/** * A simple set of functions to check our version 1.0 update service. * * @package WordPress * @since 2.3.0 */ /** * Check WordPress version against the newest version. * * The WordPress version, PHP version, and Locale is sent. Checks against the * WordPress server at api.wordpress.org server. Will only check if WordPress * isn't installing. * * @since 2.3.0 * @uses $wp_version Used to check against the newest WordPress version. * * @param array $extra_stats Extra statistics to report to the WordPress.org API. * @param bool $force_check Whether to bypass the transient cache and force a fresh update check. Defaults to false, true if $extra_stats is set. * @return mixed Returns null if update is unsupported. Returns false if check is too soon. */ function wp_version_check( $extra_stats = array(), $force_check = false ) { if ( defined('WP_INSTALLING') ) return; global $wpdb, $wp_local_package; include( ABSPATH . WPINC . '/version.php' ); // include an unmodified $wp_version $php_version = phpversion(); $current = get_site_transient( 'update_core' ); $translations = wp_get_installed_translations( 'core' ); // Invalidate the transient when $wp_version changes if ( is_object( $current ) && $wp_version != $current->version_checked ) $current = false; if ( ! is_object($current) ) { $current = new stdClass; $current->updates = array(); $current->version_checked = $wp_version; } if ( ! empty( $extra_stats ) ) $force_check = true; // Wait 60 seconds between multiple version check requests $timeout = 60; $time_not_changed = isset( $current->last_checked ) && $timeout > ( time() - $current->last_checked ); if ( ! $force_check && $time_not_changed ) return false; $locale = get_locale(); /** * Filter the locale requested for WordPress core translations. * * @since 2.8.0 * * @param string $locale Current locale. */ $locale = apply_filters( 'core_version_check_locale', $locale ); // Update last_checked for current to prevent multiple blocking requests if request hangs $current->last_checked = time(); set_site_transient( 'update_core', $current ); if ( method_exists( $wpdb, 'db_version' ) ) $mysql_version = preg_replace('/[^0-9.].*/', '', $wpdb->db_version()); else $mysql_version = 'N/A'; if ( is_multisite() ) { $user_count = get_user_count(); $num_blogs = get_blog_count(); $wp_install = network_site_url(); $multisite_enabled = 1; } else { $user_count = count_users(); $user_count = $user_count['total_users']; $multisite_enabled = 0; $num_blogs = 1; $wp_install = home_url( '/' ); } $query = array( 'version' => $wp_version, 'php' => $php_version, 'locale' => $locale, 'mysql' => $mysql_version, 'local_package' => isset( $wp_local_package ) ? $wp_local_package : '', 'blogs' => $num_blogs, 'users' => $user_count, 'multisite_enabled' => $multisite_enabled, ); $post_body = array( 'translations' => json_encode( $translations ), ); if ( is_array( $extra_stats ) ) $post_body = array_merge( $post_body, $extra_stats ); $url = $http_url = 'http://api.wordpress.org/core/version-check/1.7/?' . http_build_query( $query, null, '&' ); if ( $ssl = wp_http_supports( array( 'ssl' ) ) ) $url = set_url_scheme( $url, 'https' ); $options = array( 'timeout' => ( ( defined('DOING_CRON') && DOING_CRON ) ? 30 : 3 ), 'user-agent' => 'WordPress/' . $wp_version . '; ' . home_url( '/' ), 'headers' => array( 'wp_install' => $wp_install, 'wp_blog' => home_url( '/' ) ), 'body' => $post_body, ); $response = wp_remote_post( $url, $options ); if ( $ssl && is_wp_error( $response ) ) { trigger_error( __( 'An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums.' ) . ' ' . __( '(WordPress could not establish a secure connection to WordPress.org. Please contact your server administrator.)' ), headers_sent() || WP_DEBUG ? E_USER_WARNING : E_USER_NOTICE ); $response = wp_remote_post( $http_url, $options ); } if ( is_wp_error( $response ) || 200 != wp_remote_retrieve_response_code( $response ) ) return false; $body = trim( wp_remote_retrieve_body( $response ) ); $body = json_decode( $body, true ); if ( ! is_array( $body ) || ! isset( $body['offers'] ) ) return false; $offers = $body['offers']; foreach ( $offers as &$offer ) { foreach ( $offer as $offer_key => $value ) { if ( 'packages' == $offer_key ) $offer['packages'] = (object) array_intersect_key( array_map( 