中西北部地区反贫困可持续发展思路

中西北部地区和东部沿海地区的经济发展差距正在拉大。中西北部地区既存在相对贫困，又是一个资源富饶地区。反贫困主要抓好三方面工作：搞好基础设施，大力发展乡镇企业，大力发展文教科技事业。市场经济条件下可供选择的扶贫措施有：调整农业的单一生产结构，立足本地资源发展乡镇企业，建立多元所有制结构推动市场经济，明晰产权关系加速资源开发，建立市场中介组织，组织探索和实行异地扶贫，有效使用扶贫贷款资金，处理好中、西、北部的关系。首要的任务是转变与市场经济不相适应的观念和作风，尤其是狠抓干部作风。

市场经济条件下中西部地区反贫困可持续发展思考

本文论述了我国中西北地区在现代化建设中的战略意义，提出在市场经济条件下，加大对中西北部地区扶贫开发的力度、扶贫开发的意义以及可供选择的扶贫措施。

Regional Scale Rainfall- and Earthquake-triggered Landslide Susceptibility Assessment in Wudu County, China

Wudu County in northwestern China frequently experiences large-scale landslide events. High-magnitude earthquakes and heavy rainfall events are the major triggering factors in the region. The aim of this research is to compare and combine landslide suseeptibility assessments of rainfall- triggered and earthquake-triggered landslide events in the study area using Geographical Information System （GIS） and a logistic regression model. Two separate susceptibility maps were produeed using inventories reflecting single landslide-triggering events, i.e., earthquakes and heavy rain storms. Two groups of landslides were utilized： one group eontaining all landslides triggered by extreme rainfall events between 1995 and 2003 and the other group containing slope failures caused by the 2008 Wenchuan earthquake. Subsequently, the individual maps were combined to illustrate the loeations of maximum landslide probability. The use of the resulting three landslide susceptibility maps for landslide forecasting, spatial planning and for developing emergency response actions are discussed. The eombined susceptibility map illustrates the total landslide susceptibility in the study area.

Individual Variations of Winter Surface Air Temperature over Northwest and Northeast China and Their Respective Preceding Factors

Based on monthly mean surface air temperature （SAT） from 71 stations in northern China and NCEP/ NCAR and NOAA-CIRES （Cooperative Institute for Research in Environmental Sciences） twentieth century reanalysis data, the dominant modes of winter SAT over northem China were explored. The results showed that there are two modes that account for a majority of the total variance over northern China. The first mode is unanimously colder （warmer） over the whole of northern China. The second mode is characterized by a dipole structure that is colder （warmer） over Northwest China （NWC） and warmer （colder） over Northeast China （NEC）, accounting for a fairly large proportion of the total variance. The two components constituting the second mode, the individual variations of winter SAT over NWC and NEC and their respective preceding factors, were further investigated. It was found that the autumn SAT anomalies are closely linked to persistent snow cover anomalies over Eurasia, showing the delayed effects on winter climate over northern China. Specifically, the previous autumn SAT anomalies over the Lake Baikal （LB; 50-60°N, 85-120°E） and Mongolian Plateau （MP; 42-52°N, 80-120°E） regions play an important role in adjusting the variations of winter SAT over NWC and NEC, respectively. The previous autumn SAT anomaly over the MP region may exert an influence on the winter SAT over NEC through modulating the strength and location of the East Asian major trough. The previous autumn SAT over the LB region may modulate winter westerlies at the middle and high latitudes of Asia and accordingly affects the invasion of cold air and associated winter SAT over NWC.

The Effects of Land Cover Change on Regional Climate over the Eastern Part of Northwest China

A regional climate model （RegCM4） is em- ployed to investigate the impacts of land use/cover change （LUCC） on the climate over the eastern part of Northwest China （ENW） in the periods of 2001 and 2011. The re- sults indicated that the LUCC in ENW, which was char-acterized by desert retreat, reforestation, and farmland expansion, led to significant local changes in surface air temperature （within -0.3℃） and slight regional changes in precipitation （within -15%） in summer. In the desert retreat area, the net absorbed shortwave radiation had a greater influence than evaporative cooling, leading to increases in the daily mean and maximum temperature. Besides, the daily mean and maximum temperatures in- creased in the reforestation area but decreased in the farmland expansion area. As surface albedo showed no significant change in these regions, the temperature in- crease in the reforestation area can be attributed to a decrease in evaporation, while the opposite effect appears to have been the case in the farmland expansion area.

