TISS: a decision framework for tailing impoundment site selection

Tailing dam is one of the most important mining operations interface with surrounding environment even as long as many years after ore reserve exhausted. Therefore, appropriate design and management respect to future limitations of environmental regulations is required. Recently, effect of multiple criteria on tailing impoundment site selection makes it complex as the conventional procedures unable to answer. The systematic approach of multi attribute decision-making helps decision-makers select the most preferable decision and provide the basis of a decision support system. This paper developed new strategy based on fuzzy multi attribute group decision-making methods including: technique for order preference by similarity to ideal solution and analytical hierarchy process in fuzzy group environment. A hypothetical case is processed to demonstrate the strategy’s efficiency and results are compared and ranked so that the most preferable option is identified.     

Monitoring of playa evaporites as seen with optical remote sensing sensors: case of Chott El Jerid,Tunisia, from 2003 to present

Chott El Jerid in the Zone of Chotts of Tunisia is one of the largest endorheic basins in the world. During the dry period, from May to August, it is generally covered by continental evaporites which result from the desiccation of the lake formed after a flooding event. This lake comprises runoff water from the surrounding relief and also water resurgence. In order to map and monitor these evaporitic surfaces (mineral composition and evolution in space and time), optical multisource, multispectral, and multidate satellite data have been used. Landsat 4–5 TM, Landsat 8 OLI, SPOT 6, and Landsat Surface Reflectance (LSR) constitute the main data set. The central part of the Chott, north and south of the road crossing the Chott over 70 km from Tozeur to Kebili, has been particularly studied, because it corresponds to the major evaporite accumulation zone. These evaporites precipitated as concentric layers (a relatively rare pattern), mainly north of the road, after several recent flooding events during the last 15 years. Winds can play a significant role in the development of the evaporite layers. Image interpretation associated with field data shows that after the final desiccation of the playa lake, the mineralogy of the salt crust comprised an assemblage dominated by halite south of the road and by gypsum north of the road. Halite and gypsum are the only minerals to be identified using satellite remote sensing data. Sulfates such as gypsum can be identified thanks to a drop in reflectance in the short-wave infrared (SWIR) range caused by vibrations of the SO₄ group. Gypsum crusts are more widely distributed than halite crusts. LSR data are particularly suitable for multitemporal comparison because they are calibrated and atmospherically corrected. The classical bull’s eye pattern characterizing evaporitic deposits (from carbonates along the rims to halite, gypsum, and finally potassium-magnesium minerals in the center of the basin) is deeply disturbed by the road crossing Chott El Jerid.     

塔克拉玛干沙漠沙垄起伏地形夏季地表温度差异特征

摘 要：开展塔克拉玛干沙漠沙垄起伏地形夏季地表温度观测试验，旨在为塔克拉玛干沙漠环境陆面过程研究提供科学依据。2019年6月7日至9月2日在塔中地区，沿沙垄迎风坡以及背风坡底部、中部、上部、顶点及垄间谷地共设8个地表温度观测点。结果表明：（1）夏季沙垄地表温度最高温出现在垄间谷地，为74.63 ℃，最低温出现在迎风坡底部，为10.52 ℃；地表温度一天中在7:00左右达到最低，15:00左右达到最高。（2）晴天、多云以及浮尘天各观测点地表温度日均变化曲线呈单峰型，降水、扬沙及沙尘暴天呈双峰型；地表温度的最高温与日均值最大值均出现在晴天的垄间谷地，地表温度的最低温及日均值最小值均出现在降水天的迎风坡底部。（3）沙垄顶点与两个底部最大温差范围是顶点与背风坡底部在晴天的温差范围，为0～18.62 ℃，最小温差范围是顶点与迎风坡底部在降水天的温差范围，为0.01～6.18 ℃；迎风坡和背风坡在晴天地表温度温差范围最大，为0.01～16.93 ℃，在降水天温差范围最小，为0.01～4.15 ℃；顶点与两个底部夏季综合温差范围在0～18.62 ℃，迎风坡与背风坡夏季综合温差范围为0～16.93 ℃。塔克拉玛干沙漠地表温度受典型天气影响变化类型多样，沙垄顶点与底部、迎风坡与背风坡地表温度差异受风力及地形作用明显。     

巴基斯坦近40a气温时空变化特征分析

基于巴基斯坦不同气候区4个代表站(卡拉奇、雅各布阿巴德、奎达、德罗什)1979—2018年地面观测资料和ERA-Interim气温资料,利用一元线性回归、Mann-Kendall突变检验和Morlet小波分析,分析其气温时空变化特征。结果表明:(1)巴基斯坦过去40 a经历了先降温后增温的过程,除北部山区年平均气温增温趋势显著,四季总体都有增温,春秋两季增温趋势显著。巴基斯坦于1998年左右发生气温突变,年平均气温存在4~5、12、20~22和32 a的周期。(2)ERAInterim再分析资料与地面观测数据拟合分析显示两者相关性达到极显著水平,除北部山区外,在大部分区域误差较小,能够较好地反映巴基斯坦气温的变化特征。(3)巴基斯坦年、季平均气温空间分布地带性明显,高温区位于南部印度河平原、三角洲地区,低温区分布在北部山区,年、春季、秋季平均气温变化在空间上总体均呈现明显增长趋势.