| Eco-geologic environmental science is mainly study on the problems of the resource, environment and population. The international frontier problem currently of it is the comprehensive, quantitative and 3D visible study on the eco-geologic environment based on the "3S" technology. The Yellow River is the second largest river in China, and is famous for its suspended riverbed, frequent shifts and huge amount of sediments. Yellow River Delta is famous for its unique evolutionary features-its coastal zone is either being rapidly silted or eroded. The high rates of sediment transport and deposit make the Yellow River mouth the only estuary in the world where new land is being created at a rates of more than 20 Km2/yr. At the same time, it is eroded by oceanic waves and currents. However, because the Delta is newly formed land which is affected by the mutual evolution of the sea, land, river and marsh, its geologic environment is non-stable and ecological environment is vulnerable, so the new ecosystem is very mutability, instability and frangibility. In response to the unique evolutionary process, there are several environmental engineering problems in the Yellow River Delta, such as: instability of the Yellow River channel, earthquake, low bearing capacity of nature foundation, liquefaction, soil salinization, coastal erosion and progradation, flood storm surge, etc. Meanwhile, accompanying intensive human activities there occurred some man-made problems related to development and exploitation of groundwater, oil, gas and brine, including land subsidence, secondary soil salinization, depression cone of groundwater, saline water intrusion, land crack, water pollution, fresh water shortage, Yellow River cut-off, and desertification. So the sustainable development of Yellow River Delta is restricted by all these problems. So it is so great importance to study the countermeasures for sustainabledevelopment in terms of geoscince. On the basis of comprehensive studying on hydrogeologic, engineering-geologic, geochemical, environmental geologic conditions, the formation and evolvement of Yellow River Delta, countermeasures for preventing, mitigating and controlling the above-mentioned issues have been put forward in this paper, with the purposes of ensuring the sustainable development of the Yellow River Delta. New eco-geologic environmental study models for the same deltas are set up, systemic study method and guideline system for plain, coastal land, marsh, riverbed, city and country developing is provided.On the basis of comprehensive studying on the eco-geologic environmental factors, such as geologic structure, stratum, landform, physiognomy, geography environment, hydrogeologic, environmental geology, engineering geology and geochemistry, the comprehensive management model and spatial geography information database is set up, with the purpose of evaluating the groundwater quality, engineering geologic environment, geochemical environment and eco-geologic environmental quality. Comprehensive predication science of minerals information, geostatistics, eco-geologic environmental science, system science, operational research science, geomathematics and geologic modeling methods by 3S technology is used.1 .Environmental Geologic Background of Yellow River DeltaAccording to the second exploitation, by spatial geography information technology, of geologic data including geology structure, stratum, geophysical prospecting, geochemical exploration, remote sensing and etc., the paper get the characteristic of environmental geologic background of Yellow River Delta. The Yellow River Delta is located in the northeast part of the Jiyang graben, which is part of the large northern China depression called the Huabei depression. Archaean metamorphic rocks form the crystalline basement in the Huabei depression. The lower Paleozoic group encompasses a series of marine sediments made up mainly of carbonate rocks. Sedimentation during Mesozoic and Cenoxoic eras has resulted in a sediment sequence up to 12000m thick. The Tertiary includes shales and sandstones ofconsiderable thickness, which contain oil and salt. The Quaternary comprises the Pingyuan Group overlying the Minghuazhen Group, and is about 120-400m thick. The basement is highly faulted. The northeast part of the Yellow River Delta is located at the intersection of the Yanshan Mountain-Bohai Sea seismic belt with a northwest strike and the Yishu Fault seismic belt with a northeast strike. Geotectonic movement is very common in that area. According to the measured data of Shandong Provincial Bureau of Seismology, some faults, like Chengzikou, Gubei, Chennan, Shengbei and Dongying faults, show recent activity. This proves that the Yellow River Delta is very unstable.In response to the unique evolutionary process, the eco-geologic environment is considerably vulnerable. There are several environmental engineering problems in the Yellow River Delta.2.Formation and Environmental Evolvement of Yellow River DeltaFinding out the formation conditions, the characteristic and environmental evolvement of seashore by using geology, remote sensing, geology measurement and ancient environment resuming methods. Yellow River Delta is formed by the action of river and marine. Yellow River has the most important effect on the formation process of Yellow River Delta, the quantity of its water and sand affected the developing way and evolve speed of Yellow River Delta. In recent years, human activity have changed the evolve direction and the trend become more and more clear. However, Yellow River Delta is in progradation in terms of a long-term evolution with an rapidness speed, and the erosion will be weaken by human activity, such as build up dyke to protect against the tide.3.Geomorphology of Yellow River DeltaFinding out the feature of geomorphology and its effect on the eco-geologic environment by using the Quaternary geologic, remote sensing and environmental geologic methods. The Yellow River Delta can be subdivided into three genetically distinct landscapes, such as piedmont alluvial plain, ancient Yellow River Delta plain and modern Yellow River Deltaplain. It has great impact on the evolution of the eco-geologic environment of Yellow River Delta. The surface relief of Yellow River Delta is plane and lowness, but it is higher in southwest and become lower in northeast. The shape of the relief dominated