Saltwater intrusion and climate change impact on coastal agriculture
Paolo Tarolli, Jian Luo, Eugenio Straffelini, Yuei‐An Liou, Kim-Anh Nguyen, Rodolfo Laurenti, Roberta Masin, Vincenzo D’Agostino
Abstract
Coastal agriculture represents a significant food production and socio-economic reality in the world, as millions of people are living in coastal areas. In some regions, the optimal combination between traditions and cultivated coastal land is recognized and protected by UN initiatives such as the Food and Agriculture Organization (FAO), Globally Important Agricultural Heritage Systems (e.g., Kuttanad Below Sea Level Farming System, in India), and UNESCO World heritage (e.g., cultural landscape of the Saloum delta in Senegal, and the Trang An Landscape Complex on the Red River Delta Vietnam). Agriculture in these areas depends on optimal water resource management. Changing climatical conditions is threatening coastal agriculture's preservation and sustainability and its unique role in historical heritage. Freshwater sources close to the sea are at risk of saltwater intrusion This process results from multiple drivers: natural and anthropogenic. Climate change, with the sea-level rise first, and recently also drought, are causing, especially in river deltas, a progressive land degradation, which negatively impacts the sustainable development of agriculture, society, and economy. Droughts are responsible for particularly severe saltwater intrusion events. Indeed, lack of rainfall leads to scarce river discharge and favors marine water inland flow intrusion. The consequences for agricultural production are several: impaired plant uptake of water and essential nutrients, negative effects on crop growth and development, higher weed competition, lower soil microbial activity, and overall crop productivity reduction. Here we present the case of two critical regions that can be considered the world's hotspots of saltwater intrusion phenomenon. We also addressed possible mitigation solutions.