Spatiotemporal variation of forest land and its driving factors in the agropastoral ecotone of northern China

As an important natural resource,forest land plays a key role in the maintenance of ecological security.However,variations of forest land in the agropastoral ecotone of northern China(AENC)have attracted little attention.Taking the AENC as an example and based on remote-sensing images from 2000,2010 to 2020,we explored the spatiotemporal variation of forest land and its driving factors using the land-use transfer matrix,spatial autocorrelation analysis and spatial error model.The results showed that from 2000 to 2020,the total area of forest land in the AENC increased from 75,547.52 to 77,359.96 km^(2) and the changes were dominated by the transformations among forest land,grassland and cropland,which occurred mainly in areas with the elevation of 500-2000 m and slope of 15°-25°.There was obvious spatial agglomeration of forest land in the AENC from 2000 to 2020,with hot spots of forest land gathered in the southern marginal areas of the Yanshan Mountains and the low mountainous and hilly areas of the Loess Plateau.The sub-hot spots around hot spots moved southward,the sub-cold spots spread to the surrounding areas and the cold spots disappeared.The spatiotemporal variation of forest land resulted from the interactions of natural environment,socioeconomic and policy factors from 2000 to 2020.The variables of average annual precipitation,slope,terrain relief,ecological conversion program and afforestation policy for barren mountains affected the spatial pattern of forest land positively,while those of annual average temperature,slope and road network density influenced it negatively.

Spatio-temporal Differentiation and Driving Factors of Industrial Ecology of Restricted Development Zone from Adaptive Perspective:A Case Study of Shandong,China

Based on the adaptive analysis paradigm,this paper constructs an evaluation index system and an evaluation model of the level of industrial ecology of a restricted development zone from the perspective of the industrial system and of the environmental system,and studies the spatial-temporal differentiation characteristics and the driving factors of the level of industrial ecology of the restricted development zone of the Shandong Province,China,by using a variety of measurement methods.The results show that:1)In the temporal dimension,the level of industrial ecology of the research area increased from 2005 to 2017,while in the regional dimension,it was higher in the eastern coastal areas,followed by the northwestern area and the southwestern area;2)In the spatial dimension,from 2005 to 2017 the level of industrial ecology of the research area had a clear spatial dependence,and the regional spatial agglomeration of the restricted development zones with similar industrial ecology levels become increasingly evident;3)On the whole,the industrial ecology level in the study area had a clear spatial differentiation pattern,as it was higher in the north and in the east and lower in the south and in the west.Moreover,its evolution model changed from a‘three-core driven model’to a‘spatial scattered mosaic distribution model’,and then to a‘single-core driven model’;4)Industrial ecology was positively correlated with economic development,foreign investment,science and technology,and negatively correlated with the government role,while industrial structure and environmental regulation failed to pass the statistical significance test.

Quantifying the impact of mountain precipitation on runoff in Hotan River, northwestern China

It is of great significance to quantitatively assess the impact of mountain precipitation on inland river runoff in data scarce regions.Based on the corrected TRMM precipitation and runoff data,a variety of statistical methods were used to identify which areas of precipitation have an important impact on runoff in the Hotan River Basin,and to evaluate the effects that precipitation changes have on runoff at low,mid,high,and extremely high altitudes of mountainous areas.The results showed that:1)From 1998 to 2015,the annual runoff showed a fluctuating upward trend with a rate of 11.21×10^8 m^3/10 a(P<0.05).Runoff in every season also had an increasing trend,with summer runoff the most significant at a rate of 6.09×10^8 m^3/10 a.2)The annual runoff and precipitation changes had certain synchronization,with a correlation coefficient of 0.45(P<0.05).Among them,the correlations between precipitation and runoff changes were highest at low and mid-altitudes,with coefficients of 0.62 and 0.55,respectively(P<0.05).3)65.95%of the regional precipitation at low altitudes and 48.34%at high altitudes were significantly correlated with runoff(P<0.05),while only 38.84%and 26.58%of regional precipitation levels at mid-and extremely high altitudes were significantly correlated with runoff.4)The annual precipitation change in the basin was 1%,which would cause the annual runoff to change by 0.24%.In 1998-2015,the change of annual runoff caused by precipitation change at high altitudes was largest at a rate of−6.01%;the change rates of annual runoff caused by precipitation change in the low,mid-,and extremely high altitudes were−3.66%,−3.62%,and−3.67%,respectively.The results have significant scientific guidance for water resource management in arid basins.