The impact of highway construction upon surrounding ecosystems in the Longitudinal Range-Gorge Region of Southwestern China was detected based on field survey and experimental analysis. We conducted a study on Dali (from Dali City to Lijiang City) provincial road, Dabao (from Dali City to Baoshan City) highway and Baolong (from Baoshan City to Longling County) highway in the Longitudinal Range-Gorge Region to detect the effect of highway construction on surrounding soil quality using the method of space-for-time substitution, and predicted remediation of surrounding soil quality. The results showed that: (1) The effect of highway construction on both natural and cultivated soil quality is significant, and the effect is more significant in the period of highway construction than the period of highway in use. (2) The effects of highway construction is more apparent on downslope than upslope, and effect range was 200 m on downslope, while 150 m on upslope. (3) Soil remediation is mainly related to effect extent of highway construction, highway service time, vegetation restoration, soil organic matter and soil total nitrogen, among which, highway construction is the most important factor. (4) When vegetation coverage can be restored to 30% of the original condition, soil quality can be remedied to 44% of the original condition after 10 years, indicating that soil fertility remediation is rather difficult once it is destroyed.
相似文献Based on the land use (LU) (in 1985 and 2000) and road networks (RN) data in the Longitudinal Range-Gorge Region (LRGR), ecosystem services value (ESV) loss under the disturbance of road networks was estimated by using landscape degradation index (LDI) to clarify the effects of human activities on ecosystem service function (ESF). Results show that the ESV decreased more than 65×108 Yuan (RMB) due to the transformation of ecosystems in the study area during the past 16 years. The ecosystems influenced by road networks of different grades account for 5.4% of the total land in the study area. The ecosystems lost their ESV of 1900×108 Yuan (RMB) by the disturbance of RN. The effect of RN on the ESV decreased exponentially. The forecast shows that ESV will be decreased 1.2%/a on average in 2010 and 2020 due to RN projects. The effect of ecosystem structure change on ESV was complex and nonlinear. The disturbance of RN, one of the human activities influencing ESF is considered, further study and new method should be developed to accurately estimate the loss of ESV and the ecosystem function.
相似文献Based on analyses of key issues concerning watershed ecological security assessment including the subject, content, and methodology of assessment, this paper points out that ecological security should be assessed dynamically at different levels (e.g. watershed and ecosystem levels) with human being as the main assessment subject. Both the functional security and the structural security must be considered in watershed ecological security assessment. In order to reflect the overall and timely security status of the watershed, the PSR (pressure-state-response) method should be employed. Longitudinal Range-Gorge Region (LRGR) was researched as an example. An index system of watershed ecological security assessment has been proposed, which includes structural index, functional index, pressure and response index, and the state of ecological security is analyzed for LRGR in Yunnan Province.
相似文献For the remote areas like the Longitudinal Range-Gorge Region (LRGR), it is hard to measure the suspended sediment concentrations (SSC). This study attempted to estimate SSC by employing the three atmospheric correction methods: COST, iCOST (modified from COST) and TZB5 (newly proposed). TZB5 can more accurately determine the atmospheric transmittance along the sun-ground surface path (TAUz) from the solar zenith angle (TZ), and it uses Band 5 to eliminate the path radiance of Bands 1–4. The water surface reflectance at Band 4 obtained using TZB5 has a stronger relation with SSC within the range of 0–3000 mg/L. The developed algorithms could accurately estimate SSC directly from ETM+ images in the turbid Upper Yangtze River, and were also effective in the Middle Yangtze River.
相似文献