Response Of Saltwater Intrusion On Land Use And Soil Quality In The South Coast Of Laizhou Bay

The south coast of Laizhou Bay, which is one of the most typical areas of saltwater intrusion in China, is also a sensitive and occurring frequently region of the LUCC. The saltwater intrusion affects the soil quality from the microcosmic aspect, and then affects the LUCC. This article discussed the infection of the saltwater intrusion to the main land utility types (Including farmland, forestland, grassland and saline land. Not including the building plot ) and the soil quality of north the ChangYi city near the south coast of Laizhou Bay. The main contents are as follows:(1)Bases on the experimental datas of soil samples from ten representative soil sampling points, the data from the second nationwide general soil survey of ChangYi in 80's, and the local natural condition, this paper choosed 12 assessment indicators as soil organic matter, available nitrogen, available potassium, available phosphorus, clay content, soil bulk density , PH, porosity, salt content, salty coefficient (CL-/HCO3-+ CO32- ), groundwater buried depth and mineralization; then used different prediction models to calculated the value, and used the correlation coefficients to determine the weight of the indicators, finally, the single factor and the comprehensive evaluation of soil quality were done. Then compared the soil quality of present and the 80's, analysis the influence of saltwater intrusion on the soil quality, and showed that for the water intrusion reducing, the soil quality was improving.(2)The land use patterns affect some soil ecological processes, such as the energy and water exchange, erosion and accretion, biological cycle and crop production, different compositions of land use have important effects on nutrient and salt flow in soil. The paper analysed the difference of soil quality, soil nutrient and salt, and soil physical properties on different land use patterns. The soil environment effect of land use in a seawater intrusion region has been preliminarily discussed.(3) ) Bases on 4 remote sensing images of north the ChangYi city near the south coast of laizhou Bay in 1990, 1995, 2000 and 2004 and other sufficient data, the paper analysed the space-time change law of land use under the influence of saltwater intrusion:â‘ There are obvious differences of land use in various periods. From 1990 to 1995, the salt water intrusion was the most seriously in the 90's last century, and the land use change is the most significantly; from 1995 to 2000, as the precipitation increasing, the saltwater intrusion becoming slow, even trending to steady, the land use change is very small; from 2000 to 2004, the saltwater intrusion was relatively stable, the land use change was not obvious.â‘¡There are obvious differences of land use in different areas, the land use change in transition region is the most significantly and frequently. In the transition region, as the saltwater intrusion boundary moving from north to south, the land use changing regularly.(4)The paper analysed the spatial variability of soil salt content and the driving forces, which including the climate (precipitation and evaporation), terrain, soil structure, groundwater buried depth, groundwater mineralization and irrigation. Considering the elevation, microtopography, groundwater buried depth, groundwater mineralization, soil salt content, irrigation, drainage situation, soil organic matter, soil texture, the paper analysed the relationship of the limiting factors for farmland use.(5)At last, the paper put forward some suggestions on land resource sustainable use.