Environmental and socio-economic impacts of pipe drainage in Pakistan

Many drainage schemes and salinity control projects have been executed world wide. Pipe drainage has widely been used in Pakistan, Egypt and India to control waterlogging. The impact of pipe drainage on land and water was evaluated in this paper using data of three pipe drainage projects in Pakistan namely Khushab Salinity Control and Reclamation Project, Fourth Drainage Project in Faisalabad and Swabi Salinity Control and Reclamation Project. Data by regular monitoring of these projects were collected. The effect of pipe drainage on water table depth at these three locations has been compared. Water quality and soil salinity improvement due to the pipe drainage has also been investigated. Data, related to water table depths and discharges from drain pipes/wells, was collected. Observation wells, installed at various places by the Water and Power Development Authority, were used for collection of this data. To evaluate the impact of the projects on salinity, soil samples from all the three locations were tested. A questionnaire was prepared to get the view of the people about the projects. It was revealed that in these areas, due to subsurface pipe drainage, the percentage of the abandoned land has been considerably decreased. Over drainage was observed in a few places of the projects. The farmers at such places were asked to change their cropping patterns. Ultimately, there has been an increase in area under cultivation, crop yields and cropping intensity in the projects’ area.     

基于形态空间格局分析方法和最小累积阻力模型的北京市平原区造林工程生态格局分析

为了科学评估北京市平原区造林工程的生态影响，利用高分卫星数据获取2018—2020年北京市平原区造林面积、分布及变化信息，分析了造林工程的空间格局特征，并采用形态空间格局分析(MSPA)方法及最小累积阻力(MCR)模型，构建了北京市平原区生态网络，通过情景模拟分析造林工程对生态源地、生态廊道产生的影响。结果显示，2018—2020年北京市平原区造林工程主要沿西北东南方向实施，实现了对原有林地资源分布不均衡问题的解决。热点建设区域为北部的延庆及东南部的通州、大兴，呈现由城市边界逐步向市中心蔓延的发展趋势。在不考虑其他因素对土地利用的影响的前提下，造林工程的实施使平原区林地面积增长了9.8%。通过情景模拟发现，造林工程的实施使生态网络向连通、完整、均衡方向发展。其中，生态源地面积增长了131.0 km²,主要生态源地连通性提升了41.1%,生态廊道的分布由主要分布在西北部山区向西北、东南两个方向均有密集分布转变。综上，造林工程的生态环境效应显著，造林工程的实施对生态环境质量改善具有重要意义。     

Remote sensing imageries for land cover and water quality dynamics on the west coast of Korea

As human activities influence land cover changes, the environment on human life such as water quality, has been impacted. In particular, huge constructions or reclamation projects are responsible for dramatic land cover changes. The Saemangeum area in South Korea has been one of the largest reclamation projects to progress nearly in two decades. In this study, Landsat-5 Thematic Mapper and Landsat-7 Enhanced Thematic Mapper Plus images were used to classify land cover types in the Saemangeum area. A change detection method was utilized to determine the impacts of the reclamation project. While wetland, grassland, and urban areas were increased, forest, water, and agricultural areas were decreased during the reclamation progress. Water quality analysis related to the land cover changes was conducted to determine the influence of reclamation construction on the environment. Chemical oxygen demand and suspended sediment variability were significantly impacted by the sea current changes after the dyke construction. On the contrary, water temperature and dissolved oxygen were affected by the seasonal influences rather than the reclamation construction. Total nitrogen and total phosphorus were influenced by the fertilizers and pesticides as a result of agricultural activity. The trends of suspended sediment from Landsat images were similar with those from the ground observation sites and also impacted by the dyke construction.     

The environmental effects of salinity load in Great Menderes Basin irrigation schemes

This study aimed to assess how poor planning for irrigation led to heavy salt loads, how those salt loads adversely affected the environment, and how to identify management practices to deal with these potential problems in the Great Menderes River Basin, Aydin Plain Irrigation Scheme of Turkey for the period between 2000 and 2006. In order to determine the effects on the environment; electrical conductivity, salinity load, total amount of water table salinity, inflow and outflow salinity were measured and calculated for the research area. There was no problem on account of water table fluctuations. The mean of area prevented the plant growth by high water table was 8.5%. The percentage of the area occurring water table salinity problem was 39.2. The total amount of salt transported to the Great Menderes River and accumulated in the soil of the research area was 211,609 and 246,565 tones respectively. Salt, 458,174 tones in total, had adverse effects on the environment.     

