Land Quality Geochemical Assessment Based On The Technology Of Space

Land resource is essential to development of human society.The productivity and use of land resources are affected by land quality. With the fast development of global industry.The environment begian to deteriorate and resources start to dwindle. Land quality assessment is significant, not only in harmonizing the relationship between human and sustainable use of land but also in more rational land use programming.Fuyang district locate in Hangzhou southwest, where grain acreage reached to 113.34 million hectares, land quality especially the quality of arable land is particularly important, the total product value of agriculture is 5.35 billion yuan that 20.2 percent of Hangzhou in 2015. Hence we took Fuyang district as study area, based on the soil data element including essential elements (N, P, K, S, Ca), microelement (B, Mo, Mn), soil pH and harmful elements (As, Cd, Ni, Pb, Hg, Zn, Cu, Cr) that affect land quality. Analyzed the geochemical characteristics and spatial pattern of the factors affecting land quality and used the Fuzzy Mathematics and AHP to evaluate geochemistry of land quality, eventually came to the geochemical grade of land quality with the space technologies. Then overlay the corresponding classification scale soil map and land use map and statistic the characteristics of geochemical grade of different soil and land use types.The outcome of the analysis shows that essential elements and microelement in the soil is abundant in the area largely. The mainly nutrient elements such as N, P, organic matter and Mn are also rich in many regions. However, there are also a wide range of area which lack some nutrients such as K、S、B. What’s more, harmful elements as Cd, Zn and Cu are higher level which causes some pollution.According to land quality geochemical assessment result, excellent grade soil is mainly distributed, accounting for 83.57% of the total area. Quality soil is 0.55% which is suitable for green agricultural production; 1.86% of the area is good soil which is more appropriate for agriculture production; 13.96% of the study area is moderate soil which is not suitable for planting and should have a limit to carry out agricultural production and strengthen environmental management efforts, however, poor land is only 0.06%.Analyze the classification statistic of land quality geochemical assessment result of different soil and land use type. Firstly, as for different soil type, the comprehensive rank of red soil is higher than others that more than 90.32% is quality land, following by yellow soil, paddy soil and skeletal soil, the quality land in the above soil pattern is 89.98%,85.98% and 63.6% respectively. Regarding the different land use type, the comprehensive rank of paddy field is higher than others that more than 84.65% is quality land, following by woodland, dry land and other land, the quality land in the above soil pattern is 84.35%,83.62% and 81.61% respectively. We can see, the differences of classified features between the different land use types are not dramatically in Fuyang district.