Analysis Of Eco-environmental Geological Problems And Driving Forces In Henan Section Of The Yellow River Basin

As an important economic corridor in Henan Province,the Henan section of the Yellow River Basin provides a solid material foundation and living guarantee for the survival and development of the people in Henan Province and the whole country.In recent decades,with the global warming and the increase of human industrial and agricultural activities such as farming,mining and sand mining,the natural surface landscape in some areas of the basin has been damaged,the soil erosion has been severe,the ecological service function has been reduced,and the ecological environment has deteriorated,which has seriously affected the ecological balance of the region.As an important turning point of the topography of the Yellow River Basin,the Henan section has a special geographical location,and its ecological status is extremely critical for the implementation of the ecological protection and high-quality development of the Yellow River Basin.Therefore,there is an urgent need to explore its eco-environmental geological problems and driving forces in order to provide scientific basis and technical support for the monitoring and management of the ecological environment of the Yellow River Basin in Henan Province.The thesis is supported by the Open Fund Project of the Key Laboratory Center of the Ministry of Education for Groundwater Hydrology and Ecological Effects in Arid Areas（2014G1502022）.Based on the remote sensing images of 2001,2010 and 2019,combined with the data of regional physical geography,geology,meteorology,human activity and field investigation,this thesis takes Henan section of the Yellow River Basin as the study area,and uses“3S”technology to explore the eco-environmental geological problems and their spatiotemporal evolution characteristics from five aspects:soil erosion,soil and water conservation function,water conservation function,biodiversity maintenance function and geological hazard susceptibility.It uses the spatial superposition analysis method to comprehensively analyze the eco-environmental geological problems in the study area,and uses a combination of qualitative and quantitative methods to analyze the driving factors and key driving factors that cause these problems from natural factors and human activities.The main achievements and understandings are drawn as follows:（1）The main eco-environmental geological problems in Henan section of the Yellow River Basin are basically identified.The main eco-environmental geological problems in Sanmenxia-Zhengzhou section are:serious soil erosion,degradation of water conservation function,and prone to geological disasters.The main eco-environmental geological problems in Zhengzhou-Puyang section are:poor soil and water conservation function,degradation of water conservation function,and poor biodiversity maintenance function.From 2001 to 2019,the soil erosion,soil and water conservation function and biodiversity maintenance function of the study area showed a trend of improvement,mainly as the area of mild to severe erosion decreased by 5171.18 km²,the average amount of soil and water conservation increased by 7172.78 t·km^-2·a^-1 and the average value of biodiversity maintenance function index increased by 0.014119.The water conservation function and geological hazard susceptibility showed a slight deterioration trend,mainly as the average amount of water conservation decreased by 2249.74 m³,and the area of geological hazard prone areas increased by 1837.66 km².（2）The spatiotemporal evolution characteristics of the eco-environmental geological problems in the study area are comprehensively analyzed.From 2001 to 2019,the eco-environmental geological problems in the study area have shown a trend of obvious improvement,the areas of less serious and more serious areas have increased by 1525.19km² and 4419.63 km² respectively,and the areas of serious and particularly serious areas have decreased by 5155.93 km² and 788.89 km² respectively.The particularly serious areas are mainly concentrated on both sides of the main stream of the Yellow River in Sanmenxia-Zhengzhou section,and the less serious,more serious and serious areas are evenly distributed in the study area.（3）Factors such as rainfall,altitude,vegetation coverage and mining activities are selected to analyze the driving forces of the evolution of eco-environmental geological problems in the study area.The results show that the contribution degree of driving factors to eco-environmental geological problems in Sanmenxia-Zhengzhou section is as follows:altitude>vegetation coverage>rainfall>land use type>other factors.Altitude is the key driving factor of eco-environmental geological problems in Sanmenxia-Zhengzhou section,and its contribution degree over the years is more than 0.2.The lower the altitude,the greater the degree of human interference and the greater the degree of damage to the ecological environment and geology.The influence of driving factors on eco-environmental geological problems in Zhengzhou-Puyang section is as follows:rainfall>vegetation coverage>land use type>temperature>other factors.Rainfall is the key driving factor of eco-environmental geological problems in Zhengzhou-Puyang section,and the absolute value of correlation coefficient over the years is above 0.3.The less rainfall,the more serious the eco-environmental geological problems.There are 53 figures,23 tables and 147 references.