Regional-scale models for relating land cover to basin surface-water quality using remotely sensed data in a GIS

Plant-based management systems implementing deep-rooted, perennial vegetation have been identified as important in mitigating the spread of secondary dryland salinity due to its capacity to influence water table depth. The Glenelg Hopkins catchment is a highly modified watershed in the southwest region of Victoria, where dryland salinity management has been identified as a priority. Empirical relationships between the proportion of native vegetation and in-stream salinity were examined in the Glenelg Hopkins catchment using a linear regression approach. Whilst investigations of these relationships are not unique, this is the first comprehensive attempt to establish a link between land use and in-stream salinity in the study area. The results indicate that higher percentage land cover with native vegetation was negatively correlated with elevated in-stream salinity. This inverse correlation was consistent across the 3 years examined (1980, 1995, and 2002). Recognising the potential for erroneously inferring causal relationships, the methodology outlined here was both a time and cost-effective tool to inform management strategies at a regional scale, particularly in areas where processes may be operating at scales not easily addressed with on-site studies.     

Does irrigation with reclaimed water significantly pollute shallow aquifer with nitrate and salinity? An assay in a perurban area in North Tunisia

In Tunisia, reclaimed water is increasingly used for irrigation in order to mitigate water shortage. However, few studies have addressed the effect of such practice on the environment. Thus, we attempted in this paper to assess the impact of irrigation with reclaimed water on the nitrate content and salinity in the Nabeul shallow aquifer on the basis of satellite images and data from 53 sampled wells. Ordinary and indicator kriging were used to map the spatial variability of these groundwater chemical parameters and to locate the areas where water is suitable for drinking and irrigation. The results of this study have shown that reclaimed water is not an influential factor on groundwater contamination by nitrate and salinity. Cropping density is the main factor contributing to nitrate groundwater pollution, whereas salinity pollution is affected by a conjunction of factors such as seawater interaction and lithology. The predictive maps show that nitrate content in the groundwater ranges from 9.2 to 206 mg/L while the electric conductivity ranges from 2.2 to 8.5 dS/m. The high-nitrate concentration areas underlie sites with high annual crop density, whereas salinity decreases gradually moving away from the coastline. The probability maps reveal that almost the entire study area is unsuitable for drinking with regard to nitrate and salinity levels. Appropriate measures, such as the elaboration of codes of good agricultural practices and action programs, should be undertaken in order to prevent and/or remediate the contamination of the Nabeul shallow aquifer.     

The effects of the environment and ecology projects on lake management and water quality

In this study, the characteristics, benefits, and effects of the environment and ecology project, which has been implemented in Turkey for the first time to restore the natural life that has been spoilt and the ecological balance of Lake Bafa located in Great Meander Basin, are searched. Moreover, the water samples taken from the stations that were spotted in the lake have been analyzed for the physical and chemical changes taking place in water quality before and after the project. The water cycle occurring as a result of giving water that was raised in Great Meander River by the Rubber regulator, which is the most important element of the project, through the Serçin inlet and feeder channel; and draining the saline and low-quality water to the river bed of the Great Meander, will improve the water quality, the natural life, and the ecological balance of the lake in time. Thanks to the water given to the lake within the scope of project, the salinity of the lake water decreased from 25,500 to 22,500 mmhos cm^???1. The electrical conductivity, Na^?+?, Mg^?+?2, Ca^?+?2, Cl^???, $\text{CO}_\text{3} ^{-\text{2}}In this study, the characteristics, benefits, and effects of the environment and ecology project, which has been implemented in Turkey for the first time to restore the natural life that has been spoilt and the ecological balance of Lake Bafa located in Great Meander Basin, are searched. Moreover, the water samples taken from the stations that were spotted in the lake have been analyzed for the physical and chemical changes taking place in water quality before and after the project. The water cycle occurring as a result of giving water that was raised in Great Meander River by the Rubber regulator, which is the most important element of the project, through the Ser?in inlet and feeder channel; and draining the saline and low-quality water to the river bed of the Great Meander, will improve the water quality, the natural life, and the ecological balance of the lake in time. Thanks to the water given to the lake within the scope of project, the salinity of the lake water decreased from 25,500 to 22,500 mmhos cm( - 1). The electrical conductivity, Na+, Mg+2, Ca+2, Cl(-), CO3(-2), HCO3(-), and the amount of the organic substances were found as over the appropriate values for fishery. Besides, the decreases in the amounts of NO3(-), HN3(-) and PO4(-3) affect the living beings in the lake negatively. In addition, the measures to take are specified, so that the natural life of the Lake and the ecological balance can renew themselves within a short time.     

