1 INTRODUCTION

2 A TEST CASE: THE EUCLID DEEP SURVEY
2.1 The Euclid Deep survey
2.2 Mock galaxy samples

3 PROPERTIES OF THE MOCK SAMPLES

4 LOCAL DENSITY AND ENVIRONMENT
4.1 The ZADE method

5 GAUGING THE ACCURACY OF THE DENSITY FIELD RECONSTRUCTION

6 A TEST CASE: THE RELATION BETWEEN THE LOCAL ENVIRONMENT AND GALAXY CLUSTERS

7 SUMMARY AND CONCLUSIONS