Ecological Health Assessment Of Two Reservoirs In Guizhou Plateau

From January to December 2019,the four reservoirs of the Guizhou Plateau(Hongfeng Reservoir and Baihua Reservoir)were sampled in four seasons to conduct field investigations and surveys,and the surrounding environmental characteristics and questionnaire surveys were recorded.At the same time,referring to domestic and foreign literatures,AHP was used to establish an index system for aquatic ecological health evaluation with 5 criteria layers and 15 indicator layers.This health assessment builds a lake water ecological health assessment,which can not only understand the current water ecological health status,but also further analyze the current problems of the lake,provide feasible management suggestions for decision makers,and improve the current water ecological environment and protect the ecological environment.The stability of the system is of great significance.The main results are as follows:(1)AHP is used to determine the weight of each evaluation index,and the optimal weights of the index layers of the two reservoirs in the Guizhou Plateau are calculated.The hydrological and water resources weights of the criterion layers of the two reservoirs in the Guizhou Plateau are calculated to be 0.0607,and the physical structure state The weight is 0.1799,the chemical water quality state weight is 0.1799,the biological state weight is 0.3263,and the social service function weight is0.1068.Among them,the weight of the stability of the riparian zone of the physical structure index layer is 0.5584,the weight of the vegetation coverage of the riparian zone is 0.319,the weight of the artificial disturbance degree of the riparian zone is 0.1220;the weight of the dissolved oxygen of the chemical water quality index layer is 0.6711,and the weight of the oxygen consumption organic pollution index is 0.1144,The eutrophication state index weight is 0.2145;the biological index layer phytoplankton density weight is 0.4512,the phytoplankton diversity index weight is 0.2418,the zooplankton diversity index weight is0.2418,the epiphytic diatom index weight is 0.0651;social service function index The weight of the flood control index is 0.5068,the weight index of the water function zone is 0.1428,the weight of the water resources development and utilization index is 0.2641,and the weight of the public satisfaction is 0.0863.(2)The average daily water level of Hongfeng Reservoir and Baihua Reservoir is higher than the minimum water level,and the minimum ecological water level in the hydrological and water resou rce index layer is 100 points;the score result of the physical struct ure index of Hongfeng Reservoir is: HF-HW = 62.97 points,HF-SC H = 65.89 points,HF-JJW = 69.65 points,HF-XJSC = 80.26 points,HF-HYD = 66.61 points,HF-DB = 71.12 points,HF-YD = 78.05 poi nts,HF-PSZ = 72.92 points,HF-YCH = 81.86 points,HF-MXH = 80.64 points,HF-HLH = 82.08 points,HF-MWH = 55.59 points;Bai hua Reservoir physical structure index score results are: BH-HQ =63.80 points,BH-YJZ = 72.28 points,BH-MXH = 76.89 points,BH-GLSC = 75.69 points,BH-DB = 81.86 points,BH-DMQH = 46.20 points,BH-CCH = 68.26 points,BH-LMH = 75.69 points.(3)Hongfeng Reservoir's chemical water quality criterion layer score range result is 68.61 ? 83.28,biological criterion layer score range result is 30.85 ? 74.93;Baihua Reservoir grade score range result is 66.67? 83.85,biological criterion layer score range result is 48.40 ? 72.51.(4)Investigate and research the four indicators of water conservancy and flood control,compliance with water function zones,water resources development and utilization,and questionnaire survey.Among them,the utilization rate of water resources development of Hongfeng Reservoir has reached 74.88%,the excessive development of lake water resources,Hongfeng in 2019 The social service function of the reservoir is 57.40 points,and the social service function of Baihua Reservoir is 82.84 points in 2019.(5)The weighted sum of the weights of each index layer is used to obtain the lake health index LHI.According to the LHI index,Hongfeng Reservoir has 3 sub-health,9 health,Baihua Reservoir 8 health.Among them,Hongfeng Reservoir monitoring point LHI = 57.67 is sub-health state,HF-HYD LHI = 58.12 is sub-health state,HF-DB LHI = 59.67 issub-health state,and the remaining monitoring points LHI index is greater than 60 There is a small difference between the health status and the expected goal.The Baihua Reservoir LHI index> 60 is healthy.(6)According to the correlation analysis of pearson,the main factors affecting the LHI of Hongfeng Reservoir are TN and TP.These two elements directly affect the eutrophication of Hongfeng Reservoir,and the indirect factors are CODMn and SD;it affects Baihua The main factor of the reservoir lake health index LHI is SD,and the indirect influence factors are TN and TP.