Ecological Risk Analysis And Security Zone In Northern Shaanxi Energy Temporal Ecology

Through quantification of regional ecological risk degree the regional ecological security can be concluded, thus the hierarchical division based on regional ecological security can be accomplished. Then the specific ecological countermeasures for such region are set accord with the actual requirement of the objective regulation. And it has an important significance to regional ecological construction and sustainable development. Northern Shaanxi energy development zone has a dry climate and a fragile ecological environment, and the rapid development of energy industry in recent years led to a large amount of pollution and population pressure. According to the study area is under the condition of drought, soil and water erosion, wind erosion and desertification of land, the pollution with the process of energy development, land-use and landscape pattern change as well as other issues, it is necessary to determine the specific degree of regional ecological security through ecological safety analysis and evaluation, and discuss corresponding countermeasures.By collecting the land use data, remote sensing observation data, environmental pollution and meteorological data, terrain data, using value and other related indices, some factors are calculated, which include the pollution ecological risk, the main disaster ecological risk and the landscape ecological risk as well as the ecosystem service value about fix carbon and release oxygen, water and soil conservation, windbreak and sand-fixation, conserve water, purify air, etc. The value of the main ecosystem service function is respectively as the index of ecological benefit, and the ecological risks act as the index of ecological loss. Eventually, the final degree of ecological security level is calculated as ecosystem service benefit divided by ecological risk loss. At the same time, based on the terrain index, the climate index, hydrological index, land use index, the nature suitability for human settlement is obtained. Combining the ecological safety degree and nature suitability for human settlements, four comprehensive ecological security partitions are divided, and the corresponding countermeasures are discussed. The specific conclusions are as follows:(1) In2001-2009, the trend of regional ecosystem service value is overall rising gradually from northwest to southeast, which has significant latitude zonality and dry-wet zonal characteristics. The regional ecosystem service benefit is increased as a whole. What’s more, the trend of ecosystem service values in the9years is not entirely consistent with the wet-dry alternating climate change in regularity. Vegetation restoration is an important driving factor for the trend formation.(2) In2001-2009the high value of regional ecological risk index is mainly distributed in the transition part between the sandy region along Great Wall and the loess hilly-gully region as well as the typical loess hilly-gully region in northern Yan’an. The Variation rule for landscape ecological risks, disaster ecological risks and pollution ecological risk is out of step, and the overall trend is not obvious. So the ecosystem service function and the ecological risk are not synchronized on the space-time changes.(3) The level of regional ecological security pattern present a certain zonal distribution rule on the space, the safety is gradually increased from north to south. For a time pattern, the ecological security reflects a characteristic of "general improvement and partial deterioration". General improvement is that the ecological security with different degrees are improving over time to time in most regions in performance;"Partial deteriorating" is the decrease of ecological safety account for the low landscape stability in farmland patches and connections between trees and grasses in the short term, as well as the industrialization and urbanization create a large number of "three wastes" pollution reduced the ecological safety around towns and industrial parks.(4) The nature suitability for human settlements and ecological security has a gradient similarity in spatial pattern, but it does not strictly correspond to every sample values. Most of the cities with good economic development are in the low natural suitability in Northern Shaanxi energy development zone, and the ecological security level is relatively poor. So there is an obvious inconsistency between the ecological security and the population agglomeration on the spatial pattern.(5) According to the differences of ecological security degree and nature suitability for human settlements, the area can be divided into four subsystems, from north to south is named the windbreak and sand-fixation along Great Wall area, loess hilly farming-pastoral zone in the north area, loess hill-beam soil erosion areas, loess beam-tableland agricultural area. And measures for the establishment are discussed in the transformation of industrial structure, land use structure optimization, preservation of food security, corresponding control the interaction between ecological safety and increase farmers’ income.The innovative points of this study are as follows:(1) the integration of a variety of evaluation methods and the calculating of the ecological risk loss and ecosystem service function benefit can be as a new way for ecological security evaluation;(2) with both guarantee the kilometer scale in spatial and basis on the continuous year data analysis on temporal, this study synchronize the time and space scales to maintain a relatively high precision, that this kind of comprehensive multi-factor downscaling calculation is relatively rare;(3) the research combined nature suitability for human settlements with ecological security level to take partitions, and synchronize the zoning regulation countermeasure which consider both ecosystem and human life level, that the overall comprehensive social, economic, ecological planning is more in line with the goals of sustainable development.