Topical Collection: Groundwater-based agriculture in the Mediterranean

This essay introduces a collection of articles that explore the future of groundwater-based agriculture in the Mediterranean from an interdisciplinary perspective, in a context of declining water tables due to intensive groundwater use. The imminent crisis that many groundwater economies face due to very rapid and intense global change may have severe irreversible social, economic and environmental consequences, but could also be the opportunity to make a clear break with current agricultural development models and move towards more sustainable agricultural practices. The Mediterranean region is, therefore, an interesting case for the future of intensive groundwater use, as innovative ideas and practices may emerge and inspire similar groundwater-based agricultural systems around the world.     

Smallholder groundwater irrigation in sub-Saharan Africa: an interdisciplinary framework applied to the Usangu plains, Tanzania

A simple but comprehensive framework for analysing the potential for and constraints to groundwater development for irrigated agriculture in sub-Saharan Africa is proposed. The framework, based on food value chain principles, is applied to the sub-Saharan context and a specific catchment in Tanzania, the Usangu plains, where groundwater has been proposed as a strategic resource for augmenting food production and smallholder livelihoods and to alleviate seasonal water scarcity. The novel contribution of the work is the presentation of a tool that can be applied to support an interdisciplinary approach to systematically identify most significant barriers and most critical water management and development interventions for sustainable development of groundwater irrigation. The result of the case study shows that farmer economics, capacity, and pump and well drilling market constraints limit groundwater irrigation in the Usangu plains rather than hydrogeological conditions.     

Optimizing groundwater development strategies by genetic algorithm: a case study for balancing the needs for agricultural irrigation and environmental protection in northern China

Gaoqing Plain is a major agriculture center of Shandong Province in northern China. Over the last 30 years, the diversion of Yellow River water for intensive irrigation in Gaoqing Plain has led to elevation of the water table and increased evaporation, and subsequently, a dramatic increase in salt content in soil and rapid degradation of crop productivity. Optimal strategies have been explored, that will balance the need to extract sufficient groundwater for irrigation (to ease the pressure on diverting Yellow River water) with the need to improve the local environment by appropriately lowering the water table. Two simulation-optimization models have been formulated and a genetic algorithm (GA) is applied to search for the optimal groundwater development strategies in Gaoqing Plain, while keeping the adverse environmental impacts in check. Compared with the trial-and-error approach of previous studies, the optimization results demonstrate that using an optimization model coupled with a GA search is both effective and efficient. The optimal solutions identified by the GA will provide Gaoqing Plain with the blueprints for developing sustainable groundwater abstraction plans to support local economic development and improve its environmental quality. Li Zheng is currently a visiting scientist in the Mathematical Modeling and Analysis Group, Los Alamos National Laboratory, New Mexico, USA.     

Groundwater vulnerability assessment of the SW Trans-Danubian Central Range, Hungary

 The most important karst water reservoir of Hungary is found in the SW Trans-Danubian Central Range, selected as test area for the proposed "system approach" and the application of GIS/ARC-INFO to vulnerability mapping. In addition, a case-study exemplifies the particularities of regional karst-aquifer vulnerability, and moreover the interpretation of data and maps from the very same point of view. The work has resulted in plotting an atlas to be a useful tool in the hands of land-users and waste-disposal managers, helping them to prevent groundwater deterioration. Received: 22 July 1996 · Accepted: 12 September 1997     

Towards sustainable agriculture in post-apartheid South Africa

This paper assesses the possibility of sustainable agriculture in South Africa in the context of recent policy initiatives. The new environmental strategy for agriculture represents a significant break with policy initiatives developed during apartheid. The likelihood of sustainable farming practices being adopted in South Africa will, however, face at least three obstacles. These are the integrated structure of industrial farming, the concern over yields, and current political and economic changes in South African agriculture. It is argued that sustainable techniques are unlikely to develop in the large scale farming sector in the near future. If the considerable research and extension resources of the state are reoriented quickly enough, sustainable farming methods can be embraced by an emerging class of black commercial farmers.     