'esc_url', $offer['packages'] ), array_fill_keys( array( 'full', 'no_content', 'new_bundled', 'partial', 'rollback' ), '' ) ); elseif ( 'download' == $offer_key ) $offer['download'] = esc_url( $value ); else $offer[ $offer_key ] = esc_html( $value ); } $offer = (object) array_intersect_key( $offer, array_fill_keys( array( 'response', 'download', 'locale', 'packages', 'current', 'version', 'php_version', 'mysql_version', 'new_bundled', 'partial_version', 'notify_email', 'support_email' ), '' ) ); } $updates = new stdClass(); $updates->updates = $offers; $updates->last_checked = time(); $updates->version_checked = $wp_version; if ( isset( $body['translations'] ) ) $updates->translations = $body['translations']; set_site_transient( 'update_core', $updates ); if ( ! empty( $body['ttl'] ) ) { $ttl = (int) $body['ttl']; if ( $ttl && ( time() + $ttl < wp_next_scheduled( 'wp_version_check' ) ) ) { // Queue an event to re-run the update check in $ttl seconds. wp_schedule_single_event( time() + $ttl, 'wp_version_check' ); } } // Trigger a background updates check if running non-interactively, and we weren't called from the update handler. if ( defined( 'DOING_CRON' ) && DOING_CRON && ! doing_action( 'wp_maybe_auto_update' ) ) { do_action( 'wp_maybe_auto_update' ); } } /** * Check plugin versions against the latest versions hosted on WordPress.org. * * The WordPress version, PHP version, and Locale is sent along with a list of * all plugins installed. Checks against the WordPress server at * api.wordpress.org. Will only check if WordPress isn't installing. * * @since 2.3.0 * @uses $wp_version Used to notify the WordPress version. * * @param array $extra_stats Extra statistics to report to the WordPress.org API. * @return mixed Returns null if update is unsupported. Returns false if check is too soon. */ function wp_update_plugins( $extra_stats = array() ) { include( ABSPATH . WPINC . '/version.php' ); // include an unmodified $wp_version if ( defined('WP_INSTALLING') ) return false; // If running blog-side, bail unless we've not checked in the last 12 hours if ( !function_exists( 'get_plugins' ) ) require_once( ABSPATH . 'wp-admin/includes/plugin.php' ); $plugins = get_plugins(); $translations = wp_get_installed_translations( 'plugins' ); $active = get_option( 'active_plugins', array() ); $current = get_site_transient( 'update_plugins' ); if ( ! is_object($current) ) $current = new stdClass; $new_option = new stdClass; $new_option->last_checked = time(); // Check for update on a different schedule, depending on the page. switch ( current_filter() ) { case 'upgrader_process_complete' : $timeout = 0; break; case 'load-update-core.php' : $timeout = MINUTE_IN_SECONDS; break; case 'load-plugins.php' : case 'load-update.php' : $timeout = HOUR_IN_SECONDS; break; default : if ( defined( 'DOING_CRON' ) && DOING_CRON ) { $timeout = 0; } else { $timeout = 12 * HOUR_IN_SECONDS; } } $time_not_changed = isset( $current->last_checked ) && $timeout > ( time() - $current->last_checked ); if ( $time_not_changed && ! $extra_stats ) { $plugin_changed = false; foreach ( $plugins as $file => $p ) { $new_option->checked[ $file ] = $p['Version']; if ( !isset( $current->checked[ $file ] ) || strval($current->checked[ $file ]) !== strval($p['Version']) ) $plugin_changed = true; } if ( isset ( $current->response ) && is_array( $current->response ) ) { foreach ( $current->response as $plugin_file => $update_details ) { if ( ! isset($plugins[ $plugin_file ]) ) { $plugin_changed = true; break; } } } // Bail if we've checked recently and if nothing has changed if ( ! $plugin_changed ) return false; } // Update last_checked for current to prevent multiple blocking requests if request hangs $current->last_checked = time(); set_site_transient( 'update_plugins', $current ); $to_send = compact( 'plugins', 'active' ); $locales = array( get_locale() ); /** * Filter the locales requested for plugin translations. * * @since 3.7.0 * * @param array $locales Plugin locale. Default is current locale of the site. */ $locales = apply_filters( 'plugins_update_check_locales', $locales ); if ( defined( 'DOING_CRON' ) && DOING_CRON ) { $timeout = 30; } else { // Three seconds, plus one extra second for every 10 plugins $timeout = 3 + (int) ( count( $plugins ) / 10 ); } $options = array( 'timeout' => $timeout, 'body' => array( 'plugins' => json_encode( $to_send ), 'translations' => json_encode( $translations ), 'locale' => json_encode( $locales ), 'all' => json_encode( true ), ), 'user-agent' => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' ) ); if ( $extra_stats ) { $options['body']['update_stats'] = json_encode( $extra_stats ); } $url = $http_url = 'http://api.wordpress.org/plugins/update-check/1.1/'; if ( $ssl = wp_http_supports( array( 'ssl' ) ) ) $url = set_url_scheme( $url, 'https' ); $raw_response = wp_remote_post( $url, $options ); if ( $ssl && is_wp_error( $raw_response ) ) { trigger_error( __( 'An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums.' ) . ' ' . __( '(WordPress could not establish a secure connection to WordPress.org. Please contact your server administrator.)' ), headers_sent() || WP_DEBUG ? E_USER_WARNING : E_USER_NOTICE ); $raw_response = wp_remote_post( $http_url, $options ); } if ( is_wp_error( $raw_response ) || 200 != wp_remote_retrieve_response_code( $raw_response ) ) return false; $response = json_decode( wp_remote_retrieve_body( $raw_response ), true ); foreach ( $response['plugins'] as &$plugin ) { $plugin = (object) $plugin; } unset( $plugin ); foreach ( $response['no_update'] as &$plugin ) { $plugin = (object) $plugin; } unset( $plugin ); if ( is_array( $response ) ) { $new_option->response = $response['plugins']; $new_option->translations = $response['translations']; // TODO: Perhaps better to store no_update in a separate transient with an expiry? $new_option->no_update = $response['no_update']; } else { $new_option->response = array(); $new_option->translations = array(); $new_option->no_update = array(); } set_site_transient( 'update_plugins', $new_option ); } /** * Check theme versions against the latest versions hosted on WordPress.org. * * A list of all themes installed in sent to WP. Checks against the * WordPress server at api.wordpress.org. Will only check if WordPress isn't * installing. * * @since 2.7.0 * @uses $wp_version Used to notify the WordPress version. * * @param array $extra_stats Extra statistics to report to the WordPress.org API. * @return mixed Returns null if update is unsupported. Returns false if check is too soon. */ function wp_update_themes( $extra_stats = array() ) { include( ABSPATH . WPINC . '/version.php' ); // include an unmodified $wp_version if ( defined( 'WP_INSTALLING' ) ) return false; $installed_themes = wp_get_themes(); $translations = wp_get_installed_translations( 'themes' ); $last_update = get_site_transient( 'update_themes' ); if ( ! is_object($last_update) ) $last_update = new stdClass; $themes = $checked = $request = array(); // Put slug of current theme into request. $request['active'] = get_option( 'stylesheet' ); foreach ( $installed_themes as $theme ) { $checked[ $theme->get_stylesheet() ] = $theme->get('Version'); $themes[ $theme->get_stylesheet() ] = array( 'Name' => $theme->get('Name'), 'Title' => $theme->get('Name'), 'Version' => $theme->get('Version'), 'Author' => $theme->get('Author'), 'Author URI' => $theme->get('AuthorURI'), 'Template' => $theme->get_template(), 'Stylesheet' => $theme->get_stylesheet(), ); } // Check for update on a different schedule, depending on the page. switch ( current_filter() ) { case 'upgrader_process_complete' : $timeout = 0; break; case 'load-update-core.php' : $timeout = MINUTE_IN_SECONDS; break; case 'load-themes.php' : case 'load-update.php' : $timeout = HOUR_IN_SECONDS; break; default : if ( defined( 'DOING_CRON' ) && DOING_CRON ) { $timeout = 0; } else { $timeout = 12 * HOUR_IN_SECONDS; } } $time_not_changed = isset( $last_update->last_checked ) && $timeout > ( time() - $last_update->last_checked ); if ( $time_not_changed && ! $extra_stats ) { $theme_changed = false; foreach ( $checked as $slug => $v ) { if ( !isset( $last_update->checked[ $slug ] ) || strval($last_update->checked[ $slug ]) !