| With the quickly development of industry and society, human demands for water has beenincreasing; limited water resources cannot meet the requirments of people’s daily life and socialdevelopment. Groundwater was excessively exploited, and then some areas were changed to seriousgroundwater funnel region. Henan province is located in downstream of the Yellow River, more than247.51km2farmland was been irrigating with water diverted from the Yellow River. The project ofdiversion water from Yellow River supplied important water resources for local region, alleviating thecontradiction of water resources between different areas, made large change to the regional groundwaterdynamics and underlying surface conditions. Owing to the sediment, the river elevation was higher yearby year in the middle and lower reaches of the Yellow River Region, about5to8meters higher thanriverbed. For infiltration recharge of the Yellow River, precipitation, evaporation and other factors,groundwater buried depth is very shallow, and the aquifer groundwater salinity is also high, there isathreat of waterlogging and potential secondary salinization.In this paper, Groundwater dynamic was analyzed after irrigation with water diverted from theYellow River from1994to2010. The analysis of spatial and temporal variation of groundwater was todetermine the key effect factors of underground water dynamic; According to the existing groundwaterobservation wells, the groundwater observation network of Shangqiuwill be optimized, which willimproving the monitorefficiency of groundwater table. The main results were as follows:(1) Analysis of spatial and temporal variation of groundwater table. Results showed thatgroundwater table was different in different water level year, the overall trend wasthat the groundwatertable drops betweenFebruaryandJune, and arise to the top duringJune to September, lower a bit betweenSeptember and November, and it would be relatively stable between November and January in the nextyear. The dynamic of underground water tablewas different in different morphologicregion.Groundwater tablewere increased in both of the irrigation area and the water diversion region,such as Liang Yuan1underground water table increased fastest, at the space of1.42m/a; Thegroundwater table in the areaswhere irrigated with underground waterwas in a weak downtrend, drop atthe space of0.06m/a.(2)Geostatistics method was applied to analyze the spatial and temporal variability of groundwatertable in Shangqiu: The results showed that the groundwater tablewas geometry anisotropy.Thegroundwater table in1996presented moderate intensity spatial variation, while the2010’s spatialvariation was intensive; Due to long-term complement to groundwater, spatial correlation dimensionwas increased. There was a clearly first-order trend in direction of the groundwater table.On thewhole,underground water table was higher in northwest and lower southeast.(3)Analysis of Grey correlation underground waterdynamic. Analysis results showed thatthreeinfluence factors have greatly being influenced on underground water. The amount of groundwatermining has the highest correlation to underground water table, followed by precipitation and diversion. (4)Analysis of composition of ions in groundwater and soil salt content. Soil salinity wasincreasing during April to June, at the decline stage duringJune to September, and then rising betweenSeptember to November,while it would almost remain unchanged from November to February in thefollowing year.The groundwater salinity ofdifferent areas was quite different, and ion content variedwidely throughout the country. Anion in the groundwater mainly was CO2-3+HCO–3, kation mainly wasNa++K+. The surface soil salt content have the highest relevance with HCO-3, its grey correlation was0.95.(5) Optimization of groundwater observation network in Shangqiu.The number of undergroundwater table observation wells was optimized by the principle of classical statistics. CombiningArcGIS10.0statistical analysis module, aftervalidated analysis, the remove of the second order trendGauss model was used to analysis the spatial variation of groundwater level and correlation.The resultsshowed that only56wellswas needed to monitor the underground water dynamic in Shangqiu. Krigingis an effective method to optimize underground waterobservation network.Key word:Yellow River Diversion; Underground Water Dynamics;Soil Salinization; GroundwaterObservation Network;Geostatistics... |
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