Study On Ecological Water Demand Of Taiyangshan Lake Wetland

The Taiyangshan Lake Wetland is a rare and unique wetland in the arid zone of central Ningxia.The wetland type is mainly lake wetland,which bears the functions of ecological adjustment,tourism and leisure in the planning,and the ecological location is very important.With the development of regional economy,the degree of development and utilization of water resources has become more and more serious.As a result,wetland water resources are scarce and insufficient,and a large amount of sewage is discharged.This study collected and tested Taiyangshan Lake Wetland water samples month every month in 2019.The wetland vegetation and the coverage of main land types were investigated and analyzed and the species importance value method was used to determine the important dominant species of wetland vegetation.Combining with the survey and survey conditions,the land cover data was reIVsed to obtain the main types of wetlands covered and the size and distribution of the areas covered by each type.Principal component analysis method was used to screen the main pollutant indicators that affect the quality of lake water enIVronment,and the comprehensive pollution index method was used to judge the pollution status of each lake water enIVronment.Combining with the actual water resources of the Sun Mountain Lake Wetland,the current status of water environment analysis,the survey of vegetation species and land cover types,and the wetland ecological function planning,explore the theoretical basis for conducting research on the water demand of the Sun Mountain Lake Wetland ecological enIVronment.By setting different ecological goals,using the ecological function method to calculate the minimum and suitable ecological environment water demand of each lake area.It was expected to proIVde a reference for the improvement of the water quality of the Sun Mountain lake wetland and the regulation of the water quantity to ensure the performance of ecological functions,and to proIVde ideas for the same type of related research in arid areas.The main results of the research were as follows:(1)The wetland vegetation was statistically investigated by the sample method,and the species importance value method was used to determine that the reed occupies an important position in the herbaceous vegetation and was the dominant species.The vegetation types in the wetland mainly included the reed group,the salina group,and the alkali Pterospermum clusters,water onion clusters,pondweed clusters,cattail clusters.(2)According to the actual field survey,the land cover type data products interpreted by remote sensing images were reIVsed,and the main land types and distribution of wetlands were obtained.The land types can be dilVded into 6 types:marshland,bare land,highway land and other opaque types,grassland(salt claws),aquatic vegetation(reeds),and lake water bodies.The lake area of Dong Lake District and Xi Lake District was close to about 1.2km2,and the area of Xiao nan Lake and Nan Lake was close to about 0.18km2.The water area account for most of the lake area.(3)According to the results of principal component analysis and comprehensive pollution index analysis,the main water environment influencing factors in West Lake area were TN and CODcr;the main water environment factors in East Lake area were TN and CODMn;the main influencing factors in Xiao nan Lake were TN and CODcr;the main water environment in Nan Lake The factors were TN and BOD5.It could be seen that the concentration of organic matter and nitrogen in the lake area has exceeded the standard seriously Analyzing the overall situation of the comprehensive pollution index of each lake,the comprehensive pollution index of each month was quite different.In comparison,pollution levels in Dong Lake and Xiao nan Lake areas were relatively serious,while pollution in Xi Lake and Nan Lake areas was relatively light.(4)From the aspects of improving water quality,ensuring its ecological function water quantity,and preventing shrinkage and degradation,combined with the analysis of domestic and foreign scholars,the connotation and concept of the ecological environmental water requirement of the sun mountain lake wetland were discussed,and the ecological environmental water requirement was diIVded into ecological water requirement and environment The two parts of water demand were based on the ecological function method,combined with the current status and planning of wetland ecological functions,and then dilVded the main types of ecological water demand and enIVronmental water demand.Ecological water demand included four indicators:biological and habitat water demand,vegetation evapotranspiration water demand,lake evaporation water demand,and lake leakage water demand and enIVronmental water demand was mainly based on the amount of dilution water of the main pollutants needed to achieve the planned target.(5)Using the ecological function method calculate the ecological enIVronmental water demand of the Sun Mountain Lake Wetland.The coupling calculation method,deducting the rainfall,was used to calculated the total ecological enIVronmental water demand.Finally,the minimum ecological environment of Xiaonan Lake The total water requirement was 2,595,300 m3,the total water requirement for the suitable ecological environment was 4,630,500 m3,the total wate r requirement for the minimum ecological environment in East Lakewas 2,991,400m3,the total water requirement for the suitable ecological environment was 4,657,700 m3,and the minimum ecological environment in South Lake The total water requirement was 349,300 m3,the total water requirement for a suitable ecological environment was 569,000 m3,the minimum ecological environment water requirement of West Lake was 2,216,100 m3,and the total water requirement for a suitable ecological environment was 3,089,400 m3.