The water regime of the Monegros playa-lakes as established from ground and satellite data

Abstract

The Monegros playa-lakes are isolated saline wetlands, locally named "saladas", situated in a vulnerable semi-arid territory where agricultural expansion threatens the natural hydrologic cycle with regular artificial flooding, risking the survival of a valuable natural resource. This study aims to examine the water regime of these playalakesfrom climate data and available hydrologic records. These records are historicaland limited to a series of weekly measurements of depth and of water extent extractedfrom Landsat imagery. We have characterized the hydrological behavior of the playalakesby treating ground and satellite data separately. For this purpose, the playalakesare first grouped according to the water occurrence episodes. Then their hydrologic status is related to the previous rainfall and also to ET0, since there is a lack of local records of wind as well as brine or fresh water evaporation. The northern playa-lakes respond to rain faster than the southern ones. All playa-lakes have a significant relationship between water occurrence and rainfall accumulated within 180 days prior to an observation. A significant relationship between ET0 and water occurrence was found 1 *Corresponding author. E-mail address: ccastanneda@aragon.es (C. Castañeda), Fax: +34 976 716 335 2 for a shorter 15-day accumulation period. Quantifying the current water regime now is critical for monitoring the effects of expanding irrigation in adjacent lands. Remote sensing is well-suited to an environmental assessment for regions of difficult access with the added benefit of lowered field measurement cost. The hydrological data from the Monegros playa-lakes could be integrated with other playa environments worldwide to compare regionally specific climate conditions.

Evidence of Hydroperiod Shortening in a Preserved System of Temporary Ponds

“…Similar results have been reported in a different temporary pond system, such as the playa-lakes in the Monegros Dessert [15]. This result adds to evidence of the relevance of groundwater influxes in the hydrological regime of the ponds in the area [34].…”

“…Satellite images have been used to map large permanent wetlands [see 14 for a review] and, occasionally, to reconstruct their temporal dynamics over the past decades [15][16][17]. However, its application on seasonally flooded systems has been scarce [18][19][20][21], and, in particular, for small-sized wetlands [22] due to the difficulty of identifying waterbodies if below pixel size, e.g., [23].…”

“…A retrospective study of the presence of water in temporary ponds can constitute a high quality data set to analyse the relationship between rainfall and pond dynamics. The relation between rainfall and water presence, as derived from remote sensing data, has been previously evaluated in mediumsized and large temporary wetlands, e.g., [15,16], but such an approach has never been attempted for small temporary ponds. Doñana National Park is one of the most important wetlands in southern Europe.…”

An overview of integrated hydro-ecological studies in the MELMARINA Project: monitoring and modelling coastal lagoons—making management tools for aquatic resources in North Africa

“…When combined with ground surveys aimed at calibrating the spectral signatures of different wetland plant communities, remote sensing techniques provide an exceptional means of distinguishing spatial vegetation cover as well as determining the extent of open water and marginal disturbance (e.g. Schmidt & Skidmore, 2003;Castañeda & Herrero, 2005;MaheuGiroux & de Blois, 2005; Fig. 3).…”

An Observation Task Chain Representation Model for Disaster Process-Oriented Remote Sensing Satellite Sensor Planning: A Flood Water Monitoring Application

“…Specifically, JRB has a low flow during the winter months that reaches its peak from May to November [41]. From the perspective of hydrological phenomenon remote-sensing monitoring, the observation themes in flood disasters are mainly related to long time-series and wide-range-related water regime monitoring [48], including real-time water flow, water volume, inundated time, and flooding range. In this case, the experiment takes the flooding water from the lower section of the JRB as its observation object, which requires time-series and space continuous monitoring by using multiple remote-sensing satellite sensors.…”