing and local drought.The improved agricultural management technologies had positive effects on farmland ecological improvement,while the desert vegetation in oasis-desert ecotones showed a decreasing trend as a result of cropland reclamation and intensive drought.The desert riparian vegetation in the lower reaches of the Tarim River was greatly improved due to the implementation of the EWDP,which has been active for tens of years.These results provide comprehensive knowledge about ecological processes and mechanisms in the whole TRB and help to develop environmental restoration measures based on different ecological vulnerability grades in each sub-catchment.

Using"Three-dimensional Space Resources"for Fenlong Technology to Improve Grain Econoloy and Expand Human Living Spaces

Fenlong Technology has been applied to increase yield by 20%-50%,improve quality by 5%,and retain water by 100%in 40 kinds of crop cultivated land and saline-alkali land in 26 provinces of China.This paper clarified for the first time the scientific theory system of Fenlong Technology using three-dimensional space resources"Fenlong Agricultural Nature Theory"and the development of the relative"limits"of agricultural growth,which provides a huge power support and natural force for expanding human living spaces.Through inventing and creating a scientific and technological system of farming tools,farming machinery,farming modes,and magic weapons for cultivation,Fenlong Technology can increase grain,promote ecological development,and greatly expand the living spaces of the Chinese nation and achieve sustainable development.Using Fenlong Technology,China has expanded from the current single"cultivated land agriculture"to the"big pattern agriculture"of Fenlong"cultivated land+saline land+degraded grassland+marginal land+desertified land+river water",flexibly used 147 million ha of"three-dimensional space resources"of land,and the newly increased food,meat,and fish can feed 300 million to 400 million people,increased the water storage by 100 billion m^(3),and reduced the collection of groundwater by 20 million to 60 billion m^(3).