Agriculture,sustainability and the imperatives of policy reform

Agriculture stands alone among resource sectors in Western industrialized countries as having the fastest growth in production/productivity during post-war years. Yet that growth in productivity and accompanying high levels of sufficiency has been at the expense of such goals as adequate income, community stability and resource/environmental conservation. In the process, agriculture has mimicked trends in the economy as a whole through increased segmentation and differentiation, throughput of non-renewable resources and divergence of natural and economic processes. Within the context of prevailing policies and market forces in OECD countries in general and Canada in particular, this paper evaluates the problems facing the sector and the nature of the trade-offs being made in the pursuit of high-input agriculture. It is argued that, while agri-business and market forces are generally responsible for a weakening of the links between environment and economy, numerous market distortions, precipitated by agricultural policy, do much the same. To achieve a better balance among the production and consumption functions of the land and to achieve an approach to future agricultural production which is sustainable will require changes in many of the rules, standards and conventions influencing the growth of food and fibre. From a policy perspective, the main task ahead is to redesign and implement programs which will encourage new ‘opportunity sets’ for the economic and competitive viability of the farmer and agricultural system, while at the same time meeting the nutritional needs of society and ensuring the protection of important environmental services and amenity values.     

Sustainability indicators: geology meets economy

 Suggestions for defining and measuring sustainable development can broadly be placed in two categories: weak and strong sustainability. The concept of weak sustainability assumes that manufactured and natural capital are close substitutes. This means that the costs of environmental deterioration (e.g. groundwater damage) can be compensated by benefits from manufactured capital (e.g. income). Thus, environmental damage is valued in monetary units. The concept of strong sustainability denies the degree of substitution that weak sustainability assumes, at least for some critical elements of natural capital. This paper endorses the use of strong sustainability indicators, especially for critical loads and critical levels. These have to be pointed out by environmental scientists and/or geologists. Nevertheless, the costs and benefits of avoiding critical impacts have to be taken into consideration. Hence, a combination of strong and weak sustainability indicators is suggested. Received: 2 April 1996 · Accepted: 14 October 1996     

水资源合理调控利用发展农业节水灌溉

南皮县淡水资源短缺,咸水广布,制约农业生产的可持续发展.解决途径是合理调控利用当地水资源,开发利用浅层地下水包括微咸水和半咸水抗旱灌溉,调蓄雨季降雨径流及汛后河流来水作为补源,地下水地上水联合运用,发展农业节水灌溉,调整农业种植结构,提高水的利用效率.实现水资源可持续利用,农业生产可持续发展,生态环境良性循环,人与自然和谐相处.     

河北平原地下水开发中的问题及可持续利用

河北平原是我国严重缺水地区，但在地下水开发过程中，引起了多种环境问题，如地下水位持续下降；地下水位降落漏斗不断扩大，地下含水层疏干；地面发生沉降及出现地裂缝；海、咸水入侵等等。作者从水资源、环境和社会经济的特点出发，提出实现水资源和社会经济可持续发展的对策：全面实施节水战略，努力实现工业、农业、居民生活、生态环境的高效用水，逐步建立起节水型社会；提高城市污水资源化利用率；利用海水、咸水、减少淡水用量；实施跨流域调水；保护水资源和改善水环境是缓解河北平原缺水和环境问题的重要措施。     

华北平原水资源紧缺情势与因源

基于水资源可持续利用理念,从水资源承载能力演化周期性、经济社会需用水规模难变性和未来水资源供需关系入手,介绍近60年以来华北平原水资源情势,特别是该平原水资源量、实际用水量和地下水开采量变化特征,并结合未来10到30年区域经济社会发展需用水量趋势,识别和诊断华北平原水资源紧缺因源。结果表明：由于降水量减少导致华北平原缺水（自然资源性缺水）占该平原总缺水量的15.1%~16.4%;因管理缺陷导致水资源浪费的缺水（管理性缺水）占22.1%~24.2%;人口数量和经济社会发展规模过大导致用水量超过区域水资源承载力的缺水（政策性缺水）占59.3%~62.5%。自然资源性、管理性以及政策性缺水的解决对策不同：自然资源性缺水是不依人的意志为转移的,惟有从外域适量调水才能解决;管理性缺水可通过社会文明进步和科技进步不断修正;政策性缺水宜因势利导进行经济社会布局和产业结构调整,特别是限制高耗低效用水产业。即使南水北调工程70.3×108m3/a水进入华北平原,该平原地下水超采情势也难以得到根本性扭转。有新增水源调入或华北平原严控生活和工业用水量,同时大幅压减农业用水量,因势利导优化和逐步调整经济社会布局和产业结构,特别是灌溉农业进行规模化减蒸、降耗、节水的改造,将是缓解华北平原地下水超采和水资源紧缺的根本所在。     

