Analysis Of Land Cover Change In Northwest China And Its Driving Factors Based On Globeland30

Cropland can provide basic food security, also, it is an important economic and strategic resource, the changes of cropland directly affect the daily life of production. In recent years, cropland are occupied because of urban expansion in Northwest China, a large area of pasture are reclaimed, cropland expansion consume large amounts of water, resulting in increasing pressure on ecological and environmental protection, the contradiction between human activities and ecological environment is outstanding.This article based on the analysis of the main quality factors affecting the GlobeLand30 cropland classification data a knowledge-based quality checking method is proposed. A knowledge framework proposed for land cover map generalization with geographical distribution, culture-based, temporal stability and phonological character knowledge. Quality checking rules are constructed and a check modification interactive strategy is designed regionally to check the data from whole to parts. It has been applied to check the cropland data of Northwest China, successfully improve the two period’s data accuracy to 90.92% and 91.23%.Based on the revised cropland data, we proposed a way of cropland analysis which take into account changes in the spatial, structural change and environmental context analysis method, analyze the distribution pattern characteristics of cropland change; through conversion of cropland to other land classes knowing cropland’s destination; combining natural environmental background elements in different environments to understand the change of cropland. Combined with the natural geography, policy factors and economic development into account, reveals the drivers of cropland change in northwest China.On the whole, Northwest China’s cropland has increased in these ten years. The cropland in Xinjiang area increase the maximum and most dramatic, large area of unused land and grassland are cultivated. The increase in cultivated land area in Qinghai is not much, the increase in cropland extending from the Qinghai Lake around until the central parts. In order to solve the problem of water shortage, the government of Ningxia continuously improves the planning, land structure change obviously. The cropland in Gansu has increased slightly, but the returning farmland to forest and grass in south is significant, so the area changes the smallest. Shaanxi’s cropland is declining because of city expansion and returning farmland to forest. In a word, Northwest China’s cropland increasing result in the main occupation of the bare lawn, followed by water bodies and wetlands.In the driving force, the construction of returning farmland to forest is effective and economic and social development leads to the land expansion in a certain extent, reduce the quantity of cultivated land. But the increasing of water resources and encourage the increase of agriculture policy and tillage technology makes the cultivated land continues to increase, making the arable land in Northwest region showed an increasing trend.