Did the ecological engineering have a great impact on the land use change?

Overuse of land resources has increasingly contributed to environmental crises in China. To mitigate widespread land degradation, actions have been taken to maintain and restore the ecological environment through efforts such as ecological engineering. By analyzing trends in land use, the impact and effectiveness of ecological engineering can be determined. In this study, such changes in Huanjiang County in China were considered. In the early 1990s, an eco-immigration policy and “returning farmland to forest program” were implemented in the county, drastically impacting land use. Land use/land cover changes were detected and analyzed using remote sensing data recorded over 4 years (1995, 2000, 2005, and 2010). Land transfer flow and the rate of land use change elucidated the extent of changes, while nuclear density analysis indicated spatial agglomeration. The results indicate that, over a period of 15 years, farmland area increased, while forest area decreased initially before subsequently increasing. From 1995 to 2000, the highest transfer flow was observed in the grassland to farmland conversion (79.34%). From 2000 to 2005, the transfer flow of conversions was the highest for forest to farmland (56.79%). Land use changes were not prominent from 2005 to 2010. Direct drivers of land use change exert obvious impacts on land use, and indirect drivers impact direct drivers that are then channeled through direct anthropogenic drivers (e.g., land use policies). We found that ecological engineering has a very significant impact on land use change, and that impact varies from region to region.     

准噶尔盆地荒漠区工程建设与水土流失的关系初探

新疆北部的准噶尔盆地的荒漠地区是生态环境脆弱地区,环境极易遭到破坏,随着建设项目的增加,由于工程建设引起的水土流失现象也逐渐增多.目前对该问题的研究尚需深入.本文通过对准噶尔盆地荒漠地区工程建设与水土流失的关系的分析,并借鉴其它地区的经验,指出新疆北部的荒漠地区由于环境脆弱,各类工程均可引发水土流失, 工程建设引起的水土流失也能影响工程本身的安全,工程建设应采取措施,防止水土流失,促进环境保护与经济发展.     

Assessment for Salinized Wasteland Expansion and Land Use Change Using GIS and Remote Sensing in the West Part of Northeast China

Due to human impact under climatic variations, western part of Northeast China has suffered substantial land degradation during past decades. This paper presents an integrated study of expansion process of salinized wasteland in Da’an County, a typical salt-affected area in Northeast China, by using Geographic Information Systems (GIS) and remote sensing. The study explores the temporal and spatial characteristics of salinized wasteland expansion from 1954 to 2004, and land use/cover changes during this period. During the past 50 years, the salinized wasteland in study area have increased by 135,995 ha, and in 2004 covers 32.31% of the total area, in the meantime grassland has decreased by 104,697 ha and in 2004 covers only 13.15% of the study area. Grasslands, croplands and swamplands were found the three main land use types converted into salinized wasteland. Land use/cover changes shows that between 1954 and 2004, 48.6% of grasslands, 42.5% of swamplands, and 14.1% of croplands were transformed into salinized wasteland, respectively. Lastly, the major factors influencing salinized wasteland expansion and land use/cover changes were also explored. In general, climatic factors supplied a potential environment for soil salinization. Human-related factors, such as policy, population, overgrazing, and intensified and unreasonable utilization of land and water resources are the main causes of salinized wasteland expansion.     

Long-term monitoring of the impact of a capture-based bluefin tuna aquaculture on water column nutrient levels in the Eastern Aegean Sea, Turkey

Capture-based aquaculture of Atlantic bluefin tuna in the Mediterranean has been expanding rapidly but little is known about its environmental impact. In order to understand the consequences of this new sector, long-term monitoring is needed. For this purpose, we investigated the impact of a capture-based tuna farm located in the Gerence Bay (Aegean Sea) on the water column on a seasonal basis from 2005 to 2008, where in the water column, temperature, salinity, pH, dissolved oxygen, nutrients (nitrite, nitrate, ammonium, and phosphate), and chlorophyll a, in the sediment organic carbon variables were measured. Although highest nutrient concentrations were observed at the cage station as compared to the two controls in the production period, differences were not statistically significant between stations. Monitoring of physico-chemical parameters, nutrients, and chlorophyll a in water column together with organic carbon in sediment did not show detectable impact of fattening of Atlantic bluefin tuna. This was probably caused by strong currents present in the area, location of the cages away from the coast, hence high water depth, controlled feeding, and periodic presence of tuna farming activity in the study area.     

