Study On The Water Environment Of Larus Relictus Nature Reserve In Erdos Plateau

Erdos Relict Gull population is the largest number in the four populations. Erdos plateau is the main place where the species reproduce. The wetland in Ordos Larus Relictus Nature Reserve is located in Bojianghaizi Basin of Inner Mongolia Erdos, and Tao-Ahaizi, in the center of the wetland, is the largest lake and the most important habitat. In recent years, storage capacity of Tao-Ahaizi decreased. Beacuse the lake island disappear continuously, Larus relictus gradually moved to the Hongjiannao wetland which located in Yulin city in Shanxi province. The storage capacity of Hongjiannao is larger, and the island is more. Hongjiannao provides suitable conditions for Larus relictus survival. Ordos Larus Relictus is very sensitive to water level changes. Survival and reproduction of Larus relictus has closely related to water environment of wetland. The quality and quantity of the water environment have a significant impact on Larus relictus live. The water environment is one of the main factors in the study of wetland, but in the previous researches, there are few about it. So the researches of the quality and quantity of the water environment in the wetland have an important significance.In this paper, Erdos plateau Larus relictus habitat water environment are taken as the research object, the water environment quantity and quality are evaluated. The remote sensing data shows the change rule of T-Ahaizi and Hongjiannao for many years, and the influence factors leading to change of the lake area were analyzed. The water environment quality of Bojianghaizi Basin are analyzed. The water samples of surface water and groundwater in different periods are collected. The analysis of data samples are used to evaluated the water environment quality. In recent years, Tao-Ahaizi storage capacity has been reduced, and therefore the ion concentrations are increased in the lake.At present, Tao-Ahaizi and Hongjiannao lake area is shrinking. In 2013, Tao-Ahaizi area is 1.85km2. Lake Island disappeared gradually wnich causes Larus relictus could not reproduce here. In 2013, Hongjiannao area is 33.45km2. Because the lake appear, the number of Larus relictus increase. The reasons cause the shrinking of Tao-Ahaizi including the following points. From 1980 to 2013, the average annual rainfall decreased by about 7.45mm. The dams intercept rivers, and the supply area is reduced about 8.2%. The increasing amount of vegetation in the basin is another important reason. Hongjiannao area reduction is mainly due to the following reasons. The dams stop the river which provide supplies for the lake, and the supply area is reduced about 23.5%. The increase of vegetation changes the distribution of the water, resulting in the decrease of the lake water. In this study, single factor index method is used to evaluate the Bojianghaizi basin surface water samples with the national standard. It is shown that the surface water quality in this basin is poor. The evaluation of groundwater samples shows the quality of groundwater is good.