Sustainable Irrigation with Brackish Groundwater in Heilonggang Region, China

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可持续发展理念下的水文地质与环境地质工作

可持续发展的理念 ,要求我们重新审视与调整水文地质与环境地质工作的思路 ,寻求治本的整体性对策。以河北平原水资源条件和生态环境的根本改善以及长江中游防洪对策为例 ,探讨了可持续发展理念下的水文地质与环境地质工作的特点 ,即水文地质与环境地质工作的目标 ,是构建人和自然协调的、良性循环的优化地下水系统或地质环境系统 ;必须以多学科交叉渗透的方法 ,从成生角度对目标系统进行系统分析 ;必须应用系统工程方法 ,采取成龙配套的措施重新构建优化系统 ;为了构建优化系统 ,不仅需要理顺人与自然的关系 ,更重要的是理顺人与人的利益关系。可持续理念下的水文地质与环境地质工作 ,能够获得良好的长期社会、经济与环境效益 ,但是需要付出十分艰巨的努力。     

Assessment of agricultural groundwater users in Iran: a cultural environmental bias

Many environmental problems are rooted in human behavior. This study aimed to explore the causal effect of cultural environmental bias on ‘sustainable behavior’ among agricultural groundwater users in Fars province, Iran, according to Klockner’s comprehensive model. A survey-based research project was conducted to gathering data on the paradigm of environmental psychology. The sample included agricultural groundwater users (n = 296) who were selected at random within a structured sampling regime involving study areas that represent three (higher, medium and lower) bounds of the agricultural-groundwater-vulnerability spectrum. Results showed that the “environment as ductile (EnAD)” variable was a strong determinant of sustainable behavior as it related to groundwater use, and that EnAE had the highest causal effect on the behavior of agricultural groundwater users. The adjusted model explained 41% variance of “groundwater sustainable behavior”. Based on the results, the groundwater sustainable behaviors of agricultural groundwater users were found to be affected by personal and subjective norm variables and that they are influenced by casual effects of the “environment as ductile (EnAD)” variable. The conclusions reflect the Fars agricultural groundwater users’ attitude or worldview on groundwater as an unrecoverable resource; thus, it is necessary that scientific disciplines like hydrogeology and psycho-sociology be considered together in a comprehensive approach for every groundwater study.     

Explaining low yields and low food production in Cameroon: a farmers’ perspective

While a bottom-up approach to identifying problems affecting food production among small-scale farmers has been urged as an appropriate means of finding sustainable solutions, few studies have determined the practical process of doing so and measured the outcomes of such an approach. This paper uses information gained mainly through focus groups with small-scale farmers and semi-structured interviews, to identify farmers’ perceptions of reasons behind low yields and low agricultural production in three communities of Cameroon’s North West region. Three biophysical factors are identified as the main reasons of low production: the long and more frequent dry spells and late start of the start of the rainy season. Three socio-economic reasons are identified as most important: land scarcity, money to invest in agriculture and labour scarcity. Farmers rank their reasons based on the importance to their agricultural production in their local area. Some of the important claims made by farmers are tested using field data and statistical analysis. These include the claims that: (1) the rainy season is increasingly starting later than it used to; and (2) the length of dry spells are increasingly longer than they used to be. The results of these statistical tests are significant, showing that farmers’ knowledge of some of the local problems affecting their activities can serve as an important input into formal research and policy design. Peoples’ understanding of a problem affects the way they will act on it—in terms of searching for solutions and implementing change. Farmers can therefore provide useful insights on why they think there are large yield gaps within their local production environments. The current agricultural development policy of the Cameroon government is advocating greater public–private engagement and can benefit from farmers’ inputs and opinions in the design of relevant policies. In the same light, nonlocal based researchers and research institutions can draw on farmers’ knowledge to create and accumulate knowledge on sustainable solutions to problems of low yields and low food production in Cameroon.     

乌鲁木齐市地区地下水水文地球化学评价

通过对乌鲁木齐市区域水文地质，实测水化学资料及前人有关地下水水化学研究成果，总结了市区地下水水化学变化规律，同时对1996－2000年乌鲁木齐市地下水环境质量状况进行了水文地质化学综合评价。结果表明，1996－2000年间乌鲁木齐地下水污染面积减少，污染程度减轻，水体质量好转，地下水环境状况有明显改善。这一结果与近年来政府环境保护政策的贯彻落实，及各部门采取的防止地下水污染措施密切相关。     

