Landscape Pattern Change And Its Impact On Water Quality

Water resource is the most important source for human’s daily life. The environment of water is the urgent problem for human to protect and defend. In order to protect our environment, protect and change the water quality is become the most important work in our life. The changes of water quality impact by so many factors, such as the elevation of land, the rain and the urbanization. Moreover the changes of land use in river riparian impact by the human’s activities.Researching the relationship between water quality changes of river and the land use in river basin, is the main method for searching the changes of river riparian landscape how influences in water quality. The relationship between water quality and the changes of landscape, required the remote sensing images at different scale in space and series of sequence and the parameters data of water quality. In this paper, we describe the relationship between the changes of water quality and landscape by two parts. Firstly, we try to find the relationship the landscape metrics and the water quality parameters. Secondly, we catch the SDD from the images and research the relationship between the SDD and the landscape metrics.In this paper, we acquired the water quality data of 2010 and 2014 of Qiantang River from the Environmental Protection Bureau of Zhejiang Province. Collecting the water pollutant emissions data from the Qiantang Rive Base Water Pollution Prevention’Twelfth Five Year Plan’,while the sediment data from Sediment communique of China and the other data from Zhejiang Water Quality Bulletin. Overall, we analysis the relationship between the changes of landscape metrics and water environment by using the above data and the Landsat remote sensing images in 2000,2004,2010,2014. After retrievaling the SDD of Qiantang River through the images, discuss the influences of landscape changes in water clarity of Qiantang River. The result shows that:(1)The integral landscape pattern diversification character during 2000 to 2014 in the Qiantang River riparian are following:PD, ED, LSI and SHDI are increased, the LPI, AI and CONTAG are reduced. It means that, the fragmentation and the complexity and the heterogeneity of landscape increased, while the connectivity reduce in whole riparian landscape of Qiantang River. Moreover, the shape of patch became irregular and the distribution of patch became disperse. However those changes were have an negative impact on the water.(2) In 2000, water area of river riparian is 47631.78 hm2, after 14 years, the water area had an increase of 22.86% that was 58518.09hm2 in 2014. As the result shows that, the AI decreased 2.31% while others metrics like NP, PD, LSI and LPI increased. It indicates that the heterogeneity, fragmentation degree and the complexity of water landscape were increased. However the patch became disperse distribution so that the connectivity of landscape reduced. Above all, the changes of landscape didn’t beneficial to the water recovery.(3) The water quality changes of Qiantang River from 13 monitoring sites are follows:From 2010-2014, the water quality of Puyang export was the worst, the water quality of Zhakou and Tonglu and Tongjunshan et la were declined,while the quality of Lanjiang export and the Sandu Bridge were increased.(4)In consideration of the changes of each landscape types impact on water in 2000-2014, the water condition were worse, despite the area of wood land increased. Due to the fragmentation increased and the connectivity reduced in wood land landscape and the dispersion distribution, the water and soil would lose and the water conservation capacity would reduced, even destroy the water environment and reduce the water clarity. In contrast, farm land area was declined from 2000 to 2014, except 2004 wood area increased due to the agricultural policy. The fragmentation degree of landscape increased while the dispersion distribution of patches and the lower connectivity as a result of the landscape changes. Therefore, agriculture pollutant emissions and the water consumption of agriculture had reduced because the farm land area reduction. It is beneficial to the water recovery and the water improvement of self-purification ability. From 2000 to 2014, there was a rapid increase in the built-up area because the urbanization. In 14 years, patches became centralized distribution and the connectivity improved. The rapid expansion of built-up area due to the human activities and decreased others landscape types. As a result, the waste production form built-up area larger and larger would increase rapidly and pollute the water directly.(5) Water clarity is the one of water indicators in assessing the water quality level. The results of water clarity extraction show that the distribution of SDD were consistent to the water quality and sediment data. From the analysis between landscape pattern changes and SDD changes, we found that, water clarity was impact by many factors in the river riparian. For instance, the area of wood land and farm land,the changes of vegetation would be change the sediment in water. While the emission from human’s activities could be increase the organic pollutants.Overall, there was a closely relationship water quality between landscape pattern. There is still a serious problem in water quality of Qiantang River, though the water quality improved from 2010-2014.The results show that, it is necessary to be considered from different landscape elements in order to manage the water environment in riparian zone. First of all, developing guidance countermeasures for water pollution and pollutant emissions could be improve the water recovery. Moreover, improve the vegetation coverage and control the process of urbanization sprawl, could be advantageous to the soil erosion and vegetation conservation capacity in Qiantang River riparian. Last but not least, control the usage of fertilizers and the pesticides in agriculture strictly, could reduce the agriculture emissions of pollutants.