Climate and socio-economic systems are two global changing drivers that locally affect the water resource availability. These systems are strictly interconnected and their relationship need to be considered in the decision making process to get an integrated insight into the water system evolution and to identify possible adaptation options. Traditionally, climate and socio-economic changes have been considered separately when analysing the effects on water systems. This study, instead, aims to evaluate the future local impact of agricultural expansion by exploring the implications of socio-economic and climate changes jointly. Specifically, we rely on RCP climate projections coupled with socio-economic scenarios generated with a new analytic framework. Zambezi River basin is considered as the case study representing a meaningful example of basin experiencing rapid development in terms of population growth and agricultural expansion while being exposed to climate change impacts. Future projections are downscaled from the global to the local scale through combined dynamical-statistical method for the climate variables, and using Tethys - a new downscaling model - for the socio-economic projections. The climate variables are used to estimate the future streamflows through different hydrological models. Water irrigation demand is the key variable of socio-economic projections that together with future streamflow is used as input to feed the Zambezi water system model in order to evaluate the objectives of the three main stakeholders: agriculture, hydropower and environment. From numerical results we found out that the socio-economic drivers are crucial to evaluate future water system performaces. In particular the level of coordination among world countries, dealing with climate change mitigation policy, GDP and population could significantly influence local water availability. In the future, the water demand for agriculture is expected to be a critical factor that could increase the already existing conflict between stakeholders.
La disponibilità locale della risorsa idrica è influenzata sia dai cambiamenti climatici globali che dallo sviluppo socio-economico. Essendo questi due sistemi globali strettamente interconessi, è necessario tenere conto della loro relazione nei processi decisionali al fine di ottenere una visione integrata delle possibili evoluzioni del sistema idrico e di conseguenza sviluppare possibili opzioni di adattamento. Comunemente, gli aspetti climatici e socio-economici sono considerati separatamente nella valutazione degli impatti che questi hanno sulle risorse idriche. Questo studio invece, ha lo scopo di investigare gli impatti di una futura espansione agricola nel bacino del fiume Zambesi tenendo conto di entrambi gli aspetti climatici e socio-economici. L'analisi si basa sulle proiezioni climatiche fornite dagli RCP accoppiate a scenari socio-economici sviluppati attraverso un nuovo approccio di generazione. Il bacino dello Zambesi è stato considerato come caso studio, in quanto rappresentativo di una condizione di rapido sviluppo demografico e agricolo oltre che soggetto agli impatti del cambiamento climatico. Le proiezioni future globali di clima e socio-economia sono state riscalate sul bacino. Le prime combinando metodi dinamici e statistici, le ultime sfruttando Tethys, un nuovo modello sviluppato per il downscaling delle proiezioni socio-economiche. Le variabili climatiche così ottenute sono fornite in input a diversi modelli idrologici tramite i quali viene stimata la portata futura delle unità idrologiche principali del bacino. La domanda irrigua futura costituisce la variabile chiave relativa alle proiezioni socio-economiche che insieme alle portate è data in ingresso al modello del sistema idrico. Le performance del modello sono valuatate tramite gli obiettivi dei tre principali portatori di interesse: idroelettrico, irrigui e ambiente. Dallo studio emerge che gli aspetti socio-economici sono cruciali nella valutazione delle performance future del sistema idrico dello Zambezi. In particolare i livelli di cooperazione tra stati nei confronti delle politiche di mitigazione , il PIL e la poplazione futura hanno influenze determinanti nei confronti della disponibilità d'acqua locale. In futuro, la richiesta d'acqua per l'agricoltura ricoprirà un ruolo critico soprattutto nell'inasprimento dei già esistenti conflitti tra i principali portatori di interesse.
Robust planning of agricultural expansion in Zambezi river basin under climate and socio-economic changes
BENIGNI, BARBARA;RAIMONDO, SEBASTIAN
2017/2018
Abstract
Climate and socio-economic systems are two global changing drivers that locally affect the water resource availability. These systems are strictly interconnected and their relationship need to be considered in the decision making process to get an integrated insight into the water system evolution and to identify possible adaptation options. Traditionally, climate and socio-economic changes have been considered separately when analysing the effects on water systems. This study, instead, aims to evaluate the future local impact of agricultural expansion by exploring the implications of socio-economic and climate changes jointly. Specifically, we rely on RCP climate projections coupled with socio-economic scenarios generated with a new analytic framework. Zambezi River basin is considered as the case study representing a meaningful example of basin experiencing rapid development in terms of population growth and agricultural expansion while being exposed to climate change impacts. Future projections are downscaled from the global to the local scale through combined dynamical-statistical method for the climate variables, and using Tethys - a new downscaling model - for the socio-economic projections. The climate variables are used to estimate the future streamflows through different hydrological models. Water irrigation demand is the key variable of socio-economic projections that together with future streamflow is used as input to feed the Zambezi water system model in order to evaluate the objectives of the three main stakeholders: agriculture, hydropower and environment. From numerical results we found out that the socio-economic drivers are crucial to evaluate future water system performaces. In particular the level of coordination among world countries, dealing with climate change mitigation policy, GDP and population could significantly influence local water availability. In the future, the water demand for agriculture is expected to be a critical factor that could increase the already existing conflict between stakeholders.File | Dimensione | Formato | |
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https://hdl.handle.net/10589/139795