Drainage discharge impacts on hydrology and water quality of receiving streams in the wheatbelt of Western Australia

The use of surface and subsurface drainage to manage waterlogging and salinity in dryland (rainfed) and irrigated agricultural systems is common throughout the world. The drainage systems often discharge into natural streams. The same is true for the wheatbelt drainage systems in south-western Australia, where 11,000 km (ABS 2003) of artificial drains have been constructed within the last two decades. Prior to this study, the likely impacts of this discharge on the streambed chemistry and water quality of receiving streams were largely unknown. The study evaluated these impacts in creeks receiving the drainage discharge from engineering options in four river systems in south-western Australia. This study clearly showed elevated levels of metals ions, EC and pH in the stream water at treated sites relative to their levels at untreated sites. At most sites, impacts of drainage discharge were observed on the streambed electrical conductivity (EC) and pH (both in 1:5 extract) in the receiving streams; however, there was little evidence of impact on metal ion content in the streambed soil. The study found no clear differences in the dynamics of the watertable adjacent to streams whether they received drainage discharge or not, irrespective of the size of the artificial drainage systems.     

Dynamics of Typical Agricultural Landscape and its Relationship With Water Resource in Inland Shiyang River Watershed, Gansu Province, Northwest China

Shiyang River basin is located in Hexi Corridor, central-west Gansu province, northwest China. It is an area of typical arid to semiarid features. Based on the TM image of Liangzhou oasis and Minqin oasis in 1986 and 2000, this paper calculated and analyzed the changes of percentage and area of land use/cover types, and also have got the transformation matrix of the landscape mosaics. Dynamics of runoff and exploitation of groundwater, the most important factors influencing land use changes were also analyzed. The ratio of utilized water quantity in upper and middle reaches to that in lower reaches has increased largely from less than 2 before 1970 reached up to more than 8 since 1995; groundwater exploitation has developed progressively. As a result of overuse of groundwater, the groundwater table lowering obviously, the lowering rates reached up to 0.6–0.8 m/year in some place. In addition, the cropping patterns in study area were also distributed irrefficiently that if the planting percentage of water-wasting grain crops dropped to 50% in both oases, it could save irrigating water by 1.2×10⁸ m³ in Liangzhou oasis and 0.2×10⁸ m³ in Minqin oasis one year.     

快速城市化背景下的思雅河流域水环境分析

通过对思雅河流域连续3年的水环境质量监测,结合遥感影像获得其土地利用类型变化,据此研究城市化对水环境的影响。结果表明:2012—2014年间思雅河流域自然、农业景观面积占比减少,而建设用地面积持续增加;研究期间除TDS年均值略微下降外,其余水质指标的年均值几乎均呈递增趋势,尤以TSS和COD增加最显著;TSS、COD、NH 3-N和TP的相对标准偏差均>0.1,显著高于其余参数,说明其波动程度较大。主成分分析表明水环境变化最主要的影响因子为第一主成分(TSS、COD、NH 3-N和TP)。贵安新区大学城建设活动加重了思雅河流域水体污染趋势。     

曹妃甸围填海工程的环境影响回顾性评价

围填海回顾性评价是一项涉及面广、内容复杂的分析评价工作。要做出准确、科学的评价,就必须有一套科学的后评价方法和指标体系,评价出项目实际目标与可行性研究阶段预测情况的偏离度,从而比较客观地做出评判。文章建立了围填海工程的海洋生态环境影响回顾性评价指标体系、评价标准与评价方法,并综合运用层次分析法对曹妃甸围填海工程的海洋生态、水动力环境、水质环境和底质环境影响进行回顾性综合评价。该方法克服了传统定性评价的主观性缺点,从而得出比较客观、科学的评价结果,为衡量和分析曹妃甸围填海工程对海洋环境的累积影响及后期围填海工程的环境管理与决策提供了依据。     

Assessing Impact of Urbanization on River Water Quality In The Pearl River Delta Economic Zone, China

The Pearl River Delta Economic Zone is one of the most developed regions in China. It has been undergoing a rapid urbanization since the reformation and opening of China in 1978. This process plays a significant impact on the urban environment, particularly river water quality. The main goal of this present study is to assess the impact of urban activities especially urbanization on river water quality for the study area. Some Landsat TM images from 2000 were used to map the areas for different pollution levels of urban river sections for the study area. In addition, an improved equalized synthetic pollution index method was utilized to assess the field analytical results. The results indicate that there is a positive correlation between the rapidity of urbanization and the pollution levels of urban river water. Compared to the rural river water, urban river water was polluted more seriously. During the urban development process, urbanization and urban activities had a significant negative impact on the river water quality.     