Climate change and groundwater resources in Lao PDR

The national economy of Lao PDR is highly dependent on water resources. Consequently, the sustainable management of groundwater and successful adaptations to future climate change are major concerns. Climate projections for Lao PDR predict increased rainfall and hot weather, with more intense rainfall events and more frequent and severe droughts and floods. Under climate change, reductions in the amount and quality of groundwater are two critical problems. Reductions of the groundwater level will restrict the access of local people to groundwater resources, thereby posing a threat to food security and livelihoods. Lao PDR suffers from a limited number of human resources with the requisite skills to perform groundwater investigations and provide sustainable management. For the successful implementation of groundwater management plans, limitations associated with funding and technology should be resolved via support from the government and international cooperation. Advanced action plans for capacity building and training courses should be established to strengthen administrative and individual capacities. Technical measures, such as groundwater monitoring, aquifer characterizations, and water treatment systems, should be implemented to manage future climate change and water resource security.     

黑龙港地区农业—水资源—环境系统分析

通过现状农业—水资源—环境系统分析与诊断发现,黑龙港地区农业结构失调,背离资源条件发展农业,超采地下水,已使该区面临水资源不能永续利用、环境不断恶化的威胁;认为①立足水资源条件发展农业,是建立协调优化的农业—水资源—环境系统,实现农业可持续发展的必要前提;②采用综合措施有效利用土壤水,科学灌溉微咸水,合理开发利用地下水和地表水,是提高水资源对农业贡献的关键;③加强综合科技投入和农村市场经济建设,发展集约化农业,是在有限水资源条件下提高农业生产效率的重要保证;④提高全社会对可持续发展的认识,进行相应的能力建设,是实现黑龙港地区农业—水资源—环境协调可持续发展的社会基础。     

Towards an integrated arid zone water management using simulation-based optimisation

For ensuring both optimal sustainable water resources management and long-term planning in a changing arid environment, we propose an integrated Assessment-, Prognoses-, Planning- and Management tool (APPM). The new APPM integrates the complex interactions of the strongly nonlinear meteorological, hydrological and agricultural phenomena, considering the socio-economic aspects. It aims at achieving best possible solutions for water allocation, groundwater storage and withdrawals including saline water management together with a substantial increase of the water use efficiency employing novel optimisation strategies for irrigation control and scheduling. To obtain a robust and fast operation of the water management system, it unites process modeling with artificial intelligence tools and evolutionary optimisation techniques for managing both water quality and quantity. We demonstrate some key components of our methodology by an exemplary application to the south Al-Batinah region in the Sultanate of Oman which is affected by saltwater intrusion into a coastal aquifer due to excessive groundwater withdrawal for irrigated agriculture. We show the effectiveness and functionality of a new simulation-based water management system for the optimisation and evaluation of different irrigation practices, crop pattern and resulting abstraction scenarios. The results of several optimisation runs indicate that due to contradicting objectives, such as profit-oriented agriculture versus aquifer sustainability only a multi-objective optimisation can provide sustainable solutions for the management of the water resources in respect of the environment as well as the socio-economic development.     

Salinization and Deterioration of Groundwater Quality by Nitrate and Fluoride in the Chittur Block,Palakkad, Kerala

Chittur block represents a mid-land region of Palakkad district, Kerala and the block differs from the rest of the blocks in its climate and availability of groundwater. About 75% of the people depend on agriculture for their livelihood. Results showed that groundwater salinity levels (up to 1,963 mg/L TDS),fluoride (up to 6.3 mg/L) and nitrate (up to 141 mg/L) contents have increased significantly in tandem with the increase in groundwater abstraction. Before human intervention the chemical weathering of gneisses and granites was the main process impinging on the chemical signature of groundwater. The initial chemical equilibrium conditions change with increasing groundwater withdrawal rates and fertilizer input, in a milieu of lower natural groundwater recharge. The appearance of higher levels of bicarbonate, linked to denitrification processes, and the decrease in calcium, due to calcite precipitation, can lead to increased content of sodium and fluoride in groundwater. In this scenario the use of groundwater resources for human consumption and agriculture represents a public health risk if water management actions do not change the trend in water use in the near future. The potential loss of fertile soil by groundwater salinization must also be considered when planning sustainable policies in a region with over dependence on groundwater resources.     

试论地下水系统区域环境影响评价

本文将探讨采用环境系统分析方法，从保护地下水环境出发，把极其复杂的环境系统的结构、功能、影响和效益结合起来作为一个整体，通过由于城市发展、农业开发、以及自然环境的变迁等，对地下水环境系统的影响效应及其发展趋势，进行系统分析和评价，从而提出最有效、最经济、最优化的环境对策。对区域性地下水系统环境影响评价理论和实践方法进行了探讨。