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Research On Groundwater Sustainable Yield In Medium And Small Basins Of North China

Posted on:2010-01-29Degree:DoctorType:Dissertation
Country:ChinaCandidate:F Z ShiFull Text:PDF
GTID:1100360272996200Subject:Hydrology and water resources
Abstract/Summary:PDF Full Text Request
The water resources are of serious shortage in the medium and small basins in northern china, while the exploitation proportion of the groundwater resources is relatively huge. And there are also many issues caused by development in the water resources and water environment. The problems during the development are attributed to the following aspects: the whole or local over-exploitation; water contamination; the destroyed eco-environment; development deficiency, irrational development and mode, and so on. The paper is based on the foundation of doctoral discipline fund project-"the study on determination of the groundwater sustainable yield in medium and small basins", in which the author took part as the major executers. The early point of the research derived from the misunderstanding of the groundwater exploitation—the groundwater is over-exploited once the cone of depression is formed in a basin, however, it is not the only reason for the groundwater exploitation. In fact, many piedmont and plain reservoirs are built for cascade development in the upriver, which leads to the low flow and recharge in the downriver, the groundwater is exploited to fulfill the water needs, majority of the basins in the northern part follow this exploitation. Under the current development mode, the tremendous water resources are seriously wasted by the water surface evaporation in the upriver due to the dry climate in the northern areas, and leads to not only the reduction of the downriver runoff and the groundwater recharge, but also the serious over-exploitation and eco-environment problems. Then a proposition is proposed, that is how much is rational for groundwater exploitation in a basin. Therefore, the paper come up with the conception of the groundwater sustainable yield in the medium and small basins. The groundwater sustainable yield is relevant with many factors, which include the total amount of the water resources, rational exploitation and utilization quantity of the surface water, the flood storage capacity, the ecological water consumption, the groundwater regulation and storage capacity, the allowable groundwater exploitation capacity, the development and utilization mode of the water resources, water distribution under the various development conditions of water resources, and so on. The key problems are what the goal for water resources utilization in a basin is, what the meaning and composition of the groundwater sustainable yield is, and how to determine the quantity.To solve these problems, the paper took the northern medium and small basin as the research object due to its easily defined cycling relation of the water resources, sensitive artificial interference response and strong controllability. The paper analyzed the characteristics of the water resources in northern medium and small basin and the existing problems for the water resources development mode, then by the artificial regulation technology, put forward the conception of basin groundwater sustainable yield in the rational exploitation mode of water resources, which is based on the integrity characteristics of basin water resources, following the principle of optimal exploitation benefits and minimum environment negative effect, and the factors eco-environment water demand is also involved. The evaluation system of basin groundwater sustainable yield is also set up for better practices guiding, which is composed of the basin water cycle simulation model and the integral development benefit model and the optimization model. Then, taking the Yinma River as an example, the paper studied the groundwater sustainable yield, proposed the sustainable development mode of basin water resources and computed the groundwater sustainable yield. The results have important practical significance to the water resources utilization rate improvement, the water environment protection, and the sustainable development and utilization of basin water resources.The main results and conclusions of the paper are as follows:(1) Combining the water resources characteristics in northern medium and small basins, the paper analyzed the existing problems of the water resources development and evaluation. The causes are mainly:①the limited water resources and the increasing demand in northern area;②the serious water resources waste and deteriorated eco-environmental problems caused by irrational development mode of the water resources;③the conception of groundwater exploitable quantity, which is presently used in the evaluation and management of water resources, can not express the characteristics of the groundwater resources and can not satisfy the demands of the rational groundwater utilization and management. Based on cognition above, the paper put forward the necessity of determining the groundwater sustainable yield in northern medium and small basins, with the view of the groundwater rational utilization.(2) The formation, existence, movement and transition of basin water resources are an organic integrity system. The different development modes of basin water resources cause different hydrological responses, environmental effects and social and economic benefits. Along with increased cognition of basin hydrological system and the strengthened human intervention, the influence of human on eco-environment is more and more emphasized. The theory and methodology of the conception evaluation for groundwater exploitable quantity has always been adjusted, enriched and perfected. In order to accurately and scientifically reflect the reality of the groundwater resources to systematically guide the development and utilization of basin water resources, the paper put forward the conception of groundwater sustainable yield , and defined as follows: the exploitable, effectively rechargeable groundwater sustainable development with less negative environmental function and high utilization benefits, which can managed by artificial management of the basin water resources, through the benefits comparison of several water resources development project.(3) The paper analyzed the meaning and composition of basin groundwater sustainable yield. Compared with the groundwater general exploitable resources quantity, the concept emphatically considers integral development and utilization benefit of basin water resources and environment water demand, as well as the influence of artificial regulation to the groundwater system, which takes on the characteristics of long time series. The evaluation system of basin groundwater sustainable yield is then built, which includes the benefit model, the water cycling simulation model and the optimization model. The basin water cycling simulation model, the integral benefit model of water resources development and the demand of different ecological environment are respectively taken as a research platform, different simulation models run under different constrains, then the basin groundwater sustainable yield for the sustainable development scheme could be obtained by analyzing and evaluating the cost-benefit ratio. The evaluation system has maneuverability to evaluate the groundwater sustainable yield, which overcomes the conception definition and ambiguity.(4) Take the Yinma river, the tributary of the second Songhua river, as a typical research area, the paper determined the storage conditions of the aquifer and the characteristics of the recharge, runoff, discharge, and the groundwater chemistry by analyzing the conditions of geography, geology and hydro-geology, then, the paper studied the water cycling mode of Yinma river basin, discussed the problems of water resources development and utilization mode. Through the analysis of surface water and groundwater regulation, sustainable water resources development mode would be put forward in Yinma river basin.(5)The paper built the water cycling simulation model and integral benefit model of water resources development and computed the ecological water demand in Yinma river basin. Combined with the theory of groundwater sustainable yield, the study established the development schemes of water resources in different frequency year, obtained the water resources sustainable development schemes and basin groundwater sustainable yield in different frequency year in Yinma river basin with the integral benefit and its index as the target of the optimal development mode. The basin groundwater sustainable yield is 624 million m3/a in wet year, 539 million m3/a in normal year and 447 million m3/a in dry year. With the comparison of the current development mode with the sustainable development mode, the paper obtained the integral benefit index of the sustainable development scheme is lower than the current development scheme, but the former saves massive resources net loss, which improves the water resources utilization efficiency, and is beneficial to the sustainable development of resources and environment in Yinma river basin. The average utilization rater of water resources increases by 10.20%, resources loss rate reduces by 21.84% with the damage loss of ecological environment reduces by 39.5%. Finally, the paper simulated the long time series model and forecasted the change of the groundwater level and the flow field under the future environment change in Yinma river basin. Finally, the reliability and necessity of the sustainable development schemes were verified to ensure the social economic environment sustainable development of Yinma river basin in the further environmental change.(6) The paper finally proposed the points of the further research needed for the weakness of the thesis. That is, the contents should be improved in the interaction of surface water and groundwater, the evaluation criteria of the water resources development benefit model, the log of the eco-environment effects, etc.In conclusion, the study has an important and practical significance for the determination the groundwater development and utilization quantity, the insurance of the sustainable development and utilization of basin groundwater resources, and the reduction of the negative effects of development and utilization on the water ecology and environment.
Keywords/Search Tags:Groundwater sustainable yield, Medium and small basins, North China, Yinma River, the artificial regulation technology, integral benefit model
PDF Full Text Request
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