Early Permian Tarim Large Igneous Province in northwest China

Tarim Large Igneous Province （TLIP） is the second Late Paleozoic LIPs in China after the recognition of Emeishan LIP, and is a hot research topic in geosciences. On the basis of the analysis of research history about TLIP, this paper summarizes the re- search result during last twenty years and suggests the key research area in the future. The residual distribution range of TLIP is up to 250000 km2, and the largest residual thickness is 780 m. The eruption of basalt happened during 290-288 Ma and be- longs to LIPs magmatic event with fast eruption of magma. The lithological units of the TLIP include basalt, diabase, layered intrusive rock, breccia pipe mica-olivine pyroxenite, olivine pyroxenite, gabbro, ultramafic dyke, quartz syenite, quartz syenite porphyry and bimodal dyke. The basalt and diabase of TLIP exhibit OIB-like trace element patterns and enrichment of LILE and HFSE, and mainly belong to high TiO2 series. There is an obvious difference in isotope among the basalt from Keping and the basalt and dibase from the northern Tarim Basin. The basalt from Keping with negative eNa and high REE value derives from enriched mantle, and the diabase and basalt from the northern Tarim Basin with positive ENa and low REE value axe re- lated to depleted mantle. The crust uplifting in the Early Permian and the development of picrite and large scale dyke and for- mation of large scale V-Ti-Magnetite deposit in Wajilitag area support the view that the TLIP is related to mantle plume. The TLIP has a temporal-spatial relationship with Permian basic to ultra-basic igneous rock, which is distributed widely in Central Asia, and they represent a tectono-magmatic event with very important geodynamic setting. This paper also suggests that the deep geological process, the relation with mantle plume, mineralization, the relation with environmental change and biological evolution, and the geodynamics of the TLIP will be the key research topics in the future.

Petrology and phase equilibrium of newly found eclogites from Kekesu Valley in eastern part of southwest Tianshan HP-UHP metamorphic belt,China,and its tectonic significance

Eclogites and omphacite-bearing blueschists have been newly found in the eastern segment of the southwest Tianshan orogenic belt, Xinjiang, northwest China. After detailed petrological study, three samples including one fresh eclogite TK003, one blueschist sample TK026-8 and one retrograded eclogite TK027, were selected for phase equilibrium modeling under NC（K）MnFMASHO （N20-CaO-K20-MnO-FeO-MgO-A1203-SiO2-H：O-O） system, by thermocalc 3.33 software. Composition analyses of garnets in these three samples show typical growth zoning with Xpy and Xgrs increasing, Xspss decreasing from core to rim. Pseudosection modeling of the garnet zonation reflects that the eclogites and blueschist experienced a similar P-T evo- lution trajectory, with a near iso-baric heating in the early stage, and reached eclogite facies metamorphic field with peak P-T regime of 480-515~C, 2.00-2.30 GPa. Subsequently the rocks experienced an early iso-thermal decompression retrograde stage with P-T conditions of 515-519~C, 1.78-1.93 GPa. Variations of mineralogy and modes of these rocks are probably due to different retrograde paths as a consequence of different bulk-rock composition, as well as a variation in fluid activity during exhumation. P-T calculation and a peak geothermal gradient of 6-7~C/km indicate HP rocks in the Kekesu Valley experienced cold subducted eclogite facies metamorphism. Thus a huge oceanic subduction eclogite facies metamorphic belt in southwest Tianshan has been recognized, extending from the Kekesu Valley in the east to the Muzhaerte Valley in the west for nearly 200 kin. However, UHP evidence has not been found in the Kekesu terrane, perhaps because the slab in east part of southwest Tianshan did not subduct into such a great depth.