| The Danjiangkou reservoir lies in the upper Hanjiang basin and is the source of water for the Middle Route Project (MRP) under the South-to-North Water Transfer Scheme (SNWT) in China. The eco-environment of water resource areas plays an important role in water conservation and purification and would have significant implications for the economic prosperity in Hanjiang basin as well as for the SNWT. According to the eco-environmental characteristics and primay reco-environment issues in water resource areas, referring to the ideas of integrated study, based on temporal-spatial characteristics of land use and forest vegetation, associated with natural environmental factors including terrain, topography, geology, soil, etc, multi-scale, multi-perspective, multi-approaches were included in the research involving eco-environmental vulnerability, forest change, soil erosion, non-point pollution and hydrological responses of land use from Water Resource Areas (WRA), Danjiangkou Reservoir Area.(DRA), to Hujiashan small watershed. Based on The research results above, the ending of this paper tried to bring forward several strategies and measures for comprehensive environmental rehabilitation to enhance the ecological construction and environmental protection and insure the safety of water quality, which will provide scientific basis for environmental construction and sustainable development in water resource areas. The present study came to make important results and achievements as the following.(1) This study established an environmental information system database of WRA. Based on the database, an eco-environmental vulnerability assessment method using integrated fuzzy AHP (FAHP) and GIS was developed. According to eco-environmental conditions and anthropic effects, vulnerability was classified into five levels:potential, light, medium, heavy and very heavy. The results indicated that eco-environmental vulnerability in the DRA was moderate overall. Regions with lower eco-environmental vulnerability were located in Qinling Mountain area in the northwest, Daba Mountain area in the south and the area immediately surrounding Danjiangkou Reservoir in the east. Two regions with very high eco-environmental" vulnerability were located in the north of Danjiangkou Reservoir in Henan province and in the western part of Shanxi province.(2) Based on sources of RS images, associated with DEM, vegetation distribution map, land-use map and the corresponding socio-economic data, this paper attempted to reveal the spatio-temporal dynamics of forest cover in recent 20 years, and then utilized the canonical correspondence analysis (CCA) method to study the relationship between forestland distribution or transformation and environment parameters. The results indicated that forestland area had decreased continuously from 67631 km2 in 1980 to 61635 km2 in 1990, and then it started to increase to 65051 km2 in 2000, and the average annual rate of change had gradually dropped from-9.3% during 1980 to 1990 to 5.4% during 1990 to 2000; meanwhile, the forest landscape had a fragmentation trend. The result of the CCA order showed that the major environment variables affecting forestland distribution were elevation, rainfall and slope, and the major environment variables affecting forestland transformation were elevation, slope and population.(3) Based on RS and GIS technology, the spatial and temporal variations of soil erosion were investigated for DRA. Interpretation characteristic indexes were established from remote sensing images and other data. Results showed that from 1990 to 2007, the total erosion area of the DRA was decreased; it shows concretely as follows:the area of light soil erosion has continually expanded and the area above the moderate soil erosion was reduced.The annual change in each soil erosion level was in the order of serious erosion> very strong erosion> moderate erosion> light erosion> slight erosion> strong erosion. Overall, the change ranges of the average center of gravity in longitude were far greater than latitude for each soil erosion level. Because of the dual influence of the nature factor and the artificial factor, the conversion between each soil erosion level was very complex, and soil erosiom was at management margin damage in DRA.(4) Based on the existing studies and the export coefficient model, the non-point source (NPS) pollution load in DRA was estimated and its spatial distribution in 1990, 2000 and 2007 were simulated with RS and GIS techniques. Results indicate that the pollution load of TN has a small change from 3.325 X 104 t in 1990 to 3.379X 104t in 2000, then it increased to 3.710×104t in 2007. The pollution load of TP were 167×104t, 0.169×104t and 0.186×104t respectively in 1990,2000 and 2007. The main source of TN pollution load was dry land, and most of the TP pollution load was from people produce. Xichuan country in Henan province was the worst non-point polluted, and should be the key administration area of controlling water pollution in the future.(5) With Hujiashan small watershed as the research area, we studied the structure characteristics of land use in 15 catchments. The results showed that the major land covers in the study areas are forest and upland, and the proportion upland and residential area gradually increased from upriver to downriver in each catchment, while the proportions of forest increased.forest mainly distributed in higher altitudes and in a steep slope (15°-25°); forest mainly distributed in lower altitudes; residential area mainly distributed in flat terrain below 350 m. In the whole watershed, the distances to river from the river was in the order of forest> grassland> residential area> upland. Relative rationality indices of land use showed a decreasing trend from upriver to downriver in Hujiashan watershed(6) This paper studied the effect of land use types on nitrogen export base on the dates of land use and nitrogen expoxt in Hujiashan watershed, and a landscape index named location-weighted landscape contrast index (LCI) was calculated to evaluate the effects of landscape components'spatial distribution and land use structure on nitrogen expoxt. The result showed that the nonpoint source pollution of surface water environment was very serious and in each branch the concentration of TN and NO3--N gradually increased from upriver to downriver. The concentration of TN and NO3--N were negatively correlated with forest, grassland and water body while significant positively correlated with residential area and upland. There were conspicuous correlations among the LSI related to relative elevation, slope, relative distance and integrated LSI with the concentration of TN and NO3--N at 0.01 level, which were higher than the sum of weighted area percentage of land use (Lw) and any single land use type. This tell us LCI was good indicators of nitrogen exports and thus have big potential in non-point source ponution risk evaluation. (7) Taking Water Resource Areas of MRP as the comprehensive management region, taking small watershed as basic unit, taking eco-environment improvement and water quality protection as center, the paper considered that comprehensive planning should be used to realize comprehensive improvement. At WRA scale, it was need to establish management Institution across the region, develop water function zoning, establish special ecological protection zones and enhance the construction and preservation of the forests. At DRA scale, doing migration settlement work well and strengthening comprehensive prevention of soil erosion and non-point source pollution should be placed on the prominent position. At small watershed, it was imperative to take measures of comprehensiue treatment, including soil and water conservation project, ecological agriculture, optimizing land use structure, utilization of rural disposals and vegetative environmental buffers, etc.
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