Small reservoirs for a sustainable water resources management

Abstract

Small reservoirs are widely used for storing water, especially for irrigation purposes. During the last decades, in Italy many of these reservoirs have been dismissed, becoming an untapped resource. As a matter of fact, maintenance problems connected to these structures together with their natural tendency to silt have favored the use of other water supply resources such as withdrawal from wells.The increase of drought periods and the high water volume demand for agricultural purposes suggest to evaluate a full and rational use of all water resources, leading to a rediscovery and enhancement of untapped resources. Specifically, this research focuses on small reservoirs and on their potential contribution to a sustainable water management in agriculture. Unfortunately, there are no reliable data on their number, spatial distribution and potential storage volume. The aim of this work is to define reservoir spatial distribution and evaluate potential available water volumes. The upper Tiber river basin has been selected as a case study for the methodology proposed. The work starts from the acquisition and re-elaboration of the old census of small reservoirs, evaluating, through GIS and regression techniques, the distribution over the territory and the available volumes. Then the reservoir census and the derived database were updated for the period from 2015 up to 2019 introducing combined computational procedures of remote sensing techniques and GIS, based on satellite images and water index calculation. The results of the semi automatic procedure used show good performance in lake identification, making it a promising tool for a fast and reliable water body identification and evaluation in wide areas.

Impact of Dense Networks of Reservoirs on Streamflows at Dryland Catchments

“…In addition to the small reservoirs, the population of these regions usually uses wells for supply. The impact of small reservoirs on groundwater recharge is still unknown for dense networks of reservoirs at dryland catchments [55,56].…”

Contribution of Irrigation Ponds to the Sustainability of Agriculture. A Review of Worldwide Research

“…IPs have positive impacts on achieving agricultural sustainability, but we must consider a series of limitations. Although new approaches have been developed to estimate the number of IPs, their volume, and capacity based on the new technologies and techniques of remote sensing and geographic information systems (GISs), it is not simple to carry out these quantifications and determine their possible environmental impacts [67]. The difficulty in estimating these data is derived from the need to conduct them on a local or regional level, given the influence of a series of factors that vary in accordance with the area such as the soil conditions, the slope, or the climate [22,40].…”

“…Within the current context of scarce water resources, this line of research is particularly relevant as it is necessary to carry out a correct management of the available water resources, creating plans to ensure an optimum combination of conventional resources and other alternative resources such as desalinated or reused water, thanks to the use of IPs [57][58][59][60]. More specifically, this line of research focuses on the use of the new information technologies for developing programs to obtain reliable data regarding the number of IPs, spatial distribution, and potential storage volume with the objective of increasing the availability and quality of the water and reducing the costs of the agricultural farms [61][62][63][64][65][66][67][68].…”

Using Optical Satellite and Aerial Imagery for Automatic Coastline Mapping

“…The methods of water body extraction can generally be divided into two categories, i.e. one is the traditional supervised/unsupervised classifications using single or multiple bands and the other one based on the water-related spectral index and threshold-based approach (Casadei et al, 2019) or using thermal imagery (Costantino and Angelini, 2016). In water environment, two indexes for water mapping are widely used, the Normalized Difference Water Index (NDWI) and the modified NDWI, called MNDWI.…”