Natural Resources Faculty, Yazd University, Yazd, Iran.
Environ Monit Assess. 2009 Dec;159(1-4):267-80. doi: 10.1007/s10661-008-0628-4. Epub 2008 Dec 4.
Wind erosion is a phenomenon that is reasonably common in regions where dry winds blow. For the most part, these regions correspond to the dry lands; areas where the soil, generally, is dry and shifting and lacks vegetation for most of the year. The winds are sufficiently strong to lift and move sands and soil particles. The repeated removal of superficial layers by the action of winds can modify the texture of the topsoil, by removing the fine particles and leaving the larger particles. Dust and sandstorm (DSS) is the generic term for a serious environmental phenomenon that involves strong winds that blow a large quantity of dust and fine sand particles away from the ground and carry them over a long distance with significant environmental impacts along the way. In the realm of DSS in Iran country, the people who live in Yazd and Sistan-Baluchestan provinces form a single ecological community due to their geographic proximity and climatic contiguity. The major sources of DSS in the region are believed to be the desert and semidesert areas of the Yazd-Ardakan plain in Yazd province. Both Sistan and Baluchestan are the recipients of this dust. To address the long-range transboundary environmental problem of DSS, a regional cooperation mechanism must be established among the provinces in the region. Yazd-Ardakan plain, with area of about 650,000 ha, is located in the center of Iran, between Yazd and Ardakan cities. The mean annual rainfall is less than 65 mm. Rainfall distribution is a simple modal and more than 70% of it occurs in winter. Plant density varies from 0% to 25%, and Artemisia sieberi is the dominant plant species. The major part of Yazd-Ardakan plain is bare land. According to the recent investigation, more than 20,000-m(3) dust with less than 100-microm diameter falls down annually on Yazd city with an area of 7,000 ha. Horizontal visibility is reduced to less than 6 m in stormy days in some parts of Yazd-Ardakan plain. This phenomenon causes car accidents on the main roads of Yazd-Ardakan and can cancel the airplane flights in the stormy days. At present, it is estimated that wind erosion causes more than $6.8 million damages to socioeconomic resources in Yazd plain each year. This paper describes the pattern of occurrence of wind erosion and major contributing factors, summarizes measured rates of wind erosion, outlines the techniques used to mitigate wind erosion hazard, and suggests research priorities. Also, damages of DSS have been estimated and methods for prevention and control are suggested.
风蚀是一种在干燥风盛行的地区相当普遍的现象。在大多数情况下，这些地区与干旱地区相对应；在这些地区，土壤通常干燥、移动，且大部分时间缺乏植被。风的强度足以抬起和移动沙子和土壤颗粒。风的反复作用会将表层土壤移走，从而改变表土的质地，去除细小颗粒而留下较大颗粒。尘暴（Dust and Sandstorm，DSS）是一种涉及强风的严重环境现象的通用术语，这些强风会将大量灰尘和细沙颗粒从地面吹起，并将其携带至很远的距离，沿途会造成重大的环境影响。在伊朗的尘暴领域，居住在亚兹德省和锡斯坦和俾路支斯坦省的人们由于地理位置接近和气候相邻，形成了一个单一的生态社区。该地区尘暴的主要来源被认为是亚兹德省亚兹德-阿尔达坎平原的沙漠和半沙漠地区。锡斯坦和俾路支斯坦都是这些尘埃的接收地。为了解决尘暴的长距离跨境环境问题，该地区的各省之间必须建立区域合作机制。亚兹德-阿尔达坎平原面积约 65 万公顷，位于伊朗中心，位于亚兹德和阿尔达坎市之间。年平均降雨量小于 65 毫米。降雨分布呈简单模态，超过 70%的降雨发生在冬季。植物密度从 0%到 25%不等，优势植物种为蒿属植物。亚兹德-阿尔达坎平原的大部分地区都是裸露的土地。根据最近的调查，每年有超过 2 万立方米的直径小于 100 微米的尘埃降落在面积为 7000 公顷的亚兹德市。在亚兹德-阿尔达坎平原的部分地区，暴风雨天气下水平能见度会降至 6 米以下。这种现象会导致亚兹德-阿尔达坎主要道路上发生车祸，并且在暴风雨天气中会取消飞机航班。目前估计，每年风蚀给亚兹德平原造成的社会经济资源损失超过 680 万美元。本文描述了风蚀的发生模式和主要影响因素，总结了风蚀的实测速率，概述了减轻风蚀危害的技术，并提出了研究重点。还估算了尘暴的损失，并提出了预防和控制的方法。