Soil salinization in the agricultural lands of Rhodope District, northeastern Greece

The objective of this study was to identify seasonal and spatial trends and soil salinization patterns in a part of Rhodope District irrigated land, northeastern Greece, located east of Vistonis Lagoon. The study area is irrigated from a coastal aquifer, where salt water intrusion occurs because of extensive groundwater withdrawals. Fourteen monitoring sites were established in harvest fields in the study area, where soil samples were collected. Electrical conductivity (ECe), pH, and ion concentrations were determined in the saturated paste extract of the soil samples in the laboratory using standard methods. A clear tendency was observed for ECe to increase from April to September, i.e., within the irrigation period, indicating the effect of saline groundwater to soil. In the last years, the change from moderately sensitive (e.g., corn) to moderately tolerant crops (e.g., cotton) in the south part of the study area indicates the impacts of soil salinity. The study proposes management methods to alleviate this problem.     

Eco-Environmental Degradation in the Source Region of the Yellow River, Northeast Qinghai-Xizang Plateau

The Yellow River is the second longest river in China and the cradle of the Chinese civilization. The source region of the Yellow River is the most important water holding area for the Yellow River, about 49.2% of the whole runoff comes from this region. However, for the special location, it is a region with most fragile eco-environment in China as well. Eco-environmental degradation in the source region of the Yellow River has been a very serious ecological and socially economic problem. According to census data, historical documents and climatic information, during the last half century, especially the last 30 years, great changes have taken place in the eco-environment of this region. Such changes are mainly manifested in the temporal-spatial changes of water environment, deglaciation, permafrost reduction, vegetation degeneracy and desertification extent, which led to land capacity decreasing and river disconnecting. At present, desertification of the region is showing an accelerating tendency. This paper analyzes the present status of eco-environment degradation in this region supported by GIS and RS, as well as field investigation and indoor analysis, based on knowledge, multi-source data is gathered and the classification is worked out, deals with their natural and anthropogenic causes, and points out that in the last half century the desertification and environmental degradation of this region are mainly attributed to human activities under the background of regional climate changes. To halt further degradation of the environment of this region, great efforts should be made to use land resources rationally, develop advantages animal agriculture and protect the natural grassland.     

Agricultural nitrate monitoring in a lake basin in Central Italy: a further step ahead towards an integrated nutrient management aimed at controlling water pollution

Water pollution from point sources has been considerably reduced over the last few decades. Nevertheless, some water quality problems remain, which can be attributed to non-point pollution sources, and in particular to agriculture. In this paper the results of a study intended to assess the consequences, in terms of NO₃ water pollution, of growing a crop, whose impact in terms of P pollution is already well known, are presented. The potential consequences, in terms of water pollution from nitrates of a BMP expressly applied to reduce P pollution are also discussed. The study site is the Lake Vico basin, Central Italy, which has suffered a shift in trophic state since the mid 1990s, caused by P compounds used for intensive cultivation of hazelnut trees. The results of the monitoring campaign described in this paper allow to assert that hazelnut tree cropping has probably caused a considerable increase in nitrate concentration in the groundwater, although not in the lake water, because of the specific hydrogeological characteristics of the basin. The main conclusion is that monitoring is essential to single out environmental characteristics peculiar of a specific area, which even the most sophisticated model would not have been able to highlight. This is why monitoring and model simulations should be integrated.     

An environmental pressure index proposal for urban development planning based on the analytic network process

This paper introduces a new approach to prioritize urban planning projects according to their environmental pressure in an efficient and reliable way. It is based on the combination of three procedures: (i) the use of environmental pressure indicators, (ii) the aggregation of the indicators in an Environmental Pressure Index by means of the Analytic Network Process method (ANP) and (iii) the interpretation of the information obtained from the experts during the decision-making process.The method has been applied to a proposal for urban development of La Carlota airport in Caracas (Venezuela). There are three options which are currently under evaluation. They include a Health Club, a Residential Area and a Theme Park. After a selection process the experts chose the following environmental pressure indicators as ANP criteria for the project life cycle: used land area, population density, energy consumption, water consumption and waste generation. By using goal-oriented questionnaires designed by the authors, the experts determined the importance of the criteria, the relationships among criteria, and the relationships between the criteria and the urban development alternatives.The resulting data showed that water consumption is the most important environmental pressure factor, and the Theme Park project is by far the urban development alternative which exerts the least environmental pressure on the area. The participating experts coincided in appreciating the technique proposed in this paper is useful and, for ranking ordering these alternatives, an improvement from traditional techniques such as environmental impact studies, life-cycle analysis, etc.