the surface water and groundwater flow, always store up the water and salt around the depression, so that leading to the drought on upland, water logging in depression and alkali on second slope.4.Hydrogeologic environment of Yellow River DeltaFinding out the distributing, flowing condition, water quality, water capacity, water supply and demand situation comprehensively, by using drilling, hydrochemical, hydrogeologic and environmental geologic methods. The groundwater in the Yellow River Delta is dominated by the factors such as geologic structure, stratum lithology, ancient geography condition, landform and relief. The hydrogeologic conditions of the groundwater are more complex, and have obvious characteristics in level and vertical directions. It can be subdivided into three sections in the level direction such as entirely fresh water section, salt and fresh water lap over section and complete saltwater zone. On the other hand, it can be subdivided into shallow groundwater (<60m), middle deep groundwater (60-200m) and deep groundwater (>200m) in the vertical direction also, with the distributing area 602.2km2, 928km2, 1749km2 each other. The groundwater quality in the Yellow River Delta is very complex and has obvious zoned distribution from south to north. With the increase of total dissolved solids (TDS), the dominative anion is gradually changed from HCO3 to CI. Accompanying intensive human activities there occurred some man-made problems, such as groundwater depression cone, land depression, saline water intrusion and environmental pollution, related to development and exploitation of groundwater, oil, gas and brine.5.Engineering geologic environment of Yellow River DeltaSetting up comprehensive evaluation model for engineering geologic environment of Yellow River Delta in order to finding out its feature and evolvement law and evaluating the building suitableness of the natural foundation soil in the Delta. The natural foundation soil ofYellow River Delta is Quaternary sediment mainly, which is formed in recent years, its solidification degree is weak and made up by silt soil, silt, silt clay and clay, so it can not bear the weight of very weightily architecture. The standard of the weight it can bear is changeable in the level direction from less than 80kpa to more than 300kpa. All in all, it is decreasing gradually from piedmont alluvial plain and ancient Yellow River Delta plain to modern Yellow River Delta plain. But in the vertical direction it is more changeable in different sedimentary environment, and is increasing gradually from surface to deep of the foundation soil where have the similar quality. The quality of the foundation soil is very important for the city development, especially for the higher buildings in the city.6.Geochemistry environment of the Yellow River DeltaSetting up a comprehensive evaluation model for geochemistry environment of Yellow River Delta in order to finding out its feature and evolution law, evaluating the availability of geochemistry elements so as to guiding the agriculture and industry development, using the geochemistry, agriculture geology, hydrochemistry, and environmental chemistry methods. The content of some element such as Fe, Ca, As, N, Mg, P is insufficient in the background of Yellow River Delta, but some others as Mn, Cu, Pb, Zn, B, K, Na, Mo, F is sufficient. The content of some element as Fe, Cu, Pb, Mg, As, N in the second environment is more sufficient than in the first environment. But, the content of other element as Zn, Ca, B, Se, Hg, P, F in the first environment is more sufficient than in the second environment. All these are formed by the natural and human activity, especially the human activity in recent years such as mine exploiting, industry and agriculture development.7.Eco-geology environmental problems of Yellow River DeltaFinding out the distribution, evolvement law and formation cause of geology hazards in the Yellow River Delta, including fresh water shortage, water and soil pollution, desertification, soil salinization, depression cone of groundwater, saline water intrusion, land subsidence, using the RS, GIS, hydrogeology, hazard geology methods. Countermeasures for preventing,mitigating and controlling the above-mentioned issues have been put forward in this paper.8.Cmprehensive assessment of eco-geologic environmentOn the basis of comprehensive studying of the eco-geologic environmental data, such as petroleum geology, hydrogeology, engineering geology, environmental geology, geochemistry, landform and physiognomy and geography environment, the comprehensive management model and spatial eco-geologic environmental information database is set up by using computer, MAPGIS6.5 (developed by the Geology University of China) and MS ACCESS. It includs many databases of geologic information which is get in the field and calculate results. All these databases are got in touch with the MAPGIS spatial database in order to analysis the data and draw the geologic maps.Setting up the comprehensive assessing model of eco-geologic environment by expert clustering method as follows. Firstly, according to there is different influence factors indifferent landform of the Yellow River Delta, different assessment factor and program is selected in piedmont alluvial plain and Yellow River Delta plain. All the factors are fixed quantitatively according to the standard mark that the experts have been gave based on experiences. Secondly, the rights of all factors are got by the AHP and DELFI method. Then the mark of each factor in every point and distribution can be computed. At last, assessment of each distribution can be done by the mark and the distributive maps can be draw by the MAPGIS. The paper divided the Yellow River Delta into three distributions such as the area whose quality of eco-geology environment is better, middle and not suitable in order to guiding the industry and agriculture development or city planning.-9.Main innovative points and new development9.1 So comprehensively and completely to study the data of RS, geology, geophysical prospecting, chemical exploration, geography, hydrogeology and environmental geology of Yellow River Delta is the first time. Based on comprehensive study on the information of data be mentioned above, the paper set up the comprehensive spatial geography information...
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