| Aixi Lake basin is a relatively fourishing economic region,There are 230.000 people and many factories around Aixi Lake。In recent years a lot of waste water from industry,agricuture and domestic sewage drained into the lake. with rapid development of economy and population aroud the lake.which had polluted quality of lake seriously.much Engineering Construction made Aixi Lake small day by day , self-purification capability was weakened. An overdose of exploitation caused serious damage to the ecological balance. All of these has aggravated the Lake's eutrophia. decreased its self-clarification and made the water quality severely worse.the quanlity of the water took a sharp turn for the worse.affected economic, ecological and aesthetic value of Aixi lake as natural eco-environment should have. Forthermore ,Severely polluted water is seriously endangering the health of local people and culture fishery, which restricted economic development of Aixi Lake region。To solve the serious environmental problem day by day,It is exigent and necessary to study and work out the pollution mechanism to solve the Lake's pollution.Focused on bed bud of Aixi Lake, based on analysing the present pollution and combined age data,this article revealed pollution process in recent 50 years and worked out the relationship between human activities.The used indexes are pigments(CD,TC,Osc and Myx),granularity(grain size of mean value,average grain size,etc),biogenic silica ,sedimentation, TOC(the total carbon content ), TOC, TN, C, H and TP,C/N, N/P and C/H。The results showed that the region which is close the source of pollution,the lake is in the state of heavy euniphication; Each index is high near the source of pollution,and all sides lower;From liberation of China to mid-1990 of the last century the polluton of Aixi Lake aggravated,water power of the lake became small,the area of the lake turn smaller,the lake was in decline.the water quality became good since mid-1990,each index value became low,but kept a high degree,the area turn more smaller; each index value is relative with the strenth of human activityRelevant studies on limnology and sedimentology show that the main reason for the destruction of lake ecology is irrational development on lake. I put forward measures on lake environmental protection and recovery: because eutrophia is the largest problem we are facing at present caused accumulation of nutrient salts, from now on, drain of polluted matters of every kind should be controlled and waste water from factory, city and village should be drained after clarification;pesticide and fertilizer should be reduced in agriculture; recover lake wet land system and cultivate good lake ecology to increase the Lake's ability of clarification.. In order to reduce silt flowing into the Lake, Measures should also be taken to plant more trees and grass. The speed of enrosion must be reduced and more money should be spent on curing dirty. |
