Radiating Benefit of Windbreak and Sand Fixation in the Baijitan Nature Reserve of Lingwu, Ningxia, China

Many important ecosystem services show spatial flow characteristics, which are crucial for the study of environmental processes, such as the transformation, correlation, coordination, and management of ecosystem services at different scales. As a result, flow characteristics should be taken into account when it comes to the evaluation of ecosystem services. The study area was the Baijitan Nature Reserve, used to assess the radiating benefits of the windbreak and sand fixation from 2000 to 2019, based on wind erosion loss and sand spatial erosion models. The main results are as follows: Firstly, the fractional vegetation coverage (FVC) clearly increased over the last 20 years and the medium coverage, which accounted for 66.13%, became the main vegetation cover. The wind speed in the reserve dropped gradually as well. Secondly, sand only affected the nature reserve and the surrounding communities. When the wind speed was above a strong breeze (10.8–13.8 m/s), coarse silt could affect 26 downwind administrative regions, with an affected area of 2.13 × 106 km2. Thirdly, the benefits of windbreak and sand fixation varied with the beneficial range, including distance from the Baijitan Nature Reserve and the beneficial area. Dust deposition decreased as the beneficial distance increased. For instance, Shaanxi Province saw the greatest benefit of windbreak and sand fixation, with a dust deposition reduction of 6.87 × 107 t (1 t = 103 kg), followed by Hubei and Henan Provinces, with reductions of 5.31 × 107 t and 5.59 × 107 t, respectively. Fourthly, the periodical deposition in administrative regions decreased gradually, as did the different influence ranges. The dust depositions in the five phases of Shaanxi Province were 2.04 × 107, 1.83 × 107, 6.63 × 106, 4.65 × 106, and 3.48 × 106 t. Fifthly, medium silt, fine silt, and clay silt could easily drift long distances under the influence of sand-driving wind, thus affecting the air quality in downwind administrative regions. Sixthly, the sand source in Baijitan Nature Reserve was an important factor that caused sand–dust weather in downwind areas. The frequency of sand–dust weather was significantly higher in cities near the sand source than in other regions in downwind areas, and the correlations between particle concentrations less than 10 microns in diameter (PM10) and the time sequences of sand-driving wind reached significant levels in certain cities. We found that the windbreak and sand fixation in Baijitan Nature Reserve could offer great benefits to the downwind area. Establishing a desert nature reserve could be a great way to promote environmentally sustainable development since it could effectively reduce dust deposition and the frequency of sand–dust weather in downwind areas.

Foundry Sand Source Reduction Options: Life Cycle Assessment Evaluation

Foundries represent a significant part of the world’s economy and are a large consumer of energy and producer of solid waste. Sand-handling processes can use 5–10% of a foundry’s total energy. The goal of this research was to explore source reduction and waste minimization at a foundry, using both economic and Life Cycle Assessment (LCA) techniques to compare three secondary sand-reclamation options. LCA software modeled all sand processes at a mid-sized ferrous foundry in the USA. The LCA showed all secondary reclamation technologies, while more energy intensive at the foundry, lowered life cycle environmental impacts, including GHG emissions, ecotoxicity, and human health indicators, due primarily to source reduction and corresponding reduction in transportation both from the virgin sand source and to the landfill. Varying transportation distance had a large impact on LCA results to the point where the life cycle benefit of secondary reclamation became a liability in a zero distance scenario. Varying electricity generation to favor greener sources was also examined, but proved to have minimal impact on the LCA results. This research suggests that the greatest reduction of life cycle impacts in the sand-handling processes for a foundry is to find a geographically closer source for virgin sand.

Ecological and environmental consequences of ecological projects in the Beijing–Tianjin Sand Source Region, China

<p>Evaluation of the influences of the Beijing–Tianjin Sand Source Control Project on soil wind erosion and ecosystem services is imperative for mastering the benefits and drawbacks of the program, as well as for distinguishing more reasonable estimations to evaluate regional sustainable development. Within the Beijing–Tianjin Sand Source Region, we quantified the spatiotemporal patterns of land use/cover changes (LUCCs), soil wind erosion modulus (SWEM), and essential ecosystem services throughout 2000–2015 by utilizing field investigations, remotely sensed data, meteorological data, and modeling. The influences of ecological projects on wind erosion and ecosystem services has been subsequently assessed by using those modifications brought on via the LUCCs (e.g., conversion from cropland to grassland/woodland) during the ecological construction. The results indicated that the SWEM showed a decline and ecosystem services which included carbon storage, water retention, and air quality regulation exhibited growth driven by using both local climate exchanges and human activities such as ecological projects. Excluding the effects of climate factors, the LUCCs stemming from ecological projects caused a total SWEM decrease of 3.77 million tons during 2000–2015, of which approximately 70% was prompted by the way of the transition from desert to sparse grassland. The sub-regions of desert grassland in Bayannur, Ordos Sandy Land, and Otindag Sandy Land were hot spots for wind erosion declines and ecosystem service enhancements induced by the ecological projects. We recommend that endeavors be coordinated toward the scientific management of the degraded lands and distribution of the local populace, as well as the implementation of diverse measures in the expected hotter and drier future.</p>

Initial Laramide tectonism recorded by Upper Cretaceous paleoseismites in the northern Bighorn Basin, USA: Field indicators of an applied end load stress

Soft-sediment deformational structures associated with paleoseismicity (e.g., planar clastic dikes) exist within Upper Cretaceous Mesaverde Group strata in the Laramide Elk Basin anticline, northern Bighorn Basin (Wyoming, USA). Retrodeformation of the Elk Basin anticline to a horizontal Mesaverde Group position indicates that all basement offset is removed and that clastic dikes exhibit a dominant northeast trend. The trend of clastic dikes corresponds to the interpreted northeast-southwest direction of early Laramide layer-parallel shortening, suggesting that the development of clastic dikes recorded initiation of basement deformation and Laramide tectonism. To determine the timing of clastic dike development, we present zircon U-Pb geochronology from the stratigraphically lowest sand-source bed generating upwardly injected clastic dikes and a volcanic bentonite bed (Ardmore bentonite) above the stratigraphic interval containing clastic dikes. Weighted mean ages bracket clastic dike development between 82.4 and 78.0 Ma. Our results imply initiation of basement deformation ∼8–15 m.y. prior than other estimates in the Bighorn Basin. Therefore, we interpret the development of clastic dikes in the Elk Basin anticline to represent an initial phase of Laramide tectonism associated with an applied end load stress transmitted from the southwestern North American plate margin in response to the collision of the conjugate Shatsky Rise oceanic plateau ca. 90–85 Ma. Results demonstrate how sedimentary responses in the foreland can be used to understand tectonic processes at plate boundaries and provide spatial-temporal parameters for models of Laramide deformation.