== strval($v) ) $theme_changed = true; } if ( isset ( $last_update->response ) && is_array( $last_update->response ) ) { foreach ( $last_update->response as $slug => $update_details ) { if ( ! isset($checked[ $slug ]) ) { $theme_changed = true; break; } } } // Bail if we've checked recently and if nothing has changed if ( ! $theme_changed ) return false; } // Update last_checked for current to prevent multiple blocking requests if request hangs $last_update->last_checked = time(); set_site_transient( 'update_themes', $last_update ); $request['themes'] = $themes; $locales = array( get_locale() ); /** * Filter the locales requested for theme translations. * * @since 3.7.0 * * @param array $locales Theme locale. Default is current locale of the site. */ $locales = apply_filters( 'themes_update_check_locales', $locales ); if ( defined( 'DOING_CRON' ) && DOING_CRON ) { $timeout = 30; } else { // Three seconds, plus one extra second for every 10 themes $timeout = 3 + (int) ( count( $themes ) / 10 ); } $options = array( 'timeout' => $timeout, 'body' => array( 'themes' => json_encode( $request ), 'translations' => json_encode( $translations ), 'locale' => json_encode( $locales ), ), 'user-agent' => 'WordPress/' . $wp_version . '; ' . get_bloginfo( 'url' ) ); if ( $extra_stats ) { $options['body']['update_stats'] = json_encode( $extra_stats ); } $url = $http_url = 'http://api.wordpress.org/themes/update-check/1.1/'; if ( $ssl = wp_http_supports( array( 'ssl' ) ) ) $url = set_url_scheme( $url, 'https' ); $raw_response = wp_remote_post( $url, $options ); if ( $ssl && is_wp_error( $raw_response ) ) { trigger_error( __( 'An unexpected error occurred. Something may be wrong with WordPress.org or this server’s configuration. If you continue to have problems, please try the support forums.' ) . ' ' . __( '(WordPress could not establish a secure connection to WordPress.org. Please contact your server administrator.)' ), headers_sent() || WP_DEBUG ? E_USER_WARNING : E_USER_NOTICE ); $raw_response = wp_remote_post( $http_url, $options ); } if ( is_wp_error( $raw_response ) || 200 != wp_remote_retrieve_response_code( $raw_response ) ) return false; $new_update = new stdClass; $new_update->last_checked = time(); $new_update->checked = $checked; $response = json_decode( wp_remote_retrieve_body( $raw_response ), true ); if ( is_array( $response ) ) { $new_update->response = $response['themes']; $new_update->translations = $response['translations']; } set_site_transient( 'update_themes', $new_update ); } /** * Performs WordPress automatic background updates. * * @since 3.7.0 */ function wp_maybe_auto_update() { include_once( ABSPATH . '/wp-admin/includes/admin.php' ); include_once( ABSPATH . '/wp-admin/includes/class-wp-upgrader.php' ); $upgrader = new WP_Automatic_Updater; $upgrader->run(); } /** * Retrieves a list of all language updates available. * * @since 3.7.0 */ function wp_get_translation_updates() { $updates = array(); $transients = array( 'update_core' => 'core', 'update_plugins' => 'plugin', 'update_themes' => 'theme' ); foreach ( $transients as $transient => $type ) { $transient = get_site_transient( $transient ); if ( empty( $transient->translations ) ) continue; foreach ( $transient->translations as $translation ) { $updates[] = (object) $translation; } } return $updates; } /** * Collect counts and UI strings for available updates * * @since 3.3.0 * * @return array */ function wp_get_update_data() { $counts = array( 'plugins' => 0, 'themes' => 0, 'wordpress' => 0, 'translations' => 0 ); if ( $plugins = current_user_can( 'update_plugins' ) ) { $update_plugins = get_site_transient( 'update_plugins' ); if ( ! empty( $update_plugins->response ) ) $counts['plugins'] = count( $update_plugins->response ); } if ( $themes = current_user_can( 'update_themes' ) ) { $update_themes = get_site_transient( 'update_themes' ); if ( ! empty( $update_themes->response ) ) $counts['themes'] = count( $update_themes->response ); } if ( ( $core = current_user_can( 'update_core' ) ) && function_exists( 'get_core_updates' ) ) { $update_wordpress = get_core_updates( array('dismissed' => false) ); if ( ! empty( $update_wordpress ) && ! in_array( $update_wordpress[0]->response, array('development', 'latest') ) && current_user_can('update_core') ) $counts['wordpress'] = 1; } if ( ( $core || $plugins || $themes ) && wp_get_translation_updates() ) $counts['translations'] = 1; $counts['total'] = $counts['plugins'] + $counts['themes'] + $counts['wordpress'] + $counts['translations']; $titles = array(); if ( $counts['wordpress'] ) $titles['wordpress'] = sprintf( __( '%d WordPress Update'), $counts['wordpress'] ); if ( $counts['plugins'] ) $titles['plugins'] = sprintf( _n( '%d Plugin Update', '%d Plugin Updates', $counts['plugins'] ), $counts['plugins'] ); if ( $counts['themes'] ) $titles['themes'] = sprintf( _n( '%d Theme Update', '%d Theme Updates', $counts['themes'] ), $counts['themes'] ); if ( $counts['translations'] ) $titles['translations'] = __( 'Translation Updates' ); $update_title = $titles ? esc_attr( implode( ', ', $titles ) ) : ''; $update_data = array( 'counts' => $counts, 'title' => $update_title ); /** * Filter the returned array of update data for plugins, themes, and WordPress core. * * @since 3.5.0 * * @param array $update_data { * Fetched update data. * * @type array $counts An array of counts for available plugin, theme, and WordPress updates. * @type string $update_title Titles of available updates. * } * @param array $titles An array of update counts and UI strings for available updates. */ return apply_filters( 'wp_get_update_data', $update_data, $titles ); } function _maybe_update_core() { include( ABSPATH . WPINC . '/version.php' ); // include an unmodified $wp_version $current = get_site_transient( 'update_core' ); if ( isset( $current->last_checked ) && 12 * HOUR_IN_SECONDS > ( time() - $current->last_checked ) && isset( $current->version_checked ) && $current->version_checked == $wp_version ) return; wp_version_check(); } /** * Check the last time plugins were run before checking plugin versions. * * This might have been backported to WordPress 2.6.1 for performance reasons. * This is used for the wp-admin to check only so often instead of every page * load. * * @since 2.7.0 * @access private */ function _maybe_update_plugins() { $current = get_site_transient( 'update_plugins' ); if ( isset( $current->last_checked ) && 12 * HOUR_IN_SECONDS > ( time() - $current->last_checked ) ) return; wp_update_plugins(); } /** * Check themes versions only after a duration of time. * * This is for performance reasons to make sure that on the theme version * checker is not run on every page load. * * @since 2.7.0 * @access private */ function _maybe_update_themes() { $current = get_site_transient( 'update_themes' ); if ( isset( $current->last_checked ) && 12 * HOUR_IN_SECONDS > ( time() - $current->last_checked ) ) return; wp_update_themes(); } /** * Schedule core, theme, and plugin update checks. * * @since 3.1.0 */ function wp_schedule_update_checks() { if ( !wp_next_scheduled('wp_version_check') && !defined('WP_INSTALLING') ) wp_schedule_event(time(), 'twicedaily', 'wp_version_check'); if ( !wp_next_scheduled('wp_update_plugins') && !defined('WP_INSTALLING') ) wp_schedule_event(time(), 'twicedaily', 'wp_update_plugins'); if ( !wp_next_scheduled('wp_update_themes') && !defined('WP_INSTALLING') ) wp_schedule_event(time(), 'twicedaily', 'wp_update_themes'); if ( ( wp_next_scheduled( 'wp_maybe_auto_update' ) > ( time() + HOUR_IN_SECONDS ) ) && ! defined('WP_INSTALLING') ) wp_clear_scheduled_hook( 'wp_maybe_auto_update' ); } if ( ( ! is_main_site() && ! is_network_admin() ) || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) ) return; add_action( 'admin_init', '_maybe_update_core' ); add_action( 'wp_version_check', 'wp_version_check' ); add_action( 'upgrader_process_complete', 'wp_version_check', 10, 0 ); add_action( 'load-plugins.php', 'wp_update_plugins' ); add_action( 'load-update.php', 'wp_update_plugins' ); add_action( 'load-update-core.php', 'wp_update_plugins' ); add_action( 'admin_init', '_maybe_update_plugins' ); add_action( 'wp_update_plugins', 'wp_update_plugins' ); add_action( 'upgrader_process_complete', 'wp_update_plugins', 10, 0 ); add_action( 'load-themes.php', 'wp_update_themes' ); add_action( 'load-update.php', 'wp_update_themes' ); add_action( 'load-update-core.php', 'wp_update_themes' ); add_action( 'admin_init', '_maybe_update_themes' ); add_action( 'wp_update_themes', 'wp_update_themes' ); add_action( 'upgrader_process_complete', 'wp_update_themes', 10, 0 ); add_action( 'wp_maybe_auto_update', 'wp_maybe_auto_update' ); add_action('init', 'wp_schedule_update_checks'); El mapamundi del aguaSesiónDeControl.com
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Materia

