1,721,039 research outputs found
Problems and progress in land, water and resources rights at the beginning of the third millennium
No full textSystem dynamic approach to evaluate socio-economic-environmental factors influencing sustainability of water use in agricultural production
Full text linkSebbene l’agricoltura irrigua sia ritenuta una delle principali fonti di sfrutta-mento di entrambi le risorse idriche ed energetiche, è’ ampiamente accettato che es-sa svolge un ruolo fondamentale per lo sviluppo socio-economico di molti paesi dell' area mediterranea. Data la sua importanza, in un contesto in cui le risorse idriche sono sempre più soggette a pressioni crescenti a causa delle diverse sfide globali (ad esempio, il cambiamento climatico, la crescita demografica e lo sviluppo eco-nomico), vi è urgente necessità di gestire in maniera sostenibile le risorse idriche destinate a scopi irrigui al fine di garantire elevate rese produttive. Tuttavia, le dinamiche complesse che si instaurano all’interno di un sistema di gestione idrica ad uso irriguo rendono la gestione sostenibile delle risorse idriche di difficile attuazione. Tali sistemi, infatti, sono caratterizzati da un elevata complessità dovuta al compor-tamento di numerosi attori da cui l’utilizzo di risorse naturali dipende e che influisce sulla dinamica del sistema stesso. Non basta, dunque, guardare solo agli aspetti quantitativi dell’utilizzo di risorse idriche (e.g., impatti ammbientali), ma, al fine di supportare la loro gestione sostenibile, è indispensabile anche un’attenta conoscen-za del sistema e della sua dinamica. Da qui deriva, la necessità di affrontare le prob-lematiche della gestione delle risorse idriche in maiera olistica mediante approcci in-tegrati e multidisciplinari.
Tra gli emergenti approcci integrati e multidisciplinari, in ambito scientifico si è af-fermato recentemente il paradigma del nesso tra Acqua-Energia-Cibo, che si configu-ra come un adeguata metodologia capace di supportare la gestione sostenibile delle risorse idriche attraverso l’analisi dei complessi legami tra le risorse naturali inte-grando gli aspetti gestionali della risorsa su scala intersettoriale.
Partendo da queste premesse, al fine di affrontare olisticamente le problematiche del-la gestione sostenibile delle risorse idriche ad uso irriguo, il seguente studio di ricer-ca propone una metodologia innovativa e integrata in grado di operazionalizzare il paradigma di Acqua-Energia-Cibo a scala locale. In particolare la metodologia im-plementata è in grado di valutare le multi-implicazioni dell'uso dell'acqua irrigua at-traverso l'identificazione dei principali fattori che influiscono sul prelievo e lo sfrutta-mento delle risorse idriche. Per cui, al fine di studiare le dinamiche che si instaurano in un sistema di gestione idrica ad uso irriguo, è stato implementato un modello concettuale attraverso l’utilizzo di diagrammi causa-effetto (i.e., Causal loop Dia-grams), considerando un caso di studio rappresentativo situato al Sud Italia nella re-gione Puglia. Tale analisi ha consentito la conoscenza e la definizione dei confini so-ciali ed ambientali del sistema considerato indispenzabile per la definizione degli in-dicatori di sostenibilità rappresentativi della dinamica del sistema. Dunque, tre indici di sostenibilità basati sul concetto di "impronta" sono stati definiti per quantificare l'implicazione multidimensionale della pratica irrigua. In primo luogo, l'Indice di “Im-pronta idrica ad uso irriguo” mira a valutare l'impatto dell'uso dell'acqua irrigua sulle risorse idriche disponibili di una determinata area. In secondo luogo, l'Indice di “Im-pronta Energetica per l’irrigazione” quantifica la quantità di energia consumata per i prelievi e il pompaggio dell'acqua rispetto ai ricavi unitari delle colture. Infine, l'Indice di “Impronta economica” permette la valutazione dei benefici economici della produzione agricola rispetto ai costi dell'acqua utilizzata per l'irrigazione. Tutti gli indi-ci sono stati espressi sia in forma aggregata che separata al fine di valutare gli impatti e i benefici legati all'uso di specifiche fonti idriche quali ad esempio superficiali e sot-terranee.
Infine, l'integrazione degli approcci di cui sopra viene inoltre proposta come ele-mento innovativo del seguente lavoro di ricerca, per supportare la gestione sos-tenibile delle risorse idriche. Difatti, gli indici rappresentano uno strumento im-portante per valutare quantitativamente lo stato dello sfruttamento delle risorse, ma rivelano poco della dinamiche di un dato sistema irriguo, la cui conoscenza è indis-pensabile per valutare l’efficacia dell’implementazione di una data politica di sos-tenibilità.
