The Assessment On Low-flow Resource Carrying Capacity And A Discussion On Its Evolution In Karst Area

The precipitation in Karst is more abundant,but because of the uneven space-time distribution and the special hydrogeological structure,the difficulty of the exploitation and utilization of water resources is increased.In recent years,with the rapid development of Karst's economy,there are serious water resources waste,water pollution aggravation,water resources utilization efficiency is not high,water resources shortage.The contradiction between supply and demand of water resources is becoming more and more obvious,especially in the low water period,which has seriously hindered the sustainable development of the ecological environment and social economy in this area.In view of this situation,this paper extends the research on the bearing capacity of dry water resources in Karst area on the basis of the domestic and foreign research on the carrying capacity of water resources and the bearing capacity of dry water resources.The main contents of this paper are as follows:1.Starting from the definition of the bearing capacity of dry water resources,combining with the special hydrogeological structure of Karst area and referring to the previous research,the paper builds up the water pressure(P)bearing state(S)ecological base(B)human response(R),the conceptual model of DPSBR,and establishes the bearing capacity of the dry water resources in the Karst area.Evaluation index system.2.Taking Guiyang as the research object,the main and objective weights of each index are calculated by the analytic hierarchy process and entropy weight method.The optimal combination of the two is realized according to the principle of minimum information identification,and the bearing capacity of the dry water resources in Karst is evaluated by the set pair analysis method.The results showed that the bearing capacity of dry water resources changed from 2002 to 2006 grade III to 2007 to 2009 II to grade II to stage III of 2010 to 2015.Under the influence of grade membership F1,F2 and accumulative contact degree H1 and H2,the level of bearing capacity of dry water resources in Guiyang will gradually change from grade III to class II,and the cumulative contact degree is H1 and H.The confidence distance between 2 and H3 is gradually decreasing,which shows that the development and utilization efficiency of dry water resources in Guiyang has been greatly improved in recent years,and the contradiction of supply and demand has been alleviated to a certain extent.3.Then the grey relational grade model is used to study the same evaluation.The results show that the bearing capacity of dry water resources has changed from grade IV to grade IV in 2002,and from three to grade IV in 2004-2006 years.The bearing capacity of dry water resources in the 2007-2009 year is reduced to grade V,and the bearing capacity of dry water resources in 2010-2015 years has been promoted to grade IV.Combined with objective facts,we know that the combination weight-SPA model is more suitable for the evaluation of low water resources carrying capacity in Karst area.4.In the analysis of the evolution of the bearing capacity of the dry water resources in Karst,the evolution theory,evolution characteristics and evolution process of the bearing capacity of dry water resources are expounded,and the evolution of the bearing capacity of the dry water resources in Guiyang is analyzed with the grey relational entropy model.The results showed that the bearing capacity system of dry water resources in Guiyang was in a state of deterioration in 2002-2006 and 2008.After reasonable regulation and control,the effect appeared in 2007.Until 2009,the bearing capacity system of dry water resources entered a benign orbit,and the deterioration trend was effectively suppressed.5.the article finally puts forward some feasible suggestions and measures for the above problems and analyzes the shortcomings and innovations,aiming at providing a certain theoretical basis for improving the current or future Karst region's bearing capacity of dry water resources and planning for social development.