Este artículo ha sido escrito en Materia, web de noticias de ciencia, tecnología, salud y medio ambiente, que comparte su contenido para ser republicado.


Escrito el 25 de febrero de 2013 a las 15:13 | Clasificado en Ciencia

Hasta el 32% de la superficie continental se alimenta de acuíferos poco profundos, según un estudio publicado en ‘Science’ que ha realizado un investigador español

Mapa global de las aguas subterráneas poco profundas (Fuente: Materia)
Mapa global de las aguas subterráneas poco profundas (Fuente: Materia)

La imagen que tenemos de la Tierra está sesgada por el azul de los océanos. Debajo del suelo que pisamos también hay agua, en importantes cantidades y mucho más cerca de lo que pensamos. Ahora sabemos que hasta el 32% de las tierras del planeta están alimentadas por acuíferos subterráneos poco profundos, según ilustra un estudio publicado en el último número de Science. Ríos, humedales, lagos, valles, oasis y muchos otros entornos se nutren directamente de esas aguas que, aunque invisibles, los mantienen vivos.

En momentos en los que la sequía es una amenaza, la importancia de mantener sanos estos acuíferos es fundamental para la estabilidad de casi un tercio de los ecosistemas continentales. Proporcionan caudal a ríos y lagos en periodos sin lluvias, impiden el drenaje del terreno y proporcionan alimento a las raíces de los árboles cuando llega la temida sequía. Además, aunque se escondan influyen decisivamente en el comportamiento del clima regional, por lo que su conocimiento mejorará los modelos climáticos globales.