I risultati ottenuti consentono di trarre alcune conclusioni generali dettagliatamente spiegate nei seguenti capitoli di tesi. In primo luogo, la fitta rete di relazioni tra i di-versi attori decisionali coinvolti influenza fortemente la dinamica del sistema. In se-condo luogo, i comportamenti degli attori sono influenzati sia da fattori esterni (prez-zo di mercato del raccolto e disponibilità idrica) che da vincoli interni (ad esempio, tariffe idriche). Infine, l'efficacia a medio-lungo termine di una determinata politica è influenzata dalla dinamica del Sistema. Pertanto l’integrazione tra aspetti qualitativi della dinamica del sistema con gli aspetti quantitative di utilizzo di risorse idriche si è rivelata di fondamentale importanza per conoscere l'efficacia dell’implementazione di una plausibile politica di sostenibilità nel breve, medio-lungo termine.Irrigated agriculture plays a vital role for socio-economic development of the Mediterranean area, although it is the largest exploiter of both water and energy re-sources. Given its importance, in a context in which water resources experience in-creasing pressure due to different global challenges (i.e., climate change, growth population and economic development among others), there is an urgent need of sustainable management of irrigation water resources. Nevertheless, it is extremely challenging, especially at the local scale, due to several complex and interconnected dynamics establishing in a given irrigation system. In such systems, multiple actors are indeed involved in decision-making processes, and the use of natural resources strongly depends on their behaviors affecting the dynamics of the system itself. As result, facing sustainable management of water resources issues through only a technical knowledge is not enough. Whereas, a careful knowledge of the system and its dynamics is essential for supporting a sustainable management of water re-sources. For the above reasons, integrated approach are needed for dealing with ho-listically water management issues. Among the recent integrated approaches devel-oped in scientific literature the Water-Energy-Food Nexus is surely an useful method-ology for supporting sustainable management of water resources by studying com-plex linkages among resources and integrating management and governance across sector and scale. In order to holistically evaluate sustainable resource management, this study proposes an innovative integrated methodology capable to operationalize the Water Energy Food Nexus (WEFN) at local level evaluating the multi-dimensional implications of irrigation use by identifying the main factors controlling the selection and exploitation of water sources. In detail, a model based on Causal Loop Diagrams (CLD) was implemented in a case study, used as reference, located in Southern Italy in order to get a deeper insight into a complex irrigation system. Moreover, three sustainability indices based on the “footprint” concept were defined in order to quan-tify the multidimensional implication of irrigation practice. Firstly, the Irrigation Water Footprint Index aims to evaluate the impacts of irrigation use on the available water resources of a given area. Secondly, the Energy Footprint for Irrigation Index quanti-fies the amount of energy consumed for water withdrawals and pumping, compared to the unit crop revenue. Finally, the Irrigation Water-Cost Footprint Index supports the evaluation of the economic benefits of agricultural production, compared with the costs of water for irrigation. All indices can be expressed both in an aggregated and disaggregated form to assess the impacts and benefits related to the use of specific water sources. Moreover, the integration of the aforementioned approaches is also proposed as the innovative element for supporting the sustainable management of water resources. Indeed, indices are important instrument to quantitatively evaluate the state of resources exploitation, but they reveal little of a given irrigation system dynamics, which are essential to quantify for identifying the effectiveness of a given sustainability policy. The obtained results reveal some general conclusions. As first finding, a dense network of relationships among different decisional actors involved strongly influence the dynamic of the system. Moreover, it is clear that actor behav-iors is affected by external drivers (i.e., crop market price and water availability) and internal constraints (e.g., water tariff). At the end, the mid-long time effectiveness of a given policy is affected by system dynamic
Water stranding in the energy and agriculture sectors: The case of hydraulic fracturing in water scarce irrigated regions
No full textIn this chapter, the authors analyze global shale deposits located in water scarce areas. They quantify the volume of irrigation water that could be allocated to the more profitable activity of oil and gas extraction, and quantify the consequent volume of irrigated crops that might remain water stranded. The water scarce shale deposits are located where 91% of current calorie production relies on irrigation water. Moreover, in these areas, there is not an expected major increase in water consumption from the agriculture sector because crop yield gaps – the difference between current and maximum attainable yields – has already been closed through irrigation. The authors analyze the socio-environmental risks for local populations and discuss how this reduction in food production might increase the reliance on food imports, thereby compromising the food security and livelihoods of local populations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The value generated by irrigation in the command areas of new agricultural dams in Africa
No full textRecent years have seen continued investments in new irrigation dams across Africa, which have led to the emergence of new irrigated areas in their vicinity (or ‘command areas’). The ability to irrigate land that was previously only rainfed allows for an increase in crop production and is therefore associated with an increase in the value generated by agriculture. What is the value produced by irrigation in the command areas of new major African dams? Here we use crop water modeling under a variety of crop distribution scenarios to determine the increase in agricultural value induced by irrigation in the ‘command’ areas adjacent to the major irrigation dams. We use these estimates to determine the shadow price of irrigation water in these regions along with the increase in land value and land's economic productivity. We focus on dams built in Africa between 2000 and 2015, which are clustered in northern, east, and southern Africa. This study provides a framework to determine the economic benefits of irrigation dams and evaluate the increase in agricultural revenues resulting from access to water for irrigation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
A growing produce bubble: United States produce tied to Mexico's unsustainable agricultural water use
Full text linkGlobal analyses have revealed virtual drains and gains of water between trading countries, with Mexico ranking as one of the countries with the fastest increase in unsustainable water consumption in agriculture for export markets, since 2000. It is unclear, however, how Mexico has reshaped its crop production and associated reliance on freshwater resources to satisfy growing domestic and international markets, especially the United States (US). While the Mexico-US partnership has been identified as one supported by unsustainable irrigation water, the spatial understanding of its strain on water resources has remained at the national scale and without context of the crops driving the change. In this analysis, we focus on the evolution of Mexican agriculture since 1994, the year the North American Free Trade Agreement was enacted, to identify hotspots of water unsustainability in crop production in the domestic and US supply chain. Using a global process-based crop water model, we find that between 1994 and 2015, rainwater (or 'green' water) and irrigation (or 'blue') water consumed in the production of crops increased by one fourth nationally, while water in crops exported to the US doubled. Virtual export of blue water embodied in the trade of berries increased five orders of magnitude; a substantial growth in blue water export was also associated with trade to the US of cereals, fruits, nuts, vegetables, pulses, and tubers. Our results show that in Mexico irrigated water plays an increasingly prominent role in export agriculture, and that many healthy crops that dominate US imports from the world are grown in water scarce Mexican municipalities relying on unsustainable irrigation practices. This serves as a warning for the sustainability of future Mexican healthy food supplies, both for the domestic market and for export to the US
- …
