| As the degree of development and utilization for river water resources enhancedunceasingly, the hydrological regimes changed and the river ecosystem affected by a lot at thesame time, along with the neglect of eco-environment water demand, the ecological watershortage is serious that lead to the ecological environment deterioration. The eco-environmenthas a bearing on human survival and development; serious ecological problems affect thesocial economy sustained development. Excessive of water resouces development in WeiRiver caused the eco-environment deteriorated sharply and the ecosystem suffers from severesress. The analysis of eco-hydrology characteristics and eco-environment water research haveimportant scientific significance and practics values on acknowledge of the hydrologyregimes evolution rules and the realization of the water resources reasonable allocation.According to the daily flow sequence of Linjiacun, Xianyang and Huaxian stations and theIHA software, this paper analyzed the33Indicator of Hydrological Alternation, the degree ofhydrology change and the whole hydrologic degree, calculated the change of34enviromentalflow indicators that belongs to the Environmental Flow Components, improved the RVAmethod and the formula of the ecological water requirement satisfaction, then got theeco-environmental water demand of the three sections, and estimated the satisfaction ofecological water requirement, at last discussed the zoology problem and influence that causedby the change of river hydrology regime and environmental flow and put forward thecountermeasures of ecological scheduling. The main research contents and conclusion are asfollows:(1) The way to calculate and analysis the degree of hydrological change for all Indicatorsof Hydrologica Alteration (IHA) and whole degree of river hydrology change of Linjiacun,Xianyang and Huaxian sections after the human activities influence is the Range of VariabilityApproach (RVA) method by using IHA software. The results showed that under the humanactivity influence, the years number of most IHA parameters of three sections fell into the RVA threshold were less than expections, month average flow has a tend to be significantlyreduced, human activities made obviously affections on the month average flow, the extremeflow, flow change rate andfrequency. The eco-hydrological characteristics change degrees ofthree sections belong to overall high change and the hydrological degree were67.940%,68.682%and71.410%respectively. Higher hydrological change degree indicators include:the1-min flow, rise and decrease rate of Linjiacun section, the January flow, March flow,October flow, the number of high flow and rise rate of Xianyang section, the October flow,1-,3-,7-,30-and90-min,30-max, base flow index and rise rate of Huaxian section.(2) The tool to statistic and analyze the variations of Environment Flow Components(EFC) and environment flow indicators after human activities is IHA software. Afteraffections, the flow traffic of the three sections tends to simplification and was mostly due tolow flow and high pluse flows, the number of extremely low flow increased and showed morecentralized trend; the low flow and extremely low flow undered sifnificant influence. Greatlyinfluenced environmental flow indicators by human activities involved: part of low flow innon-flood season; the minimum value, duration, time and occurrences of extremely low flow;the maximum value, time, duration and decrease rate of high flow pluse; the decrease rate ofsmall flood and the rise and decrease rate of large flood.(3) A relatively simple method to calculater the eco-environmental water requirement hasproposed—RVA method. The eco-environmental water demand of Linjiacun, Xianyang andHuaxian sections were529.5million,1.1274billion and2.3908billion m~3repectively. Afterthe compariations with existing research results, the results showed that the results almost hasno difference with the Tennant method, and the RVA method can take as a new method tocalculate the environment water demand.(4) This paper put forward the concept and formula of ecological water requirementsatisfaction and the satisfaction of ecological water requirement of Linjiacun, Xianyang andHuaxian sections in different period has been analyzed. The results showed that thesatisfaction of ecological water requirement has a decrease trend in the whole, the time forminimum satisfied degree of ecological water requirement was focoused in May, June,Auguse and September in flood season; the volatility of three sections was relatively complex,especially during rainy season.(5) Discussed the ecological problem and influence that caused by the change of riverhydrology regime and environmental flow and put forward the ecological countermeasures ofthe unified dispatching for river water resources and the guarantee to eco-environment water demand in view of the Wei River. |
PDF Full Text Request