Las aguas poco profundas influyen en el ciclo global del agua y en el del carbono, fundamentales para el sistema climático

El trabajo necesario para realizar este atlas de los acuíferos que ayude a conocer su impacto sobre el clima se lo ha tomado un español, Gonzalo Míguez-Macho, profesor de la Universidad de Santiago de Compostela. Junto a su colega Ying Fan de la Universidad Rutgers de Nueva Jersey se dedicó a “llamar país por país” para tratar de recabar toda la información oficial sobre pozos, acuíferos y aguas subterráneas. “En Italia había que llamar región por región, porque está descentralizado. En EEUU tienen muchísima información, en Sudamérica muy poca, en África no tienen nada y en China no te lo quieren dar”, enumera Míguez-Macho como ejemplos. Allí donde no llegaban los datos oficiales, buscaban la aportación de la literatura científica.

A lo largo de varios años (los primeros datos los recogieron para otros estudios de 2007), lograron recopilar hasta 1,6 millones de pozos naturales en todo el mundo, observaciones registradas in situ de acuíferos poco profundos. Junta sobre un mapa, toda esa información no funcionaba, porque no mostraba ningún tipo de patrón espacial, sino una suma inconexa de datos. Las observaciones registradas no se distribuían uniformemente, sino que se concentran en torno a asentamientos humanos, allí donde el agua subterránea más se usa. Ahí empezó la segunda parte del trabajo, la creación de un modelo hidrológico que le diera consistencia y coherencia al mapa de todos los acuíferos del mundo.

Un modelo consistente

Metieron en la coctelera los datos que tenían junto a información real sobre el nivel del mar, el clima, y la topografía, terrenos de cada una de las regiones ciegas de información. El resultado, un modelo que lograba reproducir el nivel freático (la profundidad de esas aguas subterráneas) de todos los continentes. Sus conclusiones eran coherentes con los humedales (incluidos los más importantes del mundo, los del Convenio Ramsar) y pozos que ya se conocen.

Humedales del parque de S’Albufera de Mallorca, reconocidos por el convenio Ramsar. / Scouse and Jules

A partir de ahí, pudieron calcular el porcentaje de área global que se alimenta de estas aguas poco profundas. Alrededor del 15% corresponde a lagos de tamaño pequeño, ríos y zonas húmedas inundadas; un 2% corresponde a humedales inundados menos frecuentemente; y en torno al 5%-15% de área con capa freática accesible a las raíces de las plantas. En total, entre el 22% y el 32% de todas las superficies continentales influidas directamente. “Estos resultados sugieren que las aguas subterráneas tienen una extendida y estructurada influencia a escala global en la hidrología y ecosistemas terrestres”, concluyen los autores de este trabajo.

“Si se deprime la capa freática, si se saca de forma desmesurada el agua del subsuelo, se ven muy afectados los ecosistemas”, explica Míguez-Macho. “Es entonces cuando el humedal o incluso el río se seca, porque el acuífero ya no los nutre como debiera, como sucede en las Tablas de Daimiel o el Guadiana. No viven solo de la lluvia, el agua del subsuelo es fundamental”, asegura este investigador, que tras doctorarse en Utah y trabajar en Rutgers pudo regresar a Compostela gracias al programa Ramón y Cajal.

“Por eso es importante localizar dónde estás esos acuíferos poco profundos, porque son fundamentales para ajustar los modelos climáticos. Porque los humedales son la fuente principal de metano en la atmósfera, uno de los gases de invernadero más potentes. Las aguas subterráneas poco profundas influyen por lo tanto directamente en el ciclo global del agua y en el del carbono, partes fundamentales del sistema climático”, señala este meteorólogo.

FuenteEl primer mapamundi de las aguas subterráneas muestra su importancia para el clima

Autor: Javier Salas

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