迁移效果衡量
建立SEO转GEO迁移的效果评估体系，确保迁移不损失既有价值同时获得GEO增益

# SEO迁移保护监测框架
import json
from datetime import datetime, timedelta

def check_seo_health(migrated_pages, baseline_data):
    """检查迁移页面的SEO健康度"""
    alerts = []
    for page in migrated_pages:
        url = page['url']
        baseline = baseline_data.get(url, {})
        current = page['current_metrics']
        
        # 检查排名变化
        rank_change = current.get('avg_position', 0) - baseline.get('avg_position', 0)
        if rank_change > 5:  # 排名下降超过5位
            alerts.append({
                'url': url,
                'type': 'rank_drop',
                'severity': 'high' if rank_change > 10 else 'medium',
                'message': f'排名下降{rank_change}位'
            })
        
        # 检查流量变化
        traffic_change = (current.get('clicks', 0) - baseline.get('clicks', 0)) / max(baseline.get('clicks', 1), 1)
        if traffic_change < -0.15:  # 流量下降超过15%
            alerts.append({
                'url': url,
                'type': 'traffic_drop',
                'severity': 'high' if traffic_change < -0.3 else 'medium',
                'message': f'流量下降{abs(traffic_change)*100:.0f}%'
            })
        
        # 检查索引状态
        if not current.get('indexed', True):
            alerts.append({
                'url': url,
                'type': 'deindexed',
                'severity': 'critical',
                'message': '页面被取消索引'
            })
    
    return {
        'date': datetime.now().isoformat(),
        'total_pages': len(migrated_pages),
        'alerts': alerts,
        'critical_count': sum(1 for a in alerts if a['severity'